To study the direct transformation of methane into methanol in the lower temperature range

A considerable industrial interest has always existed in the catalytic as well as non-catalytic transformation of methane (CH4) gas into methanol (CH3OH) as an intermediate product due to its wide applications. The purpose of the present computational study was to study the homogeneous reaction kinetics of methane and to analyze the effect of operating parameters, viz. temperature, residence time and CH4/O2 input ratio on direct oxidation of CH4 into CH3OH in the lower temperature range suitable to catalytic conversion. It is found that a higher conversion of methane into methanol can be achieved by controlling the operating parameters to their optimum values. A combination of input values as CH4/O2 ratio=0.005/0.995, OH=5 ppm and T=100 °C was concluded to be optimum for direct oxidation of methane into methanol. The combination of reactions R1 (CH3OH=CH3+OH) and R15 (CH4+OH=CH3+H2O) was mainly found responsible for the formation of methanol under the present operating conditions. Though the contribution of direct oxidation of CH4 into CH3OH is very small (≈1% at the maximum) with suitable operating parameters, this advantage can be coupled with other optimum catalytic conversion conditions to enhance the production of methanol.