Scientists at Moscow research institutions have developed a new catalyst that removes nearly 100 percent of harmful sulfur impurities from diesel fuel.
According to the press office of the Russian Science Foundation, this proposed technology simplifies the fuel purification process and reduces its cost, as it does not require high temperatures and pressures.
A source at the Russian Science Foundation points out that natural oil, in addition to hydrocarbons—the main combustible component of fuel—contains sulfur compounds. Burning sulfur-containing fuel releases harmful oxides into the air, which can cause acid rain and respiratory irritation. Therefore, sulfur is removed from gasoline and diesel fuel using hydrotreating. However, this method is technically complex because it requires temperatures between 300 and 400 degrees Celsius and high pressure, and it does not remove all the stubborn aromatic sulfur compounds from the fuel.
Scientists have developed a new catalyst based on hydroxyapatite—a readily available, non-toxic, and stable mineral that can be easily synthesized from inexpensive calcium and phosphate compounds. By impregnating hydroxyapatite with a molybdate ion solution and heating it, active phosphomolybdate aggregates form on the material's surface.
The resulting catalyst, along with hydrogen peroxide, was then added to samples of unrefined diesel fuel that had not undergone desulfurization. The reaction was carried out at 70°C and atmospheric pressure. The hydrogen peroxide oxidized the sulfur compounds and then decomposed into water, preventing the formation of harmful byproducts. Over an eight-hour cycle, the catalyst removed more than 99% of the sulfur from the fuel and remained effective after five cycles.
“The combination of low-cost materials, moderate conditions, and high efficiency makes this innovation economically competitive and easily scalable,” says Margarita Goldberg, project supervisor and senior researcher at the Laboratory of Composite Ceramics and Biomaterials at the Baikov Institute of Metallurgy and Materials Science of the Russian Academy of Sciences. “In the future, we plan to develop systems capable of effectively oxidizing sulfur compounds using atmospheric oxygen, eliminating the need for hydrogen peroxide and thus significantly reducing the cost of the process.”
The study results were published in the journal Separation and Purification Technology
