1、Municipal solid waste to energy:coupled power generation with MSWTechnology and Market Outlook PaperWe support the Sustainable Development Goals3Executive summaryWith the continuous growth of global population and the concomitant energy demand,the challenges posed by environmental pollution and the

2、need to ensure a stable energy supply are affecting the development of the global economy.As such,a major focus of contemporary discussion is the required global effort to broaden the sources of energy supply,enrich the energy supply system,stabilize overall energy supply,and solve the problem of en

3、vironmental pollution.Municipal solid waste to energy(MSWtE)refers to the technique of energy recovery from municipal solid waste,especially organic waste.The residual energy is recovered in the form of various energy products through a variety of technical means,such as thermal treatment,thermo-che

4、mical treatment and bio-chemical treatment.In addition,the MSWtE technology constitutes one of the mature sources of energy supply at present.With the continuous development of science and technology,the integration of advanced power generation and the technology of MSWtE,also called coupled power g

5、eneration with MSW,will play a more significant role in solving the problem of growing municipal solid waste.In addition,this integration will ameliorate the power generation system and be conducive to achieving the zero-carbon roadmap.In summary,MSWtE is a potential technology for achieving sustain

6、able development goals in the future.This paper summarizes the existing technologies and applications of MSWtE,while highlighting the current status,challenges and standardization of MSWtE technologies.This paper is dedicated to achieving the UN Sustainable Development Goals and clarifying the role

7、and value of IEC International Standards and conformity assessment systems.Section 1 provides an overview of the energy challenges currently facing the world,states the role of municipal solid waste to energy and briefly summarizes the content framework of the entire paper.Section 2 introduces the t

8、echnology of MSWtE,including:iincineration,thermo-chemical treatment,bio-chemical treatment and other key technologies involved in the process,and describes advances in the latest technologies as well as the outlook for future technologies.Section 3 presents the current status of coupled MSWtE gener

9、ation.It discusses the role of MSWtE coupled with fossil fuel,solar,wind and nuclear power systems for environmental management and energy supply and explores future development trends in this area.Section 4 presents the challenges facing coupled MSWtE generation,mainly in terms of waste,temperature

10、,moisture and emission management.Section 5 provides an analysis of the existing relevant standardization activities.This analysis not only focuses on the current state of relevant standards but also projects a plan for future standardization development based on the future development trend of muni

11、cipal solid waste coupled power generation in the industry.Section 6 summarizes the importance of coupled municipal solid waste power generation and provides some key details concerning the outlook of related techniques and standardization.4Executive summaryDISCLAIMER:IEC Market Strategy Board Techn

12、ology and Market Outlook Papers illustrate an individual MSB members perspective on specific current or critical societal and/or technological challenges facing the IEC community.As such papers are non-consensus deliverables,dedicated project teams are not formed for their elaboration,and recommenda

13、tions are not presented.The views and opinions expressed within the content are solely those of the author.AcknowledgmentsThis technology and market outlook paper has been prepared by a project team representing a variety of organizations,working under the IEC Market Strategy Board(MSB).The project

14、team includes representatives from electrical power network businesses,research institutes,equipment vendors and academia.The project sponsor is Dr Jianbin Fan,from the State Grid Corporation of China and an IEC MSB Member.The project team would like to acknowledge IEC MSB Member Prof Lean Weng Yeoh

15、 and former IEC Technical Officer Dr Charles Jacquemart for reviewing the paper.The project team members include(in alphabetical order):Mr Yufeng Bai,Huaneng Yangtze Environmental Technology Co.,Ltd.Mr Liqun Cui,CHN ENERGY Investment Group Co.,Ltd.Dr Yang Dong,National Institute of Clean-and-Low-Car

16、bon EnergyMr Hongpei Gao,Huaneng Yangtze Environmental Technology Co.,Ltd.Dr Hao Hu,State Grid Corporation of ChinaDr Yun Huang,Institute of Process Engineering,Chinese Academy of SciencesDr Jinder Jow,National Institute of Clean-and-Low-Carbon EnergyMr Gang Lin,Huaneng Yangtze Environmental Technol

17、ogy Co.,Ltd.Mr Han Lin,Huaneng Shanghai Shidongkou Second Power PlantMr Nan Liu,State Grid Beijing Electric Power CompanyDr Guangqian Luo,Huazhong University of Science and TechnologyDr Zhou Mu,State Grid Sichuan Electric Power Research InstituteMr Yu Ru,Beijing Huaneng Yangtze Environmental Technol

18、ogy Research Institute Co.,Ltd.Dr Wenquan Ruan,Jiangnan UniversityMr Lichuang Wang,Huaneng Clean Energy Research InstituteMs Lili Xie,State Grid Sichuan Power Extra High Voltage CompanyDr Ye Yuan,Huaneng Yangtze Environmental Technology Co.,Ltd.Dr Jing Zhang,State Grid Sichuan Electric Power Researc

19、h InstituteMs Shuang Zhang,Huaneng Yangtze Environmental Technology Co.,Ltd.5Table of contentsExecutive summary 3Acknowledgments 4 List of abbreviations 7 Glossary 9Section 1 Introduction 111.1 Overview 111.2 Scope 12Section 2 Current status of MSWtE 132.1 Incineration 142.2 Thermo-chemical treatmen

20、t 142.2.1 Pyrolysis 142.2.2 Liquefaction 162.2.3 Gasification 172.3 Bio-chemical treatment process 192.3.1 Anaerobic fermentation 192.3.2 Landfill gas capture 202.3.3 Microbial fuel cell 21Section 3 Coupled power generation with MSW 233.1 Thermal power generation with MSW 233.1.1 Coal-fired power ge

21、neration with MSW 233.1.2 Gas-fired power generation with MSW 253.2 Solar power generation with MSW 253.3 Wind power generation with MSW 283.4 Nuclear power generation with MSW 28Section 4 Challenges of MSWtE 304.1 Solid waste management 304.2 Temperature management 314.3 Moisture management 314.4 E

22、missions management 326Table of contents4.4.1 Flue gas pollutants,corrosion and slagging during the coupled incineration power generation process 324.4.2 Ash emissions in the coupled incineration power generation process 33Section 5 Standards of CPG-MSW 345.1 Current situation analysis 345.1.1 IEC 3

23、45.1.2 ISO 365.1.3 Relevant standardization work in China 365.1.4 Relevant standardization work in the United States 375.1.5 Relevant standardization work in the European Union 385.2 Standardization outlook 39Section 6 Conclusions and outlook 416.1 Technical outlook 416.1.1 CPG-MSW technical outlook

24、 416.1.2 CPG-MSW normative model 426.1.3 CPG-MSW specification outlook 426.1.4 CPG-MSW evaluation system establishment 426.2 Standardization outlook 42Bibliography 44Figure 2-1 MSWtE summary 13Figure 2-2 Schematic diagram of incineration 14Figure 2-3 Schematic diagram of pyrolysis 15Figure 2-4 Schem

25、atic diagram of liquefaction 16Figure 2-5 Schematic diagram of gasification 17Figure 2-6 Supercritical water gasification processing of MSW 18Figure 2-7 Schematic diagram of biological treatment 19Figure 2-8 Schematic diagram of microbial fuel cell 21Figure 3-1 Integration of CPG-MSW with H2 polygen

26、eration system 27Figure 3-2 Tire-surface solar concentrator 27Figure 3-3 South Koreas planned system of nuclear power generation coupled with MSW 29Table 3-1 The efficiency of coal-fired power generation with MSW 44 24Table 4-1 Global status of waste management regulation 307List of abbreviationsAC

27、alternating currentAD anaerobic digestion BEMPs best environmental management practicesCCP coal combustion productCHP combined heat and powerCO carbon monoxideCO2 carbon dioxideCOD chemical oxygen demandCPG coupled power generationCPG-MSW coupled power generation with MSWCV calorific valueDC direct

28、currentDERMS distributed energy resource management systemDMS distribution management systemEMS energy management systemEMMS electricity market management systemFBC fluidized bed combustionGWP global warming potentialH2 hydrogen gasHCl hydrochloric acidHHV high heating valueHTC hydrothermal carboniz

29、ationIBA incinerator bottom ashIGCC integrated gasification combined cycleIoT Internet of ThingsLFG landfill gasMBT mechanical biological treatmentMFC microbial fuel cell Mpa megapascalTechnical andscientific terms8List of abbreviations MSW municipal solid waste MSWtE municipal solid waste to energy

30、 MWe megawatt electric NGO non-governmental organization NOx oxides of nitrogen PAH poly aromatic hydrocarbons PTC production tax credit RDF refuse derived fuel SC subcommittee SCADA supervisory control and data acquisition SCWG supercritical water gasification SDG sustainable development goal(UN)SO

31、2 sulfur dioxide SOx sulfur oxide TC technical committee VOC volatile organic compounds WtE waste to energyOrganizations,institutions and companiesACEA IEC Advisory Committee on Environmental AspectsASME The American Society of Mechanical EngineersASTM American Society of Testing Materials(formerly

32、known as)CHYE China Huaneng Yangtze Environmental Technology Co.EMAS EU Eco-Management and Audit SchemeEU European UnionIEA International Energy AgencyIEC International Electrotechnical CommissionIPCC Intergovernmental Panel on Climate ChangeISO International Organization for StandardizationMSB Mark

33、et Strategy Board(IEC)SAC Standardization Administration of ChinaUN United NationsWTERT Waste-to-Energy Research and Technology CouncilGlossaryanaerobic digestionADa series of processes in which microorganisms break down biodegradable material in the absence of oxygen NOTE AD is used for industrial

34、or domestic purposes to manage waste and/or to release energy.Much of the fermentation used industrially to produce food and drink products,as well as home fermentation,uses AD.biogenicmaterial within the waste stream that has come from biological sources and was recently growing NOTE In this contex

35、t recently means the last hundred or so years.Examples include food,paper,garden waste,wood.See also“fossil”.calorific valueCVa measure of the amount of energy contained within a certain quantity of waste that could potentially be released when completely combusted under specific conditions NOTE CV

36、is a measure of heating power and is dependent upon the composition of the bined heat and powerCHPthe use of a heat engine or a power station to generate both electricity and useful heat simultaneouslyfossilmaterial within the waste stream that has come from sources such as coal,oil and natural gas

