Desulfurization of fuels

Ultradeep desulfurization of fuel oils is used for producing not only clean fuels but also sulfur-free hydrogen used in fuel-cell systems, in which the hydrogen can be produced potentially through the reforming of fuel oils. Fuel-cell systems must be run with little-to-no sulfur content, because sulfur can irreversibly poison the precious metal catalysts and electrodes used [12]. 

Atmospheric sulfur emissions can be minimized at source by improving the process yields and desulfurization of fuels prior to combustion. The difficulty of fuel desulfurization is solid > liquid > gas. Sulfur can be removed from emissions either as S02 or H2S. Removal of the H2S can be by ... 

Method for oxidation of organic sulfur compound included in organic compound and method for oxidative desulfurization of fuel oil [104],... 

Kurane, R. Miki, K. Ukekawa, K., and Yamamoto, J., Method for oxidation of organic sulfur compound included in organic compound and method for oxidative desulfurization of fuel oil. Patent No. JP2001151748. 2001, June 05. 

Extractive Oxidative Desulfurization of fuels with Hydrogen Peroxide in presence of catalysts... 

FIGURE 2-7. Desulfurization of Fuel Organic Compounds Through Hydrotreatment... 

On the supply side, sulfur production is now controlled more by the demand for energy through the desulfurization of fuels than by the demand for sulfur per se, and this tendency is increasing. In 1965 involuntary byproduct recovered sulfur amounted to less than 20% of total elemental sulfur production in the United States and Canada, but by 1980 over 60% of all elemental sulfur resulted from refinery and natural gas processing operations. Many future hydrocarbon energy sources (coal, deep gas, heavy oil, shale, etc.) contain considerably more sulfur compared with conventional hydrocarbon fuels, and thus their exploitation will add to the ever increasing supply of by-product sulfur. 

Tam, P.S., Kittrell, J.R., and Eldridge, J.W. Desulfurization of fuel-oil by oxidation and extraction. 1. Enhancement of extraction oil yield. Industrial Engineering Chemistry Research, 1990, 29, 321. 

Hangun, Y., Alexandrova, L., Khetan, S., Horwitz, C., Cugint, A., Link, D.D., Howard, B., Collins, T.J. Oxidative desulfurization of fuels through TAML activators and hydrogen peroxide. Preprints of Papers—American Chemical Society Division of Petroleum Chemistry, 2002, 47, 42. 

Campos-Martin, J.M., Capel-Sanchez, M.C., and Fierro, J.L.G. Highly efficient deep desulfurization of fuels by chemical oxidation. Green Chemistry, 2004, 6, 557. 

The removal of the carbon-forming asphaltenes and catalyst-fouling metals also reduces the process costs for desulfurization of fuel oil. 

Ando, J., Recent Developments in Desulfurization of Fuel Oil and Waste... 

The total amount of vanadium in residual fuel oil is probably greater than in any other product of petroleum refining. About 668 million barrels of fuel oil were consumed in the United States in 1968, and this material is estimated to have contained nearly 19,000 tons of vanadium. At the current price, this amount of vanadium is worth about 100 million. Desulfurization of fuel Oil can reduce the vanadium content about proportionate to the reduction of sulfur.If fuel oil is desulfurized to reduce atmospheric pollution, can a significant amount of vanadium be recovered profitably from the catalysts used in the desulfurizing process or at some other stage in this process ... 

Cooney, C.L., D. Hopkins, D. Petrides, and D.J. Monticello, Microbial Desulfurization of Fuels A Process Engineering Perspective, Dept. Chem. Eng., M.I.T., Cambridge, MA (1991). 

Low-sulfur fuels are expensive and not readily available in many areas where population density is the greatest. Desulfurization of fuels is also expensive, and the technology for desulfurizing coal is still in the development stage. A few nuclear power plants are being built today. Safety and health concerns about nuclear facilities make it unlikely that there will be an outburst of building such facilities for some years to come. 

The physically adsorbed gas can be removal by degassing in vacuum or in an inert gas, although the elemental sulfur that is present in the form of very stable carbon-sulfur surface groups can only be recovered by heat treatment in hydrogen gas at 500°C. The work carried out by different workers on the desulfurization of fuel gases using activated carbons is discussed in more detail in Chapter 5 of this book. 

There are several options to improve (deep) desulfurization of fuels (i) better catalysts for deep HDS based on noble metals are on the market and still the focus of research (e.g., Fujikawa et al., 2001 Navarro et al., 1996 Reinhoudt et al, 1999 Robinson et al, 1999) (ii) alternative processes have been developed like the adsorption process SZorb (Sughrue, 2003) and (iii) extraction of organic S-compounds by novel extraction media like ionic liquids is now also considered (Boesmann et al, 2001 Esser et al, 2004). 

DESULFURIZATION OF FUELS BY SELECTIVE ADSORPTION FOR ULTRA-CLEAN FUELS... 

Figure 1. Pretreatment adsorptive denitrogentation and direct adsorptive desuifurization processes for the ultra deep desulfurization of fuels.

Jiang, X. Nie, Y. Li, C. Wang, Z. (2008). Imidazolium-based alkylphosphate ionic liquids -A potential solvent for extractive desulfurization of fuel. Fuel 87, 79-84, ISSN 0016-2361. 

Desulfurization of Fuels Catalyzed by Phosphotungstic Acid in Ionic Liquids at Room Temperature. Energy Fuels, 23,1354-1357, ISSN 0887-0624. 

Lissner, E. de Souza, W. F. Ferrera, B. Dupont, J. (2009). Oxidative Desulfurization of Fuels with Task-Especific Ionic Liquids. Chemsuschem, 2, 962-964, ISSN 1864-5631. 

Zhang, J. Zhu, W. Li, H. Jiang, L. Jiang, Y. Huang, W. Yan, Y. (2009). Deep oxidative desulfurization of fuels by Fenton-like reagent in ionic liquids. Green Chem., 11, 1801-1807, ISSN 1463-9270. 

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