As alkylation feedstock

Rehable estimates of annual production of biphenyl in the United States are difficult to obtain. The 1990 figure is probably on the order of 16 million kg/yr of which about half is derived from hydrodealkylation sources. About 10% of the biphenyl derived from HD A sources is consumed, as 93—95% grade, in textile dye carrier appHcations. The remainder is used for alkylation or upgraded to >99.9% grades for heat-transfer purposes. Essentially all of the high purity biphenyl produced by dehydrocondensation of ben2ene is used as alkylation feedstock or is utili2ed directly in heat-transfer appHcations. 

The main components of FCC catalysts are Zeolite Y, e.g., REY orUSY as the major active component (10 to 50%), and a binder that is typically an amorphous alumina, silica-alumina, or clay material. In addition to these main components, other zeolite components, e.g., ZSM-5, and other oxide or salt components are quite frequently used additives in the various FCC catalysts available on the market. The addition of 1 to 5% ZSM-5 increases the octane number of the gasoline. ZSM-5 eliminates feed compounds with low octane numbers because it preferentially center-cracks n-paraffins producing butene and propene [14], These short-chain olefins are then used as alkylation feedstocks... 

Butane isomerization and pentane-hexane isomerization are the two most important isomerization processes. Isobutane is utilized primarily as alkylate feedstock. Isopentanes and isohexanes have become valuable high-octane blending components in gasoline. 

Although benzene prices have escalated in recent years, a concurrent need for butenes for use in alkylates for motor fuel has also increased and butane prices have also escalated. As a result, a search for alternative feedstocks began and Amoco Chemical Co. commercialized a process in 1977 to produce maleic anhydride from butane. A plant in JoHet came on-stream in 1977 with a capacity of 27,000 t/yr (135,136). No new plants have been built in the United States based on butenes since the commercialization of butane to maleic anhydride technology. In Europe and particularly in Japan, however, where butane is in short supply and needs for butenes as alkylation feed are also much less, butenes may become the dominant feedstock (see Maleic anhydride). 

Toxicity and Environmental Fate Information for Propylene CAS 115-07-1 Sourtes. Propylene (propene) is one of the light ends formed during catalytic and thermal cracking and coking operations, it is usually collected and used as a feedstock to the alkylation unit. Propylene is volatile and soluble in water making releases to both air and water significant. 

The reachon of benzene with ethylene or propylene to form ethylbenzene or isopropylbenzene (cumene) is an industrially important transformahon, with ethylbenzene as the key building block for polystyrene and cumene as the feedstock for phenol produchon [55]. Fthylbenzene was originally produced with a Lewis acid catalyst consishng of AlCfi or a Bronsted acidic solid phosphoric acid (SPA) catalyst [56]. Both catalyst systems suffered from equipment corrosion so, in the 1980s the Mobil-Badger vapor phase alkylation process was introduced, which... 

Another alteration process is alkylation which is used to produce higher octane aviation gasoline and petrochemical feedstock for explosives and synthetic rubber. An isomerization process is also used to produce more material as an alkylation feedstock. 

World War II when the first commercial isomerization processes were introduced to manufacture isobutane as a feedstock for aviation alkylate. The Friedel-Crafts catalysts are highly active at 100°-200°F whereas the conventional platinum-alumina reforming catalysts give reasonable reaction rates only above 850°F. 

Isomerization—A refining process which alters the fundamental arrangement of atoms in the molecule, Used to convert normal butane into isobutane, as alkylation process feedstock, and normal pentane and hexane into isopentane and isohexane, high-octane gasoline components,... 

The role of various elements in the supported catalyst requires additional work to fully understand their function. There is also a dearth of information dealing with the nature of the surface of the newer catalysts subjected to various pretreatment and exposed to model compounds such as alkyl-substituted dibenzothiophene or other feedstocks. There is a need to correlate that data from such characterization with kinetic and mechanistic studies. 

Production of light olefins (propylene, n-butenes and isobutene) will be one of the main targets of FCC untis in the near future. These olefins can be fed to alkylation and etherification units to produce additional high octane environmentally acceptable gasoline components, or used as petrochemical feedstock. Johnson and Avidan (85) used higher amounts of ZSM-5 (10-20%) to increase the production of light olefins, mainly propylene. 