37、which have been locked underground for millions of years NOTE Examples include plastics made from oil.gasificationa process that converts organic or fossil-based carbonaceous materials at elevated temperatures with controlled amounts of oxygen into carbon monoxide,hydrogen,carbon dioxide and methane

38、 NOTE Gasification is a well-known technology,although its advanced use with a mixed waste feedstock has not been proven on a commercial scale.There exist several gasification plants for received MSW in Japan.incinerator bottom ashIBAa form of ash produced in incineration facilities NOTE IBA is disc

39、harged from the moving grate of municipal solid waste incinerators.Following combustion,the ash typically has a small amount of ferrous metals contained within it.This ash can be processed to standardize the material and remove contaminants in order for it to be used as an aggregate.mechanical biolo

40、gical treatmentMBTa type of waste process that combines a sorting facility with a form of biological treatment such as composting or anaerobic digestionmunicipal solid wasteMSWa waste type consisting of everyday items that are discarded by the publicNOTE Commonly known as refuse or rubbish,MSW cover

41、s household waste and household-like commercial and industrial waste(e.g.from offices or hotels).poly aromatic hydrocarbonsPAHa group of organic compounds that arise from incomplete combustion of carbon-containing materials such as oil,coal,gas,etc.NOTE PAH are often absorbed onto particles of soot

42、emitted from combustion sources.910Glossaryrefuse derived fuelRDFa fuel produced by shredding and dehydrating municipal solid waste(MSW)via a process such as mechanical biological treatment(MBT)NOTE RDF consists largely of combustible components of municipal waste such as plastics and biodegradable

43、waste.volatile organic compoundsVOCorganic chemicals that have a high vapour pressure at ordinary room temperature conditionsNOTE The high vapour pressure of VOC results from a low boiling point,which causes large numbers of molecules to evaporate or sublimate from the liquid or solid form of the co

44、mpound and enter the surrounding air.waste to energyWtEprocess of generating energy in the form of electricity and/or heat from the primary treatment of waste11Section 1 Introduction The latest Intergovernmental Panel on Climate Change(IPCC)report has revealed that climate change is observable in ev

45、ery region of the world,resulting in frequent occurrences of extreme climate events and posing a survival risk for humans 11.Many countries have enacted detailed green development plans to cope with the approaching climate crisis,among which the development of low-carbon energy systems through promo

46、tion of renewable energy and coal withdrawal is greatly valued.In 2018,the World Bank predicted that globally 3,40 billion tons of waste would be generated annually over the next three decades,representing an increase of 70%as compared to the amount registered in 2016 2.Currently,most municipal soli

47、d waste(MSW)is disposed by landfill.However,according to the World Bank database,5%of all carbon emissions are generated from solid waste management 3,and in 2007 the IPCC reported that energy recovery from solid waste effectively contributes to reducing carbon emissions and mitigating climate chang

48、e 3.Specifically,such energy recovery completes the oxidation process of substances with a high global warming potential(GWP)index and reduces the dependence of power generation on fossil fuels.The energy recovery of solid waste originated in 1874,symbolized by the launching into service of the firs

49、t incinerator in the United Kingdom.Subsequently,the first waste incineration plant in Germany was launched in 1896,however,wide application of waste incineration was then hindered by insufficient pollutant controls and flue gas treatment.Public anxieties concerning the concomitant diseases resultin

50、g from such insufficiencies and the deteriorating quality of life could not be eliminated before the 1960s.During that decade,energy recovery from solid waste was gradually retrieved due to multiple driving factors,including increasing necessity brought by rapid urbanization and developed pollutant

51、control techniques.Currently,waste incineration is recognized as the technology of municipal solid waste to energy(MSWtE).MSWtE technically converts MSW,particularly organic and biomass waste,into a variety of energy products 4.In general,MSWtE can be achieved in one of three ways:incineration,therm

52、o-chemical treatment and bio-chemical treatment.By these diversified pathways,MSWtE has become one of the most cost-effective techniques in processing solid waste.The integration of power generation and MSWtE further broadens the scopes of both applications.Nevertheless,the power-MSWtE integration s

53、till faces technical and commercial challenges,which is hastening the development of new technologies and standardization in the future.This technology and market outlook paper reviews existing technologies of MSWtE as well as coupled power generation with municipal solid waste (CPG-MSW).The paper s

54、ummarizes the challenges faced by CPG-MSW and,via a systematic categorization of related standards,makes 1.1 Overview1 Numbers in square brackets refer to the Bibliography.12Introductionproposals for further standards development regarding this technology.A focus on standards development in this are

55、a will form part of IECs contribution to achieving the UN Sustainable Development Goals(SDGs).1.2 ScopeThis technology and market outlook paper directly underpins IECs efforts toward achievement of the UN SDGs by providing referable solutions for comprehensively solving SDG 6,SDG 7,SDG 11,SDG 12 and

56、 SDG 13.In this paper,IEC investigates the use of advanced power generation to solve integration and continuity issues and for contributing to global affairs through the IEC International Standards and conformity assessment services.This paper has been prepared from an individual MSB members perspec

57、tive on specific current or critical societal and/or technological challenges facing the IEC community,and specifically for analyzing and understanding the CPG-MSW market in order that IEC be prepared strategically for the future.The MSW covered in this paper refers to solid waste generated by urban

58、 activities that has lost its original functional value or has been discarded.Coupled power generation with MSW in this paper refers to the coupling of solid waste containing residual calorific value with other energy sources for power generation,particularly organic or biomass solid waste.13As show

59、n in Figure 2-1,MSWtE can be conducted in three ways:via incineration,via thermo-chemical treatment and via bio-chemical treatment.Incineration,as a traditional technique,converts waste into thermal energy for power generation straightforwardly by combustion,whereas the thermo-chemical and bio-chemi

60、cal processes,as subsequently developed techniques in waste disposal,convert waste into secondary energy carriers(e.g.syngas,carbonized fuel,methane,etc.),which are then further combusted for power generation.Figure 2-1|MSWtE summaryMuniciple solid wasteSorting,Transportaion&StorageWaste to energy C

61、onversion TechnologyDirect combustionThermal-ChemicalBio-ChemicalIncinerationPyrolysisLiquefactionGasficationPyrolytic carbonLiquified fractionsSyn-gasAnaerobic digestionLandfilled gas captured(LFG)Fuel CellBio-gasCombustion HeatPowerSection 2 Current status of MSWtE14Current status of MSWtE2.1 Inci

62、nerationAs shown in Figure 2.2,the incineration technique disposes solid waste by controlled burning of its combustible portion to release thermal energy for driving generation turbines or heating supply.The water in this figure refers to water fed to the boiler for the purpose of generating steam f

63、or the steam cycle,and the chimney refers to the atmosphere.The Shenzhen East Environmental Protection Power Plant is one of the single largest and most advanced waste incineration plants in the world,with a single unit processing capacity of 850 ton/day and steam parameters of 6,0 Mpa/450 C.Althoug

64、h this technique is advantaged by maturity,ease in large-scale application and a capability involving 24 hours of uninterrupted energy supply,technical issues still exist,including toxic emissions(e.g.dioxin),the high cost of professional treatment of toxic emissions and equipment corrosion caused b

65、y acidic gas,etc.5,6.2.2 Thermo-chemical treatmentInstead of direct combustion,thermo-chemical treatment employs a series of chemical reactions to produce secondary products,which can further be used for power and heat generation or as secondary feed-stocks.Unlike incineration,the thermo-chemical tr

66、eatment of MSW usually requires more precise control of process conditions such as temperature,pressure,moisture,anoxic environment,etc.Based on product types from chemical reaction,the treatment is usually categorized by pyrolysis,liquefaction and gasification.2.2.1 PyrolysisIn pyrolysis,high-molec

67、ular polymers are thermally decomposed in the absence of oxygen or an inert environment into small-molecule compounds,where irreversible chemical processes(i.e.dehydration,depolymerization,fracture,rearrangement and condensation)take place at a relatively low temperature (400-900 C)7.Categorized by

68、a different heating rate and reaction residence time,pyrolysis can be further divided into slow pyrolysis,medium pyrolysis,fast pyrolysis and flash pyrolysis,resulting in different proportions in solid,liquid and gas products.Basically,the main product of the pyrolysis process is pyrolytic carbon,wi

69、th characterizations similar to those of coal,of which the formation prefers a lower pyrolysis temperature,a slower heating rate and a longer pyrolysis duration,see Figure 2-3.It should be noted that the cost of flue gas treatment and pollutant control for the pyrolysis is obviously lower than that

70、of incineration,as a smaller volume of gas is emitted by the pyrolysis.Figure 2-2|Schematic diagram of incineration15Current status of MSWtEHowever,the waste treatment efficiency and waste reduction level of the pyrolysis is lower than that of incineration.In addition,the by-product of tar further d

71、ecreases the activity of the catalysts,thus reducing the overall energy recovery rate of the pyrolysis.At present,some promising technologies have been developed for the purpose of achieving more effective pyrolysis,especially thermal hydrolysis and microwave pyrolysis.Thermal hydrolysis,also known

72、as hydrothermal carbonization(HTC),is a mild pyrolysis process,which is mainly used for energy recovery from sludge and food waste.It is considered to offer a promising technical route for organic waste treatment.By simulating the natural coalification process,the HTC technique converts solid waste

73、into coal-like substances at a rate hundreds of times faster than that of nature 8,9.This is technically achieved by exposure of the solid waste to high-temperature and high-pressure steam in order to break the molecular structure of the organism and convert the high-molecule hydrocarbon compounds i

74、nto low molecular organic substances by hydrolysis,so as to improve the solid-liquid separation effect and biodegradability of solid waste without phase changing.It is noted that the main product of HTC is solid-phase hydrothermal carbon (hydro-char),with a productivity of 50%80%10,11,12.Compared wi

75、th the traditional pyrolysis process,HTC is advantaged by the absence of any limitation on the moisture and pre-dehydration and moderate reaction conditions.However,the disposal cost may be unfavourably elevated due to a large amount of organic wastewater produced by the HTC technique 13,14.In the m

76、icrowave pyrolysis technique,involving the absorption of the microwave radiation under an anaerobic environment,heat is evenly generated and distributed from the inside out of the MSW,which decomposes organic molecules into disposable products,including small-molecule compounds,gases,oil,carbon and

