Greenhouse gas chemistry

Abstract

Abstract One of the major problems facing mankind is the global warming of the atmosphere due to man-made emissions of greenhouse gases. Mitigation of these greenhouse gas emissions to the atmosphere can be achieved by using direct control technologies (capture, disposal or chemical recycling). In this paper, we report on carbon dioxide and methane recycling with other chemicals, especially with hydrogen and oxygen, to produce liquid fuels such as. methanol. Methanol synthesis from pure CO2 is investigated with various catalysts at moderate pressures (≤ 30 bar) and temperatures (≤ 300 °C). The catalysts show good methanol activity and selectivity. The remarkable finding is that the equilibrium yields per pass over the catalysts are already reached at temperatures above 250 °C. For a stoichiometric feed, at 225 °C, 20 bar and at a space velocity of 4500 h−1, a best methanol yield equal to 7.2 % is reported. The conversion of CO2 and CH4 to methanol is also studied in a silent electrical discharge at pressures of 1 to 4 bar and temperatures close to room temperature. Methanol yields are given for mixtures of CO 2 H 2 , CH 4 O 2 and also for CH4/air mixtures.