Dibenzothiophene desulfurization

Konishi, J. Onaka, T. Ishii, Y., and Suzuki, M., Demonstration of the Carbon-Sulfur Bond Targeted Desulfurization of Benzothiophene by Thermophilic Paenibacillus Sp Strain Al 1-2 Capable of Desulfurizing Dibenzothiophene. Ferns Microbiology letters, 2000. 187(2) pp. 151-154. 

Noda, K. Watanabe, K., and Maruhashi, K., Recombinant Pseudomonas Putida Carrying Both the Dsz and Hcu Genes Can Desulfurize Dibenzothiophene in n-Tetradecane. Biotechnology Letters, 2003. 25(14) pp. 1147-1150. 

It should be noted, however, that this reaction sequence may be different from what may actually be occurring in the reactor. The reactions proceed at different rates depending on the process variables. Hydrodesulfurization of complex sulfur compounds such as dibenzothiophene also occurs under these conditions. The desulfurized product may crack to give two benzene molecules ... 

Sulfur in cmde oil is mainly present in organic compounds such as mercaptans (R-SH), sulfides (R-S-R ) and disulfides (R-S-S-R ), which are all relatively easy to desulfurize, and thiophene and its derivatives (Fig. 9.2). The latter require more severe conditions for desulfurization, particularly the substituted dibenzothiophenes, such as that shown in Fig. 9.2. Sulfur cannot be tolerated because it produces sulfuric add upon combustion, and it also poisons reforming catalysts in the refinery and automotive exhaust converters (particularly those for diesel-fueled cars). Moreover, sulfur compounds in fuels cause corrosion and have an unpleasant smell. 

Can you think of reasons why substituted dibenzothiophenes are more difficult to desulfurize than thiophene or simple thiols (see Fig. 9.2) Depending on the choice of catalyst, hydrodesulfurization can be accompanied by hydrogenation to various extents. In which of the product streams in the refinery would you choose hydrogenative HDS and in which would you not ... 

Omori T, L Monna, Y Saiki, T Kodama (1992) Desulfurization of dibenzothiophene by Corynebacterium sp. strain SYl. Appl Environ Microbiol 58 911-915. 

Matsubara T, T Ohshiro, Y Nishina, Y Izumi (2001) Purification, characterization, and overexpression of flavin reductase involved in dibenzothiophene desulfurization by Rhodococcus erythropolis D-1. Appl Environ Microbiol 67 1179-1184. 

Rhee S-K, JH Chang, YK Chang, HN Chang (1998) Desulfurization of dibenzothiophene and diesel oils by a newly isolated Gordona strain CYKSl. Appl Environ Microbiol 64 2327-2331. 

Wang P, AE Humphrey, S Krawiec (1996) Kinetic analysis of desulfurization of dibenzothiophene by Rhodo-coccus erythropolis in continuous cultures. Appl Environ Microbiol 62 3066-3068. 

Kayser, K. J. Cleveland, L. Park, H. S., et al., Isolation and Characterization of a Moderate Thermophile, Mycobacterium Phlei GTIS10, Capable of Dibenzothiophene Desulfurization. Applied Microbiology and Biotechnology, 2002. 59(6) pp. 737-745. 

Omori, T. Saiki, Y. Kasuga, K., and Kodama, T., Desulfurization of Alkyl and Aromatic Sulfides and Sulfonates by Dibenzothiophene-Desulfurizing Rhodococcus Sp Strain Syl. Bioscience Biotechnology and Biochemistry, 1995. 59(7) pp. 1195-1198. 

Denis-Larose, C. Labbe, D. Nergeron, H., et al., Conservation of plasmid-encoded dibenzothiophene desulfurization genes in several Rhodococci. Applied and Environmental Microbiology, 1997. 63 pp. 2915-2919. 

Wang, P., and Krawiec, S., Kinetic analyses of desulfurization of dibenzothiophene by Rhodococcus erythropolis in batch and fed-batch cultures. Applied and Environmental Microbiology, 1996. 62(5) pp. 1670-1675. 

Ohshiro, T. Hirata, T. Hashimoto, I., and Izumi, Y., Characterization of Dibenzothiophene Desulfurization Reaction by Whole Cells of Rhodococcus Erythropolis H-2 in the Presence of Hydrocarbon. J. Ferm. Bioeng., 1996. 82 pp. 610-612. 

Castorena, G. Suarez, C. Valdez, I., et al., Sulfur-Selective Desulfurization of Dibenzothiophene and Diesel Oil by Newly Isolated Rhodococcus Sp Strains. Ferns Microbiology Letters, 2002. 215(1) pp. 157-161. 

Lee, M. Senius, J. D., and Grossman, M. J., Sulfur-specific microbial desulfurization of sterically hindered analogs of dibenzothiophene. Applied and Environmental Microbiology, 1995. 61(12) pp. 4362-4366. 

Folsom, B. R. Schieche, D. R. DiGrazia, P. M., et al., Microbial Desulfurization of Alkylated Dibenzothiophenes From a Hydrodesulfurized Middle Distillate by Rhodococcus Erythropo-lis 1-19. Applied and Environmental Microbiology, 1999. 65(11) pp. 4967-4972. 

Kobayashi, M. Horiuchi, K. Yoshikawa, O., et al., Kinetic analysis of microbial desulfurization of model and light gas oils containing multiple alkyl dibenzothiophenes. Bioscience Biotechnology and Biochemistry, 2001. 65(2) pp. 298-304. 

Maghsoudi, S. Kheirolomoom, A. Vossoughi, M., et al., Selective desulfurization of dibenzothiophene by newly isolated Corynebacterium sp strain P32C1. Biochemical Engineering Journal, 2000. 5(1) pp. 11-16. 

Kirimura, K. Harada, K. Iwasawa, H., et al., Identification and Functional Analysis of the Genes Encoding Dibenzothiophene-Desulfurizing Enzymes From Thermophilic Bacteria. Applied Microbiology and Biotechnology, 2004. 65(6) pp. 703-713. 

Constanti, M. Giralt, J., and Bordens, A., Degradation and Desulfurization of Dibenzothiophene Sulfone and Other Sulfur Compounds by Agrobacterium MC501 and a Mixed Culture. Enzyme and Microbial Technology, 1996. 19 pp. 214-219. 

Furuya, T. KMmura, K. Kino, K., and Usami, S., Thermophilic Biodesulfurization of Naph-thothiophene and 2-Ethylnaphthothiophene by a Dibenzothiophene-Desulfurizing Bacterium, Mycobacterium Phlei WU-F1. Applied Microbiology, and Biotechnology, 2002. 58(2) pp. 237-240. 

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