77、other organic substances.The unique features of heat and mass transfer,as well as heating uniformity,benefit the microwave pyrolysis technology through easy control of the temperature,the pyrolysis process and the final products,and the reduction in time,energy demanded,thermal inertia and land area

78、 occupation.Nevertheless,the industrialization of microwave pyrolysis technology continues to be retarded by the high cost of initial investment and operation,as well as by the complex operation technologies involved 15.Figure 2-3|Schematic diagram of pyrolysis16Current status of MSWtE2.2.2 Liquefac

79、tionAs shown in Figure 2-4,one of the most efficient techniques in energy utilization in solid waste is to convert solid waste proportionally or fully into biology liquid fuel 16.Biology liquid fuel is believed to hold great prospects due to its multiple advantages,including non-existence of sulfur

80、and ash,ease of transportation and storage,availability as a clean alternative fuel against gasoline,diesel and other oil,availability as a chemical raw material for high added-value chemical products,and capability of power generation 17,18.At present,liquefaction can be technically achieved by hyd

81、rothermal liquefaction and vacuum liquefaction,however,industrial scaling of the process for entire MSW surfaces still poses some technical issues.Hydrothermal liquefaction is conducted in a solvent of water under high temperature and high pressure(200350 C,525 MPa),during which the macro-molecular

82、organisms of the MSW are eventually converted to bio-oil,aqueous products,gas and solid residues by hydrolysis,decarboxylation,deamination,and re-polymerization 19,20.Compared with other MSW biomass conversion technologies,the superiority of the hydrothermal liquefaction are apparent in wide availab

83、ility of raw materials,capability of full conversion of organic substances,acceptability to various substrates for hydrothermal liquefaction(e.g.livestock manure,food waste)and permissibility of high-moisture biomass(more than 70%)21,22.However there still exist various technical problems as listed

84、below in relation to solutions.1)Effective usage of hydrothermal liquefied bio-oil.During hydrothermal liquefaction,the quality of bio-oil could be improved by applying catalytic hydrogenation,and bio-oil can be collected and used in segments via distillation.2)The mechanism of hydrothermal liquefac

85、tion.At present,only the reaction path for the products is subject to speculation based on characterization tests,while the intermediate products are not monitored.The mechanism might be thoroughly analyzed by process sampling,or by in-situ and on-line monitoring.3)Industrial application.The scale-u

86、p of hydrothermal liquefaction technology confronts two obstacles,namely the stability of feeding and discharging the reactor under high temperature and high pressure,and the issue of collection of large amounts of raw materials.Although the above technical bottlenecks will require continual researc

87、h endeavours,hydrothermal liquefaction is still highly valued because of its prominent advantages 23.In vacuum liquefaction technology,MSW is rapidly heated up to 500600 C under a certain vacuum extent,after which generated vapor is quickly condensed into liquid,with little secondary cracking reacti

88、on.The liquid products can be either directly used as fuel or refined to constitute Figure 2-4|Schematic diagram of liquefaction17Current status of MSWtEan alternative fossil fuel product.It is worth mentioning that some solid coke and a small amount of gaseous fuel can also be generated by the vacu

89、um liquefaction process.Vacuum liquefaction is characterized by low pressure inside the reaction system and the short residence time of degradation gas.As the pyrolysis of organics is a phase-changing process from solid to gas,with an increasing volume,the low pressure under vacuum conditions lowers

90、 the boiling point of the products,which benefits the evaporation of the molecular product as well as its residence time in the reaction zone,thereby reducing the possibility of secondary cracking reactions and facilitating the formation of liquid products 24,25.However,energy consumption for the va

91、cuum condition in the reactor is still high,and the capacity as well as efficiency of the process need to be improved.Therefore,this technology will require further studies to realize industrialization.2.2.3 GasificationAs shown in Figure 2-5,via a thermo-chemical reaction at temperatures of 500-1 8

92、00 C,gasification converts hydrocarbon organic substances in MSW to combustible gas containing hydrogen,carbon monoxide and small-molecule hydrocarbons.Compared with incineration,gasification offers the advantage of less flue gas emission,a controllable reaction atmosphere and a lesser amount of gas

93、-phase pollutants.The products obtained can be used for wide applications,such as power generation,heat supply and H2 production,as well as fuel cells and Fischer-Tropsch synthesis.Nonetheless,a certain extent of chemical energy is lost during the gasification,and the treatment capacity as well as t

94、he efficiency of gasification are lower than that of incineration.Alternatively,new gasification technologies with great potential are being proposed,such as supercritical water gasification,plasma gasification and coal-water slurry co-gasification.Newly developed supercritical water gasification(SC

95、WG)technology provides a new solution for the complete endothermic-reduction conversion of MSW in supercritical water for hydrogen production,as indicated in Figure 2-6.This technology takes advantage of the special physical-chemical properties of supercritical water(temperature 374,3 C and pressure

96、 22,1 MPa),such as high solubility,high diffusivity and high reactivity.The supercritical water with these properties can be used as a homogeneous,high-rate reaction medium to gasify the elements of carbon,hydrogen and oxygen in MSW into H2 and CO2,thereby realizing the efficient gasification of MSW

97、.During the process,MSW with a high water content no longer Figure 2-5|Schematic diagram of gasification18Current status of MSWtEFigure 2-6|Supercritical water gasification processing of MSWrequires dehydration,avoiding the high processing costs associated with the drying process.Meanwhile,the nitro

98、gen and sulfur contained in MSW are deposited as ash sludge along with metallic elements and various inorganic minerals,instead of being emitted as SOx and NOx as in the conventional gasification process.The ash sludge can be discharged from the bottom of the reactor.Therefore,pollutants such as NOx

99、,SOx,and dust particles(e.g.PM2.5)can be eliminated from the source 26.The gasification product is a supercritical water-steam mixture,which can be used to produce H2,electricity,heat and steam,as well as to produce high value-added chemical products due to the high concentration of H2 and CO2.The p

100、rocess achieves efficient,clean and pollution-free conversion and utilization of MSW.Compared with traditional gasification technology,this technology offers a lot of advantages,such as higher efficiency,a clean and pollution-free process,no de-sulphurisation,denitrification and de-carbonization,lit

101、tle water consumption,low operating costs and high return on investment 27,28.Plasma technology,another newly developed technique,uses AC or DC plasma torch as a heat source for decomposing solid waste into syngas.The advantage of plasma technique is that the content of toxic substances in syngas or

102、 waste residue is much less than that of incineration and traditional gasification processes.Moreover,its yield of syngas is also considerable 29.Plasma technology ionizes the material into the rich plasma state,which is the fourth state of materials.The initial energy used to create plasma could be

103、 19Current status of MSWtEthermal energy,electric current or electromagnetic radiation.The existence of charged gas enables plasma with a high activity during reactions.Plasma technology can dispose MSW with low energy density and high temperature to decompose its organic compounds into elemental co

104、mponents,finally forming a high-energy synthetic gas mainly composed of H2 and CO.However,various challenges exist for the application of plasma gasification in MSWtE.For example,the high cost of using electricity as the initial energy is financially obstructing industrial application of the techniq

105、ue.In addition,inorganic components(glass,metal and silicate)are transformed into dense,inert and non-filterable vitrified materials during plasma reaction,which may cause atmospheric pollution.Coal-water slurry co-gasification technology grinds solid waste together with raw coal and water in a cert

106、ain proportion to make slurry with a calorific value larger than 1 000 kJ/kg,which is then sprayed into the gasifier from the top.By utilizing technical features of the coal-water slurry gasifier such as reduction atmosphere,high-temperature heating and rapid quenching,the technology finally convert

107、s the organic substances in the waste into synthetic gas dominated by H2.The gas can be directly used as clean fuel gas,or be used to produce high-purity hydrogen,pure ammonia,methanol and its derivatives,natural gas,clean fuel oil and other bulk chemicals.Basically,this technique is viewed as const

108、ituting harmless resource utilization in waste disposal.The process can be applied not only to those solid wastes with no restriction on moisture content,but also various liquid wastes.Therefore,it has significant advantages over other MSWtE technologies 30,31,32.On the other hand,coal-water slurry

109、co-gasification technology also has the weakness of involving a high consumption of water and requirements concerning the quality of solid waste,such as good slurry-forming characteristics.This weakness may lower the adaptability of coal-water slurry co-gasification in wide-area application.2.3 Bio-

110、chemical treatment processBiological treatment refers to a technique that directly or indirectly transforms the organic substances of MSW into energy by using the organisms functions 33,34,see Figure 2-7.Biological treatment offers significant advantages over incineration and conventional thermo-che

111、mical processes in that there is no dehydration treatment of the solid waste,only a small degree of ash and pollution is generated,and there is little impact on the surrounding environment.Figure 2-7|Schematic diagram of biological treatment20Current status of MSWtEHowever,the efficiency of biologic

112、al treatment is much lower than that of incineration and thermo-chemical treatment,which generally requires a longer treatment cycle.Although a lesser amount or no ash is generated,the disposal of organic wastewater may be required.At present,bio-chemical treatment technology mainly refers to anaero

113、bic fermentation.Other technologies such as landfill gas capture and microbial fuel cell are still under development.2.3.1 Anaerobic fermentationThe anaerobic fermentation process is an energy-generating and environmentally friendly biological treatment technique,which has been widely applied in the

114、 treatment of livestock manure,wastewater,organic solid waste and other waste.During anaerobic fermentation,solid waste is decomposed by microorganisms into methane under anaerobic conditions 35.The generated methane can be used for power generation and heat supply through gas turbines.The whole ana

115、erobic fermentation process usually takes 15 to 30 days,after which the residue can be used to prepare biological fertilizer or be further utilized in the incinerator.This guarantees great economic and environmental benefits for anaerobic fermentation.It should be noted that the quality of the anaer

116、obic fermentation process is affected by multiple factors,among which temperature is largely highlighted.In practice,according to the mass ratio of solid waste in the anaerobic fermentation process,it can be divided into wet fermentation(solid content is 5%15%)and dry fermentation (solid content 15%

117、)36.In contrast,although dry fermentation requires a higher technical threshold,it generally attracts more industrial attention because of simpler pre-treatment,high gas production rate,simple residue composition and less pollutants.At present,France and Germany have successfully launched dry fermen

