Mitsui process

Early developments were made by Mitsui Shipbuilding and Engineering, Ruhrchemie (molten salts), Kawasaki Heavy Industries and Mitsubishi Heavy Industries [14]. Mitsui processed low-M.W. PE and atactic PP to form ... 

FIG. 17 Schematic of Mitsui process for de-SO, (lower adsorber) and de-NO (upper adsorber). (Adapted from Ref. 58.)... 

Catalytic amination of phenol (7) at 425 °C and around 200 atmospheres has been developed by Mitsui Petrochemical Industries of Tokyo. The nature of the catalyst is unspecified, though various metallic oxides and cocatalysts have been described. One Mitsui process employs a low alkali, weakly acidic alumina catalyst. Mild conditions, high yield and selectivity are claimed. Mitsui operates both the four-step phenol (starting from benzene) and two-step nitrobenzene processes12. 

FIGURE 8.7 Schematic of Mitsui process for removal of SO2 and NO. (Adapted from Tsuzi, K. and Shiraishi, L, Fuel, 76, 549, 1997. With permission.)... 

Figure 2-6 Manufacturing route to poly(lactic acid) according to the Mitsui process.

Mitsui process for the production of polylactide by polycondensation of lactic acid. 

Mitsui Toatsu Chemical, Inc. disclosed a similar process usiag Raney copper (74) shortiy after the discovery at Dow, and BASF came out with a variation of the copper catalyst ia 1974 (75). Siace 1971 several hundred patents have shown modifications and improvements to this technology, both homogeneous and heterogeneous, and reviews of these processes have been pubHshed (76). Nalco Chemical Company has patented a process based essentially on Raney copper catalyst (77) ia both slurry and fixed-bed reactors and produces acrylamide monomer mainly for internal uses. Other producers ia Europe, besides Dow and American Cyanamid, iaclude AUied CoUoids and Stockhausen, who are beheved to use processes similar to the Raney copper technology of Mitsui Toatsu, and all have captive uses. Acrylamide is also produced ia large quantities ia Japan. Mitsui Toatsu and Mitsubishi are the largest producers, and both are beheved to use Raney copper catalysts ia a fixed bed reactor and to sell iato the merchant market. 

The largest production of acrylamide is in Japan the United States and Europe also have large production faciUties. Some production is carried out in the Eastern Bloc countries, but details concerning quantities or processes are difficult to obtain. The principal producers in North America are The Dow Chemical Company, American Cyanamid Company, and Nalco Chemical Company (internal use) Dow sells only aqueous product and American Cyanamid sells both Hquid and sohd monomer. In Europe, Chemische Eabrik Stockhausen Cie, Ahied CoUoids, The Dow Chemical Company, and Cyanamid BV are producers Dow and American Cyanamid are the only suppHers to the merchant market, and crystalline monomer is available from American Cyanamid. Eor Japan, producers are Mitsubishi Chemical Industries, Mitsui Toatsu, and Nitto Chemical Industries Company (captive market). Crystals and solutions are available from Mitsui Toatsu and Mitsubishi, whereas only solution monomer is available from Nitto. 

LARC-TPI is a linear thermoplastic PI which can be processed ia the imide form to produce large-area, void-free adhesive bonds. Mitsui Toatsu Chemicals, Inc., has obtained Hcense to produce this product commercially for appHcations such as adhesives, films, mol ding compounds, etc. These are thermooxidatively stable and show essentially no loss ia weight at 300°C ia air. Weight loss does not exceed 2—3% after isothermal aging ia air at 300°C for 550 h. 

Attempts have been made to develop methods for the production of aromatic isocyanates without the use of phosgene. None of these processes is currently in commercial use. Processes based on the reaction of carbon monoxide with aromatic nitro compounds have been examined extensively (23,27,76). The reductive carbonylation of 2,4-dinitrotoluene [121 -14-2] to toluene 2,4-diaLkylcarbamates is reported to occur in high yield at reaction temperatures of 140—180°C under 6900 kPa (1000 psi) of carbon monoxide. The resultant carbamate product distribution is noted to be a strong function of the alcohol used. Mitsui-Toatsu and Arco have disclosed a two-step reductive carbonylation process based on a cost effective selenium catalyst (22,23). 

Isobutjiene [115-11-7] or tert-huty alcohol can be converted to methacrylic acid in a two-stage, gas-phase oxidation process via methacrolein as an intermediate. The alcohol and isobutjiene may be used interchangeably in the processes since tert-huty alcohol [75-65-0] readily dehydrates to yield isobutjiene under the reaction conditions in the initial oxidation. Variations of this process have been commercialized by Mitsubishi Rayon and by a joint venture of Sumitomo and Nippon Shokubai. Nippon Kayaku, Mitsui Toatsu, and others have also been active in isobutjiene oxidation research. 

The first-stage catalysts for the oxidation to methacrolein are based on complex mixed metal oxides of molybdenum, bismuth, and iron, often with the addition of cobalt, nickel, antimony, tungsten, and an alkaU metal. Process optimization continues to be in the form of incremental improvements in catalyst yield and lifetime. Typically, a dilute stream, 5—10% of isobutylene tert-huty alcohol) in steam (10%) and air, is passed over the catalyst at 300—420°C. Conversion is often nearly quantitative, with selectivities to methacrolein ranging from 85% to better than 95% (114—118). Often there is accompanying selectivity to methacrylic acid of an additional 2—5%. A patent by Mitsui Toatsu Chemicals reports selectivity to methacrolein of better than 97% at conversions of 98.7% for a yield of methacrolein of nearly 96% (119). 

