Desulfurization and denitrification of FCC gasoline in the continuous extractor

U posljednje vrijeme postavljaju se stroge norme o kvaliteti goriva i sadržaju dozvoljenih sumporovih, dušikovih i aromatskih spojeva u gorivu, a sve s ciljem očuvanja okoliša. S obzirom da su procesi koji se trenutno koriste skupi, kao alternativa hidrodesulfurizaciji i hidrodenitrifikaciji razmatra se kapljevinska ekstrakcija s niskotemperaturnim eutektičkim otapalima. U ovom radu istražena je mogućnost primjene niskotemperaturnih eutektičkih otapala i nanofluida u procesu izdvajanja tiofena, piridina i toluena kapljevinskom ekstrakcijom iz modelne otopine koja predstavlja FCC benzin u milireaktoru. Korištena su eutektička otapala ChEg-0, ChMa-30 i TBAB-MK-0 i nanofluidi pripravljeni u njima dodatkom 0,3 vol% nanočestica Al2O3. Prije provedbe ekstrakcije, karakterizirana su korištena sekundarna otapala te modelna otopina FCC benzina. Provedena je ekstrakcija u milireaktorima s različitom duljinom cijevi te je ispitano vrijeme zadržavanja na djelotvornost ekstrakcije. Za ispitane protoke uspostavljen je segmentirani režim strujanja u milireaktoru. Otapalo na bazi tetrabutilamonijev bromid dalo je najbolje rezultate izdvajanja tri komponente iz modelne otopine benzina, a nanofluidi nisu poboljšali djelotvornost ekstrakcije.Recently, strict standards for the quality of fuel and the content of permitted sulfur, nitrogen and aromatic compounds in the fuel have been set, all with the aim of protecting the environment. Given that the processes currently in use are expensive, liquid extraction with deep eutectic solvents is considered as an alternative to hydrodesulfurization and hydrodenitrogenation. This paper investigates the possibility of using deep eutectic solvents and nanofluids in the process of extracting thiophene, pyridine and toluene by liquid extraction from a model solution representing FCC gasoline in a millireactor. The eutectic solvents ChEg-0, ChMa-30 and TBAB-MK-0 were used and the nanosuspensions prepared in them with the addition of 0.3 vol% Al2O3 nanoparticles. Prior to extraction, the secondary solvents and the FCC gasoline model solution were characterized. Extraction was carried out in millireactors with different length of the tube and the residence time for extraction efficiency was tested. A segmented flow regime in the millireactor was established for the tested flows. The tetrabutylammonium bromide solvent gave the best results of separating the three components from the gasoline stock solution, and the nanofluids did not improve the extraction efficiency