118、tation projects in MSW treatment.In addition to methane as the product,H2 can also be produced by microorganisms through anaerobic fermentation,which has manifested its development potential.At present,the technique of producing H2 by solid waste fermentation remains in the exploratory stage.The ind

119、ustrialization of the microorganisms-based H2 production technique requires improvement in yield and productivity.This may be technically achieved by screening and domesticating mixed microbial strains with sustainable and efficient H2 production and optimizing the process of H2 production.Besides,m

120、icrobial fermentation has also been used to produce liquid fuel such as ethanol and butane by using organisms in MSW,of which the process is technologically similar as in wine production.It has become one of the hot topics of current research and future development.2.3.2 Landfill gas captureLandfill

121、 is one of the most widely used waste treatment methods at present,by which organic substances are converted into landfill gas(LFG)through landfill microorganisms.The main components of this gas are CH4 and CO2,thus making LFG one of the most important greenhouse gases 37.Capturing LFG from landfill

122、s for energy supply is not only contributing to alleviating the contraction of energy supply(through reducing the primary energy supply by using the LFG from landfills),but also limiting climate change.At present,LFG is gaining in popularity as a source of natural gas for heating and is expected to

123、become a major energy source for CHP projects in the future.The process of capturing LFG includes the installation of a gas collection system.Excess gas will be burned under open or closed conditions to prevent LFG from entering the atmosphere 38.Although wide application of LFG capture is projected

124、,the following problems are yet to be solved:1)due to the large area of landfill sites with scattered LFG distribution,it is currently difficult and costly to practically realize capture of the 21Current status of MSWtEwhole gas;2)as the surrounding environment is vulnerable to leachate from LFG,it

125、is a prerequisite to provide a cost-effective solution via leachate treatment 39.2.3.3 Microbial fuel cellMicrobial fuel cell(MFC)is a bio-catalysis system that uses microorganisms to degrade MSW for power generation.It is mainly used for(domestic)wastewater treatment applications or alarm-like bios

126、ensors for detecting toxicity and high chemical oxygen demand(COD)influent concentrations.As illustrated by Figure 2-8,MFC is usually composed of a proton exchange membrane,an anode chamber and a cathode chamber 40.The anode is usually maintained in the absence of oxygen,while the cathode can be kep

127、t regardless of exposure to air or impregnation in an aerobic solution,where the electrons flow from the anode to the cathode through an external circuit.This technique is plausible for small-scale power generation in remote or dangerous areas.One example is the use of MFC for power supply in corros

128、ion and pressure monitoring sensor devices in deep-sea oil and gas pipelines.In addition,the application of MFC can also be extended to the fields of biological H2 production and biosensors.For the moment,this technique is still in its infancy and faces practical challenges of low power and low ener

129、gy density.Regarding the issue of low efficiency,a potential solution is to expand the electrode surface area to increase the power of MFC.In addition to expanding the electrode surface area,the optimal design for MFC is still under investigation,and different materials for the Figure 2-8|Schematic

130、diagram of microbial fuel cell22Current status of MSWtEelectrodes as well as more selective membranes for proton exchange are being currently developed to enhance its performance.Some research institutions also propose the use of capacitors to store the energy released by MFC.At the same time,due to

131、 the sensitivity of microorganisms to ambient temperature,MFC is strictly restricted regarding operating temperature.In addition,commercial promotion of MFC is currently also limited by the high cost of materials such as electrodes and membranes,as well as by the low buffering capacity of wastewater

132、 41.23Municipal solid waste to energy(MSWtE)technology achieves the recovery of residual energy in waste during waste disposal.Although challenges exist to application of the current MSWtE technique(to be discussed in detail in Section 4),it is still considered as a potential stable energy supplemen

133、t and an effective waste treatment method.At present,the integration of the advanced power system with MSWtE constitutes a major developing target,known as coupled power generation with MSW(CPG-MSW).The main technology of CPG-MSW includes thermal power generation with MSW,solar power generation with

134、 MSW,wind power generation with MSW and nuclear power generation with MSW.Compared with a single power generation system,the CPG-MSW combines the advantages of MSWtE and advanced power generation to realize energy recovery efficiency improvements,pollutant control and grid stabilization.As such,CPG-

135、MSW is an important supplement for advanced electric power systems and a plausible means of achieving efficient management of MSW in the future.3.1 Thermal power generation with MSWThermal power generation with MSW is the integration of MSWtE and advanced thermal power generation,which currently dom

136、inates the CPG-MSW market.This technology basically achieves energy recovery from bulk MSW with currently-in-service thermal power generation facilities.The feasible use of MSW,which is featured by complicated compositions,low calorific value and high moisture content,is technically achieved by a mi

137、xture of MSW and fossil fuel,as well as adaption of MSW energy recovery to thermal power generation.This generates considerable environmental value through reduced pollution as well as economic value by reduced generation cost.3.1.1 Coal-fired power generation with MSWCurrently,coal-fired power gene

138、ration remains a mainstay of global electricity supply.According to IEA statistics in 2019,more than 36%of global electricity comes from coal-fired power generation 42.Especially in developing countries such as China and India,coal-fired power generation contributes more than 60%of social electricit

139、y supply 43.However,in response to climate change,many countries have developed plans for coal-fired power generation retirement and reduction,and many advanced coal-fired power generation units are facing early retirement.The clean utilization of MSW energy recovery can be guaranteed by in-service

140、flue gas treatment systems of advanced coal-fired power generation to effectively eliminate the harmful gases caused by waste energy recovery,such as SOx,NOx,etc.As mentioned before,the features characterizing MSW low calorific value,high moisture content and complicated compositions pose a technica

141、l issue with regard to energy recovery.Related technological and management innovations are still important driving factors for the rapid development of this technology.In such cases,some countries rely on well-established waste sorting and pre-treatment technologies to ensure the process Section 3C

142、oupled power generation with MSW24Coupled power generation with MSWof energy recovery.For example,Lahden Lmpvoima Oy,a Finnish power plant,uses such technology to achieve MSW energy recovery.In this system,the high combustible content of MSW is sorted through local solid waste treatment plants and m

143、ade into refuse derived fuel(RDF)with high calorific value,which can be efficiently utilized by advanced thermal power generation systems.Co-firing technology represents another utilization of advanced thermal power generation for waste energy recovery.According to the combustion characteristics and

144、 actual operating conditions of existing coal-fired power generation,this technology achieves a high efficiency of energy recovery from MSW by adjusting the blending ratio.For example,the China Huaneng Group applies a 1 000 MW ultra-supercritical unit,whose actual operating efficiency is up to 45%,f

145、or the energy recovery from MSW.The operation result shows little change in operating efficiency if the MSW is blended into traditional fossil fuel.Meanwhile,co-firing technology adapts to different types of MSW,simplifies the process of waste pre-treatment and solves the problem of unstable combust

146、ion characteristics due to the complicated compositions of MSW.China Huaneng Yangtze Environmental Technology Co.,Ltd.(CHYE)has developed a pre-carbonation technology to provide high-performance RDF by flue gas heat recovery,which has been used for coal-fired power generation with various MSW under

147、different situations.The technology of combined heat and power(CHP),also known as co-generation,is a representative technology of advanced coal-fired power generation that has the potential for improving the energy recovery rate of MSWtE.It categorizes heat by the grade reached during thermal power

148、generation and constructs a scheme whereby the higher-grade heat is used for power generation,while the lower-grade heat provides a service for industrial and domestic heating.Compared with traditional thermal power generation,the application of CHP with MSW enables bulk MSW to generate electricity

149、and allows the heat that would normally be lost in the power generation process to be recovered to provide heating and/or cooling.As shown in Table 3-1,the efficiency of CHP with MSW is higher than that of normal coal-fired power generation with MSW by 10%to 20%.Hence,CHP with MSW has become one of

150、the main technologies for recovering energy from MSW in Europe.Currently,some technical researchers try to use integrated gasification combined cycle(IGCC)for energy recovery from MSW in order to realize chemical recycling and expand economic benefits.This proposal can effectively control the pollut

151、ion problem of energy recovery from MSW by pre-combustion treatment,and reduce corrosion of equipment by harmful components during the process of energy recovery from MSW.Conversion technology EfficiencyIncineration15%-27%RDF25%Combined heat and power(CHP)40%+Table 3-1|The efficiency of coal-fired p

152、ower generation with MSW 4425Coupled power generation with MSW3.1.2 Gas-fired power generation with MSWGas-fired power generation with MSW is one of the most efficient and clean techniques for energy recovery from MSW.This technique recovers energy from MSW by converting it into syngas/biogas that i

153、s enabled for gas-fired power generation.Currently,the advanced gas-fired power generation system can achieve 60%energy conversion efficiency during power generation 45.Therefore,expectations are great that gas-fired power generation with MSW can realize high-efficiency energy recovery from MSW.In a

154、ddition to achieving high efficiency,pollution can also be effectively controlled by gasification and pre-combustion treatment.For example,in 2013,gas-fired power generation with MSW was used to recover energy from MSW contaminated by the Fukushima nuclear crisis in Japan to avoid the spread of nucl

155、ear contamination 46.However,the syngas/biogas produced from MSW is different from natural gas regarding calorific value,sulfur content,CO2 content and water content.A series of purification operations are necessary to meet the requirements of gas-fired power generation.For this reason,many countrie

156、s have introduced standards to clarify and regulate the content of syngas/biogas components for gas-fired power generation,and to regulate the development and application of gas-fired power generation with MSW.Meanwhile,many countries are attempting to simplify the purification process and optimize

157、the gasification operation,in order to improve the economic benefits of gas-fired power generation with MSW.Co-gasification is an encouraged conversion scheme used in gas-fired power generation with MSW,and blending of fossil fuels and MSW is one of the most effective ways to improve the energy reco

158、very efficiency of MSWtE.Moreover,many researchers are attempting to expand the output of H2,as an efficient energy substance in gas-fired power generation with MSW.Some Chinese 47 and Indonesian 48 scholars have discovered that the utilization of supercritical water in gasification could optimize t

159、he process of gasification,where the direct use of moist MSW is enabled and the costly feed-stock-drying step is eliminated.In addition,organic reactions under supercritical water are more homogeneous,which results in a higher reaction rate.Furthermore,the experiment of combining co-gasification and