Montedison and Mitsui Petrochemical iatroduced MgCl2-supported high yield catalysts ia 1975 (7). These third-generation catalyst systems reduced the level of corrosive catalyst residues to the extent that neutralization or removal from the polymer was not required. Stereospecificity, however, was iasufficient to eliminate the requirement for removal of the atactic polymer fraction. These catalysts are used ia the Montedison high yield slurry process (Fig. 9), which demonstrates the process simplification achieved when the sections for polymer de-ashing and separation and purification of the hydrocarbon diluent and alcohol are eliminated (121). These catalysts have also been used ia retrofitted RexaH (El Paso) Hquid monomer processes, eliminating the de-ashing sections of the plant (Fig. 10) (129). 

Third-generation high yield supported catalysts are also used in processes in which Hquid monomer is polymerized in continuous stirred tank reactors. The Hypol process (Mitsui Petrochemical), utilizes the same supported catalyst technology as the Spheripol process (133). Rexene has converted the hquid monomer process to the newer high yield catalysts. Shell uses its high yield (SHAC) catalysts to produce homopolymers and random copolymers in the Lippshac process (130). 

Phenol Vi Cyclohexene. In 1989 Mitsui Petrochemicals developed a process in which phenol was produced from cyclohexene. In this process, benzene is partially hydrogenated to cyclohexene in the presence of water and a mthenium-containing catalyst. The cyclohexene then reacts with water to form cyclohexanol or oxygen to form cyclohexanone. The cyclohexanol or cyclohexanone is then dehydrogenated to phenol. No phenol plants have been built employing this process. 

Worldwide, approximately 85% of acetone is produced as a coproduct with phenol. The remaining 17% is produced by on-purpose acetone processes such as the hydration of propylene to 2-propanol and the dehydrogenation of 2-propanol to acetone. The cost of production of 2-propanol sets the floor price of acetone as long as the acetone demand exceeds the coproduct acetone supply. However, there is a disparity in the growth rates of phenol and acetone, with phenol demand projected at 3.0%/yr and acetone demand at 2.0%/yr. If this continues, the coproduct supply of acetone will exceed the total acetone demand and on-purpose production of acetone will be forced to shut down the price of acetone is expected to fall below the floor price set by the on-purpose cost production. Projections indicate that such a situation might occur in the world market by 2010. To forestall such a situation, companies such as Mitsui Petrochemical and Shinnippon (Nippon Steel) have built plants without the coproduction of acetone. 

Esterification ofTerephthalicAcid. Esterification of terephthaUc acid is also used to produce dimethyl terephthalate commercially, although the amount made by this process has declined. Imperial Chemical Industries, Eastman Kodak, Amoco, Toray, Mitsubishi, and Mitsui Petrochemical have all developed processes. Esterification (qv) generally uses a large excess of methanol in a Hquid process at 250—300°C. The reaction proceeds rapidly without a catalyst, but metal catalysts such as zinc, molybdenum, antimony, and tin can be used. Conversion to dimethyl terephthalate is limited by equiHbrium, but yields of 96% have been reported (75,76). 

Most commercial processes produce polypropylene by a Hquid-phase slurry process. Hexane or heptane are the most commonly used diluents. However, there are a few examples in which Hquid propylene is used as the diluent. The leading companies involved in propylene processes are Amoco Chemicals (Standard OH, Indiana), El Paso (formerly Dart Industries), Exxon Chemical, Hercules, Hoechst, ICl, Mitsubishi Chemical Industries, Mitsubishi Petrochemical, Mitsui Petrochemical, Mitsui Toatsu, Montedison, Phillips Petroleum, SheU, Solvay, and Sumimoto Chemical. Eastman Kodak has developed and commercialized a Hquid-phase solution process. BASE has developed and commercialized a gas-phase process, and Amoco has developed a vapor-phase polymerization process that has been in commercial operation since early 1980. 

Figure 10-6. The Mitsui Petrochemical Industries process for producing phenol and acetone from cumene (1) autooxidatlon reactor, (2) vacuum tower, (3) cleavage reactor, (4) neutralizer, (5-11 ) purification train.

CSTR Designs and Use. A patent granted to Mitsui Toatsu Chemicals, Inc. (32 ) describes a styrene polymerization process involving 3 to 5 CSTR s in series. 

Similarly, a catalytic route to indigo was developed by Mitsui Toatsu Chemicals (Inoue et al, 1994) to replace the traditional process, which dates back to the nineteenth century (see earlier), and has a low atom efficiency/high E factor (Fig. 2.15). Indole is prepared by vapour-phase reaction of ethylene glycol with aniline in the presence of a supported silver catalyst. The indole is selectively oxidised to indigo with an alkyl hydroperoxide in the presence of a homogeneous molybdenum catalyst. 

COSMOS [Cracking oil by steam and molten salts] A catalytic process for cracking petroleum or heavy oils. The catalyst is a molten mixture of the carbonates of lithium, sodium, and potassium. Developed by Mitsui and piloted in 1977. 

CP [Continuous polymerization] A continuous process for making high-density polyethylene, based on the Ziegler process but using a much more active catalyst so that de-ashing (catalyst removal) is not required. Developed by Mitsui Petrochemical Industries and upgraded into its CX process, which was first licensed in 1976. 

Hypol A process for making polypropylene, generally similar to Spheripol. Developed by Mitsui Petrochemical Company, Japan. 

Mitsui-Toatsu A high-pressure process for making urea from ammonia and carbon dioxide. Invented in 1967 by Toyo Koatsu Industries. 

MT-chlor [Mitsui Toatsu Chlorine] A process for recovering chlorine from hydrogen chloride. The hydrogen chloride is mixed with oxygen and passed through a fluidized bed of chromia/silica catalyst. Developed by Mitsui Toatsu and first operated in Japan in 1988. See also Deacon, Kel-Chlor. 

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