Part 2 CCT Overview
Basic Technologies for Advanced Coal Utilization

6A1. Modeling and Simulation Technologies for Coal Gasification
Research and development: Japan Coal Energy Center
Project type: NEDO-commissioned projectTechnology overview

1. Overview of basic technology for advanced coal utilization (BRAIN-C)
The consumption of fossil fuel impacts the environment in a

the above-mentioned basic data. On the other hand, it can also

variety of manners. There is also an impact on the environment

be used to evaluate and select useful basic data. With this taken

during the coal production, transportation, and utilization

into consideration, technology development under BRAIN-C hasprocesses. During utilization, in particular, coal dust, ash dust,

proceeded from the aspects of both useful basic dataacid gases (NOx, SOx), and carbon dioxide are discharged,

retrieval/storage as well as high-precision numerical simulation.

raising concerns of what the unregulated consumption of coal

Figure 1 shows the "BRAIN-C technology map." Results from thismay possibly have on the environment. However, technologies toproject are roughly grouped into the following three categories:

minimize the harmful impact coal utilization has on the(1) An entrained-flow gasification simulator

environment, collectively called clean coal technology (CCT), are(2) A predicted model/parameter correlative equationin widespread use in developed countries, including Japan. Given(3) A coal database

this, the "Basic Technology Development Program for Advanced(1) to (3) above are illustrated below and each is as an integral

Coal Utilization (BRAIN-C)" is focused on coal gasification

part of the results from this project, indispensable for actualtechnology and the rapid commercialization of new high-usage in a variety of situations. The appropriate utilization of eachefficiency and clean coal utilization technologies, such as coalin accordance with the application allows for full optimization.

gasification and pressurized fluidized-bed processes. Basic coaldata, from a variety of perspectives, has also been collected andcompiled. Numerical simulation is a very effective tool to predictthe characteristics of a pilot or actual production unit by utilizing

Volatilization modelTrace element data
CPC actual measurement data

Volatile contents release data

Basic database

Volatile contents database
Typicaltemperature history

Char reaction data
Reaction database

Volatile contents
Trace element
composition in quantitylta distribution modelica re dapyT aturpe
Equilibrium modeltem

Reaction
temperature
constant

Coal composition
Composition database(coal and char)+General analysis+Particle size-surface area
+Special analysis
CCSEM, XRD, EDS

Gasification simulation code

Parameter
correlative equation+ RESORT+ FLUENT
Growth flow
temTypic
pe alda ratur determination modelta etermearaption

programiaRad

Heat transmission coefficient
Heat transmission test data
Particle radiation data

Particle size
density fluctuation modelFig. 1 BRAIN-C technology map103

Adhesiondetermination equation
Adhesion dataClean Coal Technologies in Japan

2. Entrained-flow gasification simulator
An entrained-flow gasification simulator, based on thermal fluid
analysis software, computational fluid dynamics (CFD), andSimulation program(For entrained-flow gasification)

capable of simultaneously analyzing flow, reaction, and heattransmission, can calculate temperature distribution, ash

Design: Furnace design
Operation: Operating
conditions
Coal: Properties

adhesion locations, gas composition, etc., within a gasifier if
given, as input data, such parameters as reactor shapes,operating conditions, coal properties and reaction data (Fig. 2).
Highly reliable prediction results can be used for evaluating
operating condition validity, reactor design, and other informationin advance.

Pre-test judgment ofoperational validity

In the BRAIN-C program, the coal gasification reaction model
shown in Figure 3 and the particle adhesion model shown in

Ash adhesion position Temperature distribution CO concentration

Figure 4 are built within CFD in order to establish technology foran entrained-flow gasification simulator. Simulation results arethen compared with gasification furnace operating data in coal-Fig. 2 Functions of entrained-flow gasification simulator

based hydrogen production technology (HYCOL or EAGLE) toexamine the validity.
Gas-phasereaction

Product gas

Volatile contents release speed
Oxidizing agent
Volatile contents

Fixed carbon
AshFixed carbon

Gasification speed
Gasification database

AshAshFig. 3 Coal gasification process modeling

Particle viscosity:

Particle adhesion prediction conditions
Predictedvalue

Reflection
PredictedvalueAdhesion

Wall ash layer viscosity

Fig. 4 Ash viscosity-based adhesion prediction model104

Part 2 CCT Overview
Basic Technologies for Advanced Coal Utilization

Figure 5 shows an example of the comparative results between

particles can hardly adhere. On the other hand, the near-wall

the formation position of a fused ash layer and the internal

temperature and ash viscosity on the wall shown on the right side

condition of a gasifier after operations. This showed that theof Figure 6 are the result of simulation under intentionallyformation position of the fused ash layer as predicted by themodified operating conditions. For this case, the oxygen ratio atsimulator corresponded well to the position where the fused ash

the top of the chart is higher and that at the bottom is lower thanlayer actually existed, confirming the accuracy of the simulationis shown on the right side of the figure. In such cases, it wasrelative to the actual data.

