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Cost–benefit analysis of GHG emission reduction in waste to energy projects of China under clean development mechanism
Resources, Conservation and Recycling 109 (2016) 90–95
Contents lists available at ScienceDirect
Resources, Conservation and Recycling journal homepage: www.elsevier.com/locate/resconrec
Full length article
Cost–benefit analysis of GHG emission reduction in waste to energy projects of China under clean development mechanism Yuan Wang a , Shengnan Geng a , Peng Zhao a,∗ , Huibin Du b , Yu He a , John Crittenden c a School of Environmental Science and Engineering, China–Australia Centre for Sustainable Urban Development Tianjin University, No. 92 Weijin Road, Tianjin 300072, China b College of Management and Economics, Tianjin University, Tianjin 300072, China c Brook Byers Institute for Sustainable Systems, School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA, USA
a r t i c l e
i n f o
Article history: Received 31 October 2015 Received in revised form 30 January 2016 Accepted 17 February 2016 Keywords: Cost–benefit analysis Greenhouse gas Municipal solid waste Waste-to-energy
a b s t r a c t Energy recovery is widely considered an important part of hierarchy of waste management. Previously, researchers have primarily focused on cost-effectiveness analysis of solid waste management, ignoring the global warming potential (GWP) impacts. By integrating greenhouse gas (GHG) emissions and the cost–benefit analysis, we analyzed the cost–benefit of GHG emissions for two waste to energy (WtE) methods: incineration with combined heat and power (ICHP) which produces electricity and heat, and landfill disposal with landfill gas utilization (LGU). We calculated both costs and benefits per ton certified GHG emission reductions (CER) for 20 clean development mechanism (CDM) projects with WtE technology in typical northern and southern cities in China. Furthermore, benefits were analyzed under two different scenarios: benefit only from recovery energy revenues; benefit from recovery energy revenues plus gate fee revenues. The results show that: (1) ICHP projects are beneficial from the GHG reduction standpoint; (2) The ratio of CER revenues to benefit is very high during 2008–2011. However, the decrease of CER price in CDM projects causes the disposal gate fee from local government to become more and more important for these two WtE technologies, especially for LGU. However, with or without the CDM, there is still a huge GHG reduction potential in solid waste management in China. Policies should be developed to facilitate and encourage WtE, and the selection of WtE method depends on geographical region and economics. © 2016 Elsevier B.V. All rights reserved.
1. Introduction Waste to energy (WtE) can reduce the dependence on fossil fuels because it produces energy. Also, it has the added benefit of reducing GHG emissions from typical landfill operations by eliminating methane release. It is the key step in hierarchy of waste management. Hierarchy of waste management places prevention first, followed by material re-use, recycling and energy recovery on the second level, and disposal at the bottom (Jamasb and Nepal, 2010). In the short term, WtE projects will help energy recovery and reduce garbage pollution. In the long-term, it will help mitigate climate change. However, there is also negative aspects from WtE include emissions of pollutants (PCDD/F, PAH, PCB, heavy metals, particles) to the atmosphere, competitions with material recycling, etc. Indeed, there are environmental pressures for WtE projects.
∗ Corresponding author. Tel.: +86 18202272315. E-mail address: zhaopeng [email protected] (P. Zhao). http://dx.doi.org/10.1016/j.resconrec.2016.02.010 0921-3449/© 2016 Elsevier B.V. All rights reserved.
A number of published studies have assessed the lifecycle GHG emissions of various waste management options for WtE (Barton et al., 2008; Mohareb et al., 2008; Gentil et al., 2009; Zhao et al., 2009; Chandela et al., 2012; Tan et al., 2014). For example, direct emissions of GHG from the landfill systems (primarily dispersive release of methane) are the major contributions to the GHG accounting and can be up to about 1000 kg CO2 eq/t for the open dump, 300 kg CO2 eq/t for conventional landfilling of mixed waste and 70 kg CO2 eq/t for low-organic-carbon waste landfills (Manfredi et al., 2009). Provision of auxiliary fuels, materials and resources corresponded to up to 40% of the direct emission from the plants (which were 347–371 kg CO2 eq/t of waste for incineration and 735–803 kg CO2 eq/t of waste for co-combustion). Indirect downstream savings were within the range of −480 to −1373 kg CO2 eq/t of waste for incineration and within −181 to −2607 kg CO2 eq/t of waste for co-combustion (Astrup et al., 2009). With rapid economic growth and massive urbanization in China, many cities face the problem of municipal solid waste (MSW) disposal (Cheng et al., 2007). In China, the MSW clean-up and transport volume was 170.81 Mt (million tons) in 2012, of which 144.90 Mt
Y. Wang et al. / Resources, Conservation and Recycling 109 (2016) 90–95
were landfilled or incinerated. The proportions that were landfilled or incinerated were 73% and 25% respectively. Most landfills (86%) have passive and no gas capture for flaring or energy production (i.e. simple landfill) (National Bureau of Statistics of China, 2013). In developing countries, the clean development mechanism (CDM) of the Kyoto Protocol methodology permits the baseline to be open dumping and landfill without gas capture, and potential offsets in excess of 1 t CO2 eq/t of waste treated could be realized (Barton et al., 2008). Consequently, China has massive potential for GHG emission reductions in waste management operations. However, China is a vast country with vastly different climatic conditions and MSW compositions. And we need more economic researches on WtE projects which include GHG emissions, in order to choose the most viable waste management strategy for a given region. Previous work is lacking in this aspect. Accordingly, the aim of this study was to compare the cost and benefit from perspective of GHG emissions reduction. To achieve the goals, we focused on the cost–benefit analysis of GHG reductions for two main WtE technologies: incineration with combined heat and power (ICHP) and landfill with landfill gas utilization (LGU). Twenty CDM projects of WtE projects in China were selected as case studies.
