China - Coal Liqfuefaction wiht Coke Oven Gas

August 01, 2009

ScienceDirect - Fuel : Co-pyrolysis of coal with hydrogen-rich gases. 1. Coal pyrolysis under coke-oven gas and synthesis gas

We've been documenting how the by-products of our coal use, such as Carbon Dioxide and Coke Oven Gas, can be collected, and then combined with coal to actually enhance the efficiency and productivity of coal conversion processes designed to produce, as end products, liquid fuels and chemicals, or plastics manufacturing feed stocks.

From China, where a truly intensive coal-to-liquid conversion industrial development is underway, comes this research result confirming that a steel-making by-product of coal use, from the coking process, Coke Oven Gas, can be combined with coal to enhance and improve the hydrogenation of coal into valuable hydrocarbons, such as liquid fuel.

As follows:

"Co-pyrolysis of coal with hydrogen-rich gases. 1. Coal pyrolysis under coke-oven gas and synthesis gas

Hongqiang Liao, Baoqing Li and Bijiang Zhang

State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, Shanxi 030001, China

Abstract

To improve the economy of the hydropyrolysis process by reducing the cost of hydrogen, it has been suggested that cheaper hydrogen-rich gases (such as coke-oven gas, synthesis gas) could be used instead of pure hydrogen. Pyrolysis of Chinese Xianfeng lignite was carried out with real coke-oven gas (COG) and synthesis gas (SG) as reactive gases at 0.1–5 MPa and at a final temperature up to 650°C with a heating rate of 5–25°C min−1 in a 10 g fixed-bed reactor. The results indicate that it is possible to use COG and SG instead of pure hydrogen in hydropyrolysis, but that the experimental conditions must be adjusted to optimize the yields of the valuable chemicals."

Another point to be made is that the Chinese researchers seem to indicate that "recycling" the synthesis gas derived from the coal decomposition back into the pyrolysis of more coal also improves the hydrogenation process.

But, definitely: A coal-use by-product of steel-making, coke-oven gas, which was once a troublesome and polluting effluent, can be collected and added to coal as an additional raw material which enhances and improves the conversion of coal into liquid fuel.