Moist caustic leaching of coal
Abstract
A process for reducing the sulfur and ash content of coal. Particulate coal is introduced into a closed heated reaction chamber having an inert atmosphere to which is added 50 mole percent NaOH and 50 mole percent KOH moist caustic having a water content in the range of from about 15% by weight to about 35% by weight and in a caustic to coal weight ratio of about 5 to 1. The coal and moist caustic are kept at a temperature of about 300.degree. C. Then, water is added to the coal and caustic mixture to form an aqueous slurry, which is washed with water to remove caustic from the coal and to produce an aqueous caustic solution. Water is evaporated from the aqueous caustic solution until the water is in the range of from about 15% by weight to about 35% by weight and is reintroduced to the closed reaction chamber. Sufficient acid is added to the washed coal slurry to neutralize any remaining caustic present on the coal, which is thereafter dried to produce desulfurized coal having not less than about 90% by weight of the sulfur present in the coal feed removed and having an ash contentmore »
- Inventors:
-
- Elizabeth, PA
- Issue Date:
- Research Org.:
- USDOE Pittsburgh Energy Technology Center (PETC), PA (United States)
- OSTI Identifier:
- 869300
- Patent Number(s):
- 5312462
- Assignee:
- United States of America as represented by United States (Washington, DC)
- Patent Classifications (CPCs):
-
C - CHEMISTRY C10 - PETROLEUM, GAS OR COKE INDUSTRIES C10L - FUELS NOT OTHERWISE PROVIDED FOR
- Resource Type:
- Patent
- Country of Publication:
- United States
- Language:
- English
- Subject:
- moist; caustic; leaching; coal; process; reducing; sulfur; ash; content; particulate; introduced; closed; heated; reaction; chamber; inert; atmosphere; added; 50; mole; percent; naoh; koh; water; range; 15; weight; 35; ratio; kept; temperature; 300; degree; mixture; form; aqueous; slurry; washed; remove; produce; solution; evaporated; reintroduced; sufficient; acid; neutralize; remaining; thereafter; dried; desulfurized; 90; feed; removed; caustic solution; coal feed; reaction chamber; mole percent; inert atmosphere; coal slurry; aqueous slurry; particulate coal; weight ratio; water content; ash content; heated reaction; aqueous caustic; percent na; caustic leaching; closed reaction; closed heat; /44/
Citation Formats
Nowak, Michael A. Moist caustic leaching of coal. United States: N. p., 1994.
Web.
Nowak, Michael A. Moist caustic leaching of coal. United States.
Nowak, Michael A. Sat .
"Moist caustic leaching of coal". United States. https://www.osti.gov/servlets/purl/869300.
@article{osti_869300,
title = {Moist caustic leaching of coal},
author = {Nowak, Michael A},
abstractNote = {A process for reducing the sulfur and ash content of coal. Particulate coal is introduced into a closed heated reaction chamber having an inert atmosphere to which is added 50 mole percent NaOH and 50 mole percent KOH moist caustic having a water content in the range of from about 15% by weight to about 35% by weight and in a caustic to coal weight ratio of about 5 to 1. The coal and moist caustic are kept at a temperature of about 300.degree. C. Then, water is added to the coal and caustic mixture to form an aqueous slurry, which is washed with water to remove caustic from the coal and to produce an aqueous caustic solution. Water is evaporated from the aqueous caustic solution until the water is in the range of from about 15% by weight to about 35% by weight and is reintroduced to the closed reaction chamber. Sufficient acid is added to the washed coal slurry to neutralize any remaining caustic present on the coal, which is thereafter dried to produce desulfurized coal having not less than about 90% by weight of the sulfur present in the coal feed removed and having an ash content of less than about 2% by weight.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Sat Jan 01 00:00:00 EST 1994},
month = {Sat Jan 01 00:00:00 EST 1994}
}