Industrial processes Mobil-Badger process

Alkylation by zeolites made a major entry in the field of industrial catalysis through the highly acclaimed Mobil-Badger process for ethylbenzene (Csicsery, 1984, Hoelderich et al., 1988 Hoelderich and Van Bekkum, 1991) by replacing the toxic, eco-unfriendly, corrosive Friedel-Crafts reaction. A modified version developed by the National Chemical Laboratory (the Albene process), using a similar class of catalysts known as Encilites, is particularly suited to alkylation by ethyl alcohol of any concentration down to 30% (Bhowmik and Ratnasamy, 1991). 

Thus, zeolites can be used to catalyze Frieael-Crafts alkylation and acylation reactions of aromatics and heteroaromatics. Here, there are a very great number of reactions from a wide range of industrial and university laboratories the most well known one is the Mobil-Badger process. The chosen examples come from the acylation, of heteroaromatics. 

Another method to remove benzene is to react it with propylene or ethylene (benzene alkylation) to produce propylbenzene (cumene) or ethylbenzene. Commercial benzene alkylation processes in the chemical industry have been known for many years. Typically these processes require fairly pure benzene and ethylene feed. The shape selective ZMS-5 catalyst is used as a basis for ethylbenzene synthesis in the Mobil-Badger process (Chen et. al, 1989). ZSM-5 is very selective in this process as a result this process is currently used in the chemical industry to produce about 25% of world s ethylbenzene. Currently there are 12 operating Mobil-Badger EB units including a recent Shell Chemical unit which uses FCC off-gas as the ethylene feedstock source. 

Among the wide variety of organic reactions in which zeolites have been employed as catalysts, may be emphasized the transformations of aromatic hydrocarbons of importance in petrochemistry, and in the synthesis of intermediates for pharmaceutical or fragrance products.5 In particular, Friede 1-Crafts acylation and alkylation over zeolites have been widely used for the synthesis of fine chemicals.6 Insights into the mechanism of aromatic acylation over zeolites have been disclosed.7 The production of ethylbenzene from benzene and ethylene, catalyzed by HZSM-5 zeolite and developed by the Mobil-Badger Company, was the first commercialized industrial process for aromatic alkylation over zeolites.8 Other typical examples of zeolite-mediated Friedel-Crafts reactions are the regioselective formation of p-xylene by alkylation of toluene with methanol over HZSM-5,9 or the regioselective p-acylation of toluene with acetic anhydride over HBEA zeolites.10 In both transformations, the p-isomers are obtained in nearly quantitative yield. 

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... 

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