Alkylated phenol feedstocks

These condensation products are of low molecular weight (consisting of a small number of monomer units) and are therefore considered to be oligomer resins (not high polymers). Because the alkylated phenol feedstocks are alkylated at the para position, they produce non-heat-reactive resins that are not thermosetting. 

Alkylation. Benzene and phenol feedstocks are readily alkylated under Friedel-Crafts conditions to prepare extensive families of alkylated aromatics. These materials generally are intermediates in the production of surfactants or detergents such as linear alkylbenzenesulfonate (LABS) and alkylphenolethoxylate (APE). Other uses include the production of antioxidants, plasticizers, and lube additives. 

About 45% of phenol is used as a feedstock to produce bisphenol A. Another 30% is used to produce phenolic resins. An additional 10% is used to make caprolactam. About 2% is used to produce aniline. Phenol is used as a feedstock to produce alkyl-phenols such as /hnonylphenol and p-dodecylphenol. In addition, it is used to make xylenols as well as adipic acid and salicylic acid. Phenol is used in the synthesis of various dyes and biocides. 

The reachon of benzene with ethylene or propylene to form ethylbenzene or isopropylbenzene (cumene) is an industrially important transformahon, with ethylbenzene as the key building block for polystyrene and cumene as the feedstock for phenol produchon [55]. Fthylbenzene was originally produced with a Lewis acid catalyst consishng of AlCfi or a Bronsted acidic solid phosphoric acid (SPA) catalyst [56]. Both catalyst systems suffered from equipment corrosion so, in the 1980s the Mobil-Badger vapor phase alkylation process was introduced, which... 

The higher yields represent improvements in alkylation efficiency and better utilization of the benzene feedstock. The higher purities improve the efficiencies of downstream technologies, so that ultimately less energy is consumed in the styrenic and phenolic chains for producing plastic products. Another important factor is that the zeolitic catalysts are more environmentally friendly materials than aluminum chloride and SPA. 

The major industrial products from benzene are alkylated derivatives such as ethylbenzene and cumene, which are used as basic materials for the production of styrene and phenol, and long-chain alkylbenzenes, which are used as feedstocks in the manufacture of surfactants. 

Phenol production is typically carried out by add induced conversion of cumene hydroperoxide to phenol and acetone (Hock process). Cumene hydroperoxide is obtained by oxidation of cumene. The cumene feedstock for the latter reaction is provided by Friedel-Crafts alkylation of benzene with propene. Alternative routes (chlorobenzene hydrolysis, cydohexanol dehydrogenation, oxidative decarboxylation of benzoic acid) exist but are of much lower industrial relevance. 

Tertiary butyl phenol is produced from the catalytic alkylation of phenol with olefin feedstocks from petroleum cracking, Figure 11.38. 

The production of many organic compounds requires the use of a variety of industrial processes and feedstock chemicals (Wise and Fahrenthold, 1981). This results in wastewater that contains a range of aromatics including benzene, toluene, ethylbenzene, chlorinated benzenes, and nitrobenzenes. It is also known that the production of most resins (acrylic, epoxy, alkyl, polypropylene, and phenolic polyester) requires the use of monomers, which again leads to discharge of benzene, toluene, and ethyl benzene. The same may be said about the production of polycarbonates, polyester, and styrene. 

As might be expected, the type of feedstock chemical and industrial process play a key role in determining the presence of phenols in wastewater. For example, the nitration of benzene and toluene to produce nitrobenzene and dinitrotoluene also leads to the incidental formation of nitrophenol, dinitrophenol, and dinitro-o-cresol. Similarly, alkylphenols and methyl-phenols may be produced during alkylation and solvent extraction of toluene, xylene, and Cg-Q alkylphenols. Wise and Fahrenthold (1981) suggested that most industrial processes were not sources of priority pollutants because the processes do not involve critical precursor/process combinations. In addition, synthetic production methods generally lead to an increase in complexity of priority pollutant molecules. These in turn exhibit variable toxicity and persistance, which may be comparable to related priority pollutants. 

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