Energy Center - CCTR

Development of Coking/Coal Gasification Concept

December 30, 2010

Executive Summary

This report summarizes efforts for the third phase of a research project concerned with the development of a new environmentally friendly method to produce coke using a blend of Indiana and conventional metallurgical coals in a Multipurpose Coke Facility. In addition, the developed process provides for additional value streams that can further increase the benefit of the process and additionally reduce the influence of coke market price volatility. This effort has developed new technology that enhances the economics of the coke production process by enabling the use of blends of lower cost Indiana coal with conventional metallurgical coal as well as providing multiple value streams for the coke production process. The multiple process value streams are continuously optimized to maximize value. Coal samples from Indiana mines have been collected and tested for suitability in producing coke for use in blast furnaces in the steel industry. Initial test results indicate that it is possible to use coal blends containing up to 40% Indiana coal and maintain the desired chemical and physical properties for producing coke suitable for use in large blast furnaces. These samples will serve as a data base for the next phase of the testing and development efforts targeted at development of a larger scale test of the basic process.

Coke is a solid carbon fuel and carbon source produced from coal that is used to melt and reduce iron ore. Although coke is an absolutely essential part of iron making and foundry processes, currently there is a shortfall of 5.5 million tons of coke per year in the United States. The shortfall has resulted in increased imports and drastic increases in coke prices and market volatility. For example, coke delivered FOB to a Chinese port in January 2004 was priced at $60/ton, but rose to $420/ton in March 2004 and in September 2004 was $220/ton. This makes clear the likelihood that prices will remain high.

The market price of coke has varied from $130 to $800/ton since 2009. Such fluctuations have caused considerable production planning issues. The current research, through the use of optimized multiple value streams, can reduce the effects of this market volatility by providing alternative revenue streams from multiple products including coke, fertilizer, electricity, Fischer-Tropsch transportation fuels, and hydrogen. It also helps to produce jobs and a new market for Indiana coal.

This effort has considered the suitability of and potential processes for using Indiana coal for the production of coke in a mine mouth or local coking/gasification-liquefaction process. Such processes involve multiple value streams that reduce technical and economic risk. Initial results indicate that it is possible to use blended coal with up to 40% Indiana coal in a non recovery coke oven to produce pyrolysis gas that can be selectively extracted and used for various purposes including the production of electricity and liquid transportation fuels and possibly fertilizer and hydrogen. At present essentially all of the coal used for coke production in Indiana’s steel industry is imported from outside Indiana.

Indiana is home to roughly 22% of the domestic base steel production for the United States. One essential raw material needed by this industry is coke. Current 2005 forecasts indicate that the United States will produce 11,500,000 net tons of coke, but will require 17,000,000 net tons for blast furnace, foundry, and related uses.i At present, essentially no Indiana coal is being used for coke production. In 2002, Indiana’s steel industry used an estimated 10.7 million tons of coal. Of this, approximately 8.1 million tons was used for coke production.ii Essentially all of this coking coal comes from Kentucky, West Virginia and Virginia.

The significant shortfall of needed coke has placed an enormous strain on Indiana’s steel industries. This report describes initial results of the development of a process that can provide at least a partial resolution and/or mitigation of this formidable problem through the use of Indiana coal in a mine mouth or local, environmentally friendly, high efficiency coking/coal gasification facility which would increase coke supply and production, while, at the same time, reducing the cost for Indiana’s steel and foundry industry.

In this phase of the research, a new furnace and test system was placed in operation. Pyrolysis gas is now transmitted directly to the gas chromatograph for analysis through tubing connected to a selector valve. This has improved the accuracy of the data. An expansion of the test system to have the capability of testing up to 5 samples of coal simultaneously is being developed.

The next steps in this effort entail additional laboratory testing of Indiana and other coals alone and in blends in conjunction with process design efforts. Washed coal samples were obtained from Indiana coal mines in southern Indiana. These samples were sealed under Argonne gas to minimize the influence of oxygen on the characteristics of the coal. Tests of physical and pyrolysis gas characteristics of the samples are currently under way. Blends of these coals with metallurgical coal are being tested for pyrolysis gas composition as a function of temperature as well as physical and chemical characteristics. Recently, a new design non recovery coke oven has been introduced in China. This is essentially a vertical non recovery coke oven. Initial indications are that it provides the emission reduction benefits of a vertical design and additional operational benefits. This design has the potential to further extend the economic and environmental efficiency and process benefits made possible by this research effort.

The general conclusion of this study is that it is possible to use a blend of Indiana and conventional metallurgical coal to produce coke for use in various industrial applications at reduced cost while maintaining quality requirements. In addition, there is also potential to also use gas produced in the coking process for a variety of purposes including production of electricity, liquid transportation fuel, fertilizer, and hydrogen.

A patent application has been filed for the developed process by the Purdue Research Foundation. Currently efforts are underway to conduct larger scale process testing that will lead to commercialization of the process and an associated increase in the use of Indiana coal.

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CONTACTS

Marty W. Irwin, Director
Phone:  765.494.7414 or 317.232.8970
mwirwin@purdue.edu

Steven F. Son, Associate Director
Phone:  765.494.8208
sson@purdue.edu

Indiana Center for Coal Technology Research
Energy Center at Discovery Park
Purdue University
203 S Martin Jischke Drive
West Lafayette IN 47907-1971 USA
cctr@ecn.purdue.edu
Phone: 765.494.7037 (leave message, please)
Fax: 765.494.6298