Part 2 CCT Overview
Coal-fired Power Generation Technologies (Gasification Technologies)
2B1. Hydrogen-from-Coal Process (HYCOL)
Research and development: HYCOL Association [Idemitsu Kosan Co., Ltd. ; Osaka Gas Co., Ltd.;
J-POWER; Tokyo Gas Co., Ltd.; Toho Gas Co., Ltd.; Nikko Kyoseki Co., Ltd.; The Japan Steel Works, Ltd.;
Hitachi Ltd.; and Mitsui Coal Liquefaction Co., Ltd.]
Project type: NEDO entrusted project
Technology Overview
1. Background and process overview
The Hydrogen-from-Coal Process (HYCOL) is a gasification (2) Slag self-coating technology for the water-cooled tubes was
technology utilizing an entrained bed, in which pulverized coal is applied. This technology prolongs the life of the tubes and
gasified with oxygen under high temperatures and high pressure. improves the reliability of the gasifier.
Through the gasifier, medium calorific gas, rich in hydrogen and (3) A swirling gas flow distributor was developed and adopted as
carbon monoxide, is obtained. The technology is called the a technology to easily and uniformly distribute coal to multiple
"HYCOL process." Through the shift reaction, the gas yields burners.
carbon monoxide and converts steam to carbon dioxide and (4) Ash in coal is melted in the gasification furnace. The melted
hydrogen. After separating the carbon dioxide, the gas is purified ash is discharged through the slag hole located in the furnaces
to become high-purity hydrogen. hearth. As a result of the swirling gas flow, a high temperature is
Hydrogen is used in oil refineries and in the chemical industry, as maintained at the slag hole, ensuring a smooth flow of slag.
well as in the coal liquefaction process. On the other hand, the (5) The unreacted char discharged along with gas from the
gas containing carbon monoxide is expected to be used widely gasification furnace is separated by a cyclone or other such
as a raw material for synthetic chemical products, as a fuel for device to recycle the material to the gasification furnace in a
fuel cells, and as a fuel in various industries. high-temperature, high-pressure state, thus ensuring a complete
The HYCOL process has the following features: reaction.
(1) The process uses a dry-feed, one-chamber, two-stage (6) Ash in the coal is recovered as slag, which does not elute
swirling-entrained-bed gasification furnace. Pulverized coal, toxic components. Combined with the advantage of an easy
pressurized in a lock hopper, is fed, to the gasification furnace via recovery of the sulfur and nitrogen components, in the form of
burners in a swirling mode. Four burners are utilized in each H2S and NH3, respectively, the ash recovery also significantly
stage. The oxygen feed and the gasification rate at the upper contributes to a reduction in the environmental burden.
stage and lower stage are separately controlled. Throughout the Coal that has a lower fuel ratio (fixed carbon to volatile matter) is
operation, high thermal efficiency is attained, and heavy load more easily gasified.
gasification is performed.
2. Progress and development results 3. Issues and feasibility of practical application
The HYCOL association (made up of the nine above-listed The development of a coal gasification fuel cell system (IGFC) for
private companies) carried out the research and development of power generation utilizing HYCOL technology began in 1995,
the pilot plant, under entrustment from NEDO. Five private (EAGLE Project).
companies (Hitachi Ltd., Babcock-Hitachi K.K., Asahi Glass Co.,
Ltd., Shinagawa Refractories Co., Ltd., and NGK Spark Plug Co.,
Ltd.) carried out the basic study on the structure of the furnace
and on the materials, also under entrustment from NEDO.
For establishing the process, a pilot plant was constructed at
Sodegaura, Chiba. The operational study of the pilot plant was
conducted from 1991 to 1994. The performance target was
achieved, and the worlds most advanced gasification furnace
technology was established.
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Clean Coal Technologies in Japan
Water-washing
Pretreatment process Gasification process process Product gas incineration process
Boiler
Gasification
furnace
Lock Water-washing
tower
Coal hopper
Incineration
furnace Waste
Pulverized heat boiler
coal Distributor
apparatus Desulfurization unit
Lock
hopper
Air heater
Recycled gas
compressor
Ash treatment process
Fig. 1 Process flowchart of pilot plant
Pilot plant: Specifications and target performance
Coal throughput Max. 50 tons/day
Gasification agent Oxygen
Gasification pressure 30 kg/cm2(G)
Gasification temperature 1,500-1,800 C O
O2/Coal 0.8-0.9 (weight ratio)
Produced gas volume Approximately 91 kNm3/day
Gas composition CO 61%
(design) H2 31%
CO2 3%
Carbon conversion 98% or greater
Cold gas efficiency 78% or greater
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