MODELLING AND SIMULATION OF METHANE TRI - REFORMING FOR PRODUCTION OF HYDROGEN IN A MICRO - CHANNEL REACTOR

Abstract

Amongst various types of methane reforming processes such as dry reforming, steam reforming, auto thermal reforming etc., the steam reforming produces syngas having maximum H2/CO ratio. However, due to its endothermic nature, it requires external heating for the steam reforming reactions. Further, dry reforming and auto thermal reforming have their own limitations like high coke formation in case of dry reforming and lower H2/CO ratio in case of auto thermal reforming. Thus, tri-reforming is getting strong interest in recent years, in which the above three reforming reactions take place. Recently, the feasibility of tri-reforming has also been demonstrated in pilot scale KOGAS reformer using multi-tubular reactor. Although multi tubular fixed bed reactor is the common reactor configuration for reforming process, the thermal loss is relatively high in this reactor resulting lower efficiency. Application of monolith or micro channel type reactor may improve the efficiency of the reformer due to better heat integration. Application of micro-channel reactor for the reforming of methane has been reported by some literature however, there is hardly any report on the tri reforming of methane in micro channel reactor. In the present study tri-reforming of methane in micro channel reactor having 10 cm length 2 mm inner diameter and loaded with Ni based catalyst has been simulated. Model equations consisting ordinary differential equations have been simulated using ODE solver (ODE 45) in mat lab 2009 software. On the basis of simulated data it was found that methane conversion, hydrogen and CO yield and syngas production are favored by high temperature, low pressure and at limited amount of O2 in feed. As mentioned above the optimum temperature is 1000K, optimum pressure is 40 kPa and optimum feed composition CH4:H2O:CO2:O2 is 10:5:5:2. At optimum conditions the conversion of CH4 is 95%, the yield of H2 and CO is 2.06 and 1.38 respectively, the selectivity of H2 is higher than CO and H2/CO ratio is 1.49.