Carbon capture technologies are regarded as promising options to mitigate CO₂ emissions from large point sources, such as power generation facilities and energy intensive industries.

However, CO₂ capture technologies have several environmental impacts, from the system infrastructure production stage to the end of their lifetime, because of the consumption of resources in the form of materials and energy, as well as the formation of chemical by-products. All these aspects should be taken into account in order to assess and compare the real environmental sustainability of the CO₂ capture processes.

It is well established that life cycle assessment (LCA) represents a powerful tool to evaluate the most significant environmental impacts of CO₂ capture technologies throughout their lifetimes.

Using LCA methodology, this study aimed to compare life cycle emissions of membrane separation and chemical absorption processes for the post-combustion capture of one tonne of CO₂ from a subcritical coal-fired power plant. Environmental impacts were evaluated considering a hybrid approach for the life cycle inventory, combining physical and economic input data.

Simulation results highlighted that life cycle emissions of CO₂ capture based on membrane separation process were strongly related to membrane material and thickness of the dense active layer, influencing the net power consumption and membrane area requirement. Membrane configurations investigated allowed to reduce to such an extent environmental impacts compared to CO₂ capture based on monoethanoalmine (MEA) absorption. The greatest reduction potential was observed for human toxicity and impacts on freshwater and marine ecosystems, because of the elimination of environmental concerns related to solvent manufacturing and disposal of amine reclaimer wastes.

碳捕集技术被认为是减轻诸如发电设施和能源密集型产业之类的大型点源的CO ₂排放的有前途的选择。

但是，由于消耗了材料和能源形式的资源以及化学副产品的形成，从系统基础设施生产阶段到使用寿命结束，CO ₂捕获技术都会对环境产生若干影响。为了评估和比较CO ₂捕集过程的实际环境可持续性，应考虑所有这些方面。

众所周知，生命周期评估（LCA）是评估CO ₂捕集技术在其整个生命周期中对环境的最重大影响的强大工具。

这项研究使用LCA方法，旨在比较膜分离和化学吸收过程的生命周期排放，以燃烧后从亚临界燃煤电厂捕获一吨CO ₂。考虑到生命周期清单的混合方法，结合了物理和经济输入数据，对环境影响进行了评估。

仿真结果表明，基于膜分离过程的CO ₂捕集的生命周期排放与膜材料和致密活性层的厚度密切相关，从而影响净功耗和膜面积要求。与基于单乙胺（MEA）吸收的CO ₂捕集相比，所研究的膜构型可以将环境影响降低到这样的程度。由于消除了与溶剂生产和胺回收废料的处理有关的环境问题，对人类毒性及其对淡水和海洋生态系统的影响的减少潜力最大。