Historic Developments

In simple terms, the carbon/hydrogen ratio of coal is reduced in coal liquefaction by hydrogenation to the extent that coal is transformed into a synthetic crude oil (syncrude), while largely retaining its aromatic character. 

There are two types of processes available for coal liquefaction, namely direct conversion of coal with hydrogen, invented by Friedrich Bergius in 1913, and coal extraction with hydrogenating solvents, first tested in a pilot plant by Alfred Pott and Hans Broche in 1935. The products from both processes can be further hydrogenated in a second stage to obtain fuels. 

Starting date Works site Raw materials Pressure (bar) Liquid phase Gas phase Capacity (tpa) 1943/1944 

1 Coal-slurry production 2 Tubular furnace 3 Hydrogenation reactors 4 Hot separator  

5 Recycle-gas scrubber 6 Cold separator 7 Rotary kiln 8 Tubular furnace 9 Distillation 

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Tracing the historical development of quantum physics, the author describes the baffling and seemingly lawless world of leptons, hadrons, gluons and quarks and provides a lucid and exciting guide for the layman to the world of infinitesimal particles. 

J, Mehra and H, Rechenberg, The Historical Development of Quantum Theory, Springer-Verlag, New York, 1987, Vol. 5, Part 2. 

As a chemist, I should briefly discuss what my field of science is. Here 1 also reflect on its historical development and scope, which help to put in perspective the broad background on which our contemporary chemistry was built, and where my own work fits in. 

An article in the December 1988 issue of the Journal of Chemical Education traces the historical development of Markovnikov s rule In that article Markovnikov s name is spelled Markow nikoff which is the way it appeared in his original pa per written in German... 

There are two problems in the manufacture of PS removal of the heat of polymeriza tion (ca 700 kj /kg (300 Btu/lb)) of styrene polymerized and the simultaneous handling of a partially converted polymer symp with a viscosity of ca 10 mPa(=cP). The latter problem strongly aggravates the former. A wide variety of solutions to these problems have been reported for the four mechanisms described earlier, ie, free radical, anionic, cationic, and Ziegler, several processes can be used. Table 6 summarizes the processes which have been used to implement each mechanism for Hquid-phase systems. Free-radical polymerization of styrenic systems, primarily in solution, is of principal commercial interest. Details of suspension processes, which are declining in importance, are available (208,209), as are descriptions of emulsion processes (210) and summaries of the historical development of styrene polymerization processes (208,211,212). 

Distillation has been practiced in one form or another for centuries. It was of fundamental importance to the alchemists and was in use weU before the time of Christ. The historical development of distillation has been pubHshed (1) as has the history of vapor—Hquid contacting devices (2). 

Essentially, the technology of active carbon fibers is a combination of the technologies for carbon fibers and active carbons summarized above. This section is an outhne of the historical development of ACT. 

The target level assessment process for paper machine halls is the result of long historical development. The performances of installed paper machine hall ventilation systems are measured very often and the results are compared with input data used as the basis for design. As a result of these comparisons corrections are made to the design process as necessary. 

Chapter 2 is a general discnssion of die historical development of DBAs, and an overview of the applicable standards and codes is presented. 

To return to a more historical development the mercuric acetate oxidation of substituted piperidines (77) should be discussed next. This study established that the normal order of hydrogen removal from the aW-carbon is tertiary —C—H > secondary —C—H > primary —C—H, an observation mentioned earlier in this section. The effect of substitution variations in the piperidine series can be summarized as follow s l-mcthyl-2,6-dialkyl and 1-methyl-2,2,6-trialkyl piperidines, as model systems, are oxidized to the corresponding enamines the 1,2-dialkyl and l-methyl-2,5-dialkyl piperidines are oxidized preferentially at the tertiary a-carbon the 1-methyl-2,3-dialkyl piperidines gave not only the enamines formed by oxidation at the tertiary a-carbon but also hydroxylated enamines as found for 1-methyl-decahydroquinoline (48) (62) l-methyl-2,2,6,6-tctraalkyl piperidines and piperidine are resistant to oxidation by aqueous mercuric acetate and... 

F. P. Venable, The Developmeni of ihe Periodic Law, Chemical Publishing Co., Easton. Pa., 1896. This i.s Ihe first general review of periodic tables and has an almost complete colleclion of those published to that lime. J. W. Van Spronsen. The Periodic Syeiem of ihe Chemical Elements, Elsevier. Amsterdam, 1969, 368 pp. An excellent modem account of the historical developments leading up to Mendeleev s table. 

It is also important to realize that chemistry is not a static body of knowledge as defined by the contents of a textbook. Chemistry came from somewhere and is at present heading in various specific directions. It is a living self-stimulating discipline, and we have tried to transmit this sense of growth and excitement by reference to the historical development of the subject when appropriate. The chemistry of the elements is presented in a logical and academically consistent way but is interspersed with additional material which illuminates, exemplifies, extends or otherwise enhances the chemistry being discussed. 

General accounts of prototropic tautomerism have been presented by Ingold and Baker" these include an outline of the historical development of the subject in which heteroaromatic compounds are discussed incidentally, and, therefore, such a historical account will not be given here. Of historical interest are Eistert s book on tautomerism and mesomerism which was published in 1938, a review on — NH-CO— tautomerism by Arndt and Eistert published in 1938, and Heller s account of heterocyclic tautomerism which appeared in 1925. Although more recent works on heterocyclic chemistry (e.g., references 9-11) have dealt incidentally with tautomerism, no unified... 

In the developed countries, stages in the historical development of agricultural production have been characterized by differing combinations of inputs differences in relative proportion ot land, labor and capital, and in the composition of the capital inputs. 

Lindsay, R. B., ed. (1975). Energy Historical Development of the Concept. Stroudsburg, PA Dowden, Hutchinson, Ross. 

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