Comparison of amine adsorbents and strong hydroxides soluble for direct air CO2 capture by life cycle assessment method

Although diffusion and adoption of CO2 capture technologies are known as one of the main solutions of green house gas emissions, they still have environmental, economic, and performance challenges. This research presents the investigation of the process of absorption of carbon dioxide from the air by amine soluble which is also a common adsorbent of this process in comparison with the absorption of strong hydroxides, which is a relatively more up-to-date process. Regarding the absorption process with amine, a system simulation is performed by Aspen hysys software. By using the input and output data of both processes and using Simapro software, the life cycle of both processes is evaluated. The results showed that the most severe negative impact in direct air CO2 capture is on marine ecotoxicity with 13.7 kg 1,4-DCB which is for strong hydroxides and the responsible element is Calcium carbonate with the share of 90.6%. The impact on marine ecotoxicity for amine adsorbents is 8.77 kg 1,4-DCB which Diethanolami is 70.2% the cause factor. Resources consumption is 43% more in the process of absorption with amines than strong hydroxides and also environmental effects of the process of absorption with amines on human health and ecosystem is by 8% and 3% less respectively compared to absorption with strong hydroxides.