Diesel commercial processes

The installed capacities for hydrotreating distillates are predominantly moderate-pressure reactors (up to 3 MPa). Typical conditions used in today s commercial processes are summarized in Table IV (7). In the U.S., the Clean Air Act mandated that low-emission fuels will have to be developed for future use. Industry responded quickly, and by 1994 typical diesel fuels in the U.S. contained 0.05% S, with average cetane numbers of 42 and 31-37% aromatics. California imposed stricter standards, requiring 0.05% S and a minimum of 48 cetane with an emission that did not exceed that of a 10% aromatic fuel. This is the present standard for California Air Resources Board (CARB) certification. Through the development of improved processing and additives that lower emissions, Chevron was the... 

The second part of the book centers around a few catalytic applications each dealing with important commercial processes involving Ce02 in some stages. The use of ceria in auto-exhaust treatment and the role of sulfur in catalyst deactivation is specifically addressed in chapters 10 and 11 for spark ignited engines and chapter 12 for diesel engines. The relevance of ceria in total oxidation catalysis is the main... 

A spedal feature of zeolites which makes them such superb catalysts in some cases is their shape selectivity. The shape selectivity may arise in three ways reactant selectivity, product selectivity and, of lesser importance, transition state selectivity. Reactant selectivity arises from the ability of only certain molecules to be absorbed into the zeolite cavities and thus reach the active acid sites. An important commercial process that exploits this type of reactant selectivity is catalytic dewaxing. Compared to the branched isomers, the straight chain alkanes have low octane numbers and contribute to wax formation in diesel fuel. Product selectivity is derived from the fact that only certain products are of the correct dimension to escape from the zeolite once they have been formed. Transition state selectivity relies upon the fact that certain intermediates, which are formed during a chemical reaction at the active site, will not fit in... 

Conventional Transportation Fuels. Synthesis gas produced from coal gasification or from natural gas by partial oxidation or steam reforming can be converted into a variety of transportation fuels, such as gasoline, aviation turbine fuel (see Aviation and other gas turbine fuels), and diesel fuel. A widely known process used for this appHcation is the Eischer-Tropsch process which converts synthesis gas into largely aHphatic hydrocarbons over an iron or cobalt catalyst. The process was operated successfully in Germany during World War II and is being used commercially at the Sasol plants in South Africa. 

Improving stability of microbial strains in organic solvents is another challenge for enabling commercialization of desulfurization processes for gasoline and diesel applications. This was a target for a project in Klibanov s group [231], whose approach... 

SPD [Slurry phase distillate] A process for making diesel fuel, kerosene, and naphtha from natural gas. Developed by Sasol and first commercialized in South Africa in 1993. A joint venture with Haldor Topsoe for the further development and commercialization of the process was announced in 1996. Commercialization in Nigeria was announced in 1998. 

TIGAS [Topsoe integrated gasoline synthesis] A multi-stage process for converting natural gas to gasoline. Developed by Haldor Topsoe and piloted in Houston from 1984 to 1987. Not commercialized, but used in 1995 as the basis for a process for making dimethyl ether for use as a diesel fuel. 

Second-generation biofuel technologies make use of a much wider range of biomass feedstock (e.g., forest residues, biomass waste, wood, woodchips, grasses and short rotation crops, etc.) for the production of ethanol biofuels based on the fermentation of lignocellulosic material, while other routes include thermo-chemical processes such as biomass gasification followed by a transformation from gas to liquid (e.g., synthesis) to obtain synthetic fuels similar to diesel. The conversion processes for these routes have been available for decades, but none of them have yet reached a high scale commercial level. 

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