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(1) revenue from gate fee, (2) revenue from recovery energy, (3) revenue from certified emission reductions (CER) i.e. the price of carbon emission. A gate fee (or tipping fee) is generally levied to offset the cost of opening, maintaining WtE projects. In some way, the gate fee reflects the willingness to pay for mitigating local environmental pollution i.e. garbage reduction. The revenue from energy recovery and CER reflects willingness of the world to pay for mitigating global warming. There are four sources of private costs for WtE projects: (1) intial total investment, (2) land cost, (3) operation and management cost (O&M cost), (4) sales tax and surcharges (without value added tax). Due to local government support for WtE projects, there are deductions and exemptions of fees and taxes related to the land cost of WtE project; consequently, land cost was not considered in this study. The environmental cost is due to secondary pollution, including disposal of bottom ash, leachate, fly ash and flue gas emissions. WtE facilities have to implement pollution control systems. And this cost is generally included in the initial total investment and O&M cost. 2.1. Benefits model The calculation for benefit is as in the following formula:
2. Calculation approach
NPVB =
The cost and environmental implications (e.g., energy consumption, GHG emissions) of solid waste management (SWM) are important societal issues (Kaplan et al., 2009). Cost–benefit analyses are very useful to make decisions regarding which WtE technology is best for a given situation. Cost–benefit analysis is useful for decision-makers to assess positive and negative economic effects of a project or policy by measuring relevant impacts of physical and monetary values (Chang et al., 2012). The main benefit of the environmental protection industry is to improve ecosystem and human health. Unlike companies producing private goods, environmental protection industry produces public goods, i.e. clean environment and improved human health. However, this environmental benefit is difficult to evaluate objectively. From another point of view, according to Preventive Expenditure Approach (PEA) in environmental economic, the environmental benefits may be evaluated by private benefits from environmental protection projects. It is crucial to set up system boundaries and assumptions when establishing a GHG emission inventory (Braschel and Posch, 2013). The system framework for cost–benefit analysis of the WtE process is shown in Fig. 1. There are three private benefits for WtE projects:
fee
+ ETe,t × Pe + Et × PC (1 + R)t
t
2.2. Economic evaluation of WtE technologies The total costs of ICHP project and LGU projects include capital investment, O&M cost, and sales tax and surcharges. The initial total investment is spent at the beginning of the project construction period. The Net Present Value of total costs is calculated by the following formula: NPVC =
Ot + Tt t
(1 + R)t
+I
Local environmental problems Global environmental problems
CER
Cost
O&M cost Tax
(2)
where NPVC is the net present value of total costs during project operation period; Ot is the O&M cost of WtE project in year t; Tt is
Recovery Energy
Initial total investment
(1)
where NPVB is the Net Present Value of total benefits during project operation period; t is the accounting year, the scope of it is the certified period; Pfee is the gate fee per unit MSW; ETe,t is the net amount of energy recovery from WtE projects in year t; Pe is recovery energy sales price; Et is the certified emission reductions in year t; Pc is the sales price of per tonne CER; R is the discount rate.
Gate fee
Benefit
Mt × P
Disposal of secondary pollutants:
Bottom ash Leachate Fly ash Flue gas
Land cost*
* Not considered. Fig. 1. Waste management framework for cost–benefit analysis.
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Y. Wang et al. / Resources, Conservation and Recycling 109 (2016) 90–95
the sales tax and surcharges of WtE project in year t; I is the initial total investment of WtE project. 2.3. Net benefit per ton CER Benefit minus cost is a net benefit. The net benefit divided by the total certified GHG emission reductions is the net benefit from GHG emission reduction NPVE =
NPVB − NPVC
E t t
(3)
where NPVE is the net benefit to realize per tonne credit GHG emission reduction during credit period; the meaning of other parameters sees above. NPVE is an index which shows that co-benefits or ancillary benefits from WtE projects to reduce GHG emissions. 2.4. Method of accounting CER The credit emissions reduction (CER) from WtE project includes avoided CO2 emissions from fossil fuel, because MSW is considered as an energy source reduces the demand for fossil fuels. WtE also eliminates CH4 emissions from simple landfill operation in which the gas is not collected. The primary GHG emission from simple landfill operations is CH4 generated by anaerobic degradation of the waste inside the landfill body, and CH4 is 21–25 times greater than CO2 within a 100-year period for global warming potential. If simple landfill project was substituted by WtE project, these CH4 emissions would be eliminated. The CDM uses a simple landfill as baseline emissions to calculate CER for developing countries. ICHP has GHG emissions from auxiliary fuel consumption and GHG emissions from the incinerator itself, and CH4 leakage and diesel fuel used on-site in dozers, compactors and other landfill vehicles. If we want to get net CER, we need subtract the direct emissions from CER. The equation to calculate net CER from WtE follows. Et = SEt + Etbaseline − DEt
(4)
where in year t, SEt is avoided fossil CO2 emissions from energy recovery of WtE projects, and it can offset majority direct CO2 emissions from the WtE projects; Etbaseline is GHG emissions from baseline emissions, i.e., simple landfill which is methane emissions; and, DEt is direct GHG emissions. SEt and DEt is easy to calculate according to the projects parameters. SEt is equal to amount of energy recovery (electricity and/or heat) from WtE projects multiply the carbon emission factor; Due to biogenic carbon is generally accounted with a GWP of 0, as for ICHP approach, DEt include CO2 and N2 O emissions by burning non-biogenic (i.e. fossil-fuelderived) waste and auxiliary fuels, and CH4 and trace gases are not
considered significant in case of modern installations; as for LGU approach, dispersive CH4 are the prime DEt , inclusive of the postclosure lifetime of the landfill during which time LGU collection may or may not be practiced. As for Etbaseline , a First Order Decay (FOD) model is used to describe the fraction of degradable material in waste which is degraded into CH4 each year according to IPCC guidance (IPCC, 2006).
Etbaseline = CDOC × r × MCF × 1 − e−Tk × FCH4 ×
16 × (1 − OX) 12
× ε × GWPCH4
(5)
where CDOC is degradable organic component (DOC) (t CO2 eq./t MSW); r is the fraction of DOC that can decompose; MCF is methane correction factor, for anaerobic managed solid waste disposal sites, MCF = 1.0; FCH4 is the fraction of the DOC becomes CH4 ; 16/12 is molecular weight ratio CH4 /C (ratio); k is reaction constant (yr−1 ), k = ln(2) (t1/2 )−1 ; t1/2 is half-life time (yr); T is the project lifetime; OX is oxidation factor (fraction), (We used OX = 0.1 for this study; ε is collection efficiency of gas, which is about 70%; and, GWPCH4 is GWP of CH4 (t CO2 eq./t of methane). 3. Case study 3.1. Data The GHG emissions are affected by a wide variety of factors related to the composition of the waste, and climatic conditions at the site where the MSW is located. North China and South China are different in climate, MSW composition and energy supply system. Therefore, we chose 10 CDM projects locate in South China, and another 10 projects located in North China. Moreover, half of 10 southern and northern projects are ICHP projects, the other half are LGU projects. The data of these projects were collected from the database for CDM projects (UNFCCC) and field study in the facilities (Tables 1 and 2) (UNFCCC, 2013). The two-sample ttest is used to compare different projects groups. The WtE energy recovery efficiency of LGU is low, 31–118 kW h/t MSW, which is significantly lower compared to ICHP counterparts (318–439 kW h/t MSW for electricity and some projects in north China also have recovery heat) at ˛ = 0.05 level of significance. As for ICHP, energy recovery efficiency in northern China(338–439 kW h/t MSW) is not significantly different from that in southern China(318–384 kW h/t MSW) at ˛ = 0.05 level significance. For LGU, energy recovery efficiency in southern China is significantly higher (75–118 kW h/t MSW) than in northern China (31–63 kW h/t MSW) at ˛ = 0.05 level significance.
