When equipped with Carbon Capture and Storage (CCS), Waste to Energy plants can directly reduce fossil carbon dioxide emissions from post-recycling residual waste while also re-capturing atmospheric carbon dioxide via the permanent geological storage of biogenic carbon uptake. Increasingly, municipal solid waste (MSW) is treated by incineration in dedicated plants where the heat from combustion is recovered via electricity generation and district heating. Post-combustion CO2 capture with amine-based technology can achieve ultra-high CO2 capture rates such that CO2 generated in the combustion of the waste feedstock results in no direct CO2 emissions to the atmosphere. The large biogenic content of residual waste feedstock presents a particular opportunity for bioenergy with CCS (BECCS).A life cycle assessment LCA of the environmental impacts of a state-of-the-art WtE facility with CCS at ultra-high capture rates shows that adding CCS can provide a significant improvement in climate change impact, and achieve a net climate benefit. Without significant burden shifting to other environmental impact categories, the climate change impact of a WtE plant treating 500 tpd of MSW is reduced from 388 kg CO2eq/tMSW to -483 kg CO2eq/tMSW, with the biogenic CO2 captured and permanently stored accounted as negative CO2 emissions. When the avoided greenhouse gas emissions from electricity, district heating and material recovery are also included, the climate impact is -777 kg CO2eq/tMSW for a power-only WtE plant exporting 9.6 MWe, and -907 kg CO2eq/tMSW for a combined heat and power WtE plant exporting 6.2 MWe and 18.5 MWth.

Waste-to-Energy (WtE) is becoming an important application sector for carbon capture utilization and storage (CCS) due to its role in urban waste management and its inherent potential of achieving negative emissions. This study is built upon a series of modelling activities, with three representative WtE plant steam cycle configurations selected to integrate monoethanolamine (MEA) based Post-combustion CO2 Capture (PCC). With 60% biogenic carbon in the fuel, a set of key performance indicators of the investigated WtE plant configurations are presented. Results show that there is significant potential for heat recovery from the PCC process to provide heat for District Heating (DH). With advanced heat recovery, the energy utility factor (EUF) of WtE plant could be higher than that for WtE plant without PCC. Results also show that optimised process design can be used to enable ultra-high CO2 capture (99.72% in this study) to be achieved with only a marginal increase in specific reboiler duty when compared with 95% capture. This study also highlights the importance of differentiating carbon intensities for different product bases: electrical or thermal or waste, which are important when comparing WtE CCS with other carbon saving technologies. The findings of this study provide valuable information for the future implementation of carbon dioxide capture technology in the WtE sector.

Waste-to-Energy (WtE) has become an attractive application for carbon capture utilization and storage (CCS) due to its role in decarbonizing urban waste management and its inherent potential of achieving negative emissions. Building upon a series of modeling activities, the application of interim solvent storage (ISS) is researched with the objective of improving the heat supply ability of WtE combined heat and power (CHP) plants integrated with Post-combustion CO2 capture (PCC). This paper uses a mathematical programming-based methodology using a design-day approach to investigate the optimal operation of a WtE-CHP plant with the implementation of interim solvent storage. The results show that the usage of a load-following gas boiler is reduced as a result of implementing solvent storage thereby also lowering fossil CO2 emissions. The amount of wasted excess heat is also reduced. However, the plant with interim solvent storage has a lower annual profit as the increased capital costs of building storage tanks are higher than the savings from lower boiler heat usage and lower CO2 taxes with these results highly sensitive to the problem setting and input parameters. We observe that solvent storage is not operational during the summer design day suggesting that seasonal solvent or thermal storage may be a more useful alternative

