Synthetic methanol

Absolute methyl alcohol. The synthetic methanol now available is suitable for most purposes without purification indeed, some manufacturers claim a purity of 99 85 per cent, with not more than 0 1 per cent, by weight of water and not more than 0 02 per cent, by weight of acetone. Frequently, however, the acetone content may be as high as 0 1 per cent, and the water content 0-5-1 per cent. 

Synthetic lubricants Synthetic marble Synthetic membranes Synthetic methanol Synthetic musk Synthetic natural gas... 

Methanol [67-56-1] (methyl alcohol), CH OH, is a colorless Hquid at ambient temperatures with a mild, characteristic alcohol odor. Originally called wood alcohol siace it was obtained from the destmctive distillation of wood, today commercial methanol is sometimes referred to as synthetic methanol because it is produced from synthesis gas, a mixture of hydrogen and carbon oxides, generated by a variety of sources. 

Acetic acid (qv) can be produced synthetically (methanol carbonylation, acetaldehyde oxidation, butane/naphtha oxidation) or from natural sources (5). Oxygen is added to propylene to make acrolein, which is further oxidized to acryHc acid (see Acrylic acid and derivatives). An alternative method adds carbon monoxide and/or water to acetylene (6). Benzoic acid (qv) is made by oxidizing toluene in the presence of a cobalt catalyst (7). 

Ethyl gasoline is developed by General Motors Laboratories in the United States. Du Pont and Commercial Solvents begin synthetic methanol production in the United States. 

Methanol was first produced commercially in 1830 by the pyrolysis of wood to produce wood alcohol. Almost a century later, a process was developed in Germany by BASF to produce synthetic methanol from coal synthesis gas. The first synthetic methanol plant was introduced by BASF in 1923 and in the United States by DuPont in 1927. In the late 1940s, natural gas replaced coal synthesis gas as the primary feedstock for methanol production. In 1966, ICI announced the development of a copper-based catalyst for use in the low-pressure synthesis of methanol. 

Synthetic methanol was used. Since this anhydrous alcohol is hygroscopic, partially filled bottles that have been opened intermittently in the laboratory should be rejected. 

Synthetic methanol is one of the major raw materials of the organic-chemical industry. Methanol has economic stability and a stejdy growth rale ow-ing lo ihe low costs of production and diversity of applications. Nearly all Ihe methanol producers also make formaldehyde, which is... 

If the small proportion of acetone present in synthetic methanol is objectionable it may be removed when present in quantities up to 1 per cent by the following procedure (Morton and Mark, 1934). A mixture of 500 ml of methanol, 25 ml of furfural and 60 ml of 10 per cent sodium hydroxide solution is refluxed in a 2-litre round-bottomed flask, fitted with a double surface condenser, for 6-12 hours. A resin is formed which carries down all the acetone present. The alcohol is then fractionated through an efficient column, the first 5 ml which may contain a trace of formaldehyde being rejected. The recovery of methanol is about 95 per cent. 

Methanol. As is the case with ethanol, the concept of producing methanol from wood is not new. Methanol obtained from the destructive distillation of wood represented the only commercial source until the 1920s. The yield of methanol from wood by this method is low, only about 1-2 percent or 20 L/metric ton (6 gal/ton) for hardwoods and about one-half that for softwoods. With the introduction of natural gas technology, the industry gradually switched to a synthetic methanol formed from a synthesis gas (syngas) produced from reformed natural gas. Two volumes of H2 and one volume of CO are reacted in a catalytic converter at pressures of 1500-4000 psi to produce methanol. Presently, 99 percent of the methanol produced in the United States is derived from natural gas or petroleum. 

Commercial synthetic methanol (bp 65°) is 99+ per cent pure and contains only 0 to 0.5 per cent water and 0.02 to 0.10 per cent acetone. It does not form an azeotrope with water and therefore may be recovered from aqueous solutions in pure form by distillation. The small residual amount of water is best removed by treatment with magnesium methoxide. In a 2-1 flask fitted with a reflux condenser and a drying tube is placed 5 g of magnesium, 0.5 g of iodine, and 50 ml of methanol. The mixture is warmed on a steam bath until the iodine color disappears and a vigorous evolution of hydrogen occurs. If this does not occur, another 0.5 g of iodine is added and the mixture is again heated. After the methoxide has been formed, 1 1 of methanol is added, and the mixture is heated to reflux for 30 min. The alcohol is then distilled, with precautions taken to prevent entry of moisture. 

Wartime conditions encouraged the use of waste products and investigations into continuous manufacturing processes. Thus, for example, I.G. Farben manufactured N,N-dimethylaniline from aniline and dimethyl ether, a waste from the synthetic methanol process, by a continuous autoclave process. Mercaptobenzothiazole (97) was also made by a continuous autoclave process. Allied investigators after 1945 were impressed by the great extent to which a number of traditional batch processes for aryl amines and then-products had been successfully adapted to automated, continuous operation118. 

Derivation Oxidation of synthetic methanol or low-boiling petroleum gases such as propane and butane. Silver, copper, or iron-molybdenum oxide are the most common catalysts. 

Derivation By-product of synthetic methanol production, purified by rectification. 

Commercial synthetic methanol of high grade was used without further purification. This material is believed to be superior to wood alcohol for this preparation. 

The production history of synthetic methanol in the United States is shown graphically in Figure 6.3. Summarized in Table 6.3 are production and annual growth rates for 1991-1994. 

The price history in cents per gallon for synthetic methanol in the United States is shown in Figure 6.4. As production stabilized (1980s), price declined and then remained relatively constant in the range of 40-50 cents per gallon. After demand increased after 1992, prices rose correspondingly. This reflected the gasoline equivalent price for MTBE. 

Figure 6.4 U.S. price history for synthetic methanol. (Data courtesy of CMAI.)...

There are presently 16 synthetic methanol producers in the United States. These are listed in Table 6.7. Except for a small (10,000 ton/yr) plant to be built in West Covina, California, by TeraMeth, there are no expansions planned for the United States. 

EXAMPLE 3 In the thermochemical equation for the synthetic methanol process (all substances are in the gaseous state)... 

This reaction is ideally suited to continuous operation, being immediate, quantitative, smoothly exothermic, and operable in a simple tower using the liquid product sulfate as the reaction medium (see details on p. 384). The crude reaction mbcture is sufficiently pure for most uses, but distillar tion gives a product purer than that obtainable by the batch procedure. In addition, the reaction of dimethyl ether with SOj is less exothermic than the first step [reaction (1)] of the batch process and, therefore, requires less cooling. When dimethyl ether became cheaply available as a by-product of synthetic methanol production, this process for making dimethyl sulfate was soon exploited. It is interesting to note, however, that this continuous process was adopted not so much because of a large demand for the product, but because it was ideally suited for technical reasons. It yielded a purer product with no spent acid, and the raw materials were cheaply available. 

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