Kinetic Models of Deep Hydrotreating Reactions to Produce Ultralow Sulfur Diesel

Abstract

Due to the current worldwide environmental problems caused by high emissions of polluting gases such as CO, NO x , and SO x , resulting from the combustion of fossil fuels, many organizations and governments have established standards aimed at producing cleaner and more environmentally friendly fuels. These standards focus on eliminating hazardous substances, particularly the sulfur compounds in diesel, as they are among the most harmful organic compounds to both human health and the environment. Hydrotreating is the main refinery process used to produce ultralow sulfur diesel. For proper modeling and simulation of this process, it is mandatory to develop adequate kinetic models that include all the reactions taking place during the hydrotreating of gas oil, as well as the removal of the most refractory compounds present in the chemical composition of diesel, such as 4-MDBT and 4,6-DMDBT. This work reports an exhaustive discussion of the kinetic models of hydrotreating reactions for the production of ultralow sulfur diesel reported so far in the literature. The main topics include the reaction systems, type of catalysts, and operating conditions. A comparison of the reported kinetic parameters was also carried out. Finally, a set of kinetic models to be considered for the simulation of the hydrotreating process to produce ultralow sulfur diesel is proposed.

Developing an Approach for Calculating Theoretical Minimum Hydrogen Consumption during Catalytic Hydrotreating of Diesel

“…[15] In order to calculate n Ni H 2 ð Þ, when the minimum H 2 consumption was achieved, the reaction product for each type of nitrides and the number of moles of H 2 consumed per mole of nitridesshould be identified. Studies showed that a pre-hydrogenation step of the N-containing ring was generally required before the breakage of C-N. [16] As listed in Table 2, when the minimum H 2 consumption was achieved during diesel hydrotreating, 1 mol of indole generated ethylbenzene consuming 3 mol of H 2 , and 1 mol of carbazole generated cyclohexylbenzene consuming 5 mol of H 2 , and 1 mol of quinoline generated propylbenzene consuming 4 mol of H 2 , and 1 mol of benzoquinoline generated 2-propylnaphthalene consuming 4 mol of H 2. The scheme of the above reactions are shown in Figure 2.…”

Study on Diesel Hydrotreating Kinetics and the Synergistic Effect of CoMo and NiMo Catalysts

“…The study of the reaction kinetics of ultradeep hydrodesulfurization (UHDS) of diesel has always been a hot research topic. , The commonly used hydrotreating reactors include fixed-bed, moving-bed, and ebullating-bed reactors. Fixed-bed reactors are the most commonly used reactor systems in commercial hydrotreating operations.…”