Acetic consumption

Achtnich C, Schuhmann A, Wind T, Conrad R. 1995. Role of interspecies H2 transfer to sulfate and ferric iron-reducing bacteria in acetate consumption in anoxic paddy soil. FEMS Microbiology Ecology 16 61-69. 

Figure 3.5 shows the simulated ethyl acetate concentration as a function of time and compares it to the experimentally determined curve for an initial 0.05 mol/L. The two curves overlap for the initial reaction period. However, the simulation indicates complete ethyl acetate consumption after 5 min, whereas the experimental data indicates the presence of a miniscule amount of ethyl acetate in the reactor. We can, therefore, use this method to simulate the most active period of a reaction in a batch reactor. 

The mixture was prepared and allowed to achieve equilibrium to it was added an excess of urea which caused the immediate precipitation as urea nitrate of the free nitric acid present. As a result of the sudden removal of the nitric acid from the mixture, the system underwent change to re-establish the equilibrium however, the use of an excess of urea removed the nitric acid as it was produced from acetyl nitrate and acetic acid, and the consumption of acetyl nitrate proceeded to completion. Thus, by following the production of urea nitrate with the time from the addition of urea, the rate of the back reaction could be determined, and by extrapolating the results to zero time the equilibrium... 

The combined pharmaceutical appHcations account for an estimated 25% of DMF consumption. In the pharmaceutical industry, DMF is used in many processes as a reaction and crystallizing solvent because of its remarkable solvent properties. For example, hydrocortisone acetate [50-03-3] dihydrostreptomycin sulfate [5490-27-7] and amphotericin A [1405-32-9] are pharmaceutical products whose crystallization is faciHtated by the use of DMF. Itis also a good solvent for the fungicide griseofulvin/72%(97-< 7 and is used in its production. 

Of the estimated 710,000 t consumed in 1990, 25% was used to produce vinyl chloride [75-01-4] monomer (VCM), 14% for vinyl acetate [108-05-4] monomer (VAM), 23% for butanediol, 14% for industrial use, and the balance to produce other products such as acryUc acid, synthetic mbber, chlorinated solvents, and acetylene black. The demand for PVC is expected to decrease as legislation limiting its use in packaging is pending. Consequentiy, VCM consumption will also suffer. 

World methanol consumption for 1992 is shown in Figure 10 (27). The principal use of methanol has traditionally been in the production of formaldehyde [50-00-0] where typically around 40% of the world methanol market is consumed. In the United States, an increasing role for methanol has been found in the oxygenated fuels market from the use of MTBE. Another significant use of methanol is in the production of acetic acid other uses include the production of solvents and chemical intermediates. 

The greatest industrial consumption of monobasic aluminum acetate has been as a solution in the preparation of red color lakes for the dyeing of cotton. Formation of a water-resistant coating on fabrics, paper, leather, or other materials is also an important appHcation. In this process, for example, cloth is dipped into a solution of water-soluble soap, then into the aluminum salt solution, forming an insoluble, water-resistant aluminum soap coating on the fiber surfaces (10). 

Fig. 2. U.S. consumption of vinyl acetate, where represents PVAc I, poly(vinyl alcohol) (PVA) A, ethylene—vinyl acetate (EVA) O, PVB , EVOFl ...

Growth in PVAc consumption is illustrated in Eigure 3. The emulsions continue to dominate the adhesives and paint markets. It also shows the distribution of PVAc and copolymer usage by market. The companies Hsted in Table 10 are among the principal suppHers of poly(vinyl acetate)s and vinyl acetate copolymers, but there are numerous other suppHers. Many other companies produce these polymers and consume them internally in the formulation of products. 

Pig. 3. U.S. consumption of poly(vinyl acetate), where A represents paints B, adhesives C, paper coatings D, textiles E, other and P, total. 

About 69% of the total 1988 U.S. consumption of isobutyraldehyde, went into the production of isobutyl alcohol and isobutyraldehyde condensation and esterification products. The other principal isobutyraldehyde derivative markets (as a percentage of total 1988 U.S. isobutyraldehyde consumption) are neopentyl glycol (15%) isobutyl acetate (6%) isobutyric acid (5%) isobutyUdene diurea (2.5%) and methyl isoamyl ketone (1.7%). 

From 1980 to 1988, aimual cellulose acetate flake production in the United States showed a slight decrease in production from 392,000 t to 323,000 t with an aimual decline of —0.4 to —0.1% (Table 6). World demand for cellulose acetate flake has also fallen. A modest recovery has occurred in recent years as a result of the increased demand for cigarette-filter tow world consumption of cigarette-filter tow has risen about 2.5% per year since 1980 (Tables 7 and 8). In contrast, world demand for textile fibers and cellulose ester plastics decline 4.6% and 4.2% per year, respectively (Fig. 9). 

Table 7. World Consumption of Cellulose Acetate Flake, 10 t...

