Life Cycle Assessment Based Process Design of CO2 Capture Options

In the perspective of mitigating climate change, CO2 capture and storage (CCS) is considered as a promising option. To evaluate the environmental benefit of capturing CO2 it is important to make a systematic comparison including the whole life cycle from the resource extraction to the final product (i.e. electricity). Especially when comparing natural gas, coal and biomass fed processes the supply chain differences have to be accounted for. Besides the benefit in terms of greenhouse gas emissions reduction, CCS induces an energy and cost penalty due to the CO2 separation and compression. The trade-offs between environmental impacts, efficiency and costs are systematically assessed here by combining life cycle assessment (LCA) with flowsheeting, energy integration and economic evaluation in a multi-objective optimisation framework. Post- and pre-combustion CO2 capture options for electricity generation processes, using fossil and renewable resources, are analysed, compared and optimised. Multi-objective optimisations are performed for various thermo-economic and environmental objectives to highlight the influence on the optimal process design and on the decision making.