New Catalyst Removes 99% of Sulfur from Diesel at Low Temperatures

Researchers from the A.A. Baikov Institute of Metallurgy and Materials Science of the Russian Academy of Sciences have developed a catalyst capable of removing over 99% of sulfur from diesel fuel under mild conditions. The method allows fuel to be purified to meet strict environmental standards without requiring high pressure or extreme heat.

Standard hydrotreating technology typically requires temperatures between 300\u2013400\u00B0C and high pressure, yet it often fails to eliminate certain stubborn aromatic sulfur compounds. The new approach utilizes the oxidation of impurities at 70\u00B0C and atmospheric pressure.

Composition and Chemical Mechanism

The catalyst is based on hydroxyapatite—a material composed of calcium and phosphate components. Researchers modified its surface with molybdate ions to create active phosphomolybdate clusters. To initiate the purification process, hydrogen peroxide is added to the system.

Hydrogen peroxide acts as the oxidant, interacting with the molybdenum clusters to activate them for the removal of sulfur groups from the fuel. Water is the only byproduct of this chemical reaction. During tests conducted on actual diesel fuel, the catalyst removed nearly all sulfur within eight hours and maintained its activity after five cycles of use.

Limitations and Future Development

The study's findings were published in the journal Separation and Purification Technology. The authors identify a primary limitation: the current scheme requires the constant addition of hydrogen peroxide, which impacts the final cost of purification.

To address this, researchers intend to develop systems capable of oxidizing sulfur compounds directly using oxygen from the air. This transition would eliminate the need for hydrogen peroxide and further reduce costs before potential industrial scaling.

Source: This article was adapted from an original Russian-language publication by Pravda.Ru.