Biomass Cofiring and Torrefaction - Biomass Gasification, Pyrolysis and Torrefaction - page 358

and for pumping and transporting CO 2 to storage locations. Such additional
power requirement will naturally account for additional CO 2 release.
The cost of CCS is also a major factor. The additional carrying charge of
a relatively large capital investment of CCS and its operating cost when
added to the total generation cost of electricity could increase the electricity
cost by as much as 40% ( Figure 10.2 ). Considering how our society is able
to adapt to steady rise in oil price, one can hope that consumers will be able
to live with increased cost of GHG-free electricity.
The major problem is, however, the lead time for this technology. The
CCS is not likely to have worldwide commercial implementation till 2030.
At the present pace of rise in global inventory of CO 2 , if the CO 2 emission
is allowed to rise without any control, it is very much possible that earth's
temperature might rise to alarming levels while waiting for CCS to be fully
implemented. This underscores the need for biomass cofiring in the interim
period to reduce the pace of CO 2 release to the atmosphere, and therefore
the global warming, while waiting for CCS to arrive.
Figure 10.1 compares the cost of CO 2 abatement of different percentages
of biomass cofiring with that of a CCS system for a landed cost of biomass
$40/dry ton (19 MJ/kg) in a pulverized subbituminous coal-fired boiler. One
notes from this figure that the extra cost for CO 2 abatement by CCS could
be as high as 4.5 6 times that by cofiring.
Replacing an existing fossil fuel fired boiler with a new biomass-fired
boiler or switching its fuel from coal to 100% biomass can achieve the above
goal. The first option is exceptionally expensive while the second option of
fuel switch could face major technical hurdles due to the large difference in

14

12

10

8

Addl. cost for CO 2 capture
Cost without any capture

6

4

2

0

With
CCS

2%
Biomass

5%
Biomass

10%
Biomass

FIGURE 10.2 The cost of electricity generation rises with CO 2 capture, but that due to cofiring
is lower than that from carbon capture and storage (CCS). Source: Plotted with data from Al
Juaied and Whitmore (2008).