Hydrogenation of carbon dioxide in an packed-bed reactor

New methanol synthesis catalysts were tested in a conventional fixed-bed high-pressure flow reactor. The methanol synthesis work was done at modest pressures (less than or equal to 30 bar) and temperatures (less than or equal to 300 degrees C). These catalysts showed good activities and selectivities in the synthesis of methanol from pure CO2. The remarkable finding is that the equilibrium yields per pass over the catalysts were already reached for temperatures above 250 degrees C. For a stoichiometric feed, at 225 degrees C, 20 bar and at a space velocity of 4500 h(-1), a best methanol yield equal to 7.2 % was reported. The kinetics of the methanol synthesis from CO2/H-2 mixtures have also been measured at the so-called ''low pressure'' and ''low temperature'' conditions.