Table 1 ICHP project descriptions. Location
Projects name
Credit period
Disposal MSW (t/day)
Recovery energy Electricity (kW h/t MSW)
Heat (GJ/t MSW)
North China
Tianjin Binhai Municipal Solid Waste Incineration Power Generation Project Hebei Lingda Municipal Solid Waste Incineration Project Shandong MSW Incineration for Cogeneration Project in Zibo City Municipal Solid Waste Incineration Project in Jingzhou City Controlled combustion of municipal solid waste (MSW) and energy generation in Linyi City, Shandon
2011–2018 2012–2021 2009–2018 2012–2022 2009–2015
1500 1,000 1,000 800 800
390 336 439 393 338
2 0 3 0 3
South China
Xiamen Western Municipal Solid Waste Incineration Project Tianyi Municipal Solid Waste Incineration for Power Generation Project Jiangsu Qidong Tianying Waste Incineration for Power Generation Project Zigong Municipal Solid Waste Incineration Power Generation Project Yongkang MSW Incineration for Power Project
2013–2019 2010–2017 2010–2016 2013–2020 2012–2021
600 900 600 800 800
318 384 358 376 351
0 0 0 0 0
Y. Wang et al. / Resources, Conservation and Recycling 109 (2016) 90–95
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Table 2 LGU project descriptions. Location
Projects name
Credit period
Disposal MSW (t/d)
Recovery energy Electricity (kW h/t MSW)
Heat (GJ/t MSW)
North China
Tianjin Shuangkou Landfill Gas Recovery and Gas Utilization Project Beijing Haidian District Liulitun Landfill Gas Power Generation Project Dalian Maoyingzi Landfill Gas Recovery for Power Generation Project Shandong Weifang Landfill Gas to Electricity Project Luoyang Zhangluoping MSW Landfill Site LFG Recovery to Power Project
2008–2014 2013–2022 2009–2016 2010–2019 2008–2018
2700 1500 2300 600 1300
63 61 31 60 63
0 0 0 0 0
South China
Xiamen Dongfu Landfill Gas-to-Energy Project Jiaozishan Landfill Gas Recovery and Utilization Project Shenzhen Xiaping Landfill Gas Collection and Utilization Project Ningbo Yinzhou Landfill Gas Recovery and Utilization Project Chengdu Changan Landfill Gas Utilization Project
2009–2019 2007–2013 2006–2015 2012–2021 2012–2022
2000 800 3000 800 2600
85 108 90 75 118
0 0 0 0 0
Fig. 2. Contributions of the CER, energy recovery and disposal to the benefit of WtE projects.
3.2. Cost–benefit analysis The cost of WtE projects is mainly associated with technology, while benefit is not only linked to technology but also to policy. (1) As for ICHP projects, the gate fee is the main benefit. The proportion of gate fee to benefits is about 40%, next benefits come from energy recovery revenues, and exceed 30%. Yet, CER revenue is the smallest percent in the three benefits, and only about 25% (see Fig. 2). Accordingly, the gate fee is essential for ICHP projects. (2) As for LGU projects, CER is the greatest benefit among three benefits. The proportion of CER to benefits exceeds 50%, this is followed by gate fee revenues with 33%-34%. Energy recovery accounts for the remaining 13%. This means CDM is more important for LGU projects. For CDM projects, CER is an important benefit. During 2008–2011 (most projects credit period started at this time in this paper), the opportunity for developing CDM projects to attract investment to improve waste management infrastructure may be
significant. The CER price from market data of European Energy Exchange is up to D 10/t CO2 eq before 2011 (EEX, 2013). Moreover, for developing countries the CDM methodology permits the baseline scenario to be the landfill with no provision for landfill gas capture, and potential offsets (i.e. CER in this paper) in excess of 1000 kg CO2 eq/t MSW of waste treated could be realized (Barton et al., 2008). However, after 2011, CER price dropped strongly, by 2013, prices for CER had collapsed to below D 1/t CO2 eq (Fig. 3).
Fig. 3. Average CER price during 2008–2015 [EEX, 2013; ICE, 2016].
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Fig. 4. Comparison of NPVE .
For the CER price (2015), the benefit of WtE projects from carbon trading according to CDM will be minimal, and will not affect NPVE anymore. Moreover, the CER revenue benefit will not exceed 1%. We assumed two scenarios without CER revenue in this study and they are discussed below.
3.2.1. Scenario 1: Benefit only from energy recovery revenues It is assumed the WtE projects benefit is just by selling recovery energy without any other revenue. As shown in Fig. 4a, ICHP projects cannot only depend on recovery energy revenue to be profitable both in Southern cities and Northern cities. And the NPVE is
Fig. 5. Costs and benefits of WtE projects of per tonne CER.
