Beijing – Researchers in China have developed a method to considerably reduce carbon dioxide emissions during the Fischer-Tropsch Synthesis (FTS) process, a key technology in converting coal into liquid fuels and chemicals.The breakthrough involves using trace amounts of methyl bromide to suppress the formation of carbon dioxide, increasing selectivity and achieving near-zero emissions.

The study, led by Professor Ma Ding of Peking university, demonstrates that adding methyl bromide at ppm (parts per million) levels effectively “switches off” the carbon dioxide-forming route in the FTS process.This reduces carbon dioxide selectivity from approximately 30 percent to below 1 percent.

The Challenge of Carbon Dioxide in FTS

Fischer-Tropsch Synthesis has been a vital component of china’s coal-to-liquid and syngas chemical industries for years. However, the unavoidable production of carbon dioxide as a byproduct has been a major obstacle to making the process more environmentally friendly. According to professor Ma Ding, this has been a long-standing roadblock to “green upgrade” efforts.

The FTS process converts a mixture of carbon monoxide and hydrogen (syngas) into liquid hydrocarbons.A notable portion of the carbon in the syngas can be lost as carbon dioxide, reducing efficiency and increasing the carbon footprint.

How Methyl Bromide Alters the Reaction

The research team discovered that methyl bromide acts as a selective inhibitor,preventing the reaction pathways that lead to carbon dioxide formation without significantly impacting the production of desired hydrocarbons like olefins and liquid fuels.The precise mechanism is still under investigation, but preliminary findings suggest methyl bromide alters the surface chemistry of the catalyst used in the FTS process.

“Our study delivers a simple yet effective technical fix that enables green and low-carbon production of olefins or liquid fuels,” Professor Ma Ding stated.

Implications for Decarbonizing coal-to-Chemicals

The researchers believe this innovation, combined wiht renewable hydrogen sources and low-carbon dioxide coal-gasification technologies, could pave the way for a substantial reduction in carbon emissions from coal-to-liquid and coal-to-chemicals processes. This is notably vital for China, which relies heavily on coal as an energy source.

The use of renewable hydrogen, produced through electrolysis powered by solar or wind energy, would further minimize the carbon footprint of the entire process. Low-carbon dioxide coal-gasification involves capturing and storing carbon dioxide emitted during the coal gasification stage.