(560aw) Converting Biogas to Liquid Fuels By Low Energy Electrical Corona Discharge Processes

Considered as a renewable resource, biogas has abundantly available sources worldwide, such as dairies, sewage, landfills, etc. However, it is usually disposed of by flaring because of its low economic value. Therefore, the development of technologies to use biogas as feedstock to produce liquid fuels like gasoline or diesel would have a positive economic and environmental impact and stimulate new approaches in industrial chemistry.

In this work, a new process that enables the conversion of biogas to liquid transportation fuels with high energy efficiency has been developed. The approach is to employ low energy electron impact ionization through the use of a non-thermal plasma generated by an atmospheric pressure electric corona discharge. Additionally, microtechnology has been combined with this corona discharge technology because micro-scale geometry provides strong gradients with respect to temperature, concentration, pressure, and reactive species and the efficient heat and energy management [1].

Multi-discharge reactors with 10-discharge and 100-discharge have been built, and their performance proves the concept of chemical conversion of biogas and demonstrates the ability to produce long-chain hydrocarbons. In order to identify which parameters are most important in the optimization of the conversion process, the experimental design has been developed as a guide for experimental work. Major parameters under investigation include the power level per discharge, the discharge gap, the reactive gas flow rate, the synthetic biogas composition, the concentration of inert, and the gas pressure. A high LHV energy efficiency up to 95% can be achieved, and methane conversion can reach up to 65% with high selectivity (45~55%) towards C2+ hydrocarbons. Additionally, methods to prevent the production of coking and wax have been developed so the reactors can be adapted for continuous operations.

Reference:

[1] D. Mariotti, R. M. Sankaran (2010), “Microplasmas for nanomaterials synthesis,” Journal of Physics D: Applied Physics, 43 (32), pp. 323001.