Date of Award


Degree Type


Degree Name

Master of Science


Chemical and Biochemical Engineering


Dr. Hugo de Lasa


Venezuelan refineries are going to be dealing in the near future with VGOs (vacuum gas oil) feedstocks having increased amounts of aromatics. There will also be tighter sulfur content specifications in gasoline. This MESc study considers the application of an additive (HIPZ- D) together with a Y zeolite (commercial catalyst) in Fluid Catalytic Cracking (FCC) riser units. The HIPZ-D additive is a technology of PDVSA Intevep (oil research institute of Venezuela). The goal is to establish desirable conditions for using HIPZ-D additive as an effective agent for gasoline sulfur reduction. With this end, an HIPZ-D additive is contacted with blends o f thiophene or benzothiophene and 1,3,5-trimethylbenzene representing a highly aromatic gasoline. As well, various blends of HIPZ-D additive and FCC catalyst are studied in a CREC fluidized riser simulator, using temperatures, partial pressures, reaction times and

C/O ratios representatives of FCC industrial operation.

It is found that thiophene conversion over HIPZ-D under aromatic conditions occurs according to a selective adsorption process followed by thiophene alkylation, and catalytic cracking. It is also observed that the selective adsorption of thiophene over the HIPZ-D is dominant for reactions times lower than 7 s. Thus, the present MESc study describes favorable HIPZ-D additive application conditions for thiophene sulfur reduction in gasoline in FCC units.



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