160、 supercritical water has been conducted in order to achieve the desired gasification effect in supercritical water by the co-gasification of lignite and MSW.It has been found that there is a significant synergistic effect of the carbon gasification rate and the H2 production rate in the co-gasificat

161、ion process.Compared with traditional gasification of MSW,this novel combination is obviously able to improve the gasification efficiency with a higher H2 yield,leading to a higher calorific value of the synthesis gas product and ease of utilization in gas-fired power generation with MSW.In addition

162、 to a focus on domestic sludge,Chinese scholars have conducted research on supercritical water gasification of paper industry waste.Through mechanistic analysis and research experiments,the ratio of blended raw materials is determined to achieve the optimal state of co-gasification,which improves ga

163、sification efficiency,reduces the use of catalysts in the gasification process,and decreases the operating cost of MSW coupled gas-fired power generation technology.3.2 Solar power generation with MSWCompared with the traditional technology of MSWtE,solar power generation with MSW expands the utiliz

164、ation of solar power generation by achieving great yield of energy and less pollutant emissions.The integration of solar power generation and MSW can be achieved in multiple forms,which overall reduces the cost of existing solar thermal technologies and enhances the competitivity of solar thermal te

165、chnique.26Coupled power generation with MSWRecently,Denmark has launched plans to invest in a production tax credit(PTC)-based solar power generation with MSW project in Aarhus 49.Compared with single solar thermal power generation,this PTC-based project does not require an additional thermal storag

166、e system,and the MSW can provide 25%of the total load,which maintains the stable operation of the entire system by avoiding energy loss due to frequent start and stop.As measured by technicians,the annual net solar-to-electricity efficiency of this technique is 18,13%,which is higher than the conver

167、sion efficiency of 15,79%for a single trough solar thermal power system.In comparison to the traditional solid waste energy recovery technique,this technique provides greater turbine force with sufficient illumination.The integration of thermo-chemical treatment and solar power generation has furthe

168、r expanded the application of solar power generation with MSW by converting solar energy and residual energy from MSW into chemical energy in the form of H2.This technique effectively overcomes the shortcomings of intermittency,non-storability,non-uniformity and low energy flow density for the solar

169、 power.Potentially,it is able to solve the problem of grid fluctuations caused by unstable solar energy in the future.Some researchers have proposed the idea of a future centralized MSW solar power system for multi-generation 50.In this system,a flat-plate solar dryer is used to dehydrate MSW(85 C)a

170、nd a trough collector is used as a steam generator.In addition,a tower collector provides high-temperature heat(8001 200 C).For this system,solar power is used in steps in the process of energy recovery from MSW.The solar power and residual energy are converted into syngas,which can be used for gas-

171、fired power generation.The system also utilizes exothermic and waste heat,which improves the energy efficiency of the whole system.At the same time,the feasibility of establishing distributed waste treatment stations is enabled by the technical support of solar power generation with MSW.Compared wit

172、h traditional small-scale solid waste treatment,the emitted pollutants from this system are effectively limited and the yield of energy products is higher,because both solar energy and residual energy are collected 51.Currently,it is technically possible to use a dish-type solar concentrator to prov

173、ide high-temperature heat for this conversion.The resulting syngas will be cooled and purified for power generation and heat supply.Although the current energy efficiency of this distributed system is only 17,33%,it is still deemed as potentially providing a technology roadmap of energy recovery fro

174、m MSW in the future.For the future,it will be technically necessary to increase the efficiency of solar power generation with MSW.A potential technical roadmap involves using solar power generation with MSW to produce H2 by supercritical water gasification,where the biomass can be completely gasifie

175、d at a lower temperature with zero pollution 52.A pilot plant that has been operated stably for biomass disposal in China,as shown in Figure 3-1,can achieve an operational scale of 1 ton/hour treatment capacity.This trial has successfully demonstrated the possibility of direct gasification of high-w

176、ater-content MSW with solar energy.Therefore,improvement can be achieved vis-vis the energy recovery rate of MSWtE and the yield of final products.27Coupled power generation with MSWFigure 3-1|Integration of CPG-MSW with H2 polygeneration systemFigure 3.2|Tire-surface solar concentratorIn solar powe

177、r generation with MSW,advanced solar energy technique is also one of the most effective ways to improve the energy recovery rate of MSWtE.A solar concentrate system in the coupled system has been developed as shown in Figure 3.2,in which a hydrogen production system coupled with a tire-surface conce

178、ntrator as the core has been built 53.By conducting supercritical water gasification tests,a 110%gasification rate and a syngas hydrogen content of more than 50%were achieved.The experimental results further demonstrate the possibility of low-cost,resourceful,energy-efficient and harmless integrated

179、 utilization of MSW by coupling with solar energy.28Coupled power generation with MSW3.3 Wind power generation with MSWWind power generation with MSW is becoming an important supplement to wind power generation overall.In fact,abandonment of existing wind power generation is causing terrible energy

180、waste.It has been reported that the abandonment rate of wind power may exceed 20%in some areas 54.Therefore,many public utilities are mandating wind power units to be equipped with energy storage devices,which still does not provide the ultimate solution of adapting wind power generation to volatili

181、ty.According to the experience of Denmark,where 50%of the countrys installed capacity was provided by wind turbines in 2020 55,power generated by wind turbines may fluctuate by GW levels of energy within a few hours,which would cause a serious problem in power supply in case of the absence of North

182、Europe grid support.At present,advanced research has discovered that wind power generation can become more market competitive by coupling with renewable energy sources,such as biomass 56.The US National Renewable Energy Laboratory 57 has proposed a feasible method to realize wind power generation wi

183、th biomass.In cases where wind power generation exceeds the grids acceptance capacity,the surplus power will be used to generate plasma for the gasification of MSW,which ensures the continuous operation of biomass energy recovery.The syngas generated by MSWtE serves the power generation to reduce th

184、e volatility of wind power generation and stabilize power supply.Considering the similarity between MSW and biomass,the MSW is also a potential storable renewable energy source in this innovative system to stabilize the output of stand-by wind power generators.It is currently technically possible to

185、 realize wind power generation with MSW.With plasma gasification,it has successfully produced high-quality syngas and power from sewage sludge in the US,Canada,Malaysia and Japan 57.Therefore,the high-water content of MSW is no longer a bottleneck of application.Compared with wind power generation w

186、ith biomass,the advantage of wind power generation with MSW is the relief of the pressure of urban management,which contributes to a greater economic value in the future society.3.4 Nuclear power generation with MSWCurrently,the participation of nuclear energy in grid peaking is still widely controv

187、ersial.The increasing proportion of solar and wind energy inevitably raises challenges regarding stabilizing the volatility to the grid.A proportion of French nuclear power plants have already participated in grid regulation,but this practice also raises technical issues back to the nuclear power ge

188、neration.Firstly,it is easy to cause insufficient fuel consumption,which increases radioactive intensity in the spent fuel and the difficulty in spent fuel disposal at the back end 58.Secondly,equipment reliability will be affected by frequent participation of nuclear power in grid regulation,which

189、may cause catastrophic accidents or even disaster.Therefore,many countries have adopted a cautious attitude regarding the participation of nuclear power generation in the grid regulation.Fortunately,participation of nuclear power generation in grid regulation may preferably be realized by nuclear po

190、wer generation with MSW,by converting nuclear energy to storable and transportable syngas/biogas.Combining with gas-fired power generation,the whole system can present a possible pathway for the participation of nuclear power generation in grid regulation.Specifically,nuclear power generation with M

191、SW utilizes thermal energy from nuclear reactions for the gasification of MSW.The higher-temperature heat source(over 900 C)from the nuclear reactor is able to directly gasify MSW.During this process,thermal energy released by the nuclear reactor can 29Coupled power generation with MSWbe stored,whil

192、e residual energy is recovered from the waste.This avoids the energy loss caused by excess energy conversion processes and demonstrates its economic benefits for nuclear power generation 59.The Korean government is planning to conduct research to solve the problem of growing energy demand and waste

193、management issues using nuclear power generation with MSW.As shown in Figure 3-3,it is projected that the technique will use MSW and agricultural waste as raw materials to produce RDF,which afterwards is converted into syngas for gas turbine power generation by the heat from the nuclear reactor.The

194、Korean government plans to use a 500 MW nuclear reactor for the integration.According to the technical assessment,this system,which will consume 12 000 tons RDF per day,can produce 2 000 tons of diesel and 205 MWh of electricity per year.The successful operation of this integration will hopefully re

195、duce the cost of MSW disposal in Korea and reduce the cumulative CO2 generated from MSW disposal by 257 million tons over its 30-year lifetime 60.Figure 3-3|South Koreas planned system of nuclear power generation coupled with MSW30Table 4-1|Global status of waste management regulationIncome groupTot

196、al number of countriesNumber of countries with defined solid waste management laws or guidelinesNumber of countries without defined solid waste management laws or guidelinesNumber of countries with no informationShare of countries with defined solid waste management laws or guidelines(percent)High i

197、ncome78752196%Upper-middle income56474584%Lower-middle income53471589%Low income301811160%All21718782286%Section 4Challenges of MSWtEAlthough coupled power generation with MSW holds out extraordinary potential for the future,a number of challenges still exist for the application of MSWtE,including s

198、olid waste management,temperature management,moisture management and pollutant management.4.1 Solid waste managementA highly critical issue for MSWtE is the appropriate management of solid waste.In the CPG-MSW technology,there exists an optimal treatment method for different solid wastes.However,the

199、 current status of waste management is not conducive to the promotion of CPG-MSW technology.According to the World Bank,more than 90%of solid waste in low-income countries is burned and land-filled indiscriminately,without any treatment 61,which causes environmental pollution and energy waste.Less w

200、aste management regulation in low income countries is expected as shown in Table 4-1 62.31Challenges of MSWtEAnother critical issue for solid waste management is the composition of the solid waste involved,which determines the frequency of the waste collection and its treatment method.For example,in

201、 the case of domestic waste,organic waste is the highest proportion in low-income countries,while paper,plastics and other inorganic materials occupy the main proportion of MSW in high-income countries.On the other hand,the identification of hazardous characteristics of sludge and production waste i

202、s also an important task for solid waste composition management,which will directly affect the cost and investment of CPG-MSW technology.It is worth mentioning that seasonal change in solid waste composition 63 also imperceptibly increases the difficulty in energy regeneration of municipal solid was

