ABSTRACT
Heavy fuels usually contain very high amounts of complex sulfur compounds such as benzothiophenes and dibenzothiophenes leading to emission of SOx and sulfate particulate matter, which cause environmental problems such as air pollution and acid rains. Using oxidative desulfurization (ODS) process, sulfur compounds can be oxidized to sulfoxides and sulfones that can be removed using liquid-liquid extraction due to their high polarity, under mild conditions. In this study, oxidative desulfurization of a heavy fuel (Mazut, 3.1 wt% S) has been studied, with hydrogen peroxide as the oxidant and acetic acid as the catalyst. Applying ODS to Mazut commonly results in high viscosity and gum formation in the fuel. Therefore, in this study, a novel ODS procedure was developed and combined with an upgrading method to avoid this problem. The appropriate extraction solvent and the adequate solvent-to-fuel and oxidant to fuel ratios were also determined. The oxidized sulfur compounds were extracted by liquid-liquid extraction using a solvent, dimethylformamide (DMF). By using a pre-treatment method followed by a desulfurization process involving two rounds of oxidation and extraction, viscosity of fuel decreased about 87% and the sulfur content of the heavy fuel was decreased to 0.91 wt%, which means achieving 70.83% desulfurization.
Graphical abstract
Abbreviations
Bt | = | Benzothiophene |
C | = | Centigrade |
cSt | = | centi Stocke |
cP | = | centi Poise |
D | = | Desulfurization yield |
DBT | = | Dibenzothiophene |
DMF | = | Dimethylformamide |
g | = | gram |
HDS | = | Hydrodesulfurization |
ODS | = | Oxidative desulfurization |
Ox/S | = | Oxidant/Sulfur ratio |
psi | = | pound per square inch |
R | = | Recovery |
S | = | Sulfur |
SDA | = | Solvent Deasphalting |
TBHP | = | Tert-Butyl hydroperoxide |
Th | = | Thiophene |
wt | = | weight |
Disclosure statement
No potential conflict of interest was reported by the authors.
Additional information
Notes on contributors
Mehrab Sadeghi
Mehrab Sadeghi is a dedicated chemical engineer who earned his Bachelor's degree in Chemical Engineering from Iran University of Science and Technology. Building on this foundation, he furthered his expertise by obtaining a Master's degree in Process Design of Chemical Engineering. Mehrab's academic journey reflects his passion for process design and a profound understanding of the complexities within the field.
Shahrokh Shahhosseini
Dr. Shahrokh Shahhosseini is a distinguished professor of chemical engineering at Iran University of Science and Technology, a position he has held since 1999. With a Ph.D. from the University of Queensland, Australia, earned in 1998, his expertise lies in the areas of design, simulation, and process control. Throughout his illustrious career, Dr. Shahhosseini has contributed significantly to the field, evidenced by a wealth of scholarly articles that showcase his commitment to advancing knowledge and understanding in chemical engineering. His dedication to education and research has left an indelible mark on the academic landscape, both nationally and internationally.