Phenol manufacture

For the organic contaminants, the required bromine product quality wilt also be site specific. If the catalytic oxidation unit is dedicated to a single bromination process, phase separation and drying may be the only purification required. Contaminants in the recovered bromine which are either the starting materials or products of the original bromination reaction should not present a problem if present in bromine recycled to the bromination reactor. In this case, the catalytic reactor would be operated to minimize the formation of undesirable brominated byproducts. For example, if phenol is present in the waste HBr from a tribromo-phenol manufacturing process, minor tribromophenol contamination of the bromine recycled to the reactor should not be a problem. Similarly, fluorobenzene in bromine recycled to a fluorobenzene bromination process should not present a problem. 

U.S. consumption pattern 1999, 3 619t U.S. producers, 3 610t vapor-phase nitration of, 17 257 vinyl chloride reactions with, 25 632 world production by country, 3 611-612t Benzene-based catalyst technology, 15 500 Benzene-based fixed-bed process technology, 15 505-506 Benzene chlorination process, of phenol manufacture, 18 751 m-Benzenedisulfonic acid, 3 602 p-Benzenedisulfonic acid, 3 602 Benzene feedstock, 23 329 Benzene hexachloride, 3 602 Benzene manufacture, toluene in, 25 180-181... 

Benzene oxychlorination process, of phenol manufacture, 18 751 Benzeneperoxyseleninic acid, 13 466 Benzene rings, in liquid crystalline materials, 15 103-104 Benzene sulfonation process, of phenol manufacture, 18 751 Benzenesulfonic acid, 3 602 Benzene-toluene fraction, in styrene manufacture, 23 341-342 Benzene-toluene-xylene (BTX), 10 782 ... 

Cleavage products, 10 569 Cleavage reaction, in phenol manufacture, 25 749-750 Cleavage tests, 2 514 (+)-Cleavamine, 2 98 Clenbuterol, 23 14-15 Clentiazem, 5 121... 

Toluene-benzoic acid process, of phenol manufacture, 18 750 Toluene diamine (TDA), 13 797 Toluenediamine (TDA), 25 189-201. See also Toluenediamines chain extenders for, 25 197 derivatives of, 25 196-197 diazotization of, 25 192 health and safety factors related to, 25 196... 

The most prominent wood adhesives used over the last quarter of a century have been aminoplast and polyphenolic types (2). In the United States, polyphenolic adhesives continue to be predominantly used for production of weather-resistant wood products, such as structural plywoods and flake boards (3). Phenolic resin prices have increased over the past decade, generally paralleling phenol prices. This increase has occurred in part due to a continuing erosion of United States phenol manufacturing capacity and the corresponding increase in availability of phenol from other countries. Any significant increase in the price of oil (the source of phenol) itself or interruption in supply will only compound the problem and raise phenol prices even higher. 

Chlorobenzene. Chlorobenzene is an important solvent and intermediate in the production of chemicals and dyes. Its use in phenol manufacture, however, was superseded by the introduction of the cumene process. 

Phenol and its compounds are ubiquitous water pollutants that are present in the effluents of a variety of chemical industries such as coal refineries, phenol manufacturing, pharmaceuticals, and industries of resin, paint, dyeing, textile, leather, petrochemical, pulp mill, etc. [9]. Phenols are known to be toxic and also, some of them, hazardous carcinogenic that can accumulate in the food chain. Phenolic compounds are a public health risk and they are heavily regulated in many countries, and must be removed from wastewater before they are discharged into the environment [10], For example, a 10 days consumption of polluted water with low concentrations (3 ppm) of 2,4-dichlorophenol can cause vomiting, paralysis, and even death in children [11, 12]. Phenol, 2-chlorophenol, and 2,4-dichlorophenol are ranked within the 250 most hazardous pollutants [13]. In addition, chlorophenols are commonly found in chlorinated water, since phenol can react with chlorine [14],... 

Production of monochlorobenzenes peaked in the 1960s with production volume at about 600 million lb. It was down to 152 million lb in 1998. The most significant cause for the decline is the replacement of monochlorobenzene by cumene as the preferred raw material for phenol manufacture. Other reasons include the elimination of the herbicide DDT, the change of diphenyl oxide process from chlorobenzene to phenol and a significant drop in solvent use. The production volume for ODCB and PDCB were 50 and 91 million lb, respectively, in 1998. 

Components produced in lowyield that have high value. Dicyclopentadiene can be recovered from the products of steam naphtha cracking. Acetophenone is recovered as a byproduct of phenol manufacture, although it can also be made by oxidation of ethylbenzene or fermentation of cinnamic acid. 

Acetone is obtained by fermentation as a by-product of -butyl alcohol manufacture, or by chemical synthesis from isopropyl alcohol from cumene as a by-product in phenol manufacture or from propane as a by-product of oxidation-cracking. 

