Project Subjects
Expansion of fuel types and improvement of efﬁciency in IGCC
Background and Objective
Highly effective coal gasiﬁcation combined cycle power generation (IGCC) is an important technology
for electric power companies as next generation coal-based thermal power generation. Our laboratory has been
researching from the process development of the initial stage of IGCC development. Based on the experienceof our 2t/d gasiﬁer and the numerical analysis technology, we have supported the examination of the design andoperating condition of the demonstration plant. In this project, aiming at the development of commercial IGCC
in the future, for ﬂexible fuel operation, improvement of the efﬁciency and the reliability, we develop expansion
technology of fuel types in gasiﬁcation process, dry gas cleaning system for IGCC, and gasiﬁer operating condition diagnosis and trouble prediction system.

Main results
1. Development of evaluation technology on gasiﬁer characteristics for commercial scale gasiﬁer
The performance of the demonstration plant gasiﬁer was evaluated, and the design adequacy was clariﬁed. Moreover, our three-dimensional numerical simulation technology for coal gasiﬁer was veriﬁed by using
demonstration plant data, and it was conﬁrmed that the evaluation of characteristics of the commercial scalegasiﬁer was possible. From these results, a tool that can be used to design a large-scale commercial plant gasiﬁer
was constructed.
2. Development of expansion technology of fuel types in gasiﬁcation process
As a catalyst effect of the element contained in coal, the inﬂuence of Ca and K on the gasiﬁcation reactivity was clariﬁed. In addition, the existing reaction model is extended, and the reaction rate equation that wasexpressible of the change in reactivity by the effect of the catalyst was constructed (Fig. 1). These results can bereﬂected in the establishment of the technique to forecast adaptability of wide range of fuel type.
3. Development of gas cleaning system for highly-efﬁcient IGCC
Dry gas cleaning technology is essential for realization of highly-efﬁcient IGCC. But the developmentof optimum whole-dry gas cleaning system requires stepwise scale-up procedure, because dry impurity removal
processes have differing degree of developmental levels. The hybrid-type gas cleaning system (Fig. 2), which
was arranged conventional water scrubber and advanced dry desulfurization process in series, was suggested foradvantaged in early realization of higher power generating efﬁciency than wet gas cleanup system [M09016].
4. Development of gasiﬁer operating condition diagnosis and trouble prediction system
A real-time operating condition diagnosis and the trouble prediction are requested aiming at safe andsteady operation of the gasiﬁer. Next, a supporting system for gasiﬁer optimum operation that composed a partof the diagnosis and the prospect system was developed (Fig. 3). This is integration of the gasiﬁer operating
condition optimization program by the statistical processing of online data and the molten slag ﬂow monitoring
program by the image analysis. It will become an important technology for an advanced operating control of thegasiﬁer in the future.
Other reports [M09002]
42

0.004
0.003

(b)
(a)

0.002

Gasifier

Experimental
Reaction model(c)

Online data
statistical processing(d)NoInterrupt fromslag instability

0.001

Performance
Optimal?

Slag flow image
processing
BurnerNo
Slag discharge
stability
To OptimizationYesOK

0Optimization

0.2

0.4

0.6

0.8

1Feedback tooperating condition
Molten slag flow

Conversion x [-](a)Ca2.5%(Coal A)、(b)Ca5%(Coal A)、(c)Ca10%(Coal A)、(d)K2.5%(Activated Carbon)

GGH

Mercury
removal

180℃

450℃

Mercury

240℃

Mercury

129℃

Scrubber

410℃

HalidesAmmonia (partially)

Gas turbine

450℃

Power generating efficiency (HHV):
0.9 point higher than wet gas cleanup
Desulfurization

SGH

Mercury
removalAuxiliary steam

Coal Gasifier

StackNOｘ

Sulfur compounds

Hybrid-type gas cleaning system

GGHGas turbine

Power generating efficiency (HHV):
1.5 point higher than wet gas cleanup

Desulfurization

Halide Removal

Coal Gasifier

Halides

Slag flow monitoring

Fig. 3 supporting system of gasiﬁer optimum
operation
The gasiﬁcation performance and the ﬂow situation ofmolten slag can be evaluated online, and it becomes thebasic system of the gasiﬁer operating condition diagnosis
and trouble prediction system.

Whole-dry gas cleaning system

450℃

OK
Molten slag flow
monitoring camera

Operating condition optimization

Fig. 1 relation between conversion and reactivity[1]Ca has the effect of improving the reactivity in the ﬁrst stageof the reaction. On the other hand, K improves the reactivity
with the progress of the reaction. The reaction rate equationthat was able to express the change in this reactivity wasconstructed.
[1] Y. Zhang et al., Fuel 89,152−157（2010）

450℃

Yes

Denitration0

Sulfur compounds

Effluent treatment

Denitration

Reactivity dx/dt [s-1]Stable Power Supply TechnologyNOｘ

Stack: Coal derived gas: Steam: Discharged waterFig. 2 system constitution of gas cleaning systems for IGCC
Dry gas cleaning technology will be established with development of the hybrid-type gas cleaning system, which wasarranged water scrubber and dry desulfurization process in series. The ultimate purpose is to revitalize the whole-dry gas
cleaning system which is most effective for improvement of power generating efﬁciency on IGCC.

243