Power Generation - Hydrogen and Fuel Cells: Advances in Transportation and Power - page 192

Many countries and companies have channeled R&D efforts into
generating hydrogen and electricity from coal without releasing CO 2 .
Gasification and cleaning can be used that combines coal, oxygen or air,
and steam under high temperature and pressure. The process generates a
synthesis gas (syngas) of hydrogen and CO 2 . The syngas does not contain
impurities such as sulfur or mercury. A water-gas shift reaction is then
used to increase hydrogen production and create a stream of CO 2 that can
be removed and piped to a sequestration site. The hydrogen-rich gas is
sent to a Polybed Pressure Swing system for purification and transport.
The remaining gas that comes out of the system can be compressed and
sent to a combined cycle power plant. These are similar to the natural gas
combined cycle plants used today.
Hydrogen as well as syngas may also be used to power a combined
cycle plant. The plant output can be adjusted to generate more power or
more hydrogen as needed.
Cogeneration of hydrogen and electricity from coal, coupled with
CO 2 extraction needs to be an affordable and practical system for gener-
ating both energy carriers. Hydrogen could be generated from large coal
plants outside cities, close to existing coal mines, then the infrastructure
costs for delivering the hydrogen could be high.
FUTUREGEN
In 2003 the Department of Energy announced FutureGen, also known
as the Integrated Sequestration and Hydrogen Research Initiative. This is a
10-year, billion dollar project to produce a 275-MW prototype plant that will
cogenerate electricity and hydrogen and sequester 90% of the CO 2 .
This advanced coal-based, near-zero emission plant is planned to
produce electricity that is only 10% more costly than current coal-gener-
ated electricity while providing hydrogen that can compete with gasoline.
The cost of hydrogen delivery is not included in this goal.
A 2002 study for the National Energy Technology Laboratory found
that coal gasification systems with CO 2 capture could reach efficiencies of
60% or more in cogenerating hydrogen and electricity using different con-
figurations of turbines and solid oxide fuel cells (SOFCs).
Building large commercial coal gasification combined cycle units
could be difficult based on the history traditional power generators have
had with simpler chemical processes. Sequesting the CO 2 can be another
technological challenge.