Coal, alcohols from

Considerable attention has been paid to the application of CNTs as the catalyst support for Fischer Tropsch synthesis (FTS), mainly driven by utilization of the confinement effect (Section 15.2.3). In general, this process is a potential alternative to synthesize fuel (alkanes) or basic chemicals like alkenes or alcohols from syngas, which can be derived from coal or biomass. The broad product spectrum, which can be controlled only to a limited extent by the catalyst, prohibited its industrial realization so far, however, it is considered an important building block for future energy and chemical resource management based on renewables. 

The early sources of phenol were the destructive distillation of coal and the manufacture of methyl alcohol from wood. In both cases, phenol was a by-product. Recovered volumes were limited by whatever was made accidentally in the process. Initial commercial routes to on-purpose phenol involved the reaction of benzene with sulfuric acid (1920), chlorine (1928), or hydrochloric acid (1939) all these were followed by a subsequent hydrolysis step (reaction with water to get the -OH group) to get phenol. These processes required high temperatures and pressures to make the reactions go. They re multistep processes requiring special metallurgy to handle the corrosive mixtures involved. None of these processes is in commercial use today. 

It is reasonable to assume that prior to the exclusive use of chemicals derived from feedstocks other than crude oil, chemicals based on crude oil and chemicals based on alternate feedstocks will supplement each other. This situation has already arisen as is exemplified in the use of coal derived CO/H2 to hydroformylate olefins originating from mineral oil. For instance, in West-Germany Hoechst converts coal into CO/H2 which is used to prepare alcohols from naphtha derived olefins. Table IV summarizes a number of additional reactions in which this point is especially emphasized. 

Only a few of the major developments can be traced here, yet these should give a fair idea of the magnitude and importance of the aliphatic petrochemical growth. It is well to remember that some of the chemistry involved in this industry is old. Four Dutch chemists, otherwise unrecalled today, prepared ethylene dichloride by addition of chlorine to ethylene in 1795, and the synthesis of ethyl alcohol from ethylene via sulfuric acid absorption was studied by Berthelot in 1855 (8). Of course, this was coal-gas ethylene, and the commercial application of this synthesis did not occur until 75 years later, in 1929, when ethylene produced from natural gas was first converted into ethyl alcohol on a practical scale (84). 

The barium salt is easier to obtain in solid form than is the corresponding potassium salt. Dissolve 15 g. of crystallized barium hydroxide in 50 cc. of warm water and divide the solution into two equal parts. Completely saturate the one portion (in a stoppered flask) with hydrogen sulfide and then add the other portion, thus forming a solution of barium sulfide. Add about 1 cc. of carbon disulfide and shake from time to time. It is better to add the carbon disulfide by conducting a current of coal gas (from the laboratory gas supply) through a little carbon disulfide in a wash flask and thence into the solution of barium sulfide. The barium salt precipitates as a yellow crystalline powder. The filtered precipitate should be washed first with water, then with half alcohol, finally with pure alcohol and dried on a hot plate. A second crop of crystals may be obtained by allowing the wash alcohol to drain into the mother liquor. 

A newer development is the technology of the production of alcohols from gas to liquid where high molecular weight olefins can be made from natural gas or from coal gasification. This is done using the Fisher-Tropsh reaction. 

Ethjdene can be converted by simple hydration into alcohol. The process is catatytic and occurs by way of the intermediate ethyl sulphuric add, C2H6HSO4, and given a large supply of eth.3dene, the conversion into alcohol does not offer great difficulties. Its recovery from coal gas in this way is therefore theoretically possible, and Bury, at Skinningrove Coke Oven Works, has obtained i-6 gallons per ton of coal carbonized from rims of 5800 tons of coal carbonized per week Chemical Age, 1919, i, 714). 

The problem of solvation of dextrins is still unsolved in general. It was documented that even such commonly used solvents as ethanol exhibit an unusually strong interaction with dextrin, as determined by H-n.m.r. spectroscopy. The interaction of dextrin with normal alcohols from methanol to 1 -hexanol was studied by determination of their infinite-dilution activity-coefficients in dextrin - water mixtures. " Studies carried out on the adsorption of dextrin on oxidized coal revealed that hydrophobic moieties in dextrin are involved in that process. The possibility of hydrophobic bonding has made dextrin an interesting component of the media used for flotation. Dextrin acts as a flocculant (depressant). When combined with a proper additive providing action by means of hydrogen bonding, reverse flotation... 

FIGURE 20 Effect of surface-active agent (frother) on the flotation of coal with water-insoluble oily collector. Curve 1 is for flotation with kerosene curve 2 for kerosene and / -octyl alcohol. [From Melik-Gaykazian, V. I., Plaksin, I. N., and Voronchikhina, V. V. (1967). Dokl. Akad. Nauk SSSR, 173, 883.]... 

Another recent breakthrough is the commercialization of alcohols from coal using Fischer-Tropsch (FT) technology practiced by the synthetic fuels expert, Sasol. The technology produces a... 

The first vertical continuous distillation column was patented in France by Jean-Baptiste Cellier Blumenthal in 1813 for use in alcohol distilleries. The first modern book on the fundamentals of distillation, La Rectification de I alcool The Rectification of Alcohol), vins published by Ernest Sor el in 1894. The gas lights of Sherlock Holmes s London burned coal gas from the destructive distillation of coal. 

