Part 2 CCT Overview
Multi-purpose Coal Utilization Technologies (Liquefaction Technologies)

4A3. Brown Coal Liquefaction Technology (BCL)
Research and development: New Energy and Industrial Technology Development Organization;
Kobe Steel, Ltd.; Nissho Iwai Corp.; Mitsubishi Chemical Corp.; Cosmo Oil Co., Ltd.; Idemitsu Kosan Co., Ltd.;and Nippon Brown Coal Liquefaction Co., Ltd.
Project type: Development of Brown Coal Liquefaction Technology; Development of Basic Liquefaction Technology;
Coal Liquefaction International Cooperation Project; and other projects
Period: 1981-2002 (21 years)

Technology overview

1. Background and process overview
Economically recoverable coal reserves are expected to total

As shown in Figure 1, the BCL process has four stages: theabout one trillion tons, about one-half of which are comprised ofslurry dewatering stage, where water is efficiently removed fromlow-rank coal such as sub-bituminous coal and brown coal. Coal

low-rank coal; the liquefaction stage, where liquefied oil

has a larger ratio of reserves to production (R/P) than that of oil

production yield is increased by using a highly active limoniteand natural gas. For the effective utilization of coal, however, thecatalysteffective use of low-rank coal is essential. Low-rank coal containshydrotreatment stage where the heteroatoms (sulfur-containing

a large amount of water, but unlike bituminous coal and othercompounds, nitrogen-containing compounds, etc.) in the coal-

higher rank coals, has an autoignition property in a dry state.

liquefied oil are removed to obtain high quality gasoline, diesel

Consequently, brown coal liquefaction technology developmentoil, and other light fractions; and the solvent de-ashing stage

has progressed with the aim to use it to contribute to a stable

where the ash in coal and the added catalysts are efficiently

supply of energy in Japan by converting the difficult-to-use low-discharged from the process. In Asian countries, economic

rank coal into an easy-to-handle and useful product, or by using it

growth has steadily increased energy demand, and countries

to produce clean transportation fuels such as gasoline and diesel

possessing low-rank coal resources, such as Indonesia,

oil.

anticipate commercialization of the technology.

Liquefaction stage

andbottom

recyclingtechnology;

theIn-line hydrotreatment stage
Sulfurrecovery unitHydrogen

SulfurRecycle gas
Recycle gas

Slurry dewatering stage

Off gaspurification unit

Product gas(Fuel gas)

ReactorCoal(Raw brown coal)Hydrogenatedlight oil

Water
Evaporator
Fixed-bedhydrogenation
reactorDistillation column

Hydrogenatedmedium oil

Solvent de-ashing stage

Preheater
Slurry charge pump

Catalyst supply unit

Settler
CLB (heavy oil)separator
Sludge

CLB recycle

CLB

Solvent recycle
DAO (deashed heavy oil) recycle

Fig. 1 Flowchart of BCL process

61(Boiler fuel)in-lineClean Coal Technologies in Japan

2. Development objectives and developed technology
A pilot plant (Photo 1) study conducted under thegovernmental cooperation of Japan and Australia
set the following technical targets:(1) High liquefied oil production yield: 50% orgreater(2) Long-term continuous operation: 1,000 hours
or greater(3) High deashing performance: 1,000 ppm or
less(4) Establishment of new slurry dewatering
process. Through four years of operation andstudy (1987- 1990), all of the above targets wereachieved. Furthermore, scale-up data necessary
to construct commercial liquefaction plants andexpertise on plant operation were obtained
through pilot plant operation. During the study
period, (the 1990s), however, oil prices were low

Photo 1 Fifty t/d Pilot plant (Australia)

and supplies were stable worldwide. Thus, further
improvements in the economics of the coal liquefaction processcatalytic activity through bottom recycling technology; an in-line

were vequired and cleaner liquefied oil was demanded owing tohydrotreatment technology that significantly improves the quality

increased environmental concerns. Accordingly, a bench-scaleof coal-liquefied oil; and various improvements for increasing

plant (0.1 t/d) in Kobe Steel, Ltd.’s Takasago Works wasoperational reliability. Through the development work, anconstructed to conduct a study for improving the process. Results

improved BCL process (Improved Brown Coal Liquefactionof the study included the development of: a limonite catalyst, anProcess: refer to the flowchart on the preceding page) that

extremely active catalyst compared to existing liquefaction

significantly

catalysts, and one possessing superior handling properties, suchenvironmental compatibility of the brown coal liquefaction

as excellent crushing characteristics; a method to maintainprocess was established.

improvestheeconomics,reliability,and3. Progress and development results
On the basis of a memorandum of understanding on cooperativeIndonesian engineers through technical training and the supply ofcoal liquefaction research between the Agency for theliquefaction testing equipment. In 1999, the study team selectedAssessment and Application of Technology of Indonesia and thethree candidate sites for a liquefaction plant in Indonesia, andNew

Development

carried out a feasibility study on coal liquefaction, including anOrganization, a study team carried out surveys and liquefaction

economic evaluation. The feasibility study revealed that coaltests of low-rank coal in Indonesia beginning in 1994, in additionliquefaction would be economically feasible at a given oil price.

EnergyandIndustrial

Technology

to screening candidate coals for liquefaction. Furthermore, theteam endeavored to increase the technical abilities of the4. Issues and feasibility of practical application
Due to steady economic growth, energy demand in Asianenergy security of Japan, brown coal liquefaction technology thatcountries is rapidly increasing. Since the stable supply of energy

utilizes low-rank coal will play an important role.

from Asian countries to Japan significantly contributes to theReferences

1) Shunichi Yanai and Takuo Shigehisa: CCT Journal, Vol. 7, p. 29, 2003.
2) Report of the Results of the International Coal Liquefaction Cooperation Project, Cooperative Study of Development of Low GradeCoal Liquefaction Technology, 2003.

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