Y. Wang et al. / Resources, Conservation and Recycling 109 (2016) 90–95
positive from LGU projects only in Southern cities. This is mainly due to the climate conditions of southern China (i.e. higher temperature and humidity) which makes the degradation rate of organic waste far higher than that in northern China. The results show that in the tropical, moist and wet climate condition with high food wastes content, such as southern cities in China, the energy recovery benefit from LGU is more likely to offset the cost, due to the high degradation rate of organic waste. For ICHP projects, the energy recovery efficiency is higher than LGU projects (Tables 1 and 2), but the cost is also high (see Fig. 5). Therefore, no matter whether the ICHP project is in southern or northern China, the benefit from recovery energy using ICHP cannot exceed the huge cost, unless energy recovery subsidized. On the other hand, LGU projects have a much lower cost for both northern and southern China. If energy recovery is the only source of benefit, LGU is the better choice for both north and south cities in China. 3.2.2. Scenario 2: Benefit plus gate fee revenues In China, solid waste management is undertaken by the local authority, and the service includes waste collection (either from households or communal collection points) to final disposal. WtE projects get gate fee from local government. In scenario 2, gate fee is added into the benefits of WtE projects. With the gate fee, NPVE of all projects become positive (Fig. 4b). In northern China, the NPVE of ICHP projects are higher than LGU projects. In southern China, the NPVE of ICHP projects are lower than LGU project (Fig. 4b). This scenario has been close to the real situation even not including CER revenue. The main reason is the high gate fee of ICHP project in north cities. The average gate fee is about 175 CNY/t MSW in north cities, and 108 CNY/t MSW in south cities (Fig. 5b). Although cost of ICHP projects are significantly higher than LGU projects, the gate fee from governments will makes ICHP projects economically viable. According to Fig. 5, (1) large proportion of cost focuses on the initial total investment and O&M cost, (2) the cost of ICHP are higher than that of LGU, (3) benefit from energy recovery (even a combination of heat and electricity production in north China) offsets more than half of the cost for ICHP, (4) gate fee can help offsets the remaining cost for ICHP, (5) in scenario 1, LGU is the better choice, (6) in scenario 2, ICHP may be the better choice. 4. Conclusion As a way of disposing MSW, WtE technology not only generates energy but also reduces GHG emissions. There are 121 Chinese CDM projects for WtE in the database of UNFCCC. It is important to assess GHG emission reduction from WtE policy by geographical region and economic viability. With respect to climate change and economic benefit, this research chose 20 typical projects as cases to find viable WtE technologies and policies for southern and northern China. According to the cost–benefit analysis for these 20 WtE projects data under CDM, we found that: (1) ICHP projects are beneficial from the GHG reduction standpoint; (2) The gate fee is essential for economic viability of ICHP projects, while CDM is more important for LGU projects. The contribution from recovery energy is lowest among three benefits. However, with the decrease of CER price in CDM projects, the gate fee from local government becomes more and more important for these two WtE technologies, especially for ICHP projects. If local government has no strong financial support for disposal gate fee, and projects only depend on revenues from energy recovery, LGU projects are a better choice for both north and south cities in China.
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Energy efficiency of WtE projects in China is far lower than in developed countries. More efforts are required to improve the WtE energy efficiency. Chinese government put forward goal which specified that electricity generated from the waste incineration technologies will grow by 10%, reaching a proportion of 30% of the total energy mix in 5 years (Zhao et al., 2016). Therefore, with or without CDM, there is still a huge GHG reduction potential in solid waste management in China. The policy for mitigation of global warming should take advantage of this potential whereas the selection of WtE method depends on geographical region and economic viability. One limitation of this study only focused on the energy recovery step in hierarchy of waste management. Future research opportunities exist to study the whole hierarchy of waste management and LCA analysis to encompass all influences to the environment and human health. Acknowledgements This research was supported by the project in the National Science & Technology Pillar Program (No. 2014BAC26B05-01), and the National Natural Science Foundation of China (Grant Nos. 41571522 and 71273185) This work was also partially supported by Brook Byers Institute for Sustainable Systems, the Hightower Chair and Georgia Research Alliance. References Astrup, T., Møller, J., Fruergaard, T., 2009. Incineration and co-combustion of waste: accounting of greenhouse gases and global warming contributions. Waste Manage. Res. 27, 789–799. Barton, J.R., Issaias, I., Stentiford, E.I., 2008. Carbon–making the right choice for waste management in developing countries. Waste Manage. 28, 690–698. Braschel, N., Posch, A., 2013. A review of system boundaries of GHG emission inventories in waste management. J. Cleaner Prod. 44, 30–38. Chandela, M., Kwokc, G., Jackson, R., et al., 2012. The potential of waste-to-energy in reducing GHG emissions. Carbon Manage. 3 (2), 133–144. Chang, N.B., Qi, C., Islam, K., Hossain, F., 2012. Comparisons between global warming potential and cost–benefit criteria for optimal planning of a municipal solid waste management system. J. Cleaner Prod. 20, 1–13. Cheng, H.F., Zhang, Y.G., Meng, A.H., Li, Q.H., 2007. Municipal solid waste fueled power generation in China: a case study of waste-to-energy in Changchun City. Environ. Sci. Technol. 41, 7509–7515. EEX, 2013. Market Data of European Energy Exchange (EEX), https://www. eex.com/en/market-data#/market-data (accessed 2013.12.01). Gentil, E., Christensen, T.H., Emmanuelle, A., 2009. Greenhouse gas accounting and waste management. Waste Manage. Res. 27, 696–706. ICE, 2016. Market Data of Intercontinental Exchange (ICE), https://www. theice.com/market-data/reports/icefutureseurope/ECXCERIndex.shtml (accessed 2016.01.28). IPCC, 2006. IPCC Guidelines for National Greenhouse Gas Inventories. Solid Waste Disposal, Vol. 5. Chapter 3, http://www.ipcc-nggip.iges.or.jp/public/2006gl/ index.htm (accessed 2012.02.07). Jamasb, T., Nepal, R., 2010. Issues and options in waste management: a social cost–benefit analysis of waste-to-energy in the U.K. Resour. Conserv. Recycl. 54, 1341–1352. Kaplan, P.O., Ranjithan, S.R., Baulaz, M.A., 2009. Use of life-cycle analysis to support solid waste management planning for Delaware. Environ. Sci. Technol. 43, 1264–1270. Manfredi, S., Tonini, D., Christensen, T.H., Scharff, H., 2009. Landfilling of waste: accounting of greenhouse gases and global warming contributions. Waste Manage. Res. 27, 825–836. Mohareb, A.K., Warith, M.A., Diaz, R., 2008. Modelling greenhouse gas emissions for municipal solid waste strategies in Ottawa, Ontario, Canada. Resour. Conserv. Recycl. 52, 1241–1251. National Bureau of Statistics of China, 2013. The Removal and Disposal of Municipal Solid Waste, http://data.stats.gov.cn/index (accessed 2013.11.21). Tan, S.T., Hashim, H., Lim, J.S., et al., 2014. Energy and emissions benefits of renewable energy derived from municipal solid waste: analysis of a low carbon scenario in Malaysia. Appl. Energy 136, 797–804. UNFCCC, 2013. Database for CDM Projects, http://cdm.unfccc.int/ (accessed 2013.02.07). Zhao, W., Voetb, E., Zhang, Y.F., Huppes, G., 2009. Life cycle assessment of municipal solid waste management with regard to greenhouse gas emissions: case study of Tianjin, China. Sci. Total Environ. 404, 1517–1526. Zhao, X.G., Jiang, G.W., Li, A., Li, Y., 2016. Technology, cost, a performance of waste-to-energy incineration industry in China. Renewable Sustainable Energy Rev. 55, 115–130.
