CO2-free conversion of fossil fuels by multiphase plasma at ambient conditions

Heavy oil conversion to fuel products and petrochemicals are both energy and greenhouse gas (GHG) emission intensive. Chemical reactions must be activated by high temperature and pressure or both with specific catalysts. Catalysts require constant regeneration by burning off coke which emits tremendous GHGs. Scale of reaction system is usually massive to maintain high energy efficiency. Here, we show an electrical method that uses nanosecond pulsed plasma to convert liquid fuels at ambient conditions with minimized GHG emissions. Plasma was generated on the interface of natural gas bubbles and liquid fuels (hexadecane). Interaction with plasma is able to convert both into valuable products including hydrogen and intermediates. Pulsing energy was the key to liquid conversion and product selectivity. Using lower pulsing energy (20 mJ), this process converts 13% of liquid fuel and 5% of methane primarily to hydrogen and C2H2 and to intermediate products (7%) and branched alkane products (3%). Energy cost was less than 1% of the energy content of processed fuel. Higher pulsing energy (200 mJ) primarily converts liquid fuels to solid products. This method is electrical, flexible on scale and easily integrated with renewable electricity.

Automated summary

This study presents an electrical method using nanosecond pulsed plasma to convert liquid fuels into valuable products at ambient conditions with minimized GHG emissions. By adjusting pulsing energy, the process can achieve selective conversion of liquid fuels while maintaining low energy cost.