The Fischer-Tropsch process was developed by F. Fischer and H. Tropsch in 1921 to produce clean alternative fuel from coal, natural gas, and low-grade refinery products for use in automobile and diesel engines. The process entails the synthesis of hydrocarbons and other aliphatic compounds, such as alcohols, from a mixture of hydrogen and carbon monoxide (synthesis gas, or syngas). The following equation illustrates the chemical reactions involved in the process ... 

Made from chemical raw material composed of atoms of carbon in combination with other elements [1, 2] called monomers, which are basic materials including those made from coal, alcohol, natural gas and petroleum. 

Barik S, Prieto S, Harrison SB, Clausen EC, Gaddy JL (1988) Biological production of alcohols from coal through indirect liquefriction scientific note. Appl Biochem Biotechnol 18 363-378... 

Other reactions that would permit the selective formation of a given alcohol from synthesis gas are the focus of much current research, because synthesis gas is readily available by the gasification of coal or other biomass in the presence of water, or by the partial oxidation of methane. 

Pure pyridine may be prepared from technical coal-tar pyridine in the following manner. The technical pyridine is first dried over solid sodium hydroxide, distilled through an efficient fractionating column, and the fraction, b.p. 114 116° collected. Four hundred ml. of the redistilled p)rridine are added to a reagent prepared by dissolving 340 g. of anhydrous zinc chloride in a mixture of 210 ml. of concentrated hydrochloric acid and 1 litre of absolute ethyl alcohol. A crystalline precipitate of an addition compound (probable composition 2C5H5N,ZnCl2,HCl ) separates and some heat is evolved. When cold, this is collected by suction filtration and washed with a little absolute ethyl alcohol. The yield is about 680 g. It is recrystaUised from absolute ethyl alcohol to a constant m.p. (151-8°). The base is liberated by the addition of excess of concentrated... 

About half of the wodd production comes from methanol carbonylation and about one-third from acetaldehyde oxidation. Another tenth of the wodd capacity can be attributed to butane—naphtha Hquid-phase oxidation. Appreciable quantities of acetic acid are recovered from reactions involving peracetic acid. Precise statistics on acetic acid production are compHcated by recycling of acid from cellulose acetate and poly(vinyl alcohol) production. Acetic acid that is by-product from peracetic acid [79-21-0] is normally designated as virgin acid, yet acid from hydrolysis of cellulose acetate or poly(vinyl acetate) is designated recycle acid. Indeterrninate quantities of acetic acid are coproduced with acetic anhydride from coal-based carbon monoxide and unknown amounts are bartered or exchanged between corporations as a device to lessen transport costs. 

Sasol produces synthetic fuels and chemicals from coal-derived synthesis gas. Two significant variations of this technology have been commercialized, and new process variations are continually under development. Sasol One used both the fixed-bed (Arge) process, operated at about 240°C, as weU as a circulating fluidized-bed (Synthol) system operating at 340°C. Each ET reactor type has a characteristic product distribution that includes coproducts isolated for use in the chemical industry. Paraffin wax is one of the principal coproducts of the low temperature Arge process. Alcohols, ketones, and lower paraffins are among the valuable coproducts obtained from the Synthol process. 

Alternative fuels fall into two general categories. The first class consists of fuels that are made from sources other than cmde oil but that have properties the same as or similar to conventional motor fuels. In this category are fuels made from coal and shale (see Fuels, synthetic). In the second category are fuels that are different from gasoline and diesel fuel and which require redesigned or modified engines. These include methanol (see Alcohol fuels), compressed natural gas (CNG), and Hquefted petroleum gas (LPG). 

Solvent extraction using nonreactive Hquids, such as C - or C -alcohols, benzene, or benzene-alcohol mixtures, yields generally 5—20% wax or bitumen (15). The yield and composition of the product are determined primarily by the petrologic character of the coal, not its degree of coalification. Montan wax is extracted from suitable coals for a variety of purposes. 

Sasol Fischer-Tropsch Process. 1-Propanol is one of the products from Sasol s Fischer-Tropsch process (7). Coal (qv) is gasified ia Lurgi reactors to produce synthesis gas (H2/CO). After separation from gas Hquids and purification, the synthesis gas is fed iato the Sasol Synthol plant where it is entrained with a powdered iron-based catalyst within the fluid-bed reactors. The exothermic Fischer-Tropsch reaction produces a mixture of hydrocarbons (qv) and oxygenates. The condensation products from the process consist of hydrocarbon Hquids and an aqueous stream that contains a mixture of ketones (qv) and alcohols. The ketones and alcohols are recovered and most of the alcohols are used for the blending of high octane gasoline. Some of the alcohol streams are further purified by distillation to yield pure 1-propanol and ethanol ia a multiunit plant, which has a total capacity of 25,000-30,000 t/yr (see Coal conversion processes, gasification). 

Development of SASOL. Over 70% of South Africa s needs for transportation fuels are being suppHed by iadirect Hquefaction of coal. The medium pressure Fischer-Tropsch process was put iato operation at Sasolburgh, South Africa ia 1955 (47). An overall flow schematic for SASOL I is shown ia Figure 12. The product slate from this faciUty is amazingly complex. Materials ranging from hydrocarbons through oxygenates, alcohols, and acids are all produced. 

Robert Boyle, an Irish chemist noted for his pioneering experiments on the properties of gases, discovered methanol (CH3OH) in 1661. For many years methanol, known as wood alcohol, was produced by heating hardwoods such as maple, birch, and hickory to high temperatures m the absence of air. The most popular modern method of producing methanol, which IS also the least costly, is from natural gas (methane) by the direct combination of carbon monoxide gas and hydrogen in the presence of a catalyst. Methanol also can be produced more expensively from oil, coal, and biomass. 

---