Contents lists available at ScienceDirect
Resources, Conservation and Recycling journal homepage: www.elsevier.com/locate/resconrec
Full length article
Cost–benefit analysis of GHG emission reduction in waste to energy projects of China under clean development mechanism Yuan Wang a , Shengnan Geng a , Peng Zhao a,∗ , Huibin Du b , Yu He a , John Crittenden c a School of Environmental Science and Engineering, China–Australia Centre for Sustainable Urban Development Tianjin University, No. 92 Weijin Road, Tianjin 300072, China b College of Management and Economics, Tianjin University, Tianjin 300072, China c Brook Byers Institute for Sustainable Systems, School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA, USA
a r t i c l e
i n f o
Article history: Received 31 October 2015 Received in revised form 30 January 2016 Accepted 17 February 2016 Keywords: Cost–benefit analysis Greenhouse gas Municipal solid waste Waste-to-energy
a b s t r a c t Energy recovery is widely considered an important part of hierarchy of waste management. Previously, researchers have primarily focused on cost-effectiveness analysis of solid waste management, ignoring the global warming potential (GWP) impacts. By integrating greenhouse gas (GHG) emissions and the cost–benefit analysis, we analyzed the cost–benefit of GHG emissions for two waste to energy (WtE) methods: incineration with combined heat and power (ICHP) which produces electricity and heat, and landfill disposal with landfill gas utilization (LGU). We calculated both costs and benefits per ton certified GHG emission reductions (CER) for 20 clean development mechanism (CDM) projects with WtE technology in typical northern and southern cities in China. Furthermore, benefits were analyzed under two different scenarios: benefit only from recovery energy revenues; benefit from recovery energy revenues plus gate fee revenues. The results show that: (1) ICHP projects are beneficial from the GHG reduction standpoint; (2) The ratio of CER revenues to benefit is very high during 2008–2011. However, the decrease of CER price in CDM projects causes the disposal gate fee from local government to become more and more important for these two WtE technologies, especially for LGU. However, with or without the CDM, there is still a huge GHG reduction potential in solid waste management in China. Policies should be developed to facilitate and encourage WtE, and the selection of WtE method depends on geographical region and economics. © 2016 Elsevier B.V. All rights reserved.
1. Introduction Waste to energy (WtE) can reduce the dependence on fossil fuels because it produces energy. Also, it has the added benefit of reducing GHG emissions from typical landfill operations by eliminating methane release. It is the key step in hierarchy of waste management. Hierarchy of waste management places prevention first, followed by material re-use, recycling and energy recovery on the second level, and disposal at the bottom (Jamasb and Nepal, 2010). In the short term, WtE projects will help energy recovery and reduce garbage pollution. In the long-term, it will help mitigate climate change. However, there is also negative aspects from WtE include emissions of pollutants (PCDD/F, PAH, PCB, heavy metals, particles) to the atmosphere, competitions with material recycling, etc. Indeed, there are environmental pressures for WtE projects.
∗ Corresponding author. Tel.: +86 18202272315. E-mail address: zhaopeng [email protected] (P. Zhao). http://dx.doi.org/10.1016/j.resconrec.2016.02.010 0921-3449/© 2016 Elsevier B.V. All rights reserved.
A number of published studies have assessed the lifecycle GHG emissions of various waste management options for WtE (Barton et al., 2008; Mohareb et al., 2008; Gentil et al., 2009; Zhao et al., 2009; Chandela et al., 2012; Tan et al., 2014). For example, direct emissions of GHG from the landfill systems (primarily dispersive release of methane) are the major contributions to the GHG accounting and can be up to about 1000 kg CO2 eq/t for the open dump, 300 kg CO2 eq/t for conventional landfilling of mixed waste and 70 kg CO2 eq/t for low-organic-carbon waste landfills (Manfredi et al., 2009). Provision of auxiliary fuels, materials and resources corresponded to up to 40% of the direct emission from the plants (which were 347–371 kg CO2 eq/t of waste for incineration and 735–803 kg CO2 eq/t of waste for co-combustion). Indirect downstream savings were within the range of −480 to −1373 kg CO2 eq/t of waste for incineration and within −181 to −2607 kg CO2 eq/t of waste for co-combustion (Astrup et al., 2009). With rapid economic growth and massive urbanization in China, many cities face the problem of municipal solid waste (MSW) disposal (Cheng et al., 2007). In China, the MSW clean-up and transport volume was 170.81 Mt (million tons) in 2012, of which 144.90 Mt
Y. Wang et al. / Resources, Conservation and Recycling 109 (2016) 90–95
were landfilled or incinerated. The proportions that were landfilled or incinerated were 73% and 25% respectively. Most landfills (86%) have passive and no gas capture for flaring or energy production (i.e. simple landfill) (National Bureau of Statistics of China, 2013). In developing countries, the clean development mechanism (CDM) of the Kyoto Protocol methodology permits the baseline to be open dumping and landfill without gas capture, and potential offsets in excess of 1 t CO2 eq/t of waste treated could be realized (Barton et al., 2008). Consequently, China has massive potential for GHG emission reductions in waste management operations. However, China is a vast country with vastly different climatic conditions and MSW compositions. And we need more economic researches on WtE projects which include GHG emissions, in order to choose the most viable waste management strategy for a given region. Previous work is lacking in this aspect. Accordingly, the aim of this study was to compare the cost and benefit from perspective of GHG emissions reduction. To achieve the goals, we focused on the cost–benefit analysis of GHG reductions for two main WtE technologies: incineration with combined heat and power (ICHP) and landfill with landfill gas utilization (LGU). Twenty CDM projects of WtE projects in China were selected as case studies.
