Phenol consumption

The most important commercial chemical reactions of phenol are condensation reactions. The condensation reaction between phenol and formaldehyde yields phenoHc resins whereas the condensation of phenol and acetone yields bisphenol A (2,2-bis-(4-hydroxyphenol)propane). PhenoHc resins and bisphenol A [80-05-7] account for more than two-thirds of U.S. phenol consumption (1). 

Figure 2. Ratio of peak areas of the phenolated lignin to unreacted phenol as an index of phenol consumption during phenolysis.

Bisphenol. Bisphenol-A (4,4 -isopropyli-dene-diphenol) accounts for 35 percent of phenol consumption and is used mainly in the production of polycarbonates (55%) and epoxy resins (25%), two of the fastest-growing families of plastics. Other uses are in the manufacture of flame retardant such as tetrabromobisphenol-A, polysulfone resins, and polyacrylate resins. The consumption of bisphenol in the United States in 1999 topped 2.1 billion lb. 

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] ... 

The model pollutant, phenol, is photo-converted via a first order or pseudo-first order reaction consistent with equation(l-14) considering in this manner all possible sources of phenol consumption. 

Typical diagrams for phenol degradation by immobilized cells in discontinuous reaction runs are shown in Figures 5 and 6. The different lines in Fig. 5 refer to different cell concentrations, while in Fig.6 different reaction temperatures are compared. The phenol consumption rate, obtained from the slopes of these lines, divided by Xgct gives the effective specific activity of the cells in the immobilized state ... 

While the absolute value of phenol consumption rate obviously increases with increasing cell concentration, the effective specific activities are drastically decreasing, as can be seen from the legend of Figure 6. This is a typical indication for transport limitation in heterogeneous catalysis, a problem which requires a more detailed analysis to describe properly the experimental findings on catalytic efficiency in immobilized cell catalysis (8,22,24). 

Depending on the initial cell concentration, an increase of cell concentration up to a factor of 11.1 could be obtained. Increase in cell concentration Xact Qfi erally enhances phenol degradation, however, the increase of Xa(--(. leads to an increase of the Thiele modulus ji, therefore, decreasing the catalytic efficiency . So the maximum increase of absolute phenol consumption rate of 2.5 is not at all coupled to the maximum value cell concentration increase (see Table V). 

Equation 14 can be solved analytically for the initial reaction rate of a metal ion catalyzed reaction between phenol and methanal. This yields an equation for both methanal and phenol consumption that is only dependent on one conversion variable. Figure 4 shows the dependence of the rate constants on the ionic radius of the hydrated cation, based on equation 14. The formation of the chelate complex between methanal, phenol and the metal ion is the slowest reaction step (see Scheme 3). Therefore, one can observe a second order kinetic law analyzing the kinetic data. 

Make up chemical oxidizing agents very occasionally and only for detoxication or polishing treatments (traces of a few milligrams per liter of CN" or phenols). Consumption is never limited to the hannfiil compound alone, other copollutants O2 demand can increase the stoichiometry five or ten fold (see Chapter 5). 

The absorption at 1260cm , attributed to the Aryl-O-Alkyl ether group, can also provide quantification of vitamin E in untreated UHMWPE [73, 76], but with lower sensitivity. In addition, this absorption does not disappear completely upon irradiation (probably because it is converted into an Alkyl-O-Alkyl ether), being less reliable in evaluating the phenol consumption. 

E. Richaud. Kinetic modelling of phenols consumption during polyethylene thermal oxidation. European Polymer Journal 49(8), 2223-2232, August 2013. 

Phenohc resins are produced by the condensation of phenol or a substituted phenol, such as cresol, with formaldehyde. These low cost resins have been produced commercially for more than 100 years and in the 1990s are produced by more than 40 companies in the United States. They are employed as adhesives in the plywood industry and in numerous under-the-hood appHcations in the automotive industry. Because of the cycHc nature of the automotive and home building industry, the consumption of phenol for the production of phenohc resins is subject to cycHc swings greater than that of the economy as a whole. 

In 1993, worldwide consumption of phenoHc resins exceeded 3 x 10 t slightly less than half of the total volume was produced in the United States (73). The largest-volume appHcation is in plywood adhesives, an area that accounts for ca 49% of U.S. consumption (Table 11). During the early 1980s, the volume of this apphcation more than doubled as mills converted from urea—formaldehyde (UF) to phenol—formaldehyde adhesives because of the release of formaldehyde from UF products. Other wood bonding applications account for another 15% of the volume. The next largest-volume application is insulation material at 12%. 

