Design and sustainability analysis of a combined CO2 mineralization and desalination process

Abstract

CO2 mineralization sequestrates CO2 in a form of mineral carbonate through chemical reactions of CO2 with metal oxide or alkaline solution. This process is attractive because it has no risk for a leakage of hazardous materials and requires a relatively small area for sequestrating CO2 compared to geological storage. In addition, generated mineral carbonate can be used as useful chemicals if its purity is high enough. One of the recent ideas in CO2 mineralization is integrating it with desalination. Mineral ions needed for the CO2 mineralization are separated from seawater, and generated deionized seawater is used as a feed to a desalination process, such as reverse osmosis (RO), to reduce its electric energy load. The goal of this study is to design the proposed process and examine its sustainability. The overall process is designed and simulated using Aspen plus® and Matlab. Based on the simulation results, techno-economic analysis (TEA) and CO2 lifecycle assessment (CO2 LCA) are conducted to verify the sustainability. In order to identify the improvement potential of the process, a best scenario study is performed. It turns out that this process can achieve about 230tonne CO2 reduction/yr as well as relative economic benefit of almost 1million $/yr compared to a benchmark process which comprises the standalone Solvay process and RO. From the best scenario result, it can be concluded that the proposed process has the potential for further investigation as means to reduce the CO2 emission while generating economic benefits. © 2018