Phenols from cumene

The yield of acetone from the cumene/phenol process is beUeved to average 94%. By-products include significant amounts of a-methylstyrene [98-83-9] and acetophenone [98-86-2] as well as small amounts of hydroxyacetone [116-09-6] and mesityl oxide [141-79-7]. By-product yields vary with the producer. The a-methylstyrene may be hydrogenated to cumene for recycle or recovered for monomer use. Yields of phenol and acetone decline by 3.5—5.5% when the a-methylstyrene is not recycled (21). 

Synthetic phenol capacity in the United States was reported to be ca 1.6 x 10 t/yr in 1989 (206), almost completely based on the cumene process (see Cumene Phenol). Some synthetic phenol [108-95-2] is made from toluene by a process developed by The Dow Chemical Company (2,299—301). Toluene [108-88-3] is oxidized to benzoic acid in a conventional LPO process. Liquid-phase oxidative decarboxylation with a copper-containing catalyst gives phenol in high yield (2,299—304). The phenoHc hydroxyl group is located ortho to the position previously occupied by the carboxyl group of benzoic acid (2,299,301,305). This provides a means to produce meta-substituted phenols otherwise difficult to make (2,306). VPOs for the oxidative decarboxylation of benzoic acid have also been reported (2,307—309). Although the mechanism appears to be similar to the LPO scheme (309), the VPO reaction is reported not to work for toluic acids (310). 

Dihydroxyarenes can be produced from the corresponding diisopropylarenes in a manner similar to the production of phenol from cumene (206,311-315). 

Much work on the hydroperoxidation of triisopropylbenzene to make phloroglucinol, similar to the process of phenol from cumene, has been reported (149—155). The shortest route is based on readily available 4-chlororesorcinol. World production of phloroglucinol is estimated to be in excess of 200 metric tons aimuaHy (156). 

By far the preponderance of the 3400 kt of current worldwide phenolic resin production is in the form of phenol-formaldehyde (PF) reaction products. Phenol and formaldehyde are currently two of the most available monomers on earth. About 6000 kt of phenol and 10,000 kt of formaldehyde (100% basis) were produced in 1998 [55,56]. The organic raw materials for synthesis of phenol and formaldehyde are cumene (derived from benzene and propylene) and methanol, respectively. These materials are, in turn, obtained from petroleum and natural gas at relatively low cost ([57], pp. 10-26 [58], pp. 1-30). Cost is one of the most important advantages of phenolics in most applications. It is critical to the acceptance of phenolics for wood panel manufacture. With the exception of urea-formaldehyde resins, PF resins are the lowest cost thermosetting resins available. In addition to its synthesis from low cost monomers, phenolic resin costs are often further reduced by extension with fillers such as clays, chalk, rags, wood flours, nutshell flours, grain flours, starches, lignins, tannins, and various other low eost materials. Often these fillers and extenders improve the performance of the phenolic for a particular use while reducing cost. 

Phenol formed in the system due to acid-catalyzed decomposition of hydroperoxide retards the cumene oxidation. The aqueous phase withdraws phenol from the hydrocarbon phase. This is the reason why the emulsion oxidation of cumene helps to increase the yield of hydroperoxide. The addition of hydrogen peroxide into the system helps to increase the yield of hydroperoxide. 

Hercules-BP A process for making phenol from cumene, based on processes first developed by Hercules and BP and engineered by Kellogg International Corporation, and first installed at Montreal, PQ, in 1953. By 1993, more than half of the world s production of phenol was made by this process. 

Phenol has been obtained by distillation from petroleum and synthesis by oxidation of cumene or toluene, and by vapor-phase hydrolysis of chlorobenzene (USITC 1987). In 1995, 95% of U.S. phenol production was based on oxidation of cumene except at one company that used toluene oxidation and a few companies that distilled phenol from petroleum (CMR 1996). In 1995 the total annual capacity of phenol production approached 4.5 billion pounds (CMR 1996). 

Delaney JL, Hughes TW. 1979. Source Assessment Manufacture of Acetone and Phenol from Cumene. Prepared by Monsanto Research Corp., Dayton, OH. EPA-600/2-79-019D. NTIS PB80-150592, 500. 

Since zeolite catalysts are successfully introduced in the refining and petrochemical industries, it is not surprising that most of the recent advances concern incremental improvements of existing processes with the development of new generations of catalysts (e.g., dewaxing, ethylbenzene and cumene synthesis). The number of newer applications is much more limited, for example, direct synthesis of phenol from benzene and aromatization of short-chain alkanes, etc. However, both the improvement and development of processes contribute significantly to environmental advances. 

