Benzene sources

Kekule s new graphic formula for benzene. Source Kekul, Lehrbuch der organischen Chemie 0866), 2 496. 

Until 1960, coal was the source material for almost all benzene produced in Europe. Petroleum benzene was first produced in Europe by the United Kingdom in 1952, by Erance in 1958, by the Eederal Republic of Germany in 1961, and by Italy in 1962. Coal has continued to decline as a benzene source in Europe, and this is evident with the closure of coke ovens in Germany (73). Most of the benzene produced in Europe is now derived from petroleum or pyrolysis gasoline. In Europe, pyrolysis gasoline is a popular source of benzene because European steam crackers mn on heavier feedstocks than those in the United States (73). 

Loschmidt s two other possible representations for benzene. Source Loschmidt, Chemische Studien (1861), 30 (59), Schemas 182, 185. 

Loschmidt s two other possible representations for benzene. Source Loschmidt, 

Kekule s tetrahedral carbon atom model his new model for benzene. Source Museum for the History of Sciences, University of Ghent. 

Kekule s open-chain and closed-chain sausage formulas for benzene. Source Kekul, Bulletin de la Societe Chimique [2] 3 (1865) 108. 

EPA has recently found the maximum individual risks and total population risks from a number of radionuclide and benzene sources to be too low to be properly described as "significant". Specifically, benzene emissions from maleic anhydride process vents created maximum individual risks of 7.6 in 100,000 and an aggregrate yearly cancer incidence of twenty-nine thousandths of 

Figure 25.29 Phase diagram for mixtures (a) Water -1-triethylamine, (b) water -1- 2-methyl-piperidine, (c) sulfur + benzene. Source WE Acree Jr, Thermodynamic Properties of Nonelectrolyte Solutions, Academic Press, Orlando, 1 984. From (a) F Kohler and OK Rice, J Chem Phys 26, 1614 (1 957) (b) O Flaschner and B Marewen, J Chem Soc 93, 1000 (1908).

FIGURE 16.8 High efficiency analysis of a test sample using five coupled Acquity 1.7-pm columns at near ambient temperature (40 C). Analysis conditions Total column length, 450 mm flow rate, 0.17 ml/min (system) pressure, 999 bar temperature, 40°C (Polaratherm) detection, 210 nm (20 Hz). Mobile phase 30/70 acetonitrile/water. Peak identification 1 = uracil, 2 = caffeine, 3 — pyridine, 4 — aniline, 5 — phenol, 6 — acetophenone, 7 = benzene. Source Reproduced with permission from 2006 Elsevier B.V. 

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