Coke oven light oil

Coke oven light oil is a by-product of the manufacture of coke for the steel industry. When coal is subjected to high temperature carbonization, it yields 16—25 Hters /tonne of light oil that contains 3—6 vol % of mixed xylenes. 

A breakdown of the mixed xylene supply sources in the United States is summarized in Table 1 (1). As shown in Table 1, the primary source of xylenes in the United States is catalytic reformate. In 1992, over 90% of the isolated xylenes in the United States were derived from this source. Approximately 9% of the recovered xylenes is produced via toluene disproportionation (TDP). In the United States, only negligible amounts of the xylenes are recovered from pyrolysis gasoline and coke oven light oil. In other parts of the world, pyrolysis gasoline is a more important source of xylenes. 

Since the 1950s, benzene production from petroleum feedstocks has been very successful and accounts for about 95% of all benzene obtained. Less than 5% of commercial benzene is derived from coke oven light oil. 

Some of the principal Japanese producers of benzene are Mitsubishi Petrochemical Co., Ltd., Nippon Steel Chemical Co., Ltd., Sanyo Petrochemical Ltd., and Idemitsu Kosan Ltd. Until 1967, the main source of Japanese benzene was coal-based. Today, approximately 40—45% of benzene production in Japan is based on pyrolysis gasoline (74), about 40% catalytic reformate, and the remainder coke oven light oil and thermal hydrodealkylation. 

The term mixed xylenes describes a mixture containing the three xylene isomers and usually EB. Commercial sources of mixed xylenes include catalytic refonuate. pyrolysis gasoline, toluene disproportionation product, and coke-oven light oil. Ethylbenzene is present in all of these sources except toluene disproportionation product. Catalytic reformate is the product obtained from catalytic reforming processes. 

The purpose of hydrofining reactions may vary with the feedstock. Gasolines or coke-oven light oil are treated to remove gum formers, that is, readily polymerizing olefins and sulfur compounds, while hydrogenation of aromatics must be avoided. Hydrogenation of kerosenes and Diesel... 

These different requirements can be fulfilled by different catalysts, and different operating conditions will be required. In general, high pressure increases the rate of the saturation of aromatic rings. Therefore, for the hydrofining of gasolines or coke-oven light oil, pressures below 50 atm. are used. 

Application The Sulfolane process recovers high-purity C6-C9 aromatics from hydrocarbon mixtures, such as reformed petroleum naphtha (reformate), pyrolysis gasoline (pygas), or coke oven light oil (COLO), by extractive distillation with or without liquid-liquid extraction. 

Application Recovery of high-purity aromatics from reformate, pyrolysis gasoline or coke-oven light oil using extractive distillation. 

Application Recovery via extraction of high purity C6-C9 aromatics from pyrolysis gasoline, reformate, coke oven light oil and kerosene fractions. 

Component Pyrolysis gasoline Reformate Coke oven light oil... 

Krupp Koppers GmbH BTX Coke oven light oil, reformate, pyrolysis Extractive distillation for benzene, toluene and xylenes using N-formylmorpholin 22 1994... 

Kenney, J. A., "Coke-Oven, Light-Oil Distillates in the Paint and Varnish Industry" In "Protective and Decorative Coatings" John Wiley and Sons New York, 1941 Vol. I, Chap. 26. 

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