Sulfates of sodium are iadustriaUy important materials commonly sold ia three forms (Table 1). In the period from 1970 to 1981, > 1 million metric tons were consumed aimuaHy ia the United States. Siace then, demand has declined. In 1988 consumption dropped to 890,000 t, and ia 1994 to 610,000 t (1,2). Sodium sulfate is used principally (40%) ia the soap (qv) and detergent iadustries. Pulp and paper manufacturers consume 25%, textiles 19%, glass 5%, and miscellaneous iadustries consume 11% (3). About half of all sodium sulfate produced is a synthetic by-product of rayon, dichromate, phenol (qv), or potash (see Chromium compounds Fibers, regenerated cellulosics Potassium compounds). Sodium sulfate made as a by-product is referred to as synthetic. Sodium sulfate made from mirabilite, thenardite, or naturally occurring brine is called natural sodium sulfate. In 1994, about 300,000 t of sodium sulfate were produced as a by-product another 300,000 t were produced from natural sodium sulfate deposits (4). 

Dyes, Dye Intermediates, and Naphthalene. Several thousand different synthetic dyes are known, having a total worldwide consumption of 298 million kg/yr (see Dyes AND dye intermediates). Many dyes contain some form of sulfonate as —SO H, —SO Na, or —SO2NH2. Acid dyes, solvent dyes, basic dyes, disperse dyes, fiber-reactive dyes, and vat dyes can have one or more sulfonic acid groups incorporated into their molecular stmcture. The raw materials used for the manufacture of dyes are mainly aromatic hydrocarbons (67—74) and include ben2ene, toluene, naphthalene, anthracene, pyrene, phenol (qv), pyridine, and carba2ole. Anthraquinone sulfonic acid is an important dye intermediate and is prepared by sulfonation of anthraquinone using sulfur trioxide and sulfuric acid. 

Phenolics are consumed at roughly half the volume of PVC, and all other plastics are consumed in low volume quantities, mosdy in single apphcation niches, unlike workhorse resins such as PVC, phenoHc, urea—melamine, and polyurethane. More expensive engineering resins have a very limited role in the building materials sector except where specific value-added properties for a premium are justified. Except for the potential role of recycled engineering plastics in certain appHcations, the competitive nature of this market and the emphasis placed on end use economics indicates that commodity plastics will continue to dominate in consumption. The apphcation content of each resin type is noted in Table 2. Comparative prices can be seen in Table 5. The most dynamic growth among important sector resins has been seen with phenoHc, acryUc, polyurethane, LLDPE/LDPE, PVC, and polystyrene. 

The tonnage of plasticisers consumed each year exceeds the annual tonnage consumption of most plastics materials. Only PVC, the polyolefins, the styrene polymers, the aminoplastics and, possibly, the phenolics are used in large quantity. 

Formaldehyde is an important chemical in the plastics industry, being a vital intermediate in the manufacture of phenolic and amino resins. It was also used by Reppe during World War II as an important starting point for the preparation of a wide range of organic chemicals. Consumption of formaldehyde in acetal resins is still a minor outlet for the material but exceptionally pure material is required for this purpose. 

Recent estimates suggest that in the early 1990s the percentage breakdown of consumption of phenolic moulding materials in Western Europe was approximately ... 

In 1932, the first plywood hot press was installed in the United States. This marked the advent of the large market for phenolic wood adhesives [51]. By 1962, the volume of phenolic wood adhesives had reached about 33 kt (solids) in the U.S. Growth was accelerated in 1962 with the development of Southern pine plywood. By 1979, the consumption of phenolic plywood adhesives exceeded 220 kt or about 25% of phenolic resin production [51]. Phenolic adhesive demand for wood products took another jump in 1964 with the commencement of waferboard production. The first oriented strandboard (OSB) plants were built in 1981 [52]. OSB soon replaced most of the waferboard production and began a period of... 

Therefore depending upon the conditions used to simulate either in vitro or in vivo oxidation, catechins or other phenolic compounds display differences in their antioxidant properties. Catechins also limited the consumption of a-tocopherol, allowing it to act as a scavenger within cell membranes whilst the catechins scavenged aqueous peroxyl radicals near the membrane surface (Pietta and Simonetti, 1998). 

Results obtained in in vivo and ex vivo experiments are of various types. Some studies have found positive effects of the consumption of carotenoids or foods containing carotenoids on the markers of in vivo oxidative stress, even in smokers. Other studies demonstrated no effects of carotenoid ingestion on oxidative stress biomarkers of lipid peroxidation. " It should be noted that for studies using food, the activity observed may also be partly due to other antioxidant molecules in the food (phenols, antioxidant vitamins) or to the combination of actions of all the antioxidants in the food. 

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