Catalytic partial oxidation of methane to synthesis gas in a pilot-plant-scale spouted-bed reactor

The catalytic partial oxidation (CPO) of methane to synthesis gas was investigated in a conical spouted-bed reactor unit by using Ni/La/Al2O3 catalysts at pressures of 1-10bar, temperatures up to 1050 degrees C, methane-to-oxygen ratios of 1.6-2.5 and 0-40% N-2 dilution. The experimental results demonstrated that the spouted bed contacting mode is capable of dissipating the strong exotherm of the CPO reaction via particle circulation through the spout, annulus and fountain regions. The catalysts retained their activity and stability over prolonged periods of time-on-stream, indicating good balance between the oxidation and reduction cycles. However, lower than equilibrium methane conversions and syngas yields were observed because of heat losses in the freeboard. The results provide convincing evidence that near equilibrium conversions can be obtained by optimization of the freeboard design, Ni catalyst content, bed depth, and particle size. (C) 1999 Elsevier Science Ltd. All rights reserved.