203、te.For example,in Ulaanbaatar,Mongolia,the ash content of municipal waste occupies more than 60%in winter,while it is only 20%in summer.By analyzing the seasonal variation of municipal solid waste in Perm,Russia 64,it has been found that Perms municipal solid waste contained only 17%organic waste in

204、 the spring,while this percentage increased to 31,5%in the autumn.The laboratory data also shows that for organic waste only,there exist some variations in the moisture and ash content(82%moisture and 14%ash in the autumn,compared to 73%moisture and 22%ash in the winter).Changes in moisture and ash

205、content directly affect the energy efficiency of municipal solid waste,which requires more efficient waste detection and management methods as well as standards to accurately characterize solid waste for energy recovery.A suitable method of sorting municipal solid waste can improve the efficiency of

206、 CPG-MSW.4.2 Temperature managementTemperature is one of the most critical factors in CPG-MSW.Taking coal-fired coupling as an example,temperature is the key to affecting pollutant emissions.A too-low combustion temperature leads to incomplete degradation of organic pollutants such as dioxins,while

207、on the other side incomplete energy utilization will cause waste of resources.A too-high temperature causes the appearance of secondary nitrogen oxides(nitrogen oxides formed by the reaction of nitrogen in the air with oxygen).Increased nitrogen oxides rely heavily upon the nitrogen removal equipmen

208、t in the tail flue.In addition,if concentrated solar power is to be used to couple municipal solid waste energy,the degree of sunlight focus,solar irradiance per day and temperature control within the reactor need to be further studied.The differences between CPG-MSW and traditional thermal power ge

209、neration lie in a higher level of halogenated elements for the municipal solid waste,which can cause damage to sensors,control elements and control system components.Standards and technical measures related to anti-corrosion protection are important for the further promotion of CPG-MSW technology.4.

210、3 Moisture managementThe moisture in municipal solid waste reduces the energy recovery rate and may cause leachate collection problems.Therefore,solid waste dehydration is an important step in the CPG-MSW technology.However,the moisture content in municipal solid waste varies significantly.For examp

211、le,the moisture content in industrial waste is relatively low,while the moisture content in domestic waste is generally high(e.g.moisture content in domestic waste generally ranges from 50%to 70%,and the sewage sludge can even have a moisture content higher than 85%).Under the circumstances,indiscri

212、minative dehydration would lead to unnecessary energy consumption and affect the comprehensive energy recovery of solid waste.As a result,the development of a moisture detection,control and management system to achieve accurate control of moisture in 32Challenges of MSWtEthe municipal solid waste pr

213、e-treatment process is the key to further improving the efficiency of CPG-MSW technology.4.4 Emissions management Although MSWtE produces less polluting emission than traditional energy-based technologies,it still involves potential health and safety risks 65.Many efforts are being made to study the

214、 correlation between solid waste post-processing emissions and diseases such as cancer.These studies have served as a supporting reason for public health agencies and NGO activists to oppose the energy regeneration of municipal solid waste.Therefore,a strict standard of emissions management will be

215、directly related to the promotion and application of CPG-MSW technology.This is also becoming a major challenge for future municipal solid waste energization.4.4.1 Flue gas pollutants,corrosion and slagging during the coupled incineration power generation processThe flue gases from coupled solid was

216、te incineration generally carry a certain amount of harmful substances to the atmosphere.In addition to the common nitrogen oxides(NOx),sulfur oxides(mainly SO2),dust,CO,HCl,etc.,the pollutants also include non-conventional trace pollutants,such as heavy metals and dioxins,a situation which causes s

217、erious impacts on the environment and human health.The presence of pollutants also leads to elevated costs and investments in thermal treatment facilities.For example,large-scale combustion systems require expensive air pollution control systems,and in some US states solid waste coupled incineration

218、 also faces strict permit requirements for proper ash and flue gas treatment 66.Heavy metals in solid waste mainly include cadmium,lead,chromium,mercury and corresponding compounds.In the incineration process,a certain portion of the heavy metals will enter the flue gas,and another portion will form

219、 oxides or halides.The main reason for the appearance of dioxins is the inadequate combustion of solid waste.The second source of dioxins is from the catalysis of precursors which are formed from the dioxin-like substances originally contained in solid waste.A final source is from the low-temperatur

220、e resynthesis pollutants in the flue gas treatment process.Solid waste,as a highly complex combination,contains combustible components,such as plastic,wood and paper,and non-combustible components,such as bricks,rubble,metal.After incineration,the generated flue gas contains HCI,NOx,SO2 and other ac

221、idic gases,as well as sticky ash.The ash can easily adhere to the surface of the tube at the heating surface,reducing the heat transfer effect and causing a high flue gas temperature.The acidic gases not only cause great pollution to the atmosphere,but also lead to high temperature corrosion of the

222、waste incinerator,limiting the upsizing and high parameterization of the solid waste incineration equipment 67.Slagging on the heating surface has also plagued the normal and stable operation of solid waste incineration facilities,and this problem also exists in coal-fired coupled incineration units

223、.In order to reduce the corrosion of coal-fired boilers and flue gas treatment equipment by acidic pollutants from combustion,the solid waste incineration technique should be updated to control the proportion of halides and organics.Feasible approaches include:1)apply chlorination additives to coal-

224、fired units to reduce the chlorine-containing substances in the furnace,which can effectively reduce corrosion;2)optimize facility operation and management measures to control the thermal load,temperature,and air volume ratios of the units;3)develop new high-temperature corrosion-resistant materials

225、 and spray corrosion-resistant coatings to improve corrosion resistance and extend the service life of equipment,etc.33Challenges of MSWtE4.4.2 Ash emissions in the coupled incineration power generation processThe ash emission problem is mainly posed by the existence of heavy metal content in the fl

226、y ash and slag from units,which may exceed the existing environmental protection standards.Another issue regarding the ash is the increased chlorine content of fly ash due to the high chlorine content in solid waste,which may affect the subsequent utilization of fly ash.34Section 5Standards of CPG-M

227、SWStandardization is the basis of achieving quality management and consistency.Not only the specific content of the management needs standardization,but also the management methods and approaches require a relevant standard system.The latter plays a critical role in the promotion of CPG-MSW techniqu

228、e,and serves as an important bridge connecting sensors,intelligent control,electrification techniques and other cross-field applications.High-quality standards are indispensable for an efficient urban solid waste coupled power generation technique.It is necessary to study the construction and develo

229、pment of relevant standard systems and to address the challenges that may be confronted by this technique.According to the analysis contained in the previous sections of this paper,an efficient CPG-MSW technique must consider high-quality management mainly from four different perspectives:waste mate

230、rials,temperature,moisture,and pollutant emissions.As a prerequisite for successful standardization,cases and requirements must be regularly collected to build and support the standard system.Since this technique should be adapted to the trends of global environmental protection and waste treatment,

231、a universality for international standards is required,especially when it comes to specific requirements and services.The following is an analysis of some of the existing standards and standardization activities in this area.5.1 Current situation analysis5.1.1 IECSeveral IEC technical committees are

232、 carrying out work on related standards.IEC TC 27:Industrial electroheating and electromagnetic processing.This technical committee is mainly involved in the standardization of related electric heating industrial equipment,electromagnetic processing and processing technology based on electric heatin

233、g.Specifically,it includes direct and indirect resistance heating equipment,resistance trace heating equipment,induction heating equipment,electromagnetic force on materials,arc heating equipment,electroslag remelting equipment,plasma heating equipment,microwave heating equipment,dielectric heating

234、equipment,electron beam heating equipment,laser heating equipment,infrared radiation heating equipment.It is noted that,in the process of solid waste energization,the performance and stability of high temperature heating equipment directly affects the efficiency and cost of solid waste energization.

235、IEC TC 57:Power systems management and associated information exchange.This technical committee is mainly concerned with information exchange including grid and distributed energy resource models,energy management systems(EMS),distribution management systems(DMS),electricity market management system

236、s(EMMS),distributed energy resource management systems(DERMS),supervisory control and data acquisition(SCADA),transmission,distribution and microgrid management and automation,protection/remote 35Standards of CPG-MSWprotection,and related information exchange in real and non-real time for planning,o

237、peration and maintenance of the power system.Accurate and reliable energy-power management systems are necessary in multi-energy coupled systems containing energy-from-waste,in order to effectively regulate the rate of energy-from-waste,improve the overall system efficiency and reduce the overall ca

238、rbon emission of the system.IEC TC 65:Industrial-process measurement,control and automation.This committee develops international standards regarding systems and components used in industrial process measurement,control and automation.The measurement,control and system integration of municipal solid

239、 waste for coupled power generation process equipment are closely related to the activity of this TC.IEC SC 65B:Measurement and control devices.This subcommittee is primarily concerned with standardization works covering specific aspects of measurement and control,including equipment(hardware and so

240、ftware)used for industrial process measurement and control(e.g.measurement equipment,analytical equipment,actuators),and programmable logic controllers,as well as interchangeability,performance evaluation and functional definitions.IEC SC 65C:Industrial networks.This subcommittee is primarily concer

241、ned with the standardization of wired,optical and wireless industrial systems for industrial process measurement,control and manufacturing automation,as well as the standardization of equipment systems for research,development and testing purposes.Its scope includes wiring planning,interoperability,

242、coexistence and performance evaluation.IEC SC 65E:Devices and integration in enterprise systems.This subcommittee is primarily concerned with the integration of devices with industrial automation systems and the standardization of the integration of industrial automation systems with enterprise syst

243、ems.These standardization efforts are intended to address equipment attributes,classification,selection,configuration,commissioning,monitoring and basic diagnostics.Some of this standardization work concerning the integration of systems between commercial and manufacturing activities will be develop

244、ed in cooperation with ISO/TC 184.IEC TC 70:Degrees of protection provided by enclosures.This standards committee is responsible for the preparation of international standards regarding appropriate test methods for the degree of protection provided by enclosures against the ingress of solid foreign

245、matter and water and against access to hazardous areas.Moisture and solid foreign matter are common production impurities in solid waste energy processing,so protection and protection level assessment are necessary to ensure the safe and stable operation of the solid waste energy process.Thus,the de

246、velopment of relevant standards is important for the promotion and application of solid waste energy.IEC TC 111:Environmental standardization for electrical and electronic products and systems.This standards committee works closely with IECs product committees to prepare the necessary guidelines,sta

