Debunking the Myths
Despite the advantages of coal gasification, many district energy system
owners are reluctant to explore this alternative because of myths that persist
about the technology.
It’s a new technology. Actually, coal
gasification is a mature technology. In
the 1800s, gasified coal was used in the
United States to provide town gas. It was
used by the Germans in the 1940s to
manufacture diesel fuel. Today, all of the
diesel fuel in South Africa is derived
from coal. In addition, a plant has just
been constructed in Pennsylvania to produce diesel fuel.
It’s not available on an industrial
scale. In fact, there are several projects
under way at present that demonstrate
the viability of coal gasification to produce energy for both industrial and utility
use. Econo-Power, for example, has about
80 gasifiers operating in industrial plants
in China. Near Tampa, Fla., TECO Energy
is fueling its 250 MW Polk Unit 1 IGCC
plant with coal gas; and in Terra Haute,
Ind., Global Energy Inc. is using coal gas
in its 260 MW Wabash River power plant.
It’s too expensive. In reality, coal
gasification can be implemented at no
initial cost and can save operating costs.
A comparison of the relative costs of natural gas, coal and coal gas per million
Btu favors coal gas for universities whose
central plants are at least 200 MMBtu in
size (university central plants generally
range in size from 200 MMBtu to 1,000
MMBtu.):
● Natural gas: Three years ago, the cost
of natural gas averaged $4/MMBtu. In
December 2005, it spiked to $16.50/
MMBtu. Industry experts expect natural gas to be $9-$10/MMBtu for the
foreseeable future, the next five to
10 years.
● Solid coal: The cost of coal is approximately $2/MMBtu; however, the
higher initial cost of the boiler plant
– seven times that of a natural gas-fired boiler plant – plus the regulatory issues must be figured into the
life-cycle cost.
● Coal gas: In contrast, the cost of
burning coal gas averages $5-6/MMBtu.
This figure includes the cost of coal
plus the cost of the loss of energy in
the conversion process (20 percent) –
plus a gasification fee paid to the
finance-design-build-operate contractor, if the owner decides to go this
route.
It’s unreliable. Actually, coal gasification is a reliable technology. There are many
installations, particularly in Asia, that have
demonstrated high levels of availability.
Moreover, the steam plant making use of
Figure 2. Worldwide Coal, Biomass and Waste Gasification Use in Power Plants.
Year
Started
2006
1997
2000
2009
2002
1998
Plant Owner
ATI Sulcis
Elcogas SA
EPZ
Excelsior Energy
IBIL Energy Systems Ltd. (IES)
Lahden Lämpövoima Oy
Plant Name
Sulcis IGCC Project
Puertollano GCC Plant
Americentrale Fuel Gas Plant
Mesaba Energy Project
Sanghi IGCC Plant
Kymijärvi ACFBG Plant
Country
Italy
Spain
Netherlands
United States
India
Finland
Gasifier
Status
Development
Operating
Operating
Development
Operating
Operating
Total No.
Gasifiers
2
1
1
3
1
1
MWth
Output
956.9
587.8
84
0
109.1
48
Feed
Classification
Coal
Coal
Biomass/Waste
Coal
Coal
Biomass/Waste
Nuon Power Buggenum
Sekundärrohstoff-
Verwertungszentrum
Schwarze Pumpe GmbH
Sekundärrohstoff-
Verwertungszentrum
Schwarze Pumpe GmbH
Sistemas de Energia
Renovavel
Sokolovska Uhelna, A.S.
Sokolovska Uhelna, A.S.
Steelhead Energy
Sydkraft AB
Buggenum IGCC Plant
Schwarze Pumpe Power/
Methanol Plant
Netherlands
Germany
1994
1999
Operating
Operating
1
1
465.9
155.6
Coal
Biomass/Waste
Product(s)
Output
Electricity
Electricity
Electricity
Electricity
Electricity & Steam
Electricity &
District Heat
Electricity
Electricity &
Methanol
Schwarze Pumpe Power/
Methanol Plant
Germany
1964
Operating
7
410.1
Biomass/Waste
Electricity &
Methanol
Brazilian BIGCC Plant
Brazil
2006
Development
1
68.4
Biomass/Waste
Electricity
Thermoselece Vresova
Vresova IGCC Plant
Steelhead Energy
Värnamo IGCC
Demonstration Plant
Polk County IGCC Project
Fondotoce Gasification Plant
Czech Republic
Czech Republic
United States
Sweden
2005
1996
2010
1993
Construction
Operating
Development
Operating
1
26
2
1
787.4
636.4
0
14. 4
Coal
Coal
Coal
Biomass/Waste
Tampa Electric Co.
Unspecified Owner
United States
Germany
1996
1999
Operating
Operating
1
3
451.1
34.2
Coal
Biomass/Waste
Electricity
Electricity & Steam
Electricity & Syngas
Electricity &
District Heat
Electricity
Electricity
Source: Gasification Technology Council.
A Gasification Primer
Gasification, in one form or another, has been used in the chemical
industry for more than two centuries. Coal was gasified for the production
of town gas for street lighting from the mid-1800s until the early 1900s
when cleaner-burning natural gas became available. The Germans used a
process to gasify coal and then convert the coal gas into a substitute diesel
fuel during World War II. The South Africans still use this process to produce almost all of the country’s domestic diesel fuel. The U.S. military is
investigating this technology – coal to liquids – to maintain stable fuel
reserves without dependence on foreign oil.
While coal gasification for power has not been used extensively in the
U.S. due to the abundance of other fuels, implementation of MACT regulation, particularly for solid fuel boilers, and the volatility of the natural gas
market are leading to reconsideration of gasification techniques. Globally,
gasification – of coal, petroleum, petroleum coke and biomass/waste – is
used to fuel more than two dozen power plants in 12 countries. Those
using coal and biomass/waste are listed in Figure 2. In addition to electricity, many of these facilities also generate methanol, synthesis gas, steam
(often for non-heating purposes), H2, and district heating.
