Outline of technology
1.Outline of basic technology for advanced coal utilization (BRAIN-C)
In charge of research and development: Center for Coal Utilization, Japan
Project type: NEDO-commissioned project
Volatile contents release data Volatile contents database
Char reaction data Reaction database
Coal Physicality Physicality database
(coal and char) +General analysis +Particle size-surface area
+Special analysis CCSEM, XRD, EDS
Heat transmission coefficient Heat transmission test data
Particle radiation data
Parameter correlative equation
Radiation parameter
Particle size -
density fluctuation model
Volatilization model
Gasification simulation code + RESORT + FLUENT
Adhesion judgment equation
Adhesion data
Trace element data
CPC actual measurement data Basic database Trace element distribution model Program Equilibrium model Growth flowage judgment model Typical temperature history Volatile contents composition in quantity Reaction temperature constant Typical temperature data Typical temperature data
Fig. 2 Functions of Entrained-Flow Gasification Simulator
Fig. 3 Coal Gasification Process Modeling
2.Entrained flow gasification simulator
An entrained flow gasification simulator based on the thermal fluid analysis software (CFD) capable of analyzing flow, reaction, and heat transmission at the same time can calculate temperature distribution, ash adhesion locations, gas composition, etc. within a gasifier if given as input data such parameters as reactor shapes, operation conditions, coal property and reaction data. It is imaged in Fig. 2 as "Functions of an Entrained Flow Gasification Simulator." Highly reliable prediction results can be used for evaluating operational condition validity, reactor design, and others in advance. The BRAIN-C, developing a coal gasification reaction model shown in Fig. 3 and a particle adhesion model shown in Fig. 4 in basic CFD, has compared their calculation results with gasifier operation data in coal-based hydrogen production technology (HYCOL) to verify the adequacy.
Fig. 4 Ash viscosity-Based Adhesion Judgment Model
Simulation program (For entrained-flow gasification)
Ash adhesion position Temperature distribution CO concentration Pre-test judgment of
operational validity Design: Furnace shape Operation: Operational conditions Coal: Property
Particle viscosity
Particle adhesion judgment conditions Judgment value Reflection Judgment value
Adhesion
Wall ash layer viscosity
Gasification speed
Gasification database
Volatile contents release speed
Volatile contents Fixed carbon Fixed carbon Ash Ash Ash Gas-phase reaction Oxidizing agent Product gas
the formation position of fused ash layer and the internal condition of gasifier after operations. This found the formation position of fused ash layer calculated with this simulator well- corresponding to the position where the fused ash layer actually existed, endorsing the adequacy of calculation with actual data. Fig. 6 shows the result of case studies on HYCOL using gasification simulation. The near-wall temperature and ash viscosity on the wall shown on the left side of Fig. 6 are those reproduced by calculation under the condition after 1,000-hour operation . The temperature of the furnace bottom area (in red color) onto which slag flows down is found high against the low ash viscosity in the region (in blue). The temperature of the upper furnace part proves low (in green), giving conditions where particles can hardly adhere. On the other hand, the wall-near
of Fig. 6 are from the result of calculation under operational conditions changed intentionally. For this case, the oxygen ratio of the chart top is higher and that of the bottom is lower than shown on the right side of the figure. In such cases, it was found that the temperature of the furnace bottom area goes down (in orange color) and the low-ash-viscosity region (in blue) narrows while the upper furnace part becomes hot (the region in red increases) to form a region where ash is easier to adhere, probably spoiling the operating conditions.
In this way, using the gasification simulator, analysis can be easily made even if gasification conditions are altered and, therefore, an expectation is growing on its utilization in future gasification projects.
Fig. 5 Ash Adhesion Position Verification Result Fig. 6 Simulator-Based Studies
3. Predicted model/parameter correlative equation
An entrained-flow gasification simulator is generalized against various furnace shapes and operational conditions but not against each coal characteristics. It is, therefore, necessary to input such characteristics into the simulator as a parameter by types of coal. This parameter generally uses the data obtained from basic test equipment but, in view of quick evaluation, it is desirable to establish a means to obtain parameters from general analysis of coal or structural physicality data (an advanced model referring as far as to predicted correlative equations and experiment conditions). More specifically, a
generalized volatilization model and the adhesion judgment equation are among the tools to prepare parameters. In the meantime, a trace elements distribution model and an adhesion judgment equation model are models making judgments from simulation results, playing another important role. Under the BRAIN-C, thus, prediction equations around a gasification simulator have also been developed so that the simulator can be used effectively and quickly.
Temperature: high Temperature: low The low-viscosity region of the top expands. A high-viscosity region of the bottom appears. Case 3 Forecast value
Growth of slag Throttled section Pressure detection terminal Molten slag Amount of adhesion = amount of slag discharged
Wall-near temperature
4.Coal Database
The development of a correlative equation or a model indispensably requires physical and basic experiment data, including general analysis data. There is, however, a big problem that coal is different in characteristics for different lots arrived even if its brand (name of the coal mine) is the same. It was, therefore, first necessary for each of testing bodies, where physical and basic data were obtained, to use completely the same samples of coal. Fig. 7 shows a coal sample bank installed within the National Institute of Advanced Industrial Science and Technology. Such unified management of analytical test samples has materialized the shipment of identical samples to all testing research bodies.
As far as these identical sample-based data are concerned, the measurement of typical data will be completed under this project on 100 kinds of coal for general/special analysis data and, at least 10 kinds of coal, depending upon data items, for basic experiment data. Eventually, all of these measurement data are to be contained in the Internet-accessible coal database. Some of the data so far obtained have already been uploaded to the server of CCUJ for available access or retrieval as shown in Fig. 8. Many of these data are stored in an easy-to-calculate/process Excel file (see Fig. 9) and can also be downloaded.
AAn entrained-flow gasification simulator so far developed under the BRAIN-C is capable of making practical predictions through the utilization of various models and basic data. The BRAIN-C Project, soon to meet its final year in 2004, is developing a well- equipped system to make a wide choice of programs and basic data available so that you can use the products developed under this project to your hearts’ content. We are also preparing
detailed service manuals as well as giving workshops for this purpose to encourage your ingenious utilization of these products.
Despite the coal gasification technology’s predominance in this development project, those outside gasification projects are strongly invited as well to use our simulation code, at least, since it can be widely used in combustion and other sectors.
Fig. 7 Coal Sample Bank Standard Sample Coal Storage Status (AIST)
Standard Sample Coal (for delivery)
5.Diffusion of basic coal utilization technology products
Fig. 8 Coal Database Fig. 9 Basic Data Acquisition
50-liter container
Reaction data, etc. On-line retrieval
Reaction data, etc. Spreadsheet fileDownload 100 kinds of coal
General analysis/special analysis
Reaction data, etc. On-line retrieval
Reaction data, etc. Spreadsheet fileDownload 100 kinds of coal
General analysis/special analysis