Industrial Celanese process

Because ibuprofen has been a successful drug on the market for almost 30 years with no patent protection since 1985, there is a widespread competition for commercial production of this product throughout the world. As a result, several practical and economical industrial processes for the manufacture of racemic ibuprofen (14) have been developed and are in operation on commercial scales.38 Most of these processes start with isobutylbenzene (15) and go through an isobutylstyrene3 4 or an acetophenone intermediate.42 The most efficient route is believed to be the Boots-Hoechst-Celanese process, which involves 3 steps from isobutylbenzene, all catalytic, and is 100% atom-efficient (Scheme 6.1).43 44... 

Rhodium, besides cobalt, is the only metal that is used in technical-scale hydroformylation. Because of the classification of industrial hydroformylation processes made by Cornils [1], with rhodium, the third generation, after two generations of Co-based hydroformylation, process was ushered. The first plants went on stream in the 1970s (1974 Ruhrehemie (nowadays Celanese) 1976 Union Carbide Corporation (nowadays Dow) 1978 Mitsubishi Chemical Corporation). These units operate with P-ligand-modified Rh catalysts at low... 

The chemical industry manufactures a large number of antioxidants (qv) as well as uv stabilizers and their mixtures with other additives used to facilitate resin processing. These companies include American Cyanamid, BASE, Ciba—Geigy, Eastman Chemical, Elf Atochem, Enichem, General Electric, Hoechst—Celanese, Sandoz, and Uniroyal, among others. The combined market for these products in the United States exceeded 900 million in 1994 and will reach 1 billion in the year 2000. 

The second PPS process practiced commercially was developed by Kureha Chemical Industry Company. Kureha has built a commercial PPS plant in Nishiki, Fukushima (46), and has formed a joint venture, Fortron Industries, with Hoechst Celanese (47). Fortron Industries has completed a commercial PPS plant at Hoechst Celanese s plant in Wilmington, North Carolina. Fortron Industries represents the only other PPS producer in North America. Figure 3 shows a flow diagram for the Kureha PPS process. 

Acetic acid has been produced in relatively large quantities for more than 100 years. The changes in the methods used for its production over this period reflect some of the underlying general trends in the chemical industry. It was originally produced via fermentation, as were many other organic chemicals in the early days of the chemical industry. The first major synthetic process for acetic acid was based on the hydrolysis of acetylene to acetaldehyde catalyzed by mercuric ion. This process was the dominant method of production for more than 40 years, until 1955— 1960, when two new processes were developed which have dominated the acetic acid markets in the past 20 years. Celanese in the United States and British Petroleum in Europe introduced short-chain paraffin oxida-... 

Butane from natural gas is cheap and abundant in the United States, where it is used as an important feedstock for the synthesis of acetic acid. Since acetic acid is the most stable oxidation product from butane, the transformation is carried out at high butane conversions. In the industrial processes (Celanese, Hills), butane is oxidized by air in an acetic acid solution containing a cobalt catalyst (stearate, naphthenate) at 180-190 °C and 50-70 atm.361,557 The AcOH yield is about 40-45% for ca. 30% butane conversion. By-products include C02 and formic, propionic and succinic acids, which are vaporized. The other by-products are recycled for acetic acid synthesis. Light naphthas can be used instead of butane as acetic adic feedstock, and are oxidized under similar conditions in Europe where natural gas is less abundant (Distillers and BP processes). Acetic acid can also be obtained with much higher selectivity (95-97%) from the oxidation of acetaldehyde by air at 60 °C and atmospheric pressure in an acetic acid solution and in the presence of cobalt acetate.361,558... 

In 1992 BHC (Boots Hoechst-Celanese) Company commercialized a new synthetic process to manufacture ibuprofen in BHC s 3500 metric-ton-per-year facility in Bishop/TX, USA, which was cited as an industry model of environmental excellence in chemical processing technology. For its innovation, BHC was the recipient of the 1997 Alternative Synthetic Pathways Award of the Presidential Green Chemistry Challenge. 

The industrial process for the vapor-phase manufacture of vinyl acetate monomer is quite common (Daniels, 1989) and utilizes widely available raw materials. Vinyl acetate is used chiefly as a monomer to make polyvinyl acetate and other copolymers. Hoechst-Celanese, Union Carbide, and Quantum Chemical are reported U.S. manufacturers. DuPont also currently operates a vinyl acetate process at its plant in LaPorte, Texas. To protect any proprietary DuPont information, all of the physical property and kinetic data, process flowsheet information, and modeling formulation in the published paper come from sources... 

Based on this catalytic principle, ICI and Celanese developed industrial liquid phase processes which led to the construction of large scale plants. Hoechst independently developed a semi-commercial liquid-phase process. 

Improvements in existing processes accompagnied by new techniques. The first edition of this book presented 70 processes. It now discusses 140. Admittedly these are not all innovations. Many of them are different versions of the same chemical reaction or of an already existing separation method. Others, more innovative, only made headway slowly their industrial penetration was hindered by the slowdown in economic expansion new solvents in extractive distillation for benzene production, metathesis of olefins (Shell), olefins for oxo synthesis (Dimersol, Instituc Franfais du Pitrole), adiponitrile by direct hydrocyanation of butadiene (Dm Pont de Nemours), or by the conversion of 1,6-hexanediol (Celanese), laur IIactam from cyclododecane [ATO, Huls). 

Catalyst decomposition is, overall, receiving little attention in academic work on homogeneous catalysis, and only in recent years has research on decomposition and stabilization of organometallic catalysts started to expand (116), with emphasis on reactions of significant commercial interest such as hydroformylation (117), metathesis 118), crosscoupling, and polymerization 119). Ligand decomposition seems to be a key issue for industrial application, because it affects the total number of turnovers, TON. Phosphine decomposition is an unavoidable side reaction in metal-phosphine complex-catalyzed reactions and the main barrier for commercial application of homogeneous catalysts. There are a few exceptions to this statement for example, the rhodium tppts-catalyzed hydroformylation of propene, a process developed by Ruhrchemie-Rhone Poulenc (now Celanese). 

A recent study indicates that if the Wacker process proves to be substantially cheaper than the acetylene route, no more vinyl acetate plants will be built in the United States, based on the latter process (38). Table XV gives estimated production costs for manufacturing vinyl acetate. Several companies are building or have already built plants to manufacture vinyl acetate from ethylene. These include Distillers Co., Ltd., British Celanese, Imperial Chemical Industries, and Celanese Corp., to name only a few. 

Moving from a fixed to a fluidised operation also required a new catalyst. The selected VAM catalyst was an Au/Pd mix in the form of very fine spheres, so miniscule that they seem to flow almost as liquid, prepared in collaboration with the leading catalyst manufacturer Johnson Matthey. Hence, gold-based nanocatalysts are already being used for this process on an industrial scale. Fixed bed processes based on Au/Pd catalysts have been operated for some time by companies such as Celanese and Dupont. 

Vectra . [Hoechst Celanese/Engineer-ing Plastics Hoechst UK] Liq. crystal polymers, some mineral, glass, carbon fill used in electronics, fiber optics, automotive, aircraft/aerospace, chem. processing, industrial, mfg. fields, encapsulation of electronic ctunponents. 

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