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Hydrocracking is a catalytic cracking process assisted by the presence of added hydrogen gas. Unlike a hydrotreater, hydrocracking uses hydrogen to break C–C bonds (hydrotreatment is conducted prior to hydrocracking to protect the catalysts in a hydrocracking process). In 2010, 265 million tons of petroleum was processed with this technology.
A typical fluid catalytic cracking unit in a petroleum refinery. Fluid catalytic cracking (FCC) is the conversion process used in petroleum refineries to convert the high-boiling point, high-molecular weight hydrocarbon fractions of petroleum (crude oils) into gasoline, alkene gases, and other petroleum products.
The catalytic cycle is the main method for describing the role of catalysts in biochemistry, organometallic chemistry, bioinorganic chemistry, materials science, etc. Since catalysts are regenerated, catalytic cycles are usually written as a sequence of chemical reactions in the form of a loop.
Equilibrium Catalyst refers to the deactivated or spent catalyst after use in a chemical reaction. The main player in oil refining processes such as fluid catalytic cracking (FCC), hydroprocessing , hydrocracking is the catalyst or zeolitic material, that breaks down complex and long-chain hydrocarbons into simple, useful hydrocarbons.
Zeolite structure. A common catalyst support material in hydrocracking. Also acts as a catalyst in hydrocarbon alkylation and isomerization. Catalysts are not active towards reactants across their entire surface; only specific locations possess catalytic activity, called active sites. The surface area of a solid catalyst has a strong influence ...
Transfer hydrogenation usually occurs at mild temperature and pressure conditions using organic or organometallic catalysts, many of which are chiral, allowing efficient asymmetric synthesis. It uses hydrogen donor compounds such as formic acid , isopropanol or dihydroanthracene , dehydrogenating them to CO 2 , acetone , or anthracene ...
Heterogeneous catalysts for hydrogenation are more common industrially. In industry, precious metal hydrogenation catalysts are deposited from solution as a fine powder on the support, which is a cheap, bulky, porous, usually granular material, such as activated carbon, alumina, calcium carbonate or barium sulfate. [14]
The catalyst is sensitive to proton-bearing impurities. [6] The catalyst becomes irreversibly deactivated after about ten minutes at room temperature, signaled by appearance of yellow color. One deactivation process involves formation of hydride-bridged dimers. [7] As a consequence, Crabtree's Catalyst is usually used in very low catalyst loading.