247、ndards and technical reports in the environmental field.At the same time,this standards committee focuses on the development of environmental requirements for product standards to facilitate the resolution of similar environmental issues and to provide common technical approaches and solutions,thus

248、ensuring the consistency of IEC Standards and maintaining an effective link with IEC Advisory Committee on Environmental Aspects(ACEA)and ISO/TC 207.The process of municipal solid waste energization involves the treatment of numerous electrical and electronic product wastes.The related treatment req

249、uirements and guidelines are closely related to IEC TC 111.36Standards of CPG-MSW5.1.2 ISOISO has focused on technologies related to waste treatment and waste-to-energy since a very early stage.The relevant standards committees are summarized as follows.ISO/TC 28/SC 7:Liquid Biofuels.This technical

250、committee develops standards related to the terminology,classification and specification of liquid biofuels and standardizes methods of analysis and testing of pure liquid biofuels.ISO/TC 193:Natural gas.This technical committee is responsible for the standardization of terminology,quality specifica

251、tions,measurement,sampling,analysis and test methods for natural gas and its related gases,including natural gas,natural gas substitutes,natural gas and gaseous fuels(including mixtures of unconventional and renewable gases)and wet gases,as well as the calculation and measurement of thermophysical p

252、roperties and the regulation of natural gas from production to end use.ISO/TC 238:Solid biofuels.This technical committee works on developing standards related to solid biofuels derived from captive farming,agriculture,aquaculture,horticulture and forestry.ISO/TC 255:Biogas.This technical committee

253、is working to establish a system of international standards for the biogas industry and develop specifications for the development of that industry.ISO/TC 275:Sludge recovery,recycling,treatment and disposal.This technical committee develops standards regarding methods of describing,classifying,prep

254、aring,treating,recycling and management of sludge,and product management for municipal wastewater collection systems,soils,stormwater treatment,water supply treatment plants,and municipal and similar industrial water wastewater treatment plants.These standardization efforts are aimed at facilitating

255、 the selection of treatment processes and the use and disposal of sludge,which is an important component of the energy regeneration from the municipal solid waste.ISO/TC 297:Waste collection and transportation management.This technical committee works on improving market acceptance of the products t

256、hrough developing standards regarding waste collection and transport management.This standards committee seeks to reduce production,operation and maintenance costs in the waste management process through standardization of equipment,environmental efficiency,service measures,test methods,safety and h

257、ealth requirements,thereby promoting healthy and sustainable urban development and providing a standard basis for the collection and transportation of municipal solid waste in the energy-based process.ISO/TC 300:Solid recovered materials,including solid recovered fuels.This technical committee clari

258、fies the definition and description of solid recovery fuels to standardize solid recovery materials and fuels.It also standardizes the work related to municipal solid waste,commercial and industrial waste,as well as construction waste.In addition,it standardizes the process of extracting solid recov

259、ery fuels from non-hazardous waste for further utilization in the following types of plants and processes:power plants,gasification plants,pyrolysis plants,chemical recovery,and mineral utilization(e.g.cement and lime manufacturing).5.1.3 Relevant standardization work in ChinaSAC/TC42/SC5:Utilizatio

260、n of Mine Water and Waste Subcommittee is responsible for the professional scope of standardization work in national mine water quality analysis test methods,mine water quality evaluation,coal waste management and resource utilization and other fields.Among the works issued,GB/T28733-2012,Determinat

261、ion of total moisture for solid biofuels,37Standards of CPG-MSWand GB/T 28730-2012,Method for preparation of solid biofuels sample,are closely related to biomass-based solid waste energy utilization.SAC/TC124/SC 1:Sub-committee of Temperature,Mechanical Value,Level and Structural Devices works on th

262、e professional scope of the national standardization work in professional fields such as temperature,flow,mechanical quantity,level,display instruments and actuators.The work covers GB/T 11606.5-1989,The method of environmental test for analytical instruments Part 5:Change of temperature test;GB/Z 2

263、1193.3-2007,Fossil-fired steam power stations Part 3:Steam-temperature controls;GB/T 36014.2-2020,Industrial process control devices Radiation thermometers Part 2:Determination of the technical data for radiation thermometers.These standards are all related to MSWtE.SAC/TC275/SC1 is mainly responsib

264、le for standardization work related to flue gas desulfurization and complete equipment,complete municipal domestic waste treatment equipment,industrial solid waste treatment and disposal equipment.The existing standards include GB/T 28739-2012,Kitchen waste treating and utilizing equipment in cateri

265、ng services;GB/T29152-2012,Flue gas cleaning system for municipal solid waste incineration;GB/T35251-2017,Waste pyrolysis and incineration treatment device.The standards under development include 20201776-T-303,Technical requirements for plasma treatment and evaluation of hazardous waste;20201775-T-

266、303,Technical requirements of operation performance assessment for sludge pyrolysis resourcelization equipment;and 20201774-T-303,Technical requirements of operation performance assessment for town sewage MBR treatment system.The TC273 National Technical Committee for the Standardization of Ecologic

267、al Environment Monitoring Methods works on monitoring methods in the fields of water,soil,air environment and ecological and environmental monitoring,which will affect the environmental assessment of MSWtE directly.In addition,the DL/TC08 China Power Station Boiler Standardization Technical Committe

268、e has carried out technical standard works in the field of coal-fired coupled solid waste power generation in recent years.According to public information,the committee has issued or established two power industry standards for regulating the technical development of coal-fired coupled power generat

269、ion:Technical guidelines for blending urban sludge in pulverized coal boilers in power stations;and Technical specifications for pre-charging system of coal-fired coupled sludge power generation.Some local governments have also issued local standards for CPG-MSW technology,such as DB31/1291-2021,Emi

270、ssion standard for air pollutants from coal-fired and sludge coupled power plants;and DB37/T 2670-2015,Technical specification for oilfield and disposal of oilfield oil-bearing sludge by fluidized bed incineration.5.1.4 Relevant standardization work in the United StatesThe US,as the country with the

271、 most well-established waste-to-energy industry in the world,has more active standardization activities in related industrial fields.Major standards organizations in the US have developed standards related to waste-to-energy.The standard ASME PTC 34-2017,Waste combustors with energy recovery,develop

272、ed by The American Society of Mechanical Engineers(ASME)in 2017 can be used to evaluate the performance of waste boilers for energy recovery.This standard is used to determine 1)the thermal efficiency of systems for combusting waste fuels,2)the thermal capacity(heat input per unit time)of systems fo

273、r combusting waste fuels,3)the high heating value(HHV)of waste fuels.The rules and instructions given in this standard can be applied to all waste 38Standards of CPG-MSWcombustor systems with energy recovery,and its test methods can be applied to solid,liquid or gaseous waste fuels.Instructions are

274、given to determine the thermal capacity and thermal efficiency of waste combustor systems by applying the concept of using the boiler as a calorimeter.In addition,the HHV of the waste fuel can be determined by weighing the waste fuel that has been consumed during the test.In addition,the American So

275、ciety of Testing Materials(ASTM)s waste management standards provide a range of guidelines,practices and test methods related to the management process for handling residential,commercial and industrial waste.The entire system involves the transportation,processing,recycling,or disposal of waste use

276、d for health,environment and other aspects,and provides essential management standards for the local government authorities in charge of residential and metropolitan waste,industrial plants and laboratories that generate waste 68.Among the above,ASTM E2060-06(2014)covers methods for the selection an

277、d application of coal combustion products(CCPs)for chemical stabilization of trace elements from waste and wastewater,and certain advanced sulfur-controlled byproduct combustion methods such as fluidized bed combustion(FBC)for processes such as fly ash,spent dry detergents,pipeline injection and flu

278、idized beds to optimize the energy-from-waste treatment process.In addition,founded in 2002 by the Center for Earth Engineering at Columbia University and the American Energy Recovery and Utilization Association,the Waste-to-Energy Research and Technology Council(WTERT)has grown into the worlds fore

279、most research organization for solid waste recycling and energy utilization.5.1.5 Relevant standardization work in the European UnionThe European Union(EU),as an organization which has developed the worlds most detailed solid waste disposal standards,has taken the leadership in solid waste disposal/

280、energization of MSW standardization.The relevant norms for waste treatment in the EU are mainly grouped under the Waste Framework Directive and EN 12740:1999,Biotechnology Research,Development and Analytical Laboratories Guidelines for Waste Treatment,Inactivation and Testing,thus establishing a set

281、 of standards for waste management,waste separation,waste containers,waste collection,waste storage,treatment method selection,disposal methods,testing and validation of waste treatment methods and risk management.In 2018,the EU revised the Waste Framework Directive to improve the recycling rate of

282、specific waste,mainly affecting existing landfill waste,end-of-life vehicles,waste batteries and accumulators and waste electrical and electronic equipment,to further improve the EUs standards in waste treatment 69.The EUs Directive on Industrial Emissions(2010/75/EU)sets out the technical and manag

283、ement requirements for dedicated incinerators and cement kilns,boilers,and the co-treatment of solid waste for other industrial kilns,regarding waste reception requirements,facility operating conditions,pollution emission limits,monitoring requirements,etc.70.Recently,the EU has formulated a set of

284、high-potential time programmes,called Best Environmental Management Practices(BEMPs).These programmes aim to guide companies and local governments in charge of waste management to choose the best waste management instruments and programmes to achieve a circular economy.Completed by a technical worki

285、ng group of experts in relevant fields,the practice guide covers all areas of waste management,develops waste management strategies,39Standards of CPG-MSWpromotes waste prevention,establishes effective waste recycling mechanisms,and supports and stimulates the product-based reuse of waste.In additio

286、n,the practice guide provides a set of environmental performance indicators that can be used by relevant EU organizations to assess waste management performance and monitor progress,depicting the best scenarios that can be achieved for waste management.By reference to a wide range of sources,includi

287、ng environmental benefit analysis,economic analysis,case studies,references,etc.,the report is intended to provide inspiration and guidance about best practice models for relevant organizations in the sector.Moreover,the report will serve as a technical basis for the development of EU Eco-Management

288、 and Audit Scheme(EMAS),which provides significant guidance for the construction of the relevant EU standards system and the revision of standards in the future 71.5.2 Standardization outlookGlobally,the gap between developed and developing countries is becoming increasingly significant.Although som

