Thermodynamic Analysis of Temperature and Pressure on Carbon Deposition for Methane Reforming at Low Temperature in Micro-Combustor

Abstract

Aimed at problems caused by carbon deposition in the micro-combustor, such as catalyst deactivation and channel block, based on the technology of methane-wet air autothermal reforming and the effects of hydrogen and methane conversion, the influences of temperature and pressure on carbon deposition below 973K are discussed with thermodynamic analysis method in this paper. Results show that for a definite feed gas composition, carbon deposition adds with increasing temperature firstly, and then decreases. Reaction pressure is suitable to maintain at 1atm. Moreover, the increasing methane mass flow, decreasing air and steam mass flow can lead to expansion of carbon deposition temperature region exists, also lead to the amount of carbon deposition increase and the temperature peak of carbon deposition shift to higher temperature segment. Under the research conditions that methane mass flow is 6.6g/h, reaction pressure is 1atm, air-methane ratio and steam-methane ratio are respectively 2 and 1 in the micro-combustor, the temperature range of carbon deposition production is at 680∼850K. The largest carbon deposition is occurred and its mass fraction is 0.66% when the reaction temperature is at 785K, also the methane conversion rate and the mass fraction of hydrogen are approximately 53.43% and 2.37% respectively.