Techno-Economic and Environmental Assessment of Carbon Capture at a Cement Plant and CO2 Utilization in Production of Synthetic Natural Gas
12 Pages Posted: 24 Mar 2021
Date Written: February 12, 2021
The purpose of this study is to evaluate the interest of a Power-to-Gas integrated system converting CO2 from cement plan flue gas. The integrated CO2 capture and CO2 catalytic conversion into Synthetic Natural Gas (SNG) process, using H2 produced by electrolysis, is investigated and simulated in Aspen Plus. More precisely, the process chain implemented is designed to capture almost 1 ton of CO2 per hour coming from a conventional cement plant equipped with the Best Available Techniques (flue gas CO2 content of 20 mol.%). An advanced amines-based CO2 capture process is implemented applying a Rich Vapor Compression configuration including intercooling, and a blend composed of methyldiethanolamine (MDEA) and piperazine (PZ) as solvent, allowing to minimize the specific energy consumption of the process. The captured CO2 is then sent to the exothermal catalytic methanation reactor together with renewable hydrogen to produce SNG. The heat provided by the exothermal methanation reactions is recovered. A fraction of the released heat is used for the regeneration of the CO2 capture solvent, while an excess recovered heat is used to produce steam for other applications, such as capturing more CO2 or producing electricity. An economic assessment is proposed to estimate the investment and operational costs of the process chain. Finally, a Life Cycle Analysis method is performed to identify the main environmental hotspots while comparing two scenarios (cement plant with and without the integrated CO2 capture-conversion process).
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