Heterogeneous reaction kinetics of catalytic coal gasification

The gasification tests of Shenmu coal char were carried out in a pressured fixed bed reactor to investigate the effect of gasification agents (H₂O, CO₂, H₂), catalyst loading, and partial pressure of hydrogen and carbon monoxide on the carbon conversion and reaction rate. The results show that the heterogeneous reaction rate is in the order of C-H₂O >C-CO₂>C-H₂. H₂ and CO inhibit the steam gasification rate to some degrees. The inhibition of CO is much greater than that of H₂. The carbon conversion decreases by about 50% with the addition of only 5% CO at 700 ℃. A kinetic model is developed combined Langmuir-Hinshelwood (L-H) with the random pore model, considering the effect of catalyst loading and the partial pressure of gasification product gases. The deviation between predication and experiment value is less than 10%, indicating that the derived kinetic model is appropriate for describing the catalytic coal gasification with steam.