Sulfur petroleum catalyst

S02 from decomposing spent petroleum/polymer sulfuric acid catalyst, Chapter 5 10... 

Sulfuric acid is used as catalyst in petroleum refining and other industrial organic processes. The sulfuric acid catalyst is not consumed, but it becomes ineffective as it absorbs water, hydrocarbons and other chemicals over time. Its catalytic properties are maintained by bleeding off some of the contaminated spent acid and replacing the bleed with new strong acid. 

This discussion is aimed primarily at alkylation processes, which are characterized by two-phase emulsions. The traditional process includes a hydrocarbon phase in contact with a sulfuric acid catalyst to form the environment for proper alkylation. In the petroleum industry, the desired product is a high octane alka-late, but other alklation processes have other desired products. 

In the finely divided state platinum is an excellent catalyst, having long been used in the contact process for producing sulfuric acid. It is also used as a catalyst in cracking petroleum products. Much interest exists in using platinum as a catalyst in fuel cells and in antipollution devices for automobiles. 

Thiophene [110-02-17, C H S, and dibenzothiophene [132-65-OJ C22HgS, are models for the organic sulfur compounds found in coal, as well as in petroleum and oil shale. Cobalt—molybdenum and nickel—molybdenum catalysts ate used to promote the removal of organic sulfur (see Coal CONVERSION... 

In most of the nonmetaHurgical uses of molybdenum compounds the metal is coordinated by oxygen or sulfur ligands. Molybdenum nitrides, carbides, and sihcides are, however, coming under increasing study for various appHcations. Roughly 75% of all molybdenum compounds are used as catalysts in the petroleum and chemicals industries. 

Other Specialty Chemicals. In fuel-ceU technology, nickel oxide cathodes have been demonstrated for the conversion of synthesis gas and the generation of electricity (199) (see Fuel cells). Nickel salts have been proposed as additions to water-flood tertiary cmde-oil recovery systems (see Petroleum, ENHANCED oil recovery). The salt forms nickel sulfide, which is an oxidation catalyst for H2S, and provides corrosion protection for downweU equipment. Sulfur-containing nickel complexes have been used to limit the oxidative deterioration of solvent-refined mineral oils (200). 

Several processes are available for the recovery of platinum and palladium from spent automotive or petroleum industry catalysts. These include the following. (/) Selective dissolution of the PGM from the ceramic support in aqua regia. Soluble chloro complexes of Pt, Pd, and Rh are formed, and reduction of these gives cmde PGM for further refining. (2) Dissolution of the catalyst support in sulfuric acid, in which platinum is insoluble. This... 

Steam Reforming Processes. In the steam reforming process, light hydrocarbon feedstocks (qv), such as natural gas, Hquefied petroleum gas, and naphtha, or in some cases heavier distillate oils are purified of sulfur compounds (see Sulfurremoval and recovery). These then react with steam in the presence of a nickel-containing catalyst to produce a mixture of hydrogen, methane, and carbon oxides. Essentially total decomposition of compounds containing more than one carbon atom per molecule is obtained (see Ammonia Hydrogen Petroleum). 

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