Desulfurization of model and real fuels by extraction and oxidation processes using an indenylmolybdenum tricarbonyl pre-catalyst

authors	Juliao, D; Gomes, AC; Pillinger, M; Valenca, R; Ribeiro, JC; Goncalves, IS; Balula, SS
nationality	International
journal	APPLIED ORGANOMETALLIC CHEMISTRY
author keywords	desulfurization; extraction; hydrogen peroxide; indenylmolybdenum complexes; oxidation
keywords	DEEP DESULFURIZATION; INDENYL COMPLEXES; SULFUR REMOVAL; IONIC LIQUIDS; DIESEL; EPOXIDATION; POLYMERIZATION; MOLYBDENUM(II); CPMO(CO)(3)R; EFFICIENT
abstract	Regulations on the permissible levels of sulfur in transportation fuels are becoming ever more strict, with a global shift towards zero sulfur fuels, and the revamp of existing hydrodesulfurization (HDS) facilities to meet these lower caps is cost-prohibitive. Metal-catalyzed sulfoxidation chemistry is viewed as an economically viable desulfurization strategy that could complement conventional HDS technology. In the present work, the complex [eta (5)-IndMo(CO)(3)Me] (1) (Ind = indenyl) was employed in the catalytic oxidative desulfurization (CODS) of model and real liquid fuels, using aqueous hydrogen peroxide (H2O2) as oxidant. After optimization of the CODS reaction parameters (diesel/H2O2 ratio, catalyst amount, temperature), a high-sulfur (2000 ppm) model diesel containing benzothiophene, dibenzothiophene, 4-methyldibenzothiophene and 4,6-dimethyldibenzothiophene could be completely desulfurized within 2 hr under solvent-free conditions or in the presence of the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM]PF6) as extraction solvent. The catalyst formed under solvent-free conditions could be recycled without a significant decrease in desulfurization activity. The high performance of the CODS system was verified in the sulfur removal from a commercial untreated diesel fuel with a sulfur content of 2300 ppm, and a jet fuel with a sulfur content of 1100 ppm. Solvent-free CODS in combination with initial/final extraction gave desulfurization efficiencies of 70% for the diesel fuel and 55% for the jet fuel. CODS with [BMIM]PF6 in combination with initial/final extraction led to a sulfur removal of 95.9% for the diesel fuel, which is one of the best results yet reported for ODS of commercial diesels.
publisher	WILEY
issn	0268-2605
isbn	1099-0739
year published	2020
volume	34
issue	4
digital object identifier (doi)	10.1002/aoc.5490
web of science category	Chemistry, Applied; Chemistry, Inorganic & Nuclear
subject category	Chemistry
unique article identifier	WOS:000529871500048