INTERIM FINAL TECHNICAL
REPORT
November 1, 1999,
through October 31, 2000
Project
Title:
COMBUSTION TESTS ON COAL
PREPARATION WASTES FIRED THROUGH MICROCOMBUSTION UNITS
ICCI Project Number: 99-1/1.1B-1
Principle Investigator: B. C. Paul, Southern Illinois University at Carbondale
Project Manager: Ken Ho, ICCI
An effort is underway to reduce the cost of coal produced from Illinois coal mines by 33 cents to $1/ton using technology developed in ICCI and IDCCA programs. The reductions are to come by installing small microgeneration power stations fired with waste coal fines at Illinois coal mines. This project supports the commercialization effort by providing for a test burn that will demonstrate (1) that the hearth of a Combustion Coupled Gasifier (CCG) TM can handle and gasify Illinois coal fines without excessive loss, injector or auger clogging or clinker formation (2) that air emissions will meet Illinois new source performance standards (SO2 control is a major topic of this report) and (3) the ash product has commercial potential and/or relatively environmentally benign. Efforts are underway in other projects or proposed projects or private commercial activities to finalize the design and finance. Commitments from the Illinois Clean Coal Review Board have been received for partial funding of the first project.
During this project period work has been done to demonstrate that adequate fuel should be available at the two proposed mine sites, that the fuel should be suitable for the hearth design now under construction at the manufacture, and that the State’s new source performance standards for SO2 can be met, even though both mines have high sulfur coal. Beneficiation tests have also be run at the coal park to verify the operation of equipment used to enhance the feed stream.
Combustion Coupled Gasification (CCG) TM is a small gasifier technology. The fuel (in this case coal fines) is fed into a gasification chamber and heated to around 1250 F. The organic chains in the coal break down into synthetic natural gas. The syn-gas moves directly into a cyclonic burn chamber. The hot flue gas from the burn chamber moves into a boiler and powers a conventional steam cycle to produce electricity. The electricity can then be used directly at the mine site. The technology is robust, consists of mostly proven components and can be installed at mine sites for roughly the same capital cost per kilowatt of capacity as large coal fired stations can be built. Because the system uses waste fuel with a low to negative value the mine incurs little fuel cost compared to grid power plants. Because the system is already on the mine site there is no transmission cost. Most mines spend 4.5 cents to 6.2 cents per kilowatt hour for electricity and run $1 to $1.50/ton of clean coal. The operating cost for CCG based systems is about 1.7 cents per kilowatt hour. Thus the system can produce savings in the 33 cent to 60 cent per ton of coal produced even during capital payback, with larger savings in the long run.
This project supports the commercialization effort for CCG based microgeneration by providing for (1) physically demonstrated gasification of Illinois coal fines, (2)- Emissions data for permitting, (3)- ash samples for characterization of economic opportunities and proof of low environmental risk. Other projects and private efforts are committing the first mines for the system, lining up investor capital, finalizing designs and initiating permiting.
Work completed to date on this project has included size by size analysis of the fine coal refuse from Turris mine. The results show that coal with 25% ash or less is available down to and below 400 mesh. It thus appears likely that the minus 100 mesh rejects at Turris and probably Zeigler #11 have the fuel value needed to power self generation systems. Tests with the Falcon concentrator have rejected enough sulfur from the fines that with the guaranteed performance of a duct sorbant injection system the CCG based power plants will meet State new source performance standards. Further work shows that available equipment can be configured to reduce ash without use of flotation, but the hydrocyclone results were not as sharp as one would hope.
The coal for the test burn is being loading and arrangements have been made for shipping. The major task for completion is the test burn itself, which is in the hands of a subcontractor to be performed along the lines of a signed agreement with Combustion Consultants (now Renewable Energy).