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(1) revenue from gate fee, (2) revenue from recovery energy, (3) revenue from certified emission reductions (CER) i.e. the price of carbon emission. A gate fee (or tipping fee) is generally levied to offset the cost of opening, maintaining WtE projects. In some way, the gate fee reflects the willingness to pay for mitigating local environmental pollution i.e. garbage reduction. The revenue from energy recovery and CER reflects willingness of the world to pay for mitigating global warming. There are four sources of private costs for WtE projects: (1) intial total investment, (2) land cost, (3) operation and management cost (O&M cost), (4) sales tax and surcharges (without value added tax). Due to local government support for WtE projects, there are deductions and exemptions of fees and taxes related to the land cost of WtE project; consequently, land cost was not considered in this study. The environmental cost is due to secondary pollution, including disposal of bottom ash, leachate, fly ash and flue gas emissions. WtE facilities have to implement pollution control systems. And this cost is generally included in the initial total investment and O&M cost. 2.1. Benefits model The calculation for benefit is as in the following formula:
2. Calculation approach
NPVB =
The cost and environmental implications (e.g., energy consumption, GHG emissions) of solid waste management (SWM) are important societal issues (Kaplan et al., 2009). Cost–benefit analyses are very useful to make decisions regarding which WtE technology is best for a given situation. Cost–benefit analysis is useful for decision-makers to assess positive and negative economic effects of a project or policy by measuring relevant impacts of physical and monetary values (Chang et al., 2012). The main benefit of the environmental protection industry is to improve ecosystem and human health. Unlike companies producing private goods, environmental protection industry produces public goods, i.e. clean environment and improved human health. However, this environmental benefit is difficult to evaluate objectively. From another point of view, according to Preventive Expenditure Approach (PEA) in environmental economic, the environmental benefits may be evaluated by private benefits from environmental protection projects. It is crucial to set up system boundaries and assumptions when establishing a GHG emission inventory (Braschel and Posch, 2013). The system framework for cost–benefit analysis of the WtE process is shown in Fig. 1. There are three private benefits for WtE projects:
fee
+ ETe,t × Pe + Et × PC (1 + R)t
t
2.2. Economic evaluation of WtE technologies The total costs of ICHP project and LGU projects include capital investment, O&M cost, and sales tax and surcharges. The initial total investment is spent at the beginning of the project construction period. The Net Present Value of total costs is calculated by the following formula: NPVC =
Ot + Tt t
(1 + R)t
+I
Local environmental problems Global environmental problems
CER
Cost
O&M cost Tax
(2)
where NPVC is the net present value of total costs during project operation period; Ot is the O&M cost of WtE project in year t; Tt is
Recovery Energy
Initial total investment
(1)
where NPVB is the Net Present Value of total benefits during project operation period; t is the accounting year, the scope of it is the certified period; Pfee is the gate fee per unit MSW; ETe,t is the net amount of energy recovery from WtE projects in year t; Pe is recovery energy sales price; Et is the certified emission reductions in year t; Pc is the sales price of per tonne CER; R is the discount rate.
Gate fee
Benefit
Mt × P
Disposal of secondary pollutants:
Bottom ash Leachate Fly ash Flue gas
Land cost*
* Not considered. Fig. 1. Waste management framework for cost–benefit analysis.
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the sales tax and surcharges of WtE project in year t; I is the initial total investment of WtE project. 2.3. Net benefit per ton CER Benefit minus cost is a net benefit. The net benefit divided by the total certified GHG emission reductions is the net benefit from GHG emission reduction NPVE =
NPVB − NPVC
E t t
(3)
where NPVE is the net benefit to realize per tonne credit GHG emission reduction during credit period; the meaning of other parameters sees above. NPVE is an index which shows that co-benefits or ancillary benefits from WtE projects to reduce GHG emissions. 2.4. Method of accounting CER The credit emissions reduction (CER) from WtE project includes avoided CO2 emissions from fossil fuel, because MSW is considered as an energy source reduces the demand for fossil fuels. WtE also eliminates CH4 emissions from simple landfill operation in which the gas is not collected. The primary GHG emission from simple landfill operations is CH4 generated by anaerobic degradation of the waste inside the landfill body, and CH4 is 21–25 times greater than CO2 within a 100-year period for global warming potential. If simple landfill project was substituted by WtE project, these CH4 emissions would be eliminated. The CDM uses a simple landfill as baseline emissions to calculate CER for developing countries. ICHP has GHG emissions from auxiliary fuel consumption and GHG emissions from the incinerator itself, and CH4 leakage and diesel fuel used on-site in dozers, compactors and other landfill vehicles. If we want to get net CER, we need subtract the direct emissions from CER. The equation to calculate net CER from WtE follows. Et = SEt + Etbaseline − DEt
(4)
where in year t, SEt is avoided fossil CO2 emissions from energy recovery of WtE projects, and it can offset majority direct CO2 emissions from the WtE projects; Etbaseline is GHG emissions from baseline emissions, i.e., simple landfill which is methane emissions; and, DEt is direct GHG emissions. SEt and DEt is easy to calculate according to the projects parameters. SEt is equal to amount of energy recovery (electricity and/or heat) from WtE projects multiply the carbon emission factor; Due to biogenic carbon is generally accounted with a GWP of 0, as for ICHP approach, DEt include CO2 and N2 O emissions by burning non-biogenic (i.e. fossil-fuelderived) waste and auxiliary fuels, and CH4 and trace gases are not
considered significant in case of modern installations; as for LGU approach, dispersive CH4 are the prime DEt , inclusive of the postclosure lifetime of the landfill during which time LGU collection may or may not be practiced. As for Etbaseline , a First Order Decay (FOD) model is used to describe the fraction of degradable material in waste which is degraded into CH4 each year according to IPCC guidance (IPCC, 2006).
Etbaseline = CDOC × r × MCF × 1 − e−Tk × FCH4 ×
16 × (1 − OX) 12
× ε × GWPCH4
(5)
where CDOC is degradable organic component (DOC) (t CO2 eq./t MSW); r is the fraction of DOC that can decompose; MCF is methane correction factor, for anaerobic managed solid waste disposal sites, MCF = 1.0; FCH4 is the fraction of the DOC becomes CH4 ; 16/12 is molecular weight ratio CH4 /C (ratio); k is reaction constant (yr−1 ), k = ln(2) (t1/2 )−1 ; t1/2 is half-life time (yr); T is the project lifetime; OX is oxidation factor (fraction), (We used OX = 0.1 for this study; ε is collection efficiency of gas, which is about 70%; and, GWPCH4 is GWP of CH4 (t CO2 eq./t of methane). 3. Case study 3.1. Data The GHG emissions are affected by a wide variety of factors related to the composition of the waste, and climatic conditions at the site where the MSW is located. North China and South China are different in climate, MSW composition and energy supply system. Therefore, we chose 10 CDM projects locate in South China, and another 10 projects located in North China. Moreover, half of 10 southern and northern projects are ICHP projects, the other half are LGU projects. The data of these projects were collected from the database for CDM projects (UNFCCC) and field study in the facilities (Tables 1 and 2) (UNFCCC, 2013). The two-sample ttest is used to compare different projects groups. The WtE energy recovery efficiency of LGU is low, 31–118 kW h/t MSW, which is significantly lower compared to ICHP counterparts (318–439 kW h/t MSW for electricity and some projects in north China also have recovery heat) at ˛ = 0.05 level of significance. As for ICHP, energy recovery efficiency in northern China(338–439 kW h/t MSW) is not significantly different from that in southern China(318–384 kW h/t MSW) at ˛ = 0.05 level significance. For LGU, energy recovery efficiency in southern China is significantly higher (75–118 kW h/t MSW) than in northern China (31–63 kW h/t MSW) at ˛ = 0.05 level significance.
