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Title: Investigation of a sulfur reduction technique for mild gasification char. Final technical report, September 1, 1992--August 31, 1993

Technical Report ·
DOI:https://doi.org/10.2172/10132408· OSTI ID:10132408
 [1]
  1. Institute of Gas Technology, Chicago, IL (United States)

The objective of this program is to investigate the desulfurization of mild gasification char using H{sub 2}:CH{sub 4} mixtures. Mild gasification of coal produces char, liquids, and gases at 1000{degrees}--1500{degrees}F and near-ambient pressure. Char, comprising 60--70% of the product, can be used to make high-value form coke for steel making and foundries. A sulfur content below 1 wt% is desirable, and char from high-sulfur Illinois coals must be upgraded to meet this criterion. In the first year of the program, Illinois No. 6 chars were treated in a batch fluidized bed with H{sub 2}:CH{sub 4} blends containing 9--24 vol% CH{sub 4} at 1100{degrees}--1600{degrees}F and 50--200 psig. Sulfur removals up to 92.5 wt% were obtained, and the char desulfurization susceptibility was related to porosity, density, and carbon crystallite size. During the second year, the relationships among mild gasification parameters, char properties, char desulfurization susceptibility, and form coke properties were studied. Acid washing of coal to remove Ca and Fe was explored for its effect on subsequent sulfur removal, and secondary desulfurization of form coke produced from the desulfurized chars was studied. Desulfurization tests of entrained and fluidized-bed reactor chars from IBC-105 coal were completed. Acid-washing of the coal prior to mild gasification or the char prior to desulfurization increased its susceptibility to desulfurization, with sulfur content reduced to as low as 0.10 wt % dry char. Fluidized-bed chars were easier to desulfurize than entrained chars, with or without acid-washing. Form coke briquettes were prepared from selected chars and mild gasification pitch binder, and then carbonized under both N{sub 2} and H{sub 2}:CH{sub 4} atmospheres. carbonization in H{sub 2}:CH{sub 4} removed additional sulfur from the form coke. Adequate tensile strength (837 psi) was achieved in briquettes with 1.2 wt% sulfur made from desulfurized char.

Research Organization:
Illinois Dept. of Energy and Natural Resources, Springfield, IL (United States)
Sponsoring Organization:
USDOE, Washington, DC (United States)
DOE Contract Number:
FC22-92PC92521
OSTI ID:
10132408
Report Number(s):
DOE/PC/92521-T88; ON: DE94008030; TRN: 94:003522
Resource Relation:
Other Information: PBD: [1993]
Country of Publication:
United States
Language:
English