2- ethanol, oxidation

A strain of thermophilic Acetobacter - 9. patented in Japan for oxidizing ethanol in a submerged culture oxidizer at temperatures as high as 37°C with considerable savings in cooling water. Another theimophilic strain oiyAcetobacter xn.2An.. 2cm.ed full activity at 35°C, and 45% of its maximum activity at 38°C. 

Liver alcohol dehydrogenase (ADH) is relatively nonspecific and will oxidize ethanol or other alcohols, including methanol. Methanol oxidation yields formaldehyde, which is quite toxic, causing, among other things, blindness. Mistaking it for the cheap... 

The catalyst is a mixture of copper, zinc oxide, and chromium(lll) oxide. Ethanol is produced in large quantities throughout the world by the fermentation of carbohydrates. It is also prepared by the hydration of ethene in an addition reaction ... 

Porous ultrafine tin oxide ethanol gas sensors92 in the form of a thin film have been prepared from tin alkoxide by the sol-gel process. The microstructural evolution of the tin oxide films, which affected the ethanol gas-sensing properties of the films, was investigated as a function of firing temperature and solution concentration. Theoretically, it was expected that ethanol gas sensitivity would increase monotonically with decreasing film thickness, but experimental results showed a maximum sensitivity at about 70 nm. The sudden decrease of the sensitivity below the thickness of 70 nm seemed to be due to the sudden decrease of film porosity, i.e., the sudden decrease of the number of the available sites for the oxidation reaction of ethanol molecules. Thus, it seemed that below the thickness of 70 nm, the sensitivity was governed by microstructure rather than by film thickness. 

Iron complexes or microsomal nonheme iron are undoubtedly obligatory components in the microsomal oxidation of many organic compounds mediated by hydroxyl radicals. In 1980, Cohen and Cederbaum [27] suggested that rat liver microsomes oxidized ethanol, methional, 2-keto-4-thiomethylbutyric acid, and dimethylsulfoxide via hydrogen atom abstraction by hydroxyl radicals. Then, Ingelman-Sundberg and Ekstrom [28] assumed that the hydroxylation of aniline by reconstituted microsomal cytochrome P-450 system is mediated by hydroxyl radicals formed in the superoxide-driven Fenton reaction. Similar conclusion has been made for the explanation of inhibitory effects of pyrazole and 4-methylpyrazole on the microsomal oxidation of ethanol and DMSO [29],... 

Oxidation of primary alcohols leads to aldehydes and oxidation of secondary alcohols leads to ketones. This oxidation also involves the loss of two hydrogen atoms. However, unlike the oxidations discussed so far in this chapter that are mediated almost exclusively by cytochromes P450, the major enzyme involved in the oxidation of ethanol is ALD (discussed earlier in this chapter) (74). Although ALD is the major enzyme involved in the oxidation of ethanol and most other low molecular-mass alcohols, cytochromes P450, especially 2E1, can also oxidize ethanol and this enzyme is induced in alcoholics. Although comprehensive studies have not been published, it appears that cytochromes P450 are often the major enzymes involved in the oxidation of higher molecular mass alcohols. 

Source Manufactured by oxidizing ethanol with sodium dichromate and sulfuric acid or from acetylene, dilute sulfuric acid, and mercuric oxide catalyst. 

This confirms the difficulty of oxidizing ethanol at low temperatures and the necessity to work at temperatures higher than 100 °C to enhance the electrode kinetics and, thus, the performance of the DEFC. 

A similar biradical process has also been estabhshed for some mononuclear Cu complexes 17 (derived from ligand 16) and 18 that contain two iminosemiquinone radicals [156,160]. Complex 17 proved to be a good catalyst for the aerial oxidation of benzyl alcohol to benzaldehyde, while 18 even oxidizes ethanol and methanol. Primary kinetic isotope effects again confirm that H-atom abstraction from the substrate is the rate-determining step. 

Alcohol and aldehyde oxidation. Although a microsomal enzyme system has been demonstrated, which oxidizes ethanol (see above), probably the more important enzyme in vivo is alcohol dehydrogenase, which is a cytosolic enzyme (soluble fraction) and is found in the liver and also in the kidney and the lung. 

Method 6(when acardite III alone is present as stabilizer and gelatinizer) Procs a) to e)— same as in Method 4 f)In order to establish that the sample contains acardite III and not acardite 11, treat the solnfafter removal of N gas) with chromic mixt(KaCr207 + Ha S04) in order to oxidize ethanol to acetaldehyde. Treat the oxidized soln with fuchsin, previously... 

It reacts with water with evolution of nitrogen oxides. Ethanol, acetone, dry ether and primary amines react violently with nitrosyl perchlorate causing ignition or explosion. 

The oxidation reactions are summarized in Reaction 1. In the following discussion the methanol-oxidized, ethanol-oxidized, and benzene-oxidized species will be referred to respectively as 2, 3, and 4. 

In 1949 Kolthoff and Medalia (39) showed that hydroxyl radicals from hydrogen peroxide are capable of oxidizing ethanol in accordance with the following chain reaction scheme ... 

Several of the B vitamins function as coenzymes or as precursors of coenzymes some of these have been mentioned previously. Nicotinamide adenine dinucleotide (NAD) which, in conjunction with the enzyme alcohol dehydrogenase, oxidizes ethanol to ethanal (Section 15-6C), also is the oxidant in the citric acid cycle (Section 20-10B). The precursor to NAD is the B vitamin, niacin or nicotinic acid (Section 23-2). Riboflavin (vitamin B2) is a precursor of flavin adenine nucleotide FAD, a coenzyme in redox processes rather like NAD (Section 15-6C). Another example of a coenzyme is pyri-doxal (vitamin B6), mentioned in connection with the deamination and decarboxylation of amino acids (Section 25-5C). Yet another is coenzyme A (CoASH), which is essential for metabolism and biosynthesis (Sections 18-8F, 20-10B, and 30-5A). 

Oxidation Ethanol Facial flushing, cardiovascular symptoms... 

The precipitate remaining on the filter is washed with 10 ml. of benzene in order to remove the excess wuter (the ferrate ion would oxidize ethanol containing as much as 20 % water). Three to five 20-ml. portions of 95% ethanol are then drawn through the filter. The precipitate is transferred to a beaker containing 100 ml. of 95% ethanol and... 

Oxidations Ethanol, methanol, isopropanol, glycols, glycol ethers (2-butoxyethanol)... 

Alcohol metabolism Liver enzymes play a key role in the metabolism of alcohol (ethanol). As the liver oxidizes ethanol it generates acetaldehyde - the substance which helps create the hangover. The acetaldehyde is then further oxidized to acetic acid and eventually CO2 and H2O. 

Acetaldehyde Oxidation. Ethanol [64-17-5] is easily dehydrogenated oxidatively to acetaldehyde (qv) using silver, brass, or bronze catalysts. Acetaldehyde can then be oxidized in the liquid phase in the presence of cobalt or manganese salts to yield acetic acid. Peracetic acid [79-21-0] formation is prevented by the transition metal catalysts (7). (Most transition metal salts decompose any peroxides that form, but manganese is uniquely effective.)... 

---