Study On Methane Conversion To C2 Hydrocarbons With Non-equilibrium Plasma

With the gradually decrease of petroleum resources, more and more attention have been paid to the exploitation and application of natural gas. As the major component of nature gas, methane conversion became the highlight of natural gas utilization. It is well known that plasma is a very effective method to activate small molecules like methane and carbon dioxide. Furthermore, the low temperature plasma is predominantly utilized in methane conversion for its unique non-equilibrium character.In this thesis the process of methane conversion to C2 hydrocarbons with non-thermal plasma was studied. The effects of additive gases, parameters of the reactor and power supply were investigated in the multi-edge rotary electrode reactor. The results indicated that methane conversion was increased with the additive gases and the carbon deposited could also be effectively removed by hydrogen addition. Good results were obtained with small discharge distance and stainless steel inner electrode. The effects of parameters of power supply could be attributed to the electric current and the parameters of pulse have little effect on the reaction.The mechanism of methane conversion was proposed through comparing the results from the multi-edge rotary electrode reactor and dielectric barrier discharge (DBD) reactor. It was found that in the multi-edge rotary electrode reactor, methane was largely decomposed to CH and C radicals, which resulted in large amount of acetylene and a little ethane as products with lots of carbon deposited. While in the DBD reactor, methane was largely decomposed to CH3 radical which resulted in the main products of ethane and propane with little carbon deposited. With the same reactor type, the products distribution was almost constant. The methane conversion rate in the multi-edge rotary electrode reactor was much higher than that in DBD.Additionally, methane conversion in gliding arc discharge was elementary investigated. The results showed methane can be converted at lower input power and high gas flow rate, which shows an attractive outlook for the industrialization of methane conversion.