Give the equations of reactions for the preparation of phenol from cumene. 

As we learned in Chapter 8, the official production of propylene is usually about half that of ethylene, only because a large part of the propylene is used by petroleum refineries internally to alkylate gasolines. This captive use is not reported. Of the propylene used for chemical manufacture, nearly 40% is polymerized to polypropylene, to be discussed in a later chapter. Of the remaining amount of propylene, seven chemicals from the top 50 are manufactured. These are listed in Table 10.1. Their industrial manufacturing methods are summarized in Fig. 10.1. Note that four of these chemicals, cumene, phenol, acetone, and bisphenol A, are also derived from a second basic organic chemical, benzene. 

Presently there are two processes that make acetone in large quantities. The feedstock for these is either isopropyl alcohol or cumene. In the last few years there has been a steady trend away from isopropyl alcohol and toward cumene, but isopropyl alcohol should continue as a precursor since manufacture of acetone from only cumene would require a balancing of the market with the co-product phenol from this process. 

Major markets as solvents and intermediates have made the ketones important commercial products lor many years. Acetone and mcthylethyl ketone have had the most impact on the chemical industry Acetone Is used s an intermediate In methyl isobutyl ketone, methyl methacrylate, diucelonc alcohol. ketone. hisphenol-A. phiwnc. and mesityl oxide Acetone is largely produced by dehydration of isopropyl alcohol In the production of phenol from cumene, acetone is produced as a by-product This mute to acetone has tended to control its price. 

Acetone is the ketone used in largest quantity and is produced as a by-product of the manufacture of phenol via cumene. Manufacture from iso-propanol is by the reaction ... 

Phenol from cumene (zeolite catalyst) UOP/ABB Lummus MMlb/y 200 600 6.192 0.6... 

Besides the above CD processes, some of the recent novel applications of CD are outlined below. The production of amines from the hydrogenation of aniline and the selective production of diethanolamine from the reaction of monoethanolamine and ethylene oxide have been reviewed. A patent on the production of phenol from cumene hydroperoxide disclosed that solid acid catalysts such as zeolites, ion-exchange resins achieved 100% conversion with about 60 /o selectivity to phenol at 50-90°C and 0-10 psig. This process utilizes the heat of the decomposition of cumene hydroperoxide to effect the separation of the lower boiling components and hence reduces the energy cost and carbon dioxide emissions. 

Production of cymenes or isopropyl toluene from toluene and propylene is an adaptation of cumene process from benzene and propylene. Through hydroperoxidation of cumene and cleavage of the resultant molecule, phenol and acetone are produced. 

It has been recently announced that technology for separation of para- and meto-cymenes is offered by Chiyoda Corporation in Yokohama, Japan through Kellog. As in the case of phenol from benzene via cumene, acetone is obtained as a co-product during production of cresols from toluene via cymenes. 

HoUow-fiber SLMs have been used in the removal of phenol from aqueous matrices. Kujawski et al. [142, 143] studied polypropylene membranes impregnated with methyl-terbutyl ether, cumene, and/or a mixture of hydrocarbons. With Cyanex 923 (a mixture of trialkylphosphine oxides), the recoveries of phenol reached of 98% into the stripping phase from the 0.2 mol.dm solution of caustic soda [144, 145]. Carriers for phenol removal from wastewaters have included hnear monoalkyl cyclohexane [146], N,N-di(l-methyl heptyl) acetamide [147], dibenzo-18-crown-6 [148], dodecane [149], trioctylamine [150], and N-octanoylpyr-rolidine [151]. Many diluents and carriers are of synthetic origin, and so their application carries with issues of flammabUity, volatility, toxicity, and potential detrimental effects to the environment and the health of the human population [152]. 

With worldwide phenol consumption exceeding 5 million tons in 1995, optimizing production routes of this essential chemical becomes very important. As an alternative to the traditional cumene process, a one-step-synthesis of phenol from benzene is highly desirable. With a ZSM5 type zeolite in its acid form as catalyst and nitrous oxide as oxidant, benzene may be directly oxidized to phenol [1-4] ... 

Reading, W. W, How DOW makes phenol from toluene", Hydrocarbon Processing, 43 (11) 173-176 (1964). Pecka, L, Singer, P., Cumene/phenol purifreation by fractions melting" Europ. Chem. News, Large Plant SuppL, 82-84, (27 SepL 1968).. ... 

Fleming J. B Lambrix, J. R, Nixon, J. R,-1 Safety in phenol from cumene process , Hydrocarbon Processing, 55(1) 185-196(1976). ... 

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