98/03764 Large rate enhancement by calcium catalysts in the gasification of petroleum coke

Abstract

Isothermal gasification of petroleum coke with Ca(OH){sub 2} and CaCO{sub 3} has been carried out mainly under a high partial pressure of steam (80 kPa) with a thermobalance. These compounds, mixed with coke in water, increase the reaction rate, and CaCO{sub 3} shows almost the same catalytic activity as Ca(OH){sub 2} at the latter part of gasification. Fixed carbon conversion at 850 C without the Ca is 65 wt% after 2 h, whereas the catalysts achieve complete gasification within 1 h. The apparent activation energy is almost unchanged by Ca addition. H{sub 2} is the main product. The Ca increases H{sub 2} and CO{sub 2}, but it decreases CO, which leads to much higher H{sub 2}/CO ratio in the presence of the Ca. Thus, Ca(OH){sub 2} and CaCO{sub 3} promote shift reaction of CO formed with steam and are suitable for the production of H{sub 2}-rich gas from petroleum coke. (orig.)