Table 1 ICHP project descriptions. Location
Projects name
Credit period
Disposal MSW (t/day)
Recovery energy Electricity (kW h/t MSW)
Heat (GJ/t MSW)
North China
Tianjin Binhai Municipal Solid Waste Incineration Power Generation Project Hebei Lingda Municipal Solid Waste Incineration Project Shandong MSW Incineration for Cogeneration Project in Zibo City Municipal Solid Waste Incineration Project in Jingzhou City Controlled combustion of municipal solid waste (MSW) and energy generation in Linyi City, Shandon
2011–2018 2012–2021 2009–2018 2012–2022 2009–2015
1500 1,000 1,000 800 800
390 336 439 393 338
2 0 3 0 3
South China
Xiamen Western Municipal Solid Waste Incineration Project Tianyi Municipal Solid Waste Incineration for Power Generation Project Jiangsu Qidong Tianying Waste Incineration for Power Generation Project Zigong Municipal Solid Waste Incineration Power Generation Project Yongkang MSW Incineration for Power Project
2013–2019 2010–2017 2010–2016 2013–2020 2012–2021
600 900 600 800 800
318 384 358 376 351
0 0 0 0 0
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Table 2 LGU project descriptions. Location
Projects name
Credit period
Disposal MSW (t/d)
Recovery energy Electricity (kW h/t MSW)
Heat (GJ/t MSW)
North China
Tianjin Shuangkou Landfill Gas Recovery and Gas Utilization Project Beijing Haidian District Liulitun Landfill Gas Power Generation Project Dalian Maoyingzi Landfill Gas Recovery for Power Generation Project Shandong Weifang Landfill Gas to Electricity Project Luoyang Zhangluoping MSW Landfill Site LFG Recovery to Power Project
2008–2014 2013–2022 2009–2016 2010–2019 2008–2018
2700 1500 2300 600 1300
63 61 31 60 63
0 0 0 0 0
South China
Xiamen Dongfu Landfill Gas-to-Energy Project Jiaozishan Landfill Gas Recovery and Utilization Project Shenzhen Xiaping Landfill Gas Collection and Utilization Project Ningbo Yinzhou Landfill Gas Recovery and Utilization Project Chengdu Changan Landfill Gas Utilization Project
2009–2019 2007–2013 2006–2015 2012–2021 2012–2022
2000 800 3000 800 2600
85 108 90 75 118
0 0 0 0 0
Fig. 2. Contributions of the CER, energy recovery and disposal to the benefit of WtE projects.
3.2. Cost–benefit analysis The cost of WtE projects is mainly associated with technology, while benefit is not only linked to technology but also to policy. (1) As for ICHP projects, the gate fee is the main benefit. The proportion of gate fee to benefits is about 40%, next benefits come from energy recovery revenues, and exceed 30%. Yet, CER revenue is the smallest percent in the three benefits, and only about 25% (see Fig. 2). Accordingly, the gate fee is essential for ICHP projects. (2) As for LGU projects, CER is the greatest benefit among three benefits. The proportion of CER to benefits exceeds 50%, this is followed by gate fee revenues with 33%-34%. Energy recovery accounts for the remaining 13%. This means CDM is more important for LGU projects. For CDM projects, CER is an important benefit. During 2008–2011 (most projects credit period started at this time in this paper), the opportunity for developing CDM projects to attract investment to improve waste management infrastructure may be
significant. The CER price from market data of European Energy Exchange is up to D 10/t CO2 eq before 2011 (EEX, 2013). Moreover, for developing countries the CDM methodology permits the baseline scenario to be the landfill with no provision for landfill gas capture, and potential offsets (i.e. CER in this paper) in excess of 1000 kg CO2 eq/t MSW of waste treated could be realized (Barton et al., 2008). However, after 2011, CER price dropped strongly, by 2013, prices for CER had collapsed to below D 1/t CO2 eq (Fig. 3).
Fig. 3. Average CER price during 2008–2015 [EEX, 2013; ICE, 2016].
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Fig. 4. Comparison of NPVE .
For the CER price (2015), the benefit of WtE projects from carbon trading according to CDM will be minimal, and will not affect NPVE anymore. Moreover, the CER revenue benefit will not exceed 1%. We assumed two scenarios without CER revenue in this study and they are discussed below.
3.2.1. Scenario 1: Benefit only from energy recovery revenues It is assumed the WtE projects benefit is just by selling recovery energy without any other revenue. As shown in Fig. 4a, ICHP projects cannot only depend on recovery energy revenue to be profitable both in Southern cities and Northern cities. And the NPVE is
Fig. 5. Costs and benefits of WtE projects of per tonne CER.
