Ikelic - Alliance Digital Repository

COAL
ing
Combined Cycle (IGCC)
steps of the simplified Integrated Gasification
process were techni
cally feasible when gasifying both wood and coal
alone, and in wood and coal co-gasification. The
total amount of tars in sawdust gasification was
two orders of magnitude higher than in coal
gasification (Figure 1). During wood gasification,
the tars represent a significant part of the gas
heating
value and total carbon conversion.
However, the tar concentrations were reduced at
the co-gasification set point, an approximate
50/50 weight percent mixture of wood and coal.
The formation of the most harmful high molecular
weight polyaromatic compounds was almost neg
ligible at the co-gasification set point.
FIGURE 1
Linked to this is the work of The Netherlands
Energy Research Foundation (ECN) who have
examined the use of pelletized wood waste
and/or straw as a co-feedstock in a moving bed
gasifier.
In parallel to the apparatus based programs,
there are several complementary research
studies to improve the understanding of the fun
damentals of the processes.
Techno-Economic Assessment Studies
In addition to the experimental studies, a key
component of this multipartner program is the
HEAVY TAR CONCENTRATIONS IN DIFFERENT GASIFICATION CONDITIONS
c
e
S
o
2,000
1,500
H 1,000
H
as
w
Z 500
o
u
0
SOURCE: MINCHENER
;.;.
,U\,
(SD = Pine Sawdust, PC = Bituminous Coal)
SD 100%
PC 0%
970C
SD 100%
PC 0%
1010eC
c
SD75%
PC 25%
9806C STRAW
SD58%
PC 42%
960C
SD 0%
PC 100%
950C
100%
880"C
=. \y
4-27
THE SYNTHETIC FUELS REPORT, JANUARY 1995