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Title: Removal of mercury from powder river basin coal by low-temperature thermal treatment

Technical Report ·
DOI:https://doi.org/10.2172/10189789· OSTI ID:10189789

This report describes work conducted at Western Research Institute (WRI) to remove mercury from Powder River Basin (PRB) coal as part of the research performed under Task 2.1, Development and Optimization of a Process for the Production of a Premium Solid Fuel from Western US Coals, of the 1993 Annual Project Plan. In the tests minus 16 mesh PRB coal was fed to a bench-scale fluidized-bed reactor where it was heated by contact with carbon dioxide fluidizing gas. A side stream of the gas from the reactor was passed through traps containing activated carbon where mercury driven from the coal was collected. The feed coal (which contains about 0.062 milligrams of mercury/kilogram of coal), the fines elutriated from the reactor, the activated carbon, and the condensed water from the reactor were analyzed for mercury. The solid products were analyzed using cold vapor atomic adsorption spectroscopy (ASTM D3684) while the water was analyzed using US Environmental Protection Agency (EPA) Method 245.1 which is based upon reduction of mercury to elemental form followed by adsorption at a wave length of 253.7 nanometers. The results of these tests show that about 70 to 80 wt % of the mercury is removed from the coal when the temperature is raised from about 300{degree}F (149{degree}C) to about 550{degree}F (288{degree}C). The remaining 20 wt % of the mercury remains in the char at temperatures up to about 1100{degree}F (593{degree}C). About 0.5 wt % of the mercury in the feed coal is condensed with water recovered from the coal. Nearly all of the mercury driven from the coal remains in the gas stream. Fines elutriated from the reactor contain about the same concentration of mercury as the feed coal.

Research Organization:
Western Research Inst., Laramie, WY (United States)
Sponsoring Organization:
USDOE, Washington, DC (United States)
DOE Contract Number:
FC21-93MC30126
OSTI ID:
10189789
Report Number(s):
DOE/MC/30126-3916; WRI-93-R021; ON: DE95001591; BR: AA6510000/AA6525000
Resource Relation:
Other Information: PBD: Jul 1993
Country of Publication:
United States
Language:
English