Derivation (1) Purification of natural sodium sulfate from deposits or brines (2) by-product of hydrochloric acid manufacture from salt and sulfuric acid, 2NaCl + H,S04 2HC1 + Na,S04 (3) byproduct of phenol manufacture (caustic fusion process) (4) Hargreaves process. 

This process, which reached the commerdal stage between 1914 and 1918, is now the earliest phenol manufacturing technique still used on the industrial scale (one plant in Japan). Its popularity is largely due to the quality of the phenol obtained, whose purity, which was difficult to obtain by the new processes until relatively recently, was highly desirable for the synthesis of dyes. 

Fig. 10.1. Phenol manufacture by oxychlorinaiion of benzene. llooker/Raschig process.

Based on purchased cumene, t Credit given for by-products, t Phenol manufacturing facilities only. 

Note that by-products can have a major influence on the economics of a chemical process. Phenol manufacture provides a striking example of this. The original route, the benzenesulphonic acid route, has become obsolete because demand for its by-product sodium sulphite (2.2 tonnes/1 tonne phenol) has dried up. Its recovery and disposal will therefore be an additional charge on the process, thus increasing the cost of the phenol. In contrast the cumene route owes its economic advantage over all the other routes to the strong demand for the by-product acetone (0.6 tonnes/1 tonne phenol). The sale of this therefore reduces the net cost of the phenol. 

An example of the failure to recognize the need for change and the (almost) disastrous consequences is afforded by the watch-making industry. The Swiss had almost reached perfection in the manufacture of mechanical and automatic watches and not surprisingly dominated the industry. They ignored the development of the electronic watch in Japan and almost paid the ultimate price, but fortunately realized the error of their ways and adapted in the nick of time. Examples from the chemical industry include the changing routes to vinyl chloride monomer (section 3.5.1) and phenol manufacture. 

The specifications for the quality of phenol are based on its downstream application. The phenol content is generally over 99%, the water content below 0.1%. For 8-caprolactam and bisphenol A production, only a low level of carbonyl compounds is in fact tolerable. The nature of by-products accordingly depends on the respective synthesis route. Phenol produced from cumene contains acetophenone and a-methylstyrene as co-products. Phenol manufactured by the Raschig method contains small amounts of chlorophenol tar phenols contain minor proportions of nitrogen and sulfur components. 

The polymer applications of wollastonite are mainly based on its combination of acicularity, chemical inertness, whiteness and low water adsorption. Primary consuming polymers include thermoplastics, such as polypropylenes and polyamides, and thermosets, snch as polyester dough and sheet-moulding compounds, epoxies and phenolics. Manufacturers are predicting considerable growth in reinforced reaction injection moulding (RRIM) systems. 

This alternative route is similar to the process for resorcinol production, the only difference being the use of the respective diisopropylbenzene (DIPB) isomers. Hydroquinone or resorcinol is produced from p-DBPB or m-DlPB, respectively, according to the dihydroperoxide reaction. In other words, hydroquinone and resorcinol can be produced alternatively in the same manufacturing plant when the reaction processes are designed for alternatively producing the m- and p-DIPB isomers. In addition, diisopropylbenzenes (DIPBs) are by-products from the process of cumene production in phenol manufacture. 

The chief outlets are for polyurethane (di-isocyanates) 40%, rubber chemicals, herbicides minor users include dye makers (approx. 5%) and pharmaceutical manufacturers. Benzene is the feedstock and the traditional route is to nitrate this and then to reduce the nitrobenzene to aniline. Catalytic hydrogenation has displaced iron/ferrous chloride reduction in this and analogous reductions e.g. in the manufacture of toluidines. Amination of phenol manufactured from cumene (Vol. I, p. 366) has been patented (Figure 2.8). The yield claimed is 99% though the economic viability is uncertain. 

The reaction of formaldehyde with unsubstituted phenols leads to either soluble or cross-linked resins since condensation occurs at either ortho or para positions. Monosubstituted [35] (ortho or para) phenols give cross-linking with difficulty but phenols doubly substituted in ortho or para positions yield only low molecular weight products. If only one ortho or para position is available on the phenol then the phenol cannot produce resins and reacts with difficulty with aldehydes [33]. Sometimes cresols and phenol are blended together to obtain fully cured resins. In addition to phenol, the other important phenols that are used to give phenolic resins are o-cresol, mixed cresols, / -/e/ r-butylphenol (from isobutylene and phenol), p-phenylphenol (by-product from phenol manufacture), resorcinol, and cardanol (from cashew nutshell liquid). 

Phenolics Manufacturer s recommendations Not recommended for use in mouse and rat colonies by laboratory animal care workers, but have not been able to document specific objections for this in the literature... 

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