Propylene alkylates

Propylene. Propylene alkylation produces a product that is rich in dimethylpentane and has a research octane typically in the range of 89—92. The HF catalyst tends to produce somewhat higher octane than does the H2SO4 catalyst because of the hydrogen-transfer reaction, which consumes additional isobutane and results in the production of trimethylpentane and propane. 

Alkenes, Cyclic Alkenes, and Dienes Alkenes, Cyclic Alkenes, and Dienes Ethylene Propylene Alkyl Halides Alkynes Aluminum Americium Amides Amides Carbofuran Dimethyl Acetamide Amines Antimony... 

One of the major items contributing to the high processing cost is the cost of the catalyst consumed. This is particularly true for propylene alkylation, where the catalyst cost is about 2.5 to 3.0 cents per gallon of alkylate produced. Several courses that research might follow in order to reduce catalyst consumption would be the development of a more efficient reactor, a more efficient catalyst, or an additive which would retard catalyst degeneration. 

Disproportionation of primary Cy alkylate (from propylene) with isobutane under alkylation conditions probably accounts for the near-equal amounts of isopentane and isohexanes found in propylene alkylate. 

Thus, propylene dimerization could result in the formation of both isohexanes and isooctanes. However, little propylene dimerization is thought to take place since It should result in the formation of mainly 2,3-dlmethyl-butane a small amount of this isohexane is found in propylene alkylate. 

Cracking or scission of large Ions Is believed to be of minor significance. Both of the products (there are others) are subject to further reaction under alkylation conditions and can account for a number of Isoparaffins commonly formed In propylene alkylate In minor amounts. 

TABLE II. SmiLAaiTY OF Cg FRACTIONS IN ISOBUTENE AND PROPYLENE ALKYLATES... 

Reducing side reactions does not always mean greatly improved octane ratings. Propylene alkylate was only slightly improved at the low temperature, because the hydrogen transfer reaction was inhibited along with undesirable side reactions. 

If cooling is not provided in the settler, the temperature may rise, apparently due to continued reaction, as often is the case in the alkylation settlers in propylene alkylation. 

However, production of xylenols from isomeric xylene mixtures or individual isomers via propylene alkylation has not been attempted so far, neither established commercially nor even been tried in a laboratory or pilot plant. As in benzene and toluene alkylation processes it has been reported that Mitsubishi Gas Chemical Co., Japan obtained 3,5 xylenol by oxidation of 3,5-dimethyl cumene by alkylation of m-xylene with propylene to 3,5-dimethyl cumene hydroperoxide and thereafter its cleavage to 3,5-xylenol. Economics of the process did not justify its commercialization [1,38]. 

However, from economic and environmental point of view both USA and Japan use the propylene alkylation route, as this method of manufacture is more amenable to continuous operations with recycle stream. The alkylation with propylene and isomerization are carried out upto 240° C with traditional solid phosphoric acid (SPA) catalyst and more recently with anhydrous AICI3 catalyst. Final catalytic oxidation at 90-110°C gives the hydroperoxide, as in cumene and cymene processes, which on cleavage with dilute sulfuric acid gives 2-naphthol in high overall yield. [53]... 

Diamiet. [Kao Corp. SA] Edioxylated propylene alkyl fatty diamine emulsifier, dispersant, corrosion inhibitor, wetting agent... 

A variety of other copolymers have been studied including propylene-but-l-ene (by C n.m.r.), ethylene-vinyl acetate ( H), propylene-alkyl acrylates ( H, C), isobutylene- -pinene ( H, C), isobutylene-trifluoro-... 

Fig. 3.8 Plot of melting temperature against volume fraction of polymer for isotactic poly(propylene)-alkyl phenol mixtures. (From Nakajima and Fujiwara (24))...

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