Desulfurization, coal

R. W. Coughlin, R. D. Siegel, and C. Rai, eds., AICbE Sjmp. Ser. 70, (137) (1974). Contains four papers on flue gas desulfurization, four papers on coal desulfurization, and three papers on petroleum desulfurization. 

Flotation or froth flotation is a physicochemical property-based separation process. It is widely utilised in the area of mineral processing also known as ore dressing and mineral beneftciation for mineral concentration. In addition to the mining and metallurgical industries, flotation also finds appHcations in sewage treatment, water purification, bitumen recovery from tar sands, and coal desulfurization. Nearly one biUion tons of ore are treated by this process aimuaHy in the world. Phosphate rock, precious metals, lead, zinc, copper, molybdenum, and tin-containing ores as well as coal are treated routinely by this process some flotation plants treat 200,000 tons of ore per day (see Mineral recovery and processing). Various aspects of flotation theory and practice have been treated in books and reviews (1 9). 

E. P. Stambaugh in Coal Desulfurization, Chemical and Physical Methods, ACS Symposium Series 64, American Chemical Society, Washington, D.C., 1977, p. 198. 

Corex process. The Corex or Cipcor process has integral coal desulfurizing, is amenable to a variety of coal types, and generates electrical power in excess of that required by an iron and steel mill which can be sold to local power grids. A Corex plant is in operation in South Africa, and other plants are expected to be operational in South Korea and India. 

Some cokeless technologies in use or under development include the Japanese direct iron ore smelting (DIOS) process, in which molten iron is produced directly with coal and sinter feed ore, the HIsmelt process, where ore fines and coal are used to achieve a production rate of 8 t/h using ore directly in the smelter, and the Corex process, which has an integral coal desulfurizing step, making it amenable to a variety of coal types.14... 

At the beginning of the 1990s, Houston Industries developed an enzymatic process ( Enzymatic Coal Desulfurization ) protected in Canada and US [83,84], Although, the application was focused to coal desulfurization it may also be applicable to crude oil and fossil fuel-derived liquids. The processes claim the removal of both, organic as well as inorganic sulfur species. The process was described as using ground coal (10-50 p,m) slurried with water, while the oil was treated in an aqueous emulsion. 

The second patent describes the use of a microbial mixed culture (Hansenula sydowiorum, Hansenula ciferrii, Hansenula lynferdii, and/or Cryptococcus albidus) in coal desulfurization [160], In this process, the raw mined coal is ground to a particle size smaller than 200 mesh forming a slurry with water, at a solids concentration of less than 40wt%. The bacterial cultures are then inoculated into the feedstock slurry. An incubation step is carried out at a temperature near 25°C and at a pH close to neutral. The highest removal achieved was in the range of 46% S removal. 

R. A. Meyers, Coal Desulfurization. Dekker, New York, 1977 L. D. Smoot (ed.), Fundamentals of Coal Combustion. Elsevier, Amsterdam, 1993 R. C. Eliot, Coal Desulfurization Prior to Combustion. Noyes Data, Park Ridge, New Jersey, 1978. 

In a coal desulfurization study, Narayan et al. (50) were able to extract an appreciable amount of elemental sulfur (36% of total sulfur) with perchloroethylene at 120 °C from weathered coal, but not from fresh coal. Hackley et al. (51) determined the isotopic composition of elemental sulfur extracted by perchloroethylene and obtained results consistent with the interpretation that the elemental sulfur originates from the oxidation of pyrite. 

Paris, B. In Coal Desulfurization. Chemical and Physical Methods Wheelock, T. D., Ed. ACS Symposium series No. 64 American Chemical Society Washington, DC, 1977 pp 22-31. 

Rasa coal has generated substantial interest over the years because of its high organic sulfur content. Information concerning the nature and distribution of organic sulfur moieties in coal is desirable for the design and evaluation of coal desulfurization processes. A major impediment to the character-... 

Coal Desulfurization by Programmed-Temperature Pyrolysis and Oxidation... 

In this work, consideration has been given to the significance of the peaks and shoulders in the gas profiles from PTP and PTO to provide insight into the processes of coal desulfurization. 

Fossil fuels—Environmental aspects—Congresses. 2. Environmental chemistry—Congresses. 3. Coal-Desulfurization—Environmental aspects—Congresses. 

Stambaugh, E. P. "Hydrothermal coal process," in Coal Desulfurization Chemical and Physical Methods (ACS SympV Series 64),... 

Coal Desulfurization and Demineralization by Molten Caustic Mixtures... 

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