Addressing climate change and the sustainable management of municipal solid waste (MSW) are two important societal challenges, as recognized by the 2015 Paris Climate Agreement and by the EU Action Plan for a Circular Economy Package [1]. One possible solution to both of these challenges is to combine Waste-to-Energy (WtE) technologies with carbon capture and storage (CCS) to achieve a net environmental benefit. Under the scope of NEWEST-CCUS project , this work conducts a quantitative evaluation of the environmental performance and presents work to date on assessing the negative emissions potential of WtE with CCS across Europe.Approximately 252 Mt of municipal waste was generated in the EU in 2019, of which 28% was treated in energy recovery facilities and 23.4% was disposed in landfill sites [2]. As landfilling is being phased out in Europe [3], the importance of recovering the energy content from the household and commercial waste remaining after prevention, recycling and composting is increasing. Waste-to-Energy (WtE) facilities using incineration are indeed gaining importance in Europe, with approximately 500 WtE plants in operation in 2019 treating approximately 100 Mt of municipal solid waste [4]. These plants can significantly reduce the volume and weight of MSW and prevent various pollutants from being emitted, while producing useful electricity and heat.CCS is the main decarbonization option for the WtE sector in Europe. Further, combining WtE and CCS has the potential to create a carbon sink over the life cycle of waste by preventing emission of biogenic carbon, which has been ‘drawn down’ atmospheric CO2 via photosynthesis. The ratio of biogenic to fossil carbon content of MSW varies significantly but is generally between 50 and 70% [5], with a typical content of around 60% [4]. However, there is a need to develop a rigorous and robust methodology to account for the negative carbon emissions potential when capturing and permanently storing biogenic CO2 from waste incineration.This article presents an attributional Life Cycle Assessment (LCA) to assess the environmental impact of combusting municipal waste in a conventional WtE facility with moving grate technology and equipped with an amine (solvent) based carbon capture plant. The capture plant operates with a capture level of 99.7% so that all CO2emissions arising from fuel combustion are avoided. This assessment considers real operation parameters obtained from rigorous process modelling of the integrated WtE and carbon capture systems to account for the avoided environmental impacts of producing combined heat and power (CHP) as well as the avoided impacts from metal recovery. In addition, this paper outlines a method and average waste composition for assessing the potential for negative emissions from WtE + CCS at the European scale. Four WtE configurations were assessed: power-only WtE; WtE with integrated Combined Heat and Power (CHP); power-only WtE with CCS and WtE with CHP and CCS. The four cases were found to impart environmental benefits across the majority of the eighteen impact categories considered, reflecting results from [6]. In the context of greenhouse gas control, when CHP or CCS is configured with WtE, a benefit is also imparted in the Global Warming impact category. Within a 95% confidence interval the median values are: 151 kgCO2eq/tMSW (64 to 241); -97 kgCO2eq/tMSW (-227 to 33); -648 kgCO2eq/tMSW (-785 to -514) and -772 kgCO2eq/tMSW (-925 to -630) for the power-only WtE, CHP WtE, power-only WtE + CCS, CHP WtE + CCS cases respectively. In general, the contribution to climate change impact associated to the materials used in the physical infrastructure is relatively small, while the direct ‘stack’ GHG emissions dominate for the configurations without CCS. The avoided impacts due to electricity and heat generation are also significant, and always larger than the avoided impacts of IBA mineral and metal recovery.An overview of the assessment of European potential for negative emissions from WtE and CCS is provided, with focus on developing an average European waste composition which could be used in process and LCA modelling to enable the European potential to be accurately assessed using a life cycle approach. Further, the effect of national power system emissions intensity on avoided (and thus negative) emissions shows that for countries with annual average emissions intensities above 460 kg even the power-only WtE plant could be climate neutral, although this is subject to realizing the avoided impacts, as well as the targeted trends of global decarbonization of electricity.

The deployment of Carbon Capture and Storage technologies in the waste management sector can make municipal and industrial waste a strategic resource for climate change mitigation. The generation of energy, in the form of electricity and heat, via the processing and incineration of waste already avoids methane emissions from landfill. The addition of CCS to Waste-to-Energy plants with CO2 capture levels close to 99% can reduce their CO2 emissions to the atmosphere close to zero. With CCS, biogenic carbon in waste becomes a domestic source of negative emissions with a supply chain that would complement other negative emission technologies, such as Bio-Energy with CCS (BECCS). The NEWEST-CCUS project is an ongoing €2.5M multidisciplinary (2019-2022) project involving academics and researchers from six organisations and four European countries. It seeks to improve understanding of technologies and opportunities for negative emissions in the waste-to-energy sector. This paper outlines the broad range of activities undertaken by the consortium in response to key challenges facing the sector.