Spanish researchers have optimised a mild method to remove sulfur from fuel that could make life a lot easier for oil refineries that are under increasing pressure to reduce sulfur in fuels.

Burning trace amounts of organosulfur compounds in fuel has long been known to yield sulfur oxides that poison catalytic converters and can also cause acid rain. Environmental legislation dictates that refineries must cut sulfur levels further still in the future. Current sulfur removal technology utilises hydrodesulfurisation (HDS), requiring high pressure hydrogenation reactors and with limitations on the substrates that will respond to treatment. An alternative energy- and cost-efficient technique is called for to meet the new stringent specifications.

Jose Fierro and colleagues from Instituto de Catalisis y Petroleoquimica in Madrid, explored factors influencing the oxidative desulfurisation (ODS) of aromatic sulfur-containing compounds. They applied the resulting conditions to kerosene, lowering sulfur levels by over 99 per cent. The authors suggest that a feasible, economic solution to cleaner, greener fuel would be to integrate their process after the HDS step in existing refineries.

Sula Armstrong