IHI Corporation

Turning a Poorly Utilized
Fuel into a Useful Fuel
Twin IHI Gasifier (TIGAR®) can expand
the application of lignite and biomass.
The Twin IHI Gasifier (TIGAR®) is a circulating fluidized bed-type gasifier that can beoperated under milder conditions than other gasifiers. Based on proven fluidized bed andplant technologies, IHI can provide an economically attractive gasification process.

Twin IHI Gasifier (TIGAR®) pilot plant

Various types of energy sources are used in the world;
they include fossil fuels such as oil, natural gas, and coalas well as nuclear power, hydropower, wind power, solarpower, and biomass. Fossil fuels play a major role among
these sources because of their high energy density, ease oftransportation, and ease of use. Of these, oil is widely usedas transportation fuel and chemical raw materials. However,oil reserves are predominantly in the Middle East and theprice is unstable. Natural gas has no sulfur content andemits less CO2 than other fossil fuels. This environmentallyfriendly property is encouraging growth in its consumption.

10Correspondingly, the price is expected to increase in thefuture. Meanwhile, coal reserves are the most abundantamong the fossil fuels. It is distributed throughout many
countries, and most importantly, among politically stablecountries. Additionally, the price per calorific value is low
and stable in comparison with oil and natural gas, whichis the reason why coal is a key energy source in many
countries. However, half of the coal reserves consist of socalled low rank coals such as lignite and sub-bituminous
coal with high moisture and oxygen content, and thus, lowcalorific value (types of coals are described in the mini

V o l . 4 5 N o . 1 2 0 12

BusinessGermany(40.7 billion t)

Europe(67.3 billion t)
31%
42%

100%

7%

9%

16%

India
(60.6 billion t) 93% 20%
Indonesia(5.5 billion t) 53%

China (114.5 billion t)
Rest of Asia
(47.6 billion t)
46%

27%

49%
100%

34%

52%
2%

48%

3%
Australia(76.4 billion t)

South Africa(30.1 billion t)

53%

13%
13%

55%

29%

: Bituminous coal
: Sub-bituminous coal
: Lignite

Canada (6.6 billion t)

31%
62%

27%

Rest of 91%Africa(1.5 billion t)

7%Russia (157 billion t)

United States(237.3 billion t)
45%

42%
Colombia(6.7 billion t)

6%

94%
9%
Rest of SouthAmerica91%(5.7 billion t)

World coal reserves
Based on data from WEC, “Survey of Energy Resources 2010”
Low rank coalLignite
195.4 billion t(22.7%)
Recoverable Bituminous
coal andreserves
anthracite(end of 2008)
860.9 billion 404.8 billion t(47.0%)
t
Sub-bituminous coal
260.8 billion t(30.3%)

Coal reserve by ranks

comment box). Lignite, moreover, requires careful handlingdue to the ease with which it ignites. For these reasons, lowrank coals are generally not suitable for use as an energy
source, despite their cheaper price. As low rank coals are
unsuitable for long-distance transportation and storage,
their utilization is limited to places such as coal fired power
plants near coal mines.
By contrast, the synthetic gas from coal mainly contains
H2 and CO, these gases can be directly used for power
generation such as in gas turbines or gas engines, orthey can be converted into chemical raw materials ortransportation fuel through chemical reactions.
Major substances derived by the chemical reactions areammonia, dimethyl ether (DME), methanol, and methane.
Methane can be applied as a Substitute Natural Gas(SNG) to processes where natural gas is usually used.
Moreover, a liquid fuel called Coal-to-Liquid (CTL) canbe obtained as a fuel-like oil and also as a chemical raw
material. Therefore, economic and efficient gasification canconvert low rank coal into various fuels with high calorificvalue and high value-added chemical raw materials, andultimately make a great contribution to the economy andeffective utilization of resources.

The gasification process used by TIGAR ® is a suitable
technology for many applications. TIGAR® can be applied
to many kinds of feedstocks, from low rank coals including
lignite, to biomass including wood chips, and produce fuels
and chemicals having high added value.
The TIGAR ® process is based on proven circulating
fluidized bed technology with twin reactors, a gasifier anda combustor. In the gasifier, coal is introduced and volatile
matter and part of the char of the coal is gasified withsteam in fluidized bed. Since this gasification reaction isendothermic, external heat sources are required.
The combustor supplies the required heat for thegasif ication reaction as follows. The remaining charafter gasification is introduced into the combustor withcirculated bed material. In the combustor, the char isburned in air and the required heat is produced by thecombustion of the char. Then hot circulating bed material
heated by the combustion is carried to the gasifier after
separation by the cyclone equipped at the combustor exit.
TIGAR® has the following features:(1) Gasification under low temperature and atmosphericpressure
The entrained bed gasifier used for the Integrated
Coal Gasification Combined Cycle (IGCC) which has
already been commercialized, needs to operate under
the high temperature and pressure of 1 500°C and3 MPa as it involves a process to melt and recover ash(melting point is around 1 200°C to 1 500°C) in coal. Incontrast, lignite coal contains highly volatile matter andcan be easily gasified at temperatures below 1 000°C.
It is considered inefficient to gasify at such a hightemperature.
TIGAR® targets lignite as a feedstock and does not
melt ash content. TIGAR® can be operated under therelatively low temperature range of 800°C to 900°C at
atmospheric pressure. Therefore, in comparison withother high-temperature/pressure gasifiers, TIGAR ®
has the advantages of being an efficient gasification

V o l . 4 5 N o . 1 2 0 1211

IHI Corporation

Twin IHI Gasifier
TIGAR®

Synthesis

H2,CO

Shift reaction

Coal/biomass

ProductsNo reactions

Feedstock

Application
Gas turbine, gas engine fuel,direct reduction ironmanufacturing

H2Chemical raw material(ex. ammonia), fuel cell, etc.

