Industrial processes phenol

The industrial process for preparing the reagent usually permits a little hydrolysis to occur, and the product may contain a little free calcium hydroxide or basic chloride. It cannot therefore be employed for drying acids or acidic liquids. Calcium chloride combines with alcohols, phenols, amines, amino-acids, amides, ketones, and some aldehydes and esters, and thus cannot be used with these classes of compounds. 

The most widely used industrial synthesis of phenol is based on isopropylbenzene (cumene) as the starting material and is shown m the third entry of Table 24 3 The eco nomically attractive features of this process are its use of cheap reagents (oxygen and sulfuric acid) and the fact that it yields two high volume industrial chemicals phenol and acetone The mechanism of this novel synthesis forms the basis of Problem 24 29 at the end of this chapter... 

Propylation of benzene with propylene, catalyzed by supported phosphoric acid (or related catalysts such as AlCl ), gives cumene [98-82-8] in another important industrial process. Cumene (qv), through the intermediacy of cumene hydroperoxide, is used in the manufacture of phenol (qv). Resorcinol similarly can be made from y -diisopropylbenzene (6). 

One of the industrial processes for the preparation of phenol, discussed in Section 24.6, includes an acid-catalyzed rearrangement of cumene hydroperoxide as a key step. This reaction proceeds by way of an intermediate hemiacetal ... 

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.

The only investigation so far refers to the second reaction of a two-step industrial process, the Hock process, which is used for phenol production world-wide [64]. 

One major problem of the industrial process of phenol methylation is the low yield with respect to methanol, due to its decomposition consequently, a large excess of methanol is usually fed in order to reach an acceptable per-pass conversion of phenol. This aspect, however, is often forgotten in scientific literature, and only... 

While the major emphasis in the analysis of phenols in seawater has been on those compounds introduced by industrial processes, as much phenolic material is probably added by the disintegration of fixed algae in the intertidal regions. A high value for total phenols, particularly in coastal waters, cannot be interpreted simply as a high degree of industrial pollution the kinds of phenols present must also be ascertained. 

Baekeland A process for making organic polymers by reacting phenols with formaldehyde. Based on an observation by A. von Bayer in 1872 and developed into an industrial process by L. H. Baekeland from 1905 to 1909. It was used to make Bakelite, one of the first commercial plastics. The first industrial manufacture began in Germany in 1910. 

The oxidative carbonylation of alcohols and phenols to carbonates can be catalyzed by palladium or copper species [154-213]. This reaction is of particular practical importance, since it can be developed into an industrial process for the phosgene-free synthesis of dimethyl carbonate (DMC) and diphenyl carbonate (DPC), which are important industrial intermediates for the production of polycarbonates. Moreover, DMC can be used as an eco-friendly methylation and carbonylation agent [214,215]. The industrial production of DMC by oxidative carbonylation of methanol has been achieved by Enichem [216] and Ube [217]. 

The rearrangement reaction continues to be of synthetic utility, often involved in industrial processes. Patent references (e.g. Reference 48) refer to the formation of 4-amino phenols. Often the reactant nitro compound is reduced (to the hydroxylamine) in an acid environment so that the two-stage reaction can be accomplished as a one-pot synthesis. 4-Amino phenol itself 45 can be made in high yield directly from nitrobenzene49 and the 4-methoxy aniline derivative 46 similarly from 2-methylnitrobenzene by hydrogenation in MeOH/H2S0450. 

Since the oxidative polymerization of phenols is the industrial process used to produce poly(phenyleneoxide)s (Scheme 4), the application of polymer catalysts may well be of interest. Furthermore, enzymic, oxidative polymerization of phenols is an important pathway in biosynthesis. For example, black pigment of animal kingdom "melanin" is the polymeric product of 2,6-dihydroxyindole which is the oxidative product of tyrosine, catalyzed by copper enzyme "tyrosinase". In plants "lignin" is the natural polymer of phenols, such as coniferyl alcohol 2 and sinapyl alcohol 3. Tyrosinase contains four Cu ions in cataly-tically active site which are considered to act cooperatively. These Cu ions are presumed to be surrounded by the non-polar apoprotein, and their reactivities in substitution and redox reactions are controlled by the environmental protein. 

