(526f) Longevity Study of Microscale Non-Thermal Plasma Reforming of Methane to Higher Hydrocarbons and Syngas

Using a non-thermal electrical plasma, reactions that usually require high temperatures and pressures can take place with reactant chemical species near ambient conditions. Instead of thermal molecular collisions causing reactions, a plasma-reaction system utilizes high energy electrons colliding with reactant species in order to disrupt bonds and ultimately force reactions.

Performing these reactions at the microscale level has the advantage of decreasing the space between the electrodes that create the electrical plasma. By reducing the size, less voltage is required in order to generate these plasmas which reduces the costs of the necessary power electronics. This also decreases the bypass of the system, due to the small volume of the channel compared to the volume of the discharge. The electron temperature can range from several 1,000 to 30,000 ᵒC – several orders of magnitude larger than what would be required by most reactions.

In this study, carbon-hydrogen bonds are broken which allows for longer hydrocarbons to form. By creating longer hydrocarbons from methane, this process transforms electrical energy into chemical potential energy. The major products of this process are syngas, C₂ hydrocarbons and trace amounts of higher hydrocarbons. Wax products have been found to exist downstream from the discharge on the reactor channel walls. One major drawback of this approach is the rapid coking of the reactor channel at long (1+ hours) run times, leading to eventual flow anomalies, unfavorable product diffusion and eventually reactor failure.

Recent results showing how longevity (20+ hour run time) in these systems can be achieved and maintained will be presented.