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positive from LGU projects only in Southern cities. This is mainly due to the climate conditions of southern China (i.e. higher temperature and humidity) which makes the degradation rate of organic waste far higher than that in northern China. The results show that in the tropical, moist and wet climate condition with high food wastes content, such as southern cities in China, the energy recovery benefit from LGU is more likely to offset the cost, due to the high degradation rate of organic waste. For ICHP projects, the energy recovery efficiency is higher than LGU projects (Tables 1 and 2), but the cost is also high (see Fig. 5). Therefore, no matter whether the ICHP project is in southern or northern China, the benefit from recovery energy using ICHP cannot exceed the huge cost, unless energy recovery subsidized. On the other hand, LGU projects have a much lower cost for both northern and southern China. If energy recovery is the only source of benefit, LGU is the better choice for both north and south cities in China. 3.2.2. Scenario 2: Benefit plus gate fee revenues In China, solid waste management is undertaken by the local authority, and the service includes waste collection (either from households or communal collection points) to final disposal. WtE projects get gate fee from local government. In scenario 2, gate fee is added into the benefits of WtE projects. With the gate fee, NPVE of all projects become positive (Fig. 4b). In northern China, the NPVE of ICHP projects are higher than LGU projects. In southern China, the NPVE of ICHP projects are lower than LGU project (Fig. 4b). This scenario has been close to the real situation even not including CER revenue. The main reason is the high gate fee of ICHP project in north cities. The average gate fee is about 175 CNY/t MSW in north cities, and 108 CNY/t MSW in south cities (Fig. 5b). Although cost of ICHP projects are significantly higher than LGU projects, the gate fee from governments will makes ICHP projects economically viable. According to Fig. 5, (1) large proportion of cost focuses on the initial total investment and O&M cost, (2) the cost of ICHP are higher than that of LGU, (3) benefit from energy recovery (even a combination of heat and electricity production in north China) offsets more than half of the cost for ICHP, (4) gate fee can help offsets the remaining cost for ICHP, (5) in scenario 1, LGU is the better choice, (6) in scenario 2, ICHP may be the better choice. 4. Conclusion As a way of disposing MSW, WtE technology not only generates energy but also reduces GHG emissions. There are 121 Chinese CDM projects for WtE in the database of UNFCCC. It is important to assess GHG emission reduction from WtE policy by geographical region and economic viability. With respect to climate change and economic benefit, this research chose 20 typical projects as cases to find viable WtE technologies and policies for southern and northern China. According to the cost–benefit analysis for these 20 WtE projects data under CDM, we found that: (1) ICHP projects are beneficial from the GHG reduction standpoint; (2) The gate fee is essential for economic viability of ICHP projects, while CDM is more important for LGU projects. The contribution from recovery energy is lowest among three benefits. However, with the decrease of CER price in CDM projects, the gate fee from local government becomes more and more important for these two WtE technologies, especially for ICHP projects. If local government has no strong financial support for disposal gate fee, and projects only depend on revenues from energy recovery, LGU projects are a better choice for both north and south cities in China.
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Energy efficiency of WtE projects in China is far lower than in developed countries. More efforts are required to improve the WtE energy efficiency. Chinese government put forward goal which specified that electricity generated from the waste incineration technologies will grow by 10%, reaching a proportion of 30% of the total energy mix in 5 years (Zhao et al., 2016). Therefore, with or without CDM, there is still a huge GHG reduction potential in solid waste management in China. The policy for mitigation of global warming should take advantage of this potential whereas the selection of WtE method depends on geographical region and economic viability. One limitation of this study only focused on the energy recovery step in hierarchy of waste management. Future research opportunities exist to study the whole hierarchy of waste management and LCA analysis to encompass all influences to the environment and human health. Acknowledgements This research was supported by the project in the National Science & Technology Pillar Program (No. 2014BAC26B05-01), and the National Natural Science Foundation of China (Grant Nos. 41571522 and 71273185) This work was also partially supported by Brook Byers Institute for Sustainable Systems, the Hightower Chair and Georgia Research Alliance. References Astrup, T., Møller, J., Fruergaard, T., 2009. Incineration and co-combustion of waste: accounting of greenhouse gases and global warming contributions. Waste Manage. Res. 27, 789–799. Barton, J.R., Issaias, I., Stentiford, E.I., 2008. Carbon–making the right choice for waste management in developing countries. Waste Manage. 28, 690–698. Braschel, N., Posch, A., 2013. A review of system boundaries of GHG emission inventories in waste management. J. Cleaner Prod. 44, 30–38. Chandela, M., Kwokc, G., Jackson, R., et al., 2012. The potential of waste-to-energy in reducing GHG emissions. Carbon Manage. 3 (2), 133–144. Chang, N.B., Qi, C., Islam, K., Hossain, F., 2012. Comparisons between global warming potential and cost–benefit criteria for optimal planning of a municipal solid waste management system. J. Cleaner Prod. 20, 1–13. Cheng, H.F., Zhang, Y.G., Meng, A.H., Li, Q.H., 2007. Municipal solid waste fueled power generation in China: a case study of waste-to-energy in Changchun City. Environ. Sci. Technol. 41, 7509–7515. EEX, 2013. Market Data of European Energy Exchange (EEX), https://www. eex.com/en/market-data#/market-data (accessed 2013.12.01). Gentil, E., Christensen, T.H., Emmanuelle, A., 2009. Greenhouse gas accounting and waste management. Waste Manage. Res. 27, 696–706. ICE, 2016. Market Data of Intercontinental Exchange (ICE), https://www. theice.com/market-data/reports/icefutureseurope/ECXCERIndex.shtml (accessed 2016.01.28). IPCC, 2006. IPCC Guidelines for National Greenhouse Gas Inventories. Solid Waste Disposal, Vol. 5. Chapter 3, http://www.ipcc-nggip.iges.or.jp/public/2006gl/ index.htm (accessed 2012.02.07). Jamasb, T., Nepal, R., 2010. Issues and options in waste management: a social cost–benefit analysis of waste-to-energy in the U.K. Resour. Conserv. Recycl. 54, 1341–1352. Kaplan, P.O., Ranjithan, S.R., Baulaz, M.A., 2009. Use of life-cycle analysis to support solid waste management planning for Delaware. Environ. Sci. Technol. 43, 1264–1270. Manfredi, S., Tonini, D., Christensen, T.H., Scharff, H., 2009. Landfilling of waste: accounting of greenhouse gases and global warming contributions. Waste Manage. Res. 27, 825–836. Mohareb, A.K., Warith, M.A., Diaz, R., 2008. Modelling greenhouse gas emissions for municipal solid waste strategies in Ottawa, Ontario, Canada. Resour. Conserv. Recycl. 52, 1241–1251. National Bureau of Statistics of China, 2013. The Removal and Disposal of Municipal Solid Waste, http://data.stats.gov.cn/index (accessed 2013.11.21). Tan, S.T., Hashim, H., Lim, J.S., et al., 2014. Energy and emissions benefits of renewable energy derived from municipal solid waste: analysis of a low carbon scenario in Malaysia. Appl. Energy 136, 797–804. UNFCCC, 2013. Database for CDM Projects, http://cdm.unfccc.int/ (accessed 2013.02.07). Zhao, W., Voetb, E., Zhang, Y.F., Huppes, G., 2009. Life cycle assessment of municipal solid waste management with regard to greenhouse gas emissions: case study of Tianjin, China. Sci. Total Environ. 404, 1517–1526. Zhao, X.G., Jiang, G.W., Li, A., Li, Y., 2016. Technology, cost, a performance of waste-to-energy incineration industry in China. Renewable Sustainable Energy Rev. 55, 115–130.