Oxy-CO 2 reforming of methane to syngas over CoO x/MgO/SA-5205 catalyst

Abstract

The oxy-CO 2 methane reforming reaction (OCRM) has been investigated over CoO x supported on a MgO precoated highly macroporous silica–alumina catalyst carrier (SA-5205) at different reaction temperatures (700–900 °C), O 2/CH 4 ratios (0.3–0.45) and space velocites (20,000–100,000 cc/g/h). The reaction temperature had a profound influence on the OCRM performance over the CoO/MgO/SA-5205 catalyst; the methane conversion, CO 2 conversion and H 2 selectivity increased while the H 2/CO ratio decreased markedly with increasing reaction temperature. While the O 2/CH 4 ratio did not strongly affect the CH 4 and CO 2 conversion and H 2 selectivity, it had an intense influence on the H 2/CO ratio. The CH 4 and CO 2 conversion and the H 2 selectivity decreased while the H 2/CO increased with increasing space velocity. The O 2/CH 4 ratio and the reaction temperature could be used to manipulate the heat of the reaction for the OCRM process. Depending on the O 2/CH 4 ratio and temperature the OCRM process could be operated in a mildly exothermic, thermal neutral or mildly endothermic mode. The OCRM reaction became almost thermoneutral at an OCRM reaction temperature of 850 °C, O 2/CH 4 ratio of 0.45 and space velocity of 46,000 cc/g/h. The CH 4 conversion and H 2 selectivity over the CoO/MgO/SA-5205 catalyst corresponding to thermoneutral conditions were excellent: 95% and 97%, respectively with a H 2/CO ratio of 1.8.