Stuart S. Shih

Bio: Stuart S. Shih is an academic researcher from Mobil. The author has contributed to research in topics: Catalysis & Octane rating. The author has an hindex of 19, co-authored 39 publications receiving 1073 citations. Previous affiliations of Stuart S. Shih include ExxonMobil.

Gasoline upgrading process

Abstract: Low sulfur gasoline of relatively high octane number is produced from a cracked, sulfur-containing olefinic naphthas by hydrodesulfurization followed by treatment over an acidic catalyst comprising an intermediate pore size zeolite such as zeolite ZSM-5 in combination with molybdenum. The use of the molybdenum in combination with the zeolite has been found to give improved catalytic activity coupled with lower coking, longer catalyst life and other advantages.

Catalyst comprising a hydrogenation metal and a delaminated layered silicate

Abstract: There is provided a catalyst comprising at least one hydrogenation metal, such as Ni and Mo, supported on a delaminated layered silicate, such as kenyaite, which has been swollen and calcined. There is also provided a method for making this catalyst. There is further provided a process for using this catalyst to demetalize a petroleum feedstock, such as a gas oil.

Hydrocracking process with partial liquid recycle

Abstract: A hydrocracking process employing a hydrocracking catalyst based on zeolite beta together with a metal hydrogenation/dehydrogenation component recycles the unconverted, hydrocracked bottoms fraction to the hydrocracking step for improvements in distillate selectivity and denitrogenation without loss of catalyst activity while improving dewaxing of the unconverted bottoms fraction. The process typically operates at low to moderate hydrogen pressures up to 1500 psig (10445 kPa) with low hydrogen consumptions typically below 800 SCF/Bbl (142 n.l.l. -1 ). Denitrogenation is notably high at 90 weight percent or higher.

New design approaches to ultra-clean diesel fuels by deep desulfurization and deep dearomatization

Abstract: This paper is a selective review on design approaches and associated catalysis and chemistry for deep desulfurization and deep dearomatization (hydrogenation) of hydrocarbon fuels, particularly diesel fuels. The challenge for deep desulfurization of diesel fuels is the difficulty of removing the refractory sulfur compounds, particularly 4,6-dimethyldibenzothiophene, with conventional hydrodesulfurization processes. The problem is exacerbated by the inhibiting effect of polyaromatics and nitrogen compounds, which exist in some diesel blend stocks on deep HDS. With the new Environmental Protection Agency (EPA) Tier II regulations to cut the diesel sulfur from current 500 ppmw down to 15 ppmw by June 2006, refineries are facing major challenges to meet the fuel sulfur specification along with the required reduction of aromatics contents. The principles and problems for the existing hydrodesulfurization processes, and the concepts, advantages and disadvantages of various new approaches will be discussed. Specifically, the following new design approaches for sulfur removal will be discussed: (1) novel catalysts for ultra-deep hydrodesulfurization under conventional HDS process conditions; (2) new design concept for sulfur-tolerant noble metal catalysts for low-temperature hydrogenation; (3) new desulfurization process by sulfur adsorption and capture under H2; (4) new desulfurization process by selective adsorption at ambient temperature without H2 and a related integrated process concept; (5) oxidative desulfurization in liquid-phase; and (6) biodesulfurization.

Perspectives in catalytic applications of mesostructured materials

Abstract: This review paper deals with proven and potential applications of mesoporous molecular sieves in catalysis. In addition to introduction and conclusion, the text is divided into two parts, respectively, dedicated to the design of solid catalysts and catalyst supports and to some relevant examples of catalytic processes.