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Title: Molten-Caustic-Leaching (Gravimelt) system integration project. Final report

Technical Report ·
DOI:https://doi.org/10.2172/10179993· OSTI ID:10179993

The objectives of this program were to design, construct, shakedown and operate an integrated MCL test circuit to demonstrate the technical capability of the process for producing a demineralized and desulfurized coal that meets New Source Performance Standards (NSPS), to test process conditions aimed at lower costs, and to deliver product coal. These objectives were met by the procurement, construction, and operation of the integrated test circuit. Shakedown and a 63-test process matrix resulted in the production of about 3,700 pounds of treated coal. Product MCL coal may be used to displace oil in some turbine and diesel engines and may be used in the retrofit of oil-fired boilers. Two high sulfur, high ash coals and one medium sulfur, high ash coal representative of the Eastern United States coal production were processed: Pittsburgh No. 8 (Powhatan No. 6 mine), Kentucky No. 9, and Pittsburgh No. 8 (Blacksville No. 2 mine). Although mild kiln operating conditions (325 to 415{degree}C and 1 to 2.3 hours residence time) and low caustic to coal ratios (1:1 to 3:1) were used, the combination of continuous operation and rigorous exclusion of air from the system allowed the production of MCL coal that had product sulfur content was well below NSPS standards, very low carbonate production, very little volatile losses, and low alkali retention by the product MCL coal. Optimization testing resulted in a product coal containing 0.2 to 0.4 percent sulfur (0.26 to 0.6 lbs SO{sub 2}/million Btu) and 0.15 to 0.5 percent ash with more than 90 percent organic sulfur removal, {approximately}95 percent SO{sub 2} reduction from run-of-mine coal, {approximately}91 percent SO{sub 2} reduction from precleaned process feed coal, and with heat content of about 14,000 Btu per pound.

Research Organization:
TRW Space and Electronics Group, Redondo Beach, CA (United States). Applied Technology Div.
Sponsoring Organization:
USDOE, Washington, DC (United States)
DOE Contract Number:
AC22-86PC91257
OSTI ID:
10179993
Report Number(s):
DOE/PC/91257-T18; ON: DE93041259
Resource Relation:
Other Information: PBD: Mar 1993
Country of Publication:
United States
Language:
English