Tunable Quantum Cascade Laser Absorption Spectroscopy for Plasma Assisted Oxidative Coupling of Methane to C2 Based Products

Abstract

The oxidative coupling of methane is a process of converting methane to ethane and ethylene by dehydrogenation through oxygen atoms over the catalytic surface. The operation temperature of this experiment is generally close to 1000 K to achieve sufficient yield. It is estimated that for this process to be economically feasible the yield has to be greater than 30% with selectivity close to 95%. In order to operate at a lower temperature, increase the yield and make it more energy-efficient, the problem is approached using advance nanomaterial and plasma assistance. To study this we used a Tunable Quantum Cascade Laser Absorption Spectroscopy to measure various species involved in the process. By tuning the laser over a particular wavenumber, the concentration of a particular species is found out using the absorption spectrum. Here, we explain the details of how the setup is designed, developed, and assembled with initial experiments to calibrate C 2 based species. A correlation between the experimental results and the calculated spectrum from the HITRAN database is achieved.