Municipal solid waste gasification in semi-industrial conditions using air-CO2 mixtures

The gasification of MSW (municipal solid wastes) using CO2 as a gasifying agent has been object of growing interest in recent years. Although quite limited, studies have shown that CO2 can behave as a catalyst and accelerate the thermal cracking of volatiles as well as minimize tar formation, and even give a positive contribute to environment. Despite these promising features, it is still necessary to develop mathematical models able to assist the advance of this technology. A previously published numerical model validated for numerous substrates (including MSW) and operating conditions in a pilot scale plant was used as a baseline to study MSW gasification with air-CO2 mixtures. Real MSW data from Oporto metropolitan area were used as model inputs and numerical results were validated against experimental ones. Results demonstrate that increasing CO2 content boosts carbon conversion, CO2 conversion, and cold gas efficiency while mitigating tar production. Also, due to the ability to tailor H-2/CO ratio, air-CO2 mixtures can be used for catalyst-based Fischer Tropsch synthesis and particularly for the production of specific chemicals such as urea, methanol and acetic acid. (C) 2016 Elsevier Ltd. All rights reserved.