Über das Lignin

Schrauth, Walther

doi:10.1002/ange.19230362102

Cited by 20 publications

(4 citation statements)

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“…Nuclear structure found by Schrauth (41) conditions may be expected to exist in a peat bog, the significance of the lignin-cellulose controversy may be regarded as considerably lessened by the work of Schrauth ( 41) who showed that one of the main products obtained by Willstátter and Kalb (49) in the reduction of lignin, cellulose, and other carbohydrates possessed properties practically identical with synthetic 9,10-perhydrobenzophenanthrene, Figure 1A. As a result of this study Schrauth (40) suggested that the coalforming vegetable matter may first have been converted into compounds of the nature shown in Figure IS. A molecule of this type would be expected readily to undergo condensation in various ways, giving molecules of unlimited size, and containing nitrogen and sulfur by reaction with other compounds.…”

Section: Chemistry Of Coal Formationsupporting

confidence: 52%

Twenty-Five Years' Progress in Gas and Fuel Chemistry The Chemical: Coal

Lowry¹

1934

Ind. Eng. Chem.

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Section: Chemistry Of Coal Formationsupporting

confidence: 52%

Twenty-Five Years' Progress in Gas and Fuel Chemistry The Chemical: Coal

Lowry¹

1934

Ind. Eng. Chem.

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“…Since Hawley and Harris (6) have shown that the aromatic compound, lignin, may be prepared from the aliphatic compound, cellulose, we need not concern ourselves with which of the two is the mother substance of coal. Furthermore, Schrauth (17) has shown that the products obtained by Willstátter and Kalb {21) from the reduction of lignin, cellulose, and sugars Figure 1 A. Hydrocarbon skeleton found by Schrauth (17) in the products obtained by Willstátter and Kalb (21) by the reduction of lignin, cellulose, and sugars. B.…”

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Thermal Decomposition of the “Coal Hydrocarbon”

Lowry¹

1934

Ind. Eng. Chem.

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necessary, may be accomplished by air-blowing after the hydrocarbon atmosphere has been replaced by an inert one. Refining of BenzeneBenzene derived from the pyrolysis of natural gas appears to differ from coal-tar benzene only in the relative proportions of its constituents, and the same general methods of refining are applicable in both cases. Where the product of pyrolysis is intended as a blending stock, the following are some of the methods of treatment available: inhibitors, sulfuric acid treatment, hydrogenation, fractionation and the separate treatment of the fraction, and vapor-phase refining.Bound up with this question of refining is also the maximum permissible sulfur content of the benzene. The normal product using metal tubes contained 0.5 per cent sulfur, and this, for blending purposes, was considered satisfactory.Pyrolysis benzene is a very suitable material for the testing of inhibitors, and considerable success can be expected by this method.Sulfuric acid refining has proved satisfactory, in that the product, after treatment, is stable and of good quality, but this method is wasteful of what may be useful unsaturated material. Details need not be given as these follow the normal refining lines.Hydrogenation may be applied to the benzene as a whole, and this has been tried with some success, but attention was concentrated on the hydrogenation of such highly unsaturated fractions of the benzene as the styrene fraction. The purpose of this was to produce extremely useful antiknock materials like ethyl benzene and so avoid loss of unsaturated hydrocarbons in refining. The more saturated parts of the benzene might then be refined using sulfuric acid.Vapor-phase refining methods, using such substances as zinc chloride, did not prove to be highly successful in the case of pyrolysis benzene. Influence of Pressure on Pyrolysis of HydrocarbonsLarge-Scale Pyrolysis of Natural Gas. On the semitechnical scale, tests were carried out using metal tubes in the furnace section at a pressure of 30 pounds per square inch gage. This, unfortunately, was a limiting pressure owing to the construction of the plant. The heating system consisted of 12 X 2 inch i. d. tubes in series, of which the first eight were ordinary 2-inch steel tubes and corresponding return bends, while the four hottest tubes were of H. R. 4. steel with return bends of the same material. A lagged expansion box was used.Operation at 30 pounds per square inch was compared with operation at 6 pounds per square inch using stripped gas of specific gravity 1.00 to 1.01. The throughput was increased from 1800 to 2800 cubic feet per hour at the higher pressure.The benzene production was little changed and was of the order of 1.1 gallon per 1000 cubic feet of nitrogen-and hydrogen sulfide-free gas, Under 30 pounds per square inch pressure the plant was easier to run than at the lower pressure, heat transfer was improved, throughput increased, and yield remained the same. AcknowledgmentAcknowledgment is due the Angio-Persian Oil Company, Ltd., for making th...

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“…Further, while an average molecular weight of 300 appears low, an aromatic hydrocarbon of seven closely condensed rings has a molecular weight of only 302, and it should be noted that the molecular weight of the largest condensed aromatic structures which have been actually isolated from coal or pitch is smaller than this. It is also of interest that Fuchs (12), in picturing a hypothetical humic acid molecule, suggests a structure containing five condensed rings as the building unit, while Schrauth's (18) building element contains four six-membered and three five-membered condensed rings.…”

Section: Molecular Weight Measurementsmentioning

confidence: 99%

The Polymeric Character of Bituminous Coal.

Howard¹

1936

J. Phys. Chem.

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The bituminous coals occupy an intermediate position in what has been called (15) the "coal band" (figure 1). Such organic substances as lignin and humic acids lie at one end of this band, and anthracite coal and graphite at the other. Whether lignin or cellulose is looked upon as the essential progenitor of bituminous coals, it appears that in the coalification process the simple linear polymeric structure, which is generally accepted for cellulose and which has been proposed (11) for lignin, is modified in the sense of the formation of a tridimensional polymer by linkages between the linear units. Whatever the mechanism, there is no doubt that the process is characterized by increasing enrichment in ring structures (6). The higher the rank of the coal, the more complete is the condensation to such structures, until graphite, the limiting member of the series, is reached. The establishment of a building unit in such a polymer obviously presents great difficulties, and we can perhaps never obtain as satisfactory a picture for the structure of such a substance as we have for cellulose and the polymeric esters, lactones, and anhydrides.The essentially "chemical" character of polymerization has been emphasized in recent years (7), and in those cases where the energetics of the process have been investigated, the reactions have been shown to be exothermic; hence, one would expect elevated temperatures to displace the equilibrium toward depolymerization. Many such cases have long been known among the addition polymers such as styrene and rubber, and more recently the ready thermal reversibility of such purely condensation types as the polymeric latitones and anhydrides has also been pointed out (8).A typical bituminous coal from the Pittsburgh seam contains carbon, hydrogen, and oxygen in approximately the same ratio as coumarone, CsH60, which has a normal boiling point of 170°C.; the coal contains somewhat less oxygen and more hydrogen and such polar groups as hydroxyl and carboxyl are present, if at all, in very small amounts. Thus on the basis of composition alone, one would expect bituminous coal to distill completely at moderate temperatures. Its low volatility is ob-1 Presented before the

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Über das Lignin

Cited by 20 publications

References 13 publications

Twenty-Five Years' Progress in Gas and Fuel Chemistry The Chemical: Coal

Twenty-Five Years' Progress in Gas and Fuel Chemistry The Chemical: Coal

Thermal Decomposition of the “Coal Hydrocarbon”

The Polymeric Character of Bituminous Coal.

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