found that the temperature at the bottom of the furnace

Figure 6 shows the result of case studies on HYCOL using adecreases (shown in orange) and the low-ash-viscosity region

gasification simulation. The near-wall temperature and ash(shown in blue) narrows while the upper part of the furnace

viscosity on the wall shown on the left side of Figure 6 are thosebecomes hot (the region in red increases) to form a region wherereproduced by simulation after 1,000 hours of operation. The

it is easier for ash to adhere, categorized as less desirable

temperature of the bottom area of the furnace (shown in red inoperating conditions.

upper image) into which slag flows are high versus the low ash

By using the gasification simulator in this manner, analysis canviscosity in the bottom area of the furnace (shown in blue in thebe easily made even if gasification conditions are altered. Thislower image). The temperature of the upper part of the furnace is

has resulted in growing expectations for use of the simulator inlow (shown in green in upper image), providing conditions where

future gasification projects.

Case 3 Forecast value
Near-wall temperature
Temperature:highGrowth of slag

Temperature:low

Throttled section
Ash viscosity on the wall
The low-viscosity
region at thetop expands.

Pressure
detection terminal
Amount of adhesion= amount of slag discharged

A high-viscosity
region at thebottom appears.

Molten slag

Fig. 5 Ash adhesion position verification results

Fig. 6 Simulator-based studies

3. Predicted model/parameter correlative equation
The entrained-flow gasification simulator can be applied toequations for estimations and experimental conditions). Morevarious furnace designs and operating conditions, but it is not

specifically, a generalized volatilization model and the adhesion

applicable to all types of coal. It is, therefore, necessary to input

determination equation are among the tools to prepare

coal characteristics into the simulator by coal-type as aparameters. In the meantime, a trace elements distribution model

parameter. This parameter generally uses the data obtained fromand an adhesion determination equation model offer determinations

basic test equipment but, from the vantage of obtaining a prompt

from simulation results, playing another important role. Under theevaluation, it is desirable to establish a means to obtain theBRAIN-C, therefore, prediction equations around a gasification

parameters from a general analysis of coal or from structural

simulator have also been developed so that the simulator can becomposition data (an advanced model incorporating correlative

used effectively and quickly.

105

Clean Coal Technologies in Japan

4. Coal databaseThe

developmentofacorrelativeequation

or

model

indispensably requires physical and basic experiment data,
including general analysis data. There is, however, a significant
issue in that the characteristics of coal differ by lot, even if the20-liter containers

coal has come from the same coal mine. It was, therefore, firstnecessary for each testing body that obtained physical and basic
data to use exactly the same coal samples. Figure 7 shows acoal sample bank built within the National Institute of Advanced
50-liter containers

Industrial Science and Technology. Such unified management ofanalytical test samples has enabled the shipment of identicalsamples to all testing research bodies.

Standard sample coal storage (AIST)

As far as the identical sample-based data is concerned, themeasurement of typical data will be completed under this projectfor 100 types of coal for general/special analysis data, and for atleast ten types of coal, depending upon the data criteria, for basic
experiment data. Eventually, all of this measurement data will becompiled in an Internet-accessible coal database. Some of thedata thus far obtained, as shown in Figure 8, has already been
uploaded to JCOAL’s server and is accessible or retrievable.
Much of this data is stored in an easy-to-calculate/process Excel
file (Fig. 9) and can also be downloaded.
Standard sample coal (for delivery)
Fig. 7 Coal sample bank

100
100 types
types ofof coalcoal
GeneralGeneral analysis/special
analysis/special analysis
analysis

Reaction
Reaction data,data, etc.
etc.

Reaction
Reaction data,data, etc.
etc.

Spreadsheet
Spreadsheet file
file download
download

On-lineOn-line retrieval
retrievalFig. 8 Coal database

Fig. 9 Basic data acquisition

5. Dissemination of basic coal utilization technology products
An entrained-flow gasification simulator thus far developed underworkshops for the purpose of encouraging the optimal utilization

BRAIN-C is capable of making practical predictions through theof these products, were also being prepared.

utilization of various models and basic data. The BRAIN-C

Despite the predominance of coal gasification technology in thisProject, finished in 2004, developed a well-equipped system todevelopment project, other types of gasification projects are strongly

make a wide selection of programs and basic data available soencouraged to use the simulation code, since it can be widely usedthat the products developed under this project could be used

for combustion simulation as well as in other applications.

without limitation. Detailed service manuals, as well as106