Coal, distillation theory

On his return from America, Mendel eff was again sent to study the naphtha springs in the south of Russia. He did not confine his work to the gathering of statistics and the enunciation of theories. He developed in his own laboratory a new method for the commercial distillation of these products and saved Russia vast sums of money. He studied the coal region on the banks and basin of the Donetz River and opened it to the world. He was an active propagandist for Russia s industrial development and expansion, and was called upon to help frame a protective tariff for his country. 

Theories of Formation of Benzene, etc.—Theories of the formation of these benzene products in the distillation of coal have been investigated principally by Berthelot, and his conclusions are, in general In the first place, coal decomposes by heat yielding simple paraffin compounds such as methane, ethylene, acetylene, alcohol, acetic acid, etc. These compounds when subjected to higher temperatures polymerize into benzene, and the higher hydrocarbons naphthalene, anthracene, phenanthrene, etc., and into derivatives of these such as phenol, aniline, pyridine, etc. 

The conversion of biomass materials to high octane gasoline has been actively pursued for many years. Historically, methanol was made in very low yields by the destructive distillation of hardwoods. More recently, the manufacture of methanol has been by the reaction of synthesis gas over catalysts at high pressures. In theory, any carbon source can be used for this catalytic generation of methanol, but in practice, biomass has not been advantageous relative to coal or natural gas. Other approaches to making liquid fuel from biomass have involved the fermentation of biomass to ethanol in a rather slow process. The conversion of biomass to alcohols is technically feasible, but the utilization of the alcohols as transportation fuels will require modifications to the... 

The fixed carbon (FC) represents the mass percentage of free carbon contained in the coal or coke, as received, excluding the carbon contained in volatile matter (hydrocarbon). In theory, it corresponds to the solid residue other than ash obtained after a destructive distillation performed under inert atmosphere. In practice, it is a value calculated, according to standard ASTM D3172, by subtraction of the mass of the volatile matter, ash content and moisture, with the result being expressed as a percentage of the total mass. 

The first account of the destructive distillation of coal was published in 1726. Large-scale continuous stills with fractionating towers similar to modern industrial stills were devised for the distillation of alcoholic beverages in the first half of the nineteenth century and later adapted to coal and oil refining. Laboratory distillation similarly advanced with the introduction of the Liebig condenser around 1850. The modern theory of distillation was developed by Ernest Sorel and reduced to engineering terms in his Distillation et rectification industrielles (1899). 

Hahnemann stated that two salts dissolved in water decompose one another by double affinity when one at least of the new salts is less soluble (and hence more coherent) than either of the original compounds, a proposition afterwards developed by Berthollet (see p. 645). Among his homoeopathic remedies was a causticum (Meyer s acidum pingue, see p. 145) prepared by distilling freshly-slaked lime with water and acid potassium sulphate (1830). Hahnemann s book on fuels deals with the proper use of coal, coke, briquettes, etc. He appears to have remained true to the phlogiston theory. 

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