Plant phenol hydrogenation

The adipic acid process is a relatively complex process and essentially contains two plants phenol hydrogenation and KA oil oxidation. We should therefore assume at least four shift positions for each plant, say nine total. For a Northeast Asia basis, we expect that the salary cost per shift position will be lower than the typical 50,000 per year that we would assume for a U.S. Gulf Coast plant. As a first approximation this is estimated as 30,000/y. The remaining salary and overhead costs are fixed following the assumptions given in Section 6.2.4. 

Estimate the fixed capital cost, the working capital, the cash cost of production, and total cost of production for a new 400,000 metric ton per year (400 kMTA) adipic acid plant located in Northeast Asia. The prices of adipic acid, phenol, hydrogen, and nitric acid have been forecasted for Northeast Asia as 1400/MT, 1000/MT, 1100/MT, and 380/MT, respectively. Assume a 15% cost of capital and a 10-year project life. 

The introduction in 1974 of a temporary modification into a well designed and constructed plant, which used the oxidation route, led to a disaster. A bypass line of about 0.5 m in diameter linking two reaction vessels ruptured after 2 months, and over 40 tonnes of cyclohexane, initially at 155°C but with a normal boiling point of 80°C flash evaporated, mixed with air and exploded, killing 28 people and destroying the plant. This disaster at Flixborough, UK, led to a public inquiry. Subsequently, when the plant was rebuilt the alternative process route based on phenol hydrogenation was used. 

Fig. 2.4 Some common simple plant phenolic adds, cinnamic acid derivatives on the right and benzoic acid derivatives on the left, where H equals hydrogen, OH equals hydroxy, and OMe equals methoxy...

In our early attempts to study monoterpene metabolism in peppermint we found that leaf extracts browned badly, and the only enzyme activity we could demonstrate was an uncharacterized phenol oxidase. After several years of frustration we found that the problems were due largely to plant phenolics. Many plant phenolics bind tightly to proteins by hydrogen bonding and are not removed by conventional procedures such as dialysis. 

The recovery area of the plant employs fractionation to recover and purify the phenol and acetone products. Also in this section the alpha-methylstyrene is recovered and may be hydrogenated back to cumene or recovered as AMS product. The hydrogenated AMS is recycled as feedstock to the reaction area. The overall yield for the cumene process is 96 mol %. Figure 1 is a simplified process diagram. 

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. 

Benzene Oxychlorin tion. In the benzene oxychlorination process, also known as the Raschig Hooker process, benzene is oxychlorinated with hydrogen chloride, air, and with the presence of iron and copper chloride catalyst to form chlorobenzene. The reaction occurs at 200—260°C and atmospheric pressure. The chlorobenzene is hydrolyzed at 480°C in the presence of a suitable catalyst to produce phenol and chloride. The yield of phenol is - 90 mol% of theoretical. These plants have been shut down for environmental and economic reasons. 

Production of a-methylstyrene (AMS) from cumene by dehydrogenation was practiced commercially by Dow until 1977. It is now produced as a by-product in the production of phenol and acetone from cumene. Cumene is manufactured by alkylation of benzene with propylene. In the phenol—acetone process, cumene is oxidized in the Hquid phase thermally to cumene hydroperoxide. The hydroperoxide is spHt into phenol and acetone by a cleavage reaction catalyzed by sulfur dioxide. Up to 2% of the cumene is converted to a-methylstyrene. Phenol and acetone are large-volume chemicals and the supply of the by-product a-methylstyrene is weU in excess of its demand. Producers are forced to hydrogenate it back to cumene for recycle to the phenol—acetone plant. Estimated plant capacities of the U.S. producers of a-methylstyrene are Hsted in Table 13 (80). 

Caprolactam. At the same time that Dow was constmcting toluene to phenol plants, Snia Viscosa (28—30) introduced two processes for the manufacture of caprolactam (qv) from benzoic acid. The earlier process produced ammonium sulfate as a by-product, but the latter process did not. In either process benzoic acid is hydrogenated to cyclohexanecarboxyHc acid [98-89-5] which then reacts with nitrosylsulfuric acid to form caprolactam [105-60-2]. 

Dutch State Mines (Stamicarbon). Vapor-phase, catalytic hydrogenation of phenol to cyclohexanone over palladium on alumina, Hcensed by Stamicarbon, the engineering subsidiary of DSM, gives a 95% yield at high conversion plus an additional 3% by dehydrogenation of coproduct cyclohexanol over a copper catalyst. Cyclohexane oxidation, an alternative route to cyclohexanone, is used in the United States and in Asia by DSM. A cyclohexane vapor-cloud explosion occurred in 1975 at a co-owned DSM plant in Flixborough, UK (12) the plant was rebuilt but later closed. In addition to the conventional Raschig process for hydroxylamine, DSM has developed a hydroxylamine phosphate—oxime (HPO) process for cyclohexanone oxime no by-product ammonium sulfate is produced. Catalytic ammonia oxidation is followed by absorption of NO in a buffered aqueous phosphoric acid... 

The gas plant products, namely fuel gas, Cfs, 4, and gasoline, contain sulfur compounds that require treatment. Impurities in the gas plant products are acidic in nature. Examples include hydrogen sulfide (HjS), carbon dioxide (COj), mercaptan (R-SH), phenol (ArOH), and naphthenic acids (R-COOH). Carbonyl and elemental sulfur may also be present in the above streams. These compounds are acidic. 

Takahama, U. Oniki, T. A peroxidase/phenolics/ascorbate system can scavenge hydrogen peroxide in plant cells. Physiol. Plantarum 1997, 101, 845-852. 

Microautoclave data was also obtained with Wilsonville Batch I solvent utilizing Indiana V coal. Batch I solvent was obtained from Wilsonville in mid-1977. Other batches of recycle solvent were received later. Batch I solvent had inspections most like the Allied 24CA Creosote Oil used for start-up at the Wilsonville Pilot Plant. Succeeding batches of solvent received by CCDC showed substantial differences, presumably due to equilibration at various operating conditions. As the Wilsonville solvent aged and became more coal derived, the solvent aromaticity decreased with an increase in such compounds as indan and related homologs. The decrease in aromaticity has also been verified by NMR. A later solvent (Batch III) also showed an increase in phenolic and a decrease in phenanthrene (anthracene) and hydrogenated phenanthrene (anthracene) type compounds. 

MnP catalyzes hydrogen-peroxide-dependent oxidation of Mn to Mn, which in turn oxidizes phenolic components of lignin [102]. Oxidative demethylation, dechlorination, and decolorization of bleach plant effluent by the MnP of Phanerochaete chrysosporium has been demonstrated [103,104]. 

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