Phenol and substituted phenol compounds (Fig. 19) are known to be widespread as components of industrial wastes. These compounds are made worldwide in the course of many industrial processes, as for example in the manufacture of plastics, dyes, drugs, and antioxidants, and in the pulp and paper industry. Organophosphorus and chlorinated phenoxyacids also yield chlorinated and nitrophenols as major degradation products. 4-Nitrophenol was reported as a breakdown product after the hydrolysis and photolysis of Parathion in water and chlorinated phenols are formed by the hydrolysis and photolysis of chlorinated phenoxyacid herbicides [251-253]. 

Mat r industries use phenolic materials in their manufacturing processes. Phenol is also used in the production of dmgs, weed killers, and synthetic resins. Phenol and its derivatives are present in the wastewaters of industries such as cooking, pulp mills, paint and dyes, wine distilleries, oil and gasoline, synthetic rabber, textiles, pharmaceuticals, solvent, manufacture of pesticides, paper, and wood etc. [1]. 

Schmidt, R.J. (2005) Industrial catalytic processes-phenol production. Appl. 

Let us recall that by the sol-gel method one can obtain very efficiently very well-defined systems such as Ti silicalite, which can be considered as a single site system where titanium is tetracoordinated in a zeolitic matrix and undergoes epoxidation of propylene or hydroxylahon of benzene to phenol. Bear in mind that it took industry more than 20 years to realize such an industrial processes (Dow-BASF process) [1]). 

The polymerization and crosslinking of phenol-formaldehyde is a highly useful industrial process. However, the reactions that take place are quite difficult to handle in a quantitative manner for a number of reasons. The assumption of equal reactivity of all functional groups in a monomer, independent of the other functional groups in the molecule and of whether the others are reacted, is dubious in this polymerization. Consider, for example, the routes by which trimethylolphenol (XXIb) can be produced in this system ... 

The production of hydroquinone and catechol by TS-1 catalyzed hydroxylation of phenol with H2O2 appeared competitive with respect to existing industrial processes. A new industrial process has been developed based on TS-1 and a plant for the production of 10,000 tons/y of diphenols has been built in Ravenna, Italy [7], It operates since 1986 with excellent results. A plant for the industrial production of TS-1 has also been built to provide the diphenols plant with the required amount of catalyst. 

The production of diphenols from phenol and H2O2 on TS-1 has proved competitive with other industrial processes and a plant has been built which operates since 1986 with excellent results. 

Phenol aldehydes are generally pleasant-smelling products. Some of them are particularly important as fragrance and flavor materials. Anisaldehyde and certain derivatives of protocatechu aldehyde (3,4-dihydroxybenzaldehyde) are well-known representatives. The monomethyl ether of protocatechu aldehyde, vanillin, is perhaps the most widely used flavor material. Other important derivatives of this aldehyde are veratraldehyde (dimethyl ether) and heliotropin (formaldehyde acetal derivative) they are not only used as fragrance and flavor substances, but also are intermediates in many industrial processes. 

Until the late 1890s, coumarin was obtained commercially only from natural sources by extraction from tonka beans. Synthetic methods of preparation and industrial manufacturing processes were developed starting principally from ortho-creso (Raschig process), phenol (Pechmann reaction) and salicylaldehyde (Perkin reaction). Various methods can be used to obtain coumarin from each of these starting materials. In order to be suitable for perfumery uses, synthetic coumarin must be highly pure (Bauer et al., 1988 Boisde Meuly, 1993). 

Before an immobilized enzyme can be used for an industrial process, it is essential to characterize it in terms of its catalytic and kinetic properties. A quantitative assay must be developed to measure the activity, kinetic parameters, and stability of the enzyme. In a coupling reaction, H202 rapidly reacts with phenol and 4-aminoantipyrine (electron donor) in the presence of peroxidase to produce a quinoneimine chromogen (Equation E12.2, Figure El 1.2), which is intensely colored with a maximum absorbance at 510 nm. (This is the same as the product formed in the analysis of cholesterol in Experiment 11.)... 

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