Life Cycle Sustainability Assessment Of Bioelectricity With Carbon Capture And Storage Technology

Climate change is a major global problem that affects human survival and hinders the sustainable development of society.In 2015,the Paris Agreement agreed at the 21st United Nations Climate Change Conference set the 2℃or 1.5℃temperature control target of for global response to climate change.The international community is trying to reduce greenhouse gas emissions by improving energy efficiency,developing renewable energy and deploying CO₂ Capture and Storage（CCS）.However,according to the existing emission scale,the remaining carbon budget will be used up within 20 years,then world will be in a long-term irreversible serious impact.Therefore,the negative emission technology that can isolate CO₂ in the atmosphere is indispensable to achieve the goal of temperature control.Bioenergy with CCS（BECCS）refers to the process of using biomass to absorb CO₂ in the atmosphere,after energy conversion,the captured CO₂ will be isolated for a long time,which is a typical negative emission technology.In order to cope with climate change,BECCS technology needs to contribute about 600billion tons of CO₂ cumulative emission reduction at the end of this century.As the main contributor of global energy-related carbon emissions,the power sector is facing tremendous pressure in emission reduction.The combination of BECCS technology and power generation technology is expected to provide a win-win sustainable development path to the power sector to cope with climate change and alleviate the energy crisis.Although BECCS technology has passed the technical demonstration,it has not been widely used in any industrial field.From the perspective of life cycle,there are still many uncertain factors affecting this technology combination,such as the impact of bioenergy supply chain on carbon intensity,water resources and land demand,the impact of power plant biomass transformation and CCS transformation on the overall economic feasibility,and the impact of BECCS project on local employment and residents safety.In order to solve the scientific problems faced in the process of large-scale sustainable deployment of BECCS projects,this paper focuses on the methodology and application of life cycle sustainable assessment of BECCS projects,and comprehensively applies scientific methods such as literature analysis,life cycle assessment,comparative analysis,qualitative and quantitative combination,theoretical and empirical combination to evaluate the environment,economy,society and sustainable performance of BECCS projects from the perspective of life cycle.The innovative work was carried out as follows:（1）Based on the hour-level input-output data onto each process,a life cycle assessment（LCA）model is constructed for BECCS projects with different fuel configurations,and 10 environmental impact categories are evaluated and analyzed in details from the perspective of midpoint impact.The results show that the transformation of biomass and CCS in coal-fired power plants will lead to the transfer of environmental burden.PB-CCS power plant can achieve 877 kg CO₂-e/MWh of negative emissions from the whole life cycle.In addition,BECCS technology can also significantly improve the two environmental impacts on acid and eutrophication,but cause the deterioration of seven environmental impacts such as resource depletion and toxicity.（2）The life cycle cost accounting model of BECCS project is constructed,and the corresponding levelized cost of electricity（LCOE）and various emission reduction costs are evaluated in detail.Based on the consideration of various existing incentive policies,the economic feasibility of BECCS project is optimized and the optimal incentive combination strategy is determined.The results show that in the absence of incentive policies,BECCS power plant is not economically feasible for large-scale deployment,and the LCOE（168.6 USD/MWh）is about 3.5 times of the traditional power plant.Under the existing tax credit and feed-in tariff subsidies,the critical carbon price required by the BECCS power plant is only 26.21 USD/t CO₂.（3）In view of the foreground and background processes related to the BECCS project,a social index system covering multiple stakeholders and impact subcategories is constructed.On the basis of forming a social life cycle list at the national,sector and enterprise levels,the potential social effects of BECCS project are identified and analyzed.The results show that the overall social effect of BECCS project in the whole life cycle is better than that of traditional coal-fired power generation project,but social problems related to biomass acquisition and CCS need to be solved,such as the employment of child labor,low wages of workers,weak emergency prevention ability and the degree of harmony with local residents,etc.In addition,it expands and deepens the current social life cycle assessment（SLCA）methods,which can provide case reference to relevant researchers.（4）From the perspective of different cultures,the evaluation results in environmental,economic and social dimensions are integrated.Based on 31 indicators of three dimensions,the sustainable development index is constructed.By analyzing the sustainable performance of different energy conservation and emission reduction schemes in the power sector,the optimal sustainable development path is determined.BECCS project has good environmental and social effects,but the high cost directly affects its sustainable performance.From the perspective of egalitarianism and hierarchism,the overall sustainable performance of BECCS project is only slightly lower than that of biomass power generation project.The specific path of sustainable development depends on the selected cultural perspective,that is,the weight value of each triple bottom line.