Cellulose acetate ester plastics are produced largely in the United States, Western Europe, and Japan. World consumption is assumed to be approximately equivalent to production of cellulose ester plastics in these three regions. Courtesy of CEH Estimates. 

The cellulose esters with the largest commercial consumption are cellulose acetate, including cellulose triacetate, cellulose acetate butyrate, and cellulose acetate propionate. Cellulose acetate is used in textile fibers, plastics, film, sheeting, and lacquers. The cellulose acetate used for photographic film base is almost exclusively triacetate some triacetate is also used for textile fibers because of its crystalline and heat-setting characteristics. The critical properties of cellulose acetate as related to appHcation are given in Table 10. 

A rather impressive Hst of materials and products are made from renewable resources. For example, per capita consumption of wood is twice that of all metals combined. The ceUulosic fibers, rayon and cellulose acetate, are among the oldest and stiU relatively popular textile fibers and plastics. Soy and other oilseeds, including the cereals, are refined into important commodities such as starch, protein, oil, and their derivatives. The naval stores, turpentine, pine oil, and resin, are stiU important although their sources are changing from the traditional gum and pine stumps to tall oil recovered from pulping. 

Ethanol s use as a chemical iatemiediate (Table 8) suffered considerably from its replacement ia the production of acetaldehyde, butyraldehyde, acetic acid, and ethyUiexanol. The switch from the ethanol route to those products has depressed demand for ethanol by more than 300 x 10 L (80 x 10 gal) siace 1970. This decrease reflects newer technologies for the manufacture of acetaldehyde and acetic acid, which is the largest use for acetaldehyde, by direct routes usiag ethylene, butane (173), and methanol. Oxo processes (qv) such as Union Carbide s Low Pressure Oxo process for the production of butanol and ethyUiexanol have totaUy replaced the processes based on acetaldehyde. For example, U.S. consumption of ethanol for acetaldehyde manufacture declined steadily from 50% ia 1962 to 37% ia 1964 and none ia 1990. Butadiene was made from ethanol on a large scale duriag World War II, but this route is no longer competitive with butadiene derived from petroleum operations. 

Over 80% of the market is accounted for by suspension homopolymer, 13% by emulsion and paste-forming homopolymer, and the rest is mainly bulk homopolymer and vinyl chloride-vinyl acetate copolymer. In Western Europe about two-thirds of consumption is in the field of unplasticised PVC. 

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. 

There has been a steady increase in demand for polyacetals over the years, with global nameplate capacity increasing from about 260 000 t.p.a. at the begirming of the 1980s to about 600 000 t.p.a. at the end of the century. In the same period consumption has risen from about 140 000 t.p.a. to about 480 000 t.p.a. In terms of nameplate capacity the acetal copolymers dominate the homopolymers by a ratio of the order of 3 1. 

Succinyl-CoA derived from propionyl-CoA can enter the TCA cycle. Oxidation of succinate to oxaloacetate provides a substrate for glucose synthesis. Thus, although the acetate units produced in /3-oxidation cannot be utilized in glu-coneogenesis by animals, the occasional propionate produced from oxidation of odd-carbon fatty acids can be used for sugar synthesis. Alternatively, succinate introduced to the TCA cycle from odd-carbon fatty acid oxidation may be oxidized to COg. However, all of the 4-carbon intermediates in the TCA cycle are regenerated in the cycle and thus should be viewed as catalytic species. Net consumption of succinyl-CoA thus does not occur directly in the TCA cycle. Rather, the succinyl-CoA generated from /3-oxidation of odd-carbon fatty acids must be converted to pyruvate and then to acetyl-CoA (which is completely oxidized in the TCA cycle). To follow this latter route, succinyl-CoA entering the TCA cycle must be first converted to malate in the usual way, and then transported from the mitochondrial matrix to the cytosol, where it is oxida-... 

Homogeneous catalysis by lin compounds is also of great indusirial importance. The use of SnCU as a Friedel-Crafts catalyst for homogeneous acylation, alkylation and cyclizaiion reactions has been known for many decades. The most commonly used industrial homogeneous tin catalysis, however, are the Sn(ll) salts of organic acids (e.g. acetate, oxalate, oleale, stearate and ocToate) for the curing of silicone elasloniers and, more importantly, for the production of polyurethane foams. World consumption of tin catalysts for the.se Iasi applications alone is over 1000 tonnes pa. 

In 1996, consumption in the western world was 14.2 tonnes of rhodium and 3.8 tonnes of iridium. Unquestionably the main uses of rhodium (over 90%) are now catalytic, e.g. for the control of exhaust emissions in the car (automobile) industry and, in the form of phosphine complexes, in hydrogenation and hydroformylation reactions where it is frequently more efficient than the more commonly used cobalt catalysts. Iridium is used in the coating of anodes in chloralkali plant and as a catalyst in the production of acetic acid. It also finds small-scale applications in specialist hard alloys. 

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