Sulfur- and nitrogen-containing compounds contained in refined petroleum products form harmful gases during combustion. To regulate harmful emissions into the environment, strict requirements are introduced to control their content in petroleum products. By the traditional method – catalytic hydrotreating – it is difficult to achieve high-quality purification from these compounds. In addition, this method requires the use of strict conditions: high temperatures and pressures (600-700 K; 20-50 bar), and also entails high costs of hydrogen and expensive catalysts.
A new method for cleaning light petroleum products from sulfur- and nitrogen-containing compounds was proposed by researchers from the N.S. Kurnakov Institute of General and Inorganic Chemistry (IONH) of the Russian Academy of Sciences, subordinate to the Ministry of Education and Science of Russia. They suggest using environmentally friendly selective solvents based on completely renewable water-soluble polymers. The method will allow more efficient purification of refined petroleum products, besides the proposed method is cheaper than the traditional one.
Moscow chemists have suggested that one of the most promising methods of purification of light hydrocarbon fractions from sulfur- and nitrogen–containing heterocyclic compounds is liquid extraction. The use of commercially available and fireproof water-soluble polymers as extractants can significantly increase the efficiency and environmental safety of this process. According to scientists, similar polymers can be purchased in Russia, and some of them are produced in our country. Equally important is the possibility of regeneration of the extractants used and their repeated reuse.
Scientists have successfully applied water-soluble polymers to purify light hydrocarbon fractions from impurity products.
"Modern methods of refining oil products include processes that require significant energy consumption, capital investment, as well as the use of toxic and flammable reagents. The use of water-soluble polymers solves these problems. For the first time, we proposed an integrated approach to the process of extraction and separation of quinoline, indole and thiophene from light hydrocarbon fractions using polymers – polyvinylpyrrolidone and polyethylene glycol – with their subsequent regeneration due to carbon dioxide treatment. We have shown that the use of an aqueous solution of polyvinylpyrrolidone is effective for primary purification from nitrogen-containing compounds and allows further unhindered removal of sulfur-containing compounds using polyethylene glycol. In our opinion, such a two-stage cleaning has very good prospects. In addition, we propose a new approach to polymer regeneration, which makes it possible to effectively isolate thiophene, quinoline and indole," says one of the authors of the article, senior researcher at the Laboratory of Theoretical Foundations of Chemical Technology of the IONKH RAS, Candidate of Chemical Sciences Yulia Zahodyaeva.
The authors believe that the combination of polymer extraction and carbon dioxide extraction is a more economical and environmentally friendly method for industrial purification of petroleum products from sulfur– and nitrogen-containing heterocyclic substances, since in this case expensive reagents and catalysts are not required.
The study was partially carried out within the framework of the state task of the Ministry of Education and Science of Russia in accordance with the priorities of the SNTR of the Russian Federation. The results of the study are published in one of the international journals (Chemical Engineering Research and Design https://www.sciencedirect.com/science/article/abs/pii/S0263876222007444 ?via%3Dihub).
Information provided by the press service of the Ministry of Education and Science of Russia
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