Simultaneous removal of CO2 and salts from saline water by a combined process

Abstract

The emission of CO2 has been increasing steadily and with the increasing demand of desalinated water (especially in Gulf Cooperation Council countries) this is expected to increase at a faster rate. CO2 removal from sour natural gas, from the water desalination power plants and similar sources is important not only to these industries but also to reduce the effect on global warming. In this study, a simple process is investigated experimentally to remove CO2 from a synthetic mixture of natural gas containing it. The method is based on the modified Solvay process and involves the chemical reaction between CO2 and ammonia in saline solution. The process can reduce CO2 by about 99% and at the same time reduce water salinity by 40%. The process is potentially much more effective than the amine scrubbing process, without the operational problems for environmental damage posed by monoethanolamine organic compounds. The innovative process shows the technical feasibility of sweetening natural gas in the laboratory-scale operation. It can also be applied to the removal of CO2 from polluting sources like car exhaust. Simultaneous reduction of salinity is additional benefit of this process.