289、e developed countries have formulated relevant standards and regulations,there still exists considerable resistance to promoting standardization globally.With the advent of a new wave of global urbanization and a continuously rising global population,the demand for energy and effective solid waste m

290、anagement is growing in tandem.In this situation,CPG-MSW technology will be assigned a monumental historical mission and responsibility to address these needs simultaneously.CPG-MSW involves a wide range of techniques and industries.Due to complex material sources,the original standards for solid wa

291、ste recycling are not applicable to MSW energy technologies.Therefore,the introduction of appropriate standards of utilization,assessment and evaluation concerning energy recovery from MSW is highly urgent.These testing procedures will be conducive to realizing effective energy recovery from MSW,ach

292、ieving globalization and ensuring access to affordable,reliable,sustainable and modern energy for all.On this basis,given the current state of advanced technology,advanced equipment research and development,demonstration applications,and transformation of scientific and technological achievements,th

293、e necessity is non-negligible for the construction of a standardization system of relevant efficient MSWtE management,combined with electrification and digital technology.As the technology develops,intelligent solutions will be found to solve the problem of energy recovery from MSW.In turn,it is pos

294、sible to promote the construction of waste-free cities and the achievement of sustainable development goals.It is important to alleviate pollution caused by ineffective solid waste management and address the approaching challenge of climate change.The establishment and improvement of a long-term sup

295、ervision and management mechanism is significant for energy recovery from MSW.Low cost and environmentally friendly options will be easier to adopt 72.This system asks related countries to develop relevant international standards and conformity assessment systems jointly.This co-constructed system i

296、s the basis for realizing the standardization goal of one standard,one certification,global access in the field of CPG-MSW.Moreover,the need exists for strengthening digital wisdom supervision.The Internet of Things(IoT)provides technical support for the construction of a solid waste management plat

297、form,which is helpful for realizing account management and electronic records in waste management.In addition,it can strengthen the supervision capacity of information interaction technology.The industrialized development of coupled power generation would benefit from the existence of a special inte

298、rnational association charged with coordinating the project of MSWtE by unifying 40Standards of CPG-MSWrelevant technical issues across domains,connecting all aspects of the system and ensuring the operability of an integrated platform for energy recovery from MSW.From a system perspective,this asso

299、ciation would consider the various components of the system and provide solutions from multiple standpoints.The association could also be expanded further with comprehensive consideration of social development needs and could integrate the technical field of coupled power generation with MSW as a co

300、mplete and open standard system.This system could promote the selection of innovation paths about the technical and management development of CPG-MSW.It is also important to be aware of the changing role of MSWtE in the power system.In current research on the application of multi-energy systems coup

301、led with solid waste energy,residual energy has been transformed from power generation to energy storage.With the rapid technological development of clean energy generation worldwide,the installed capacity of clean energy generation has increased significantly.Under these conditions,efficient,safe a

302、nd reliable energy storage technology has become the key to the development of supplemental power in the future.Compared with other energy storage technologies,MSWtE can achieve both thermal and electrical energy storage.These features allow it to be used in multiple scenarios in meeting more flexib

303、le requirements.Recently,various related technologies are gradually moving from the laboratory to practical applications,such as nuclear power,wind power and solar energy coupled with the application of MSWtE.However,it must be admitted that at this stage,challenges still exist to applying coupled p

304、ower generation with MSW.Various processes,including detection,monitoring,control,operation and management are still in the developing stage.Thus,the related standardization work will effectively lead and accelerate promotion of the application of CPG-MSW.Currently,the lack of standards concerning t

305、he coupling system is an important factor restricting the industrialization of CPG-MSW.Issues necessitating the development of standards include:1)Accurate control system:temperature is a key factor affecting the energy of solid waste.Hence an accurate temperature control unit will effectively impro

306、ve the efficiency of the energy of solid waste.However,the applicability of high-performance temperature control systems(including sensors,electronic components,etc.for coupled solid waste power generation)is not available at present.2)Reliable system compatibility:in the process of coupling differe

307、nt energy systems,there will always be some potential safety hazards.Whether the compatibility of coupled systems will be characterized by long stability will depend on the specific technical details and demonstration validation.3)Flexible dispatching:the flexibility of power generation in regulatio

308、n is one of the necessary conditions in the power system.But at present the peaking flexibility of CPG-MSW is not clear.4)Widespread acceptance:the specific technical paths and solutions for coupled MSW power generation are still subject to disagreement among countries,preventing a unified understan

309、ding.The process of international standardization is significant in strengthening mutual understanding and demands among countries,selecting appropriate development routes,reducing duplication of efforts and eliminating relevant barriers.41CPG-MSW is not only a technique to improve the efficiency of

310、 energy recovery from MSW,but also a scheme for coupling MSWtE with modern power generation to offset the shortfall of modern power generation capacity.The technique also constitutes one of several comprehensive solutions to alleviate disposal land use and environmental pollution of MSW and ensure t

311、he stable supply of urban power.Existing coupled power generation with MSW technologies include thermal power generation coupled with MSW,solar power generation coupled with MSW,wind power generation coupled with MSW and nuclear power generation coupled with MSW.Some coupling technologies have alrea

312、dy been in service in a variety of applications,such as MSW coupled with CHP,biogas power generation and coal co-generation,while other new technologies are still emerging,such as solar power generation with MSW,wind power generation with MSW and nuclear power generation with MSW.All of them will tr

313、igger further ideas and breakthroughs to realize cleaner power generation coupled with MSW in the future.At the same time,the integration of energy recovery from MSW and new power generation potentially reduces the rate of abandoned wind power,realizes long-hour and large-load peak regulation by nuc

314、lear power generation and achieves ample utilization of regional and distributed solar thermal resources.It is believed that with technical development,CPG-MSW will become indispensable for achieving the goal of human sustainable development by offering affordable,clean and reliable energy.In order

315、to achieve efficient MSW energy recovery,extensive studies should be conducted on temperature management,raw material management,moisture management and pollutant management of the coupled system.At the same time,the coupled system may present new challenges,such as divergent characteristics among d

316、ifferent power generation technologies,and potential secondary pollution and hazards from the system.Understanding and solving these difficulties and challenges will constitute one of the most important directions for future scientific technology and standard work in this area.6.1 Technical outlook6

317、.1.1 CPG-MSW technical outlookThe work is considered to be carried out along the entire technical chain of source reduction intelligent classification efficient transformation clean utilization deep processing preciseicontrol with the core principle being reduction,reuse and harmlessness.This emphas

318、izes development of the theoretical system for energy utilization and pollution synergy control adapted to the characteristics of MSW,and the entire technical set of CPG-MSW.The result is a systematic and comprehensive solution and promotion model for MSW and energy problems,and establishment of a s

319、eries of integrated demonstration bases for leading promotion of the necessary scientific and technological support and comprehensively guaranteeing the capability of coupled power generation with MSW.The above would benefit the industry scale of CPG-MSW and provide technical assistance in improving

320、 technological efficiency and supporting construction of an ecological civilization and stable energy.Section 6Conclusions and outlook42Conclusions and outlookFull-process clean control is a basic aim of CPG-MSW,where the development path includes theoretical research works on the energy utilization

321、 of MSW,pollution control technology concerning the entire process of CPG-MSW,per-treatment of CPG-MSW including waste sorting technologies and improvement in technical standards,specifications and the product certification system.This would also benefit the popularization of advanced CPG-MSW.6.1.2

322、CPG-MSW normative modelIndustrialized development and a quantified basis for energy-based technologies require a standardized technology processing model in conjunction with the standardization system.The standardized model has the following effects:1)scientific reference for technology selection,in

323、vestment analysis and project operation and maintenance;2)the basis for a project feasibility study;3)the basis for project plan preparation and post-project evaluation.This provides necessities in detailed experiments and evaluations on different existing system techniques of CPG-MSW,especially on

324、large-scale standardized MSW energy-based disposal projects and systems.By obtaining detailed system data,screening key system functions for key impacts and evaluation indicators,the standardized model can be derived in favour of technology selection as well as the effects of prediction and evaluati

325、on.6.1.3 CPG-MSW specification outlookThe most critical issue for efficient CPG-MSW is the precise selection of suitable MSW as raw material.The MSW used for coupled power generation in this paper refers to MSW with a certain calorific value that can be coupled with other energy sources for power ge

326、neration(e.g.organic or biomass solid waste),which is also referred to as energy-based MSW here.The energy properties of MSW should be properly defined and matched according to the needs of different coupled power generation system techniques.Thus,the corresponding specifications and standards provi

327、de an essential foundation.6.1.4 CPG-MSW evaluation system establishmentCoupled power generation is an effective method for solving the problem of large amounts of MSW and serious environmental pollution and also represents a new trend in efforts to solve the stable demand of urban energy.However,th

328、e amount and compositions of MSW generated by different cities vary greatly and the energy demand of each city is also different.In addition,the choice of a power generation system that can combine traditional petrochemical energy or clean energy is also different.But the assessment index of CPG-MSW

329、 evaluation should be characterized by a basic commonality.The establishment of consistent and effective evaluation systems,such as for energy efficiency,economic efficiency,and environmental efficiency,promotes the development and implementation of CPG-MSW and nourishes higher efficiency,lower cost

330、 and environmentally friendly property.6.2 Standardization outlookRelevant standards specifying effective techniques for CPG-MSW,as well as an authoritative reference basis,are fundamentally supportive for the CPG-MSW application.In addition,by specifying MSW adaptable to coupled power generation,mi

331、smatches with existing power generation systems or contradiction between energy demand and material demand in actual promotion are more likely to be avoided.Specifically,the endeavours that TC 27,TC 57 and TC 65 of IEC and TC 238,TC 255,TC 275,TC 282,TC 300 of ISO and other standards committees devo

332、te to covering related technologies are indispensable for the environment,technology and industry 43Conclusions and outlookprogress of CPG-MSW.Even so,at the stage of industrialization,creation of a new TC in IEC or ISO will be fundamentally important for forming a globally prevailing standard syste

333、m for CPG-MSW.During the standardization process,cooperation with global energy and power industry associations not only enhances the authority and global interoperability of standards development,but also provides effective solutions to key problems of CPG-MSW.Considering that MSW with sufficient calorific value can constitute an important component of new power systems,reliable certification can