CH4(Substitute natural gas)

Substitute for natural gas

Methanol
DME
CTLTransportation fuelChemical raw materials

Gas

LiquidVarious use of syngas

process for lignite and having low initial, operation, andmaintenance costs owing to the fact that expensive heatand pressure-resistant mechanisms/components are notnecessary.
IHI has already reflected proven circulating fluidized
bed technologies in the TIGAR® design.
(2) Syngas with high calorific value
Generally, as is the case with many other gasifiers, theheat required for the gasification process is supplied by
the combustion of a part of the feedstock in the gasifier.
For this purpose, oxygen generated by an expensive Air
Separation Unit (ASU) is injected into the gasifier asa gasification agent. In contrast, TIGAR® uses heatedsand circulating from the combustor to derive therequired heat for gasification while steam is used as agasification agent in the gasifier. Hence, oxygen is not

Flue gas
Combustor

SyngasFuel inlet

SteamGasifier

Air

Structure and principle of the Twin IHI Gasifier (TIGAR®)

12necessary for the gasification reaction. Additionally, airis fed into the combustor in order to provide combustion
heat. Since the combustor and gasifier are separated
from each other and only heated sand circulates into
the gasifier, flue gas does not mix with syngas. It isthus possible to obtain syngas with high calorific value,
which is also suitable for chemical raw materials.
(3) Multi-fuel application
TIGAR® can also accept biomass as feedstock. Since
the gasifier is a fluidized bed gasifier, it is sufficient tofeed coarsely crushed feedstock for gasification. Coaland biomass can be utilized simultaneously. As a formof renewable energy, biomass gasification can contributeto CO2 reduction.
This gasif ier, with its many advantages, was called
TIGAR® (Twin IHI Gasifier). IHI started its developmentin 2004. The Ministry of Economy, Trade and Industry
has been supporting it since 2010. At present, TIGAR®
will enter its next stage, from a pilot plant with a coalfeeding rate of 6 t/d to a demonstration plant with a scaleup capacity of 50 t/d. IHI is planning to demonstrate aTIGAR® 50 t/d plant in Indonesia, where low rank coals
are abundant and the development of technology for
their utilization is actively supported. In this project, thefeasibility of its scaled-up design will be confirmed andmaintainability and durability will be verified throughseveral thousand hours of operation.
In the commercialization phase following successful
demonstration, the first aim is to replace natural gas as a raw
material, which is used in an Indonesian fertilizer factory.
The fertilizer company can save on plant operation costs if
the cheap lignite abundantly available in Indonesia can begasified to substitute for expensive natural gas. Natural gas
can be shifted from domestic consumption to LNG export
to acquire foreign currency. Further, the increase of LNG
export from Indonesia is desirable for the energy security ofJapan as an importer of a large amount of LNG.

V o l . 4 5 N o . 1 2 0 12

Business(FY)
2004

2005

Basic test
Simulation

2006

Benchtest
0.1 t/d

2007

2008

2009

2010

2011

2012

2013

2014

2015

Pilot plant
6 t/d
IHI
Yokohama
50 t/dBasic test equipment

Demonstration plant
Planned in Indonesia

300 - 1 000 t/dCommercial plant

Ammonia plant (1 000 t/d)

Development schedule for the Twin IHI Gasifier (TIGAR®)In the commercialization phase, our business targets
are not limited to the fertilizer industry, but include otherindustries as well. IHI aims to expand TIGAR® business inseveral countries such as India and Australia where there
are abundant reserves of lignite.
In addition to developed technology based on circulating

fluidized bed boilers, IHI has experience in material
handling systems, including coal handling, and Liquefied
Natural Gas (LNG) plants. Based on much experience asa plant manufacturer, IHI aims to verify the advantages ofTIGAR® as soon as possible in order to contribute to theeffective utilization of resources.

Mini comment box
Various types of coals
Types: Carbon

Characteristics: Hydrogen: OxygenPlants
Peat

Formed mainly in marshy areas when plant material is deposited and carbonized without fully
decaying.

LigniteCoal with carbon content of 70 - 78% and high water and oxygen content, distinctive of low
coalification.

Sub-bituminouscoal

Coal with carbon content of 78 - 83% and water content. Used as fuel for fine-powder coal boilers for
power generation and industrial purposes because of its good ignition performance and high calorific value.

Bituminous
coal

Relatively soft coal with carbon content of 83 - 90% containing bitumen. What is commonly referred toas coal is usually this bituminous coal.

Anthracite

Coal with the highest level of coalification. The carbon content is over 90%. It is characterized by theextremely small amount of smoke and smell during combustion.

Graphite
Diamond

Examples of substances containing 100% carbon.
020406080100(%)

Since the Carboniferous period about 350 million years ago until the Neogene period about a few million years ago, plant materials deposited in theground were decomposed by fungi and were compressed around their carbon content due to the pressure of crustal deformation under geothermalheat (coalification). The resultant coal also contains hydrogen, oxygen, and trace amounts of sulfur, nitrogen, silicon, aluminum, and calcium. Generally,
the older the coal, the higher the proportion of carbon (higher level of coalification) and greater calorific value.

Inquiries:
Energy Operations, IHI Corporation
Phone: +81-3-6204-7800
Website: www.ihi.co.jp/en/V o l . 4 5 N o . 1 2 0 1213