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The typical hydrofluoric acid (HF) alkylation unit requires far less acid than a sulfuric acid unit to achieve the same volume of alkylate. The HF process only creates a small amount of organofluorine side products which are continuously removed from the reactor and the consumed HF is replenished.
Hydrogen fluoride (HF) and aluminium chloride (AlCl 3) are the two major catalysts for the alkylation of benzene with linear mono-olefins. The HF-based process is commercially dominant; however, the risk of releasing HF (a poisonous substance) into the environment became a concern particularly after the Clean Air Act Amendment. In 1995, a solid ...
The company invented an HF alkylation process in 1940. [13] The American petrochemical industry took off, first making such as styrene , ethylene , propylene and butadiene . [ 2 ] After the war, it formed a subsidiary, Phillips Chemical Co., which entered the fertilizer business by producing anhydrous ammonia from natural gas. [ 14 ]
Alkylation in petroleum refining is a process through which olefins and parafins are combined to form high molecular weight isoparaffins. [3] Alkylation uses hydrofluoric acid (hf acid), a highly corrosive substance that dissolves a wide range of materials, particularly the oxides. Monel valves are generally used in the most critical phases of ...
The process involves dehydrogenation of n-paraffins to olefins, and subsequent reaction with benzene using HF as catalyst. For example, in oil refineries "alkylate", a component of high- octane petrol ( gasoline ), is generated in alkylation units, which combine C 3 and C 4 olefins and iso -butane .
Because, however, the product ketone forms a rather stable complex with Lewis acids such as AlCl 3, a stoichiometric amount or more of the "catalyst" must generally be employed, unlike the case of the Friedel–Crafts alkylation, in which the catalyst is constantly regenerated. [13] Reaction conditions are similar to the Friedel–Crafts ...
Similalrly, Hf(OTf) 4 shows excellent activity in Friedel-Crafts alkylation’s, and enabled the alkylation of benzene with benzylic and tertiary alkyl chlorides. Hf(OTf) 4-catalyzed Friedel-Crafts alkylation has been utilized in the total synthesis of the altertoxin III framework. This approach provided a more efficient synthesis of the fused ...
Transalkylation reactions of six to ten carbon methylated aromatics are often performed with the cofeed of hydrogen gas, over a zeolite based solid catalyst. Industrial processes operate the transalkylation reactor at elevated temperature and pressure to achieve desired process economics.