Aluminum Alkyl Chain Growth. Ethyl, Chevron, and Mitsubishi Chemical manufacture higher, linear alpha olefins from ethylene via chain growth on friethylaluminum (15). The linear products are then used as oxo feedstock for both plasticizer and deteigent range alcohols and because the feedstocks are linear, the linearity of the alcohol product, which has an entirely odd number of carbons, is a function of the oxo process employed. Alcohols are manufactured from this type of olefin by Sterling, Exxon, I Cl, BASF, Oxochemie, and Alitsubishi Chemical. 

At the present time, the trend seems to be toward reduced alkylate production and reduction or elimination of propylene as a feedstock. This is based upon currently reduced gasoline demands and high value of propylene as a petrochemical. In any event, if the percentage of butylenes in the feed increases, sulfuric acid alkylation will assume a more clear-cut advantage on the basis of barrel-octane superiority. 

Despite the high selectivity of the reaction, the formation of by-products must be thoroughly monitored since severe specifications are usually imposed on the C4 raffinate (the C4 stream leaving the plant after the isobutene elimination) used later on as a feedstock to alkylation, metathesis or 1-butene extraction (where oxygenates act as poisons). 

Alkyl Formate Production. In the past few years, formate esters have become an important class of organic compounds mainly because of their versatility as chemical feedstock (16,36-42), and as raw materials for the perfume and fragrance industry (43-46). Specifically, formate esters (methyl, ethyl, pentyl, etc.) have been used as starting material for the production of aldehydes (36), ketones ( ), carboxylic acids (37-40), and amides ( ). For example, methyl formate can be hydrolyzed to formic acid (39,40) or catalytically isomerized to acetic acid ( ). On the other hand, alkyl formates have been employed in the perfume and fragrance industry in amounts of approximately 1000 to 3000 Ib/year (43—46). Among the formates that have been commonly used for these purposes are octyl ( ), heptyl ( ), ethyl ( ), and amyl ( ) formates. 

Oxidation of waste plastics, such as polyethylene, polypropylene, polystyrene, poly (alkyl acrylates), and nylon 6,6, with NO/O2 for 16 h at 170°C, led to mixtures of carboxylic acids, for which uses would have to be developed if this method was applied to large volumes of waste plastics.180 Hydrogenation of polyethylene at 150C>C for 10 h over a sil-ica/alumina-supported zirconium hydride catalysts gave a 100% conversion to saturated oligomers.181 Polypropylene gave a 40% conversion to lower alkanes at 190°C for 15 h. It is not clear what use these materials would have, other than serving as a feedstock for a petroleum refinery. 

The light alkenes (propene, butene and pentene) are important feedstocks for alkylation, oligomerization and the synthesis of ethers (refs. 1,2). MTBE (methyl tert-butyl ether) and TAME (tert-amyl methyl ether) have research octane numbers of 118 and 112 respectively. These premium blend stocks are synthesised by reaction of methanol with isobutene or isopentene (refs. 3,4). The reaction with methanol is selective towards the branched alkenes so that a mixture may be treated and the straight chain alkenes recovered for other processing such as alkylation. 

To this end, monodentate phosphine or bidentate PX (X=P, N, O) ligands have usually been employed as ancillary ligands for transition-metal-catalyzed reactions, with bulky tertiary alkyl phosphines proving particularly effective. Significant advances have been achieved in the use of less active aryl chlorides (bond strength C-Cl>C-Br>C-I) as chemical feedstock [5], with a number of processes mediated by palladium-bulky phosphine systems. This success is often explained by the effect of bulk and electron richness at the metal center along the catalytic cycle depicted in Fig. 1 [6]. 

Regardless of the type of linear olefin used as the feedstock, there are three different types of alkylation processes currently available to produce LAB. The differences between the alkylation processes are determined by the type of catalyst used. Until 1990, the most widely nsed alkylation process employed HF acid as the Lewis-type catalyst. In this process, liqnid HF acid is used to catalyze the alkylation of benzene with the linear olefins. A second process involves the use of an aluminum chloride (AICI3) slurry as the catalyst. The presence of water with both HF acid and AICI3 acts as a co-catalyst to transform each of these catalysts into active species. The third and newest commercial alkylation process to produce LAB uses a solid bed catalyst, which eliminates the safety, handling, and disposal issues that are otherwise inherent with the other two processes. 

The LAB product is recovered by distillation. Typically, the distillation scheme is similar to the fractionation section of an HF alkylation unit. Benzene is recovered and recycled along with n-parafflns if n-parafflns are used as the feedstock. The HAB is separated in the third column... 

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