UNN chemists develop a new petroleum refining method using solar energy
A semiconductor with perovskite structure developed by scientists at the Lobachevsky University Research Institute for Chemistry converts solar energy into chemical energy, making it much easier to remove sulphur-containing compounds from oil, which harm oil refinery equipment and affect the quality of oil products.
A special semiconductor with tungsten and molybdenum is activated by ordinary sunlight, whereas its counterpart, titanium dioxide, starts working only when exposed to UV light, using only 5% of the sun's energy.
Researchers at UNN laboratories of inorganic materials and high-purity materials technology have developed a semiconductor with simpler composition, learned how to synthesise it in one step, without loss of efficiency, and also found that the introduction of molybdenum in the photocatalyst Bi2WO6 increases the activity of the compound, expanding the range of visible light absorption.
"Our two-year research into photocatalysis aims to find an alternative way of removing sulphur compounds from liquid hydrocarbons and cleaning water from organic compounds. Unlike catalytic hydrodesulphurisation, which occurs under very harsh conditions, our process takes place at room temperature and atmospheric pressure. This significantly increases the energy efficiency of purification from sulphur compounds," explains Artyom Belousov, Senior Researcher at the UNN Research Institute for Chemistry, one of the authors of the innovation.
According to the scientists, the resulting solid solution with tungsten and molybdenum can also be used in the timber industry to purify sulphate turpentine containing more than 1000 ppm of sulphur.
"Typically, sulphur compounds are disposed of by acid-alkali treatment. This has an impact on the stringent equipment requirements and results in waste water that is difficult to recycle. With the help of solar energy and our photocatalyst, these processes can also be simplified, making them safer and more environmentally friendly," says Artyom Belousov.
In the future, scientists plan to optimise the conditions for producing photocatalysts and enhance their useful properties.
"We removed sulphur compounds using hydrogen peroxide as an oxidizer. It is a promising idea to oxidize sulphur-containing impurities with ordinary atmospheric oxygen, and to study the process of photocatalytic desulphurization in application to diesel fuel or sulphate turpentine," adds Artyom Belousov.
The research is financially supported by the Ministry of Science and Higher Education of the Russian Federation. The results have been published in the journal Processes.
The UNN scientists' work addresses one of the objectives of the strategic project "Fundamental Principles of Future Technologies", one of Lobachevsky University’s four strategic projects, which won the "Research Leadership" track of the Priority 2030 programme: using solar energy to initiate chemical processes and engineering new materials to implement the processes.