Abstract:

In this work, a life cycle assessment (LCA) methodology was applied to access the carbon emission and potential environment impacts of the integrated gasification combined cycle (IGCC) power plant with pre-combustion carbon capture. The assessment was carried out by SimaPro software modeling. The global warming potential (GWP), terrestrial acidification potential (TAP), carcinogenic human toxicity potential (HTPc), non-carcinogenic human toxicity potential (HTPnc), terrestrial ecotoxicity potential (TETP), freshwater ecotoxicity potential (FETP), freshwater eutrophication potential (FEP) and the related contributors were investigated and compared for the IGCC power plants with/without carbon capture and storage (CCS). The results showed that compared to the power plant without carbon capture, flue gas carbon emissions decreased by 88% after carbon capture, while the GWP caused by coal and chemical supply and auxiliary power consumption increased by 18% and 20%, respectively. The GWP of the CCS process was 39.02 kg CO₂-eq, and the total life-cycle GWP of the power plant was 257 kg CO₂-eq, with a reduction of 72%. Besides the sharp drop in GWP, the potential environmental impact of the plant, including TAP, HTPc, HTPnc, TETP, FETP and FEP, increased to 119%—170% compared to the benchmark plant without CCS. The increase in coal and chemical supply was the primary contributor to the rise in HTPc. The CCS unit was the primary contributor to the increase of potential environmental impact except HTPc, and the CCS unit accounted for 15%—34% of the potential environmental impact of the plant.

Key words: coal combustion, CO₂ capture, greenhouse gas, sustainability, model, simulation, environment

摘要：

为评估整体煤气化联合循环（IGCC）电厂耦合燃烧前碳捕集与封存（CCS）的碳排放及环境影响，采用全生命周期评价（LCA）方法，利用SimaPro软件建模，研究了未实施/实施碳捕集IGCC电厂的全球变暖潜值（GWP）、陆地酸化潜值（TAP）、致癌人体毒性潜值（HTPc）、非致癌人体毒性潜值（HTPnc）、陆地生态毒性潜值（TETP）、淡水生态毒性潜值（FETP）及淡水富营养化潜值（FEP）七种环境影响类型及其主要贡献源，并对未实施/实施碳捕集IGCC电厂的各类环境影响程度进行比较。结果表明，相比于未实施碳捕集，碳捕集后电厂的烟气碳排放降低88%，煤炭与化学品供应与辅机用电所造成的GWP分别上升了18%和20%，CCS过程的GWP为39.02 kg CO₂-eq，电厂生命周期总GWP为257 kg CO₂-eq，降低了72%。除GWP显著下降外，捕集电厂的TAP、HTPc、HTPnc、TETP、FETP和FEP环境影响潜值均上升至未捕集电厂的119%~170%。煤炭和化学品供应的增加是HTPc上升的主要因素，而CCS单元是除HTPc外其他环境影响潜值上升的主要贡献源，占捕集电厂各类环境影响潜值的15%~34%。

关键词: 煤燃烧, 二氧化碳捕集, 温室气体, 可持续性, 模型, 模拟, 环境