Part 2 CCT Overview
Technologies for Coal Resources Development

1A4. Environment-friendly Resource Development Technology
Technology Overview

1. Background
Through on-site demonstrations of carbon dioxide fixation in coal

recovery through the underground gasification of coal resources,

seams, the reservoir characteristics of coal seams in Japan werewhich may offer significant environmental benefits. The

identified in order to collect basic data on carbon dioxide. In

development and commercialization of CDM projects were also

addition to conventional coal preparation and reforming, andaddressed.

CMM collection and utilization, efforts were made to study energy
2. Technologies to be developed(1) Coal preparation and reforming technology[1] Coal preparation technology is used in Indonesia toefficiently sort raw coal with different properties in order toensure stable product quality and reduce the environmental
burden. Japan manufactured part of the equipment necessary
for improving existing coal preparation plants in Indonesia. To
introduce jigging feedback control using on-line ash monitors
to the coal preparation process in Indonesia, Japan
formulated a control rule on a trial basis from the results of a
feedback control applicability test.
[2] To promote the effective use of low-rank coal, a reforming

Flotation machine

plant using the upgrading brown coal (UBC) process (rawcoal processing capacity: 5 tons/day) was subjected to test
operations in Indonesia, where, compared to other countries,
a relatively higher percentage of brown coal reserves exist. In
the UBC process, low-rank coal is dehydrated in an oil slurry
to stabilize it and make it water-repellent under moderateconditions. In the test plant, various types of Indonesian coalwith different properties were tested. The data obtained wasused for evaluation tests on spontaneous combustion,combustibility and other properties. It was ultimately
confirmed that the reformed coal had handling properties andcombustibility equal to or greater than those of bituminous

Heavy media cyclone

coal.

Effluent thickener
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Clean Coal Technologies in Japan(2) Global environmental technology[1] To suppress the release of carbon dioxide (CO2) to theCO2 is injected at the maximum allowable pressure that willatmosphere, a preliminary test on a new technology to

not induce the crushing of the coal seam. More than 900

sequester CO2 in deep coal seams has been conducted intons of CO2 are planned to be injected. Hydraulic fracturing

the southern part of Yubari City in Hokkaido. The site

tests of the coal seams are due to be conducted to improve

injection test will be conducted through FY2006, aiming togas injections and coal productivity.

successfully sequester CO2 in PW-1, a methane gas[2] A site test of a technique for the stable collection andobservation well. Since the injection well IW-1, drilled inutilization of methane gas escaping from coal mines wasFY2003, is expected to have lower permeability due to CO2

carried out at an abandoned domestic mine in Hokkaido.

absorption and swelling, N2 gas is injected to reduce CO2
absorption and subsequently improve the permeability. N2
gas is also used as a preliminary gas for CO2 sequestration.

Current status

Capture and utilization

MethaneTotal methane emissions from coal mines
worldwide are 25 million tons per year, of
which 6% is captured and utilized.
(Source: IEA- Global methane and the coal industry)

Boiler andgenerator
ExhaustfanExhaust
fanGas tank

Main shaft

MethaneExhaust
shaft

Coal seam

MethaneGas released tothe surface

Coal seam

MethaneConceptual drawing of coal mine methane gas capture and utilization

22Gasreleasedfromunderground

Exhaustshaft

Methane