JP2008088331A - Heat foaming characteristic of coal gasification slag, method for estimating optimum baking temperature and its program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To estimate heat foaming characteristics and an optimum baking temperature without actually preparing coal gasification slag. <P>SOLUTION: A foaming state after baking the coal gasification slag is estimated from crystal precipitation characteristics by performing thermodynamic equilibrium calculations based on elemental compositions of ash content of coal and baking conditions of the coal gasification slag. The optimum baking temperature for foaming the coal gasification slag is estimated from the crystal precipitation characteristics by performing two or more thermodynamic equilibrium calculations based on the elemental compositions of ash content of coal and the baking conditions of the coal gasification slag and estimating the crystal precipitation characteristics of the coal gasification slag at tow or more baking temperatures. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for predicting the heating and foaming characteristics and optimum firing temperature of coal gasification slag and a program therefor. More specifically, the present invention relates to a method for predicting the quality of heating and foaming characteristics of coal gasification slag obtained by coal gasification treatment of coal and the optimum firing temperature for foaming, and a program therefor.

  Coal gasification combined power generation is expected to be put to practical use as a highly efficient and environmentally friendly power generation system. From the coal gasification furnace, which is the core facility of this coal gasification combined cycle power generation, almost all of the ash content in the fuel coal is discharged as glassy coal gasification slag, and this amount is about about 250 MW class power plants. Large amount of 20,000 tons / year.

  Various techniques for effectively using the coal gasification slag discharged in large quantities as resources have been proposed. For example, it is proposed that coal gasified slag is fired and foamed to be used as an artificial lightweight aggregate (Non-Patent Document 1, Non-Patent Document 2).

  By the way, depending on the type of coal used in the coal gasification furnace, the discharged coal gasification slag may hardly exhibit the heating and foaming characteristics. Therefore, in the past, coal gasification slag was actually produced from various types of coal, and after this sample was calcined, the absolute dry density was measured. From the measurement results, the elemental composition of coal gasification slag showing good heating foaming characteristics. (See, for example, Patent Document 1). The optimum firing temperature for foaming has also been determined based on the measurement results obtained by preparing multiple coal gasification slags from various coals, firing these samples at various temperatures, and measuring the absolute dry density. Was.

In addition, since bituminous coal is often used for coal gasification combined power generation, the study of the elemental composition of coal gasification slag optimal for foaming focuses on SiO ₂ and Al ₂ O ₃ which are the main components of bituminous coal ash. (For example, see Patent Document 1 and Non-Patent Document 2).
JP 2004-269302 A Report of Central Research Institute of Electric Power Industry U02059 Report of Electric Power Central Research Laboratory W03040

  However, when coal gasification slag is actually produced and the heat foaming characteristics etc. are examined, a large cost is required for operation of the high pressure gasifier for coal gasification treatment. In addition, much labor and time are required to calcine coal gasification slag and measure the absolute dry density. When actually producing coal gasification slag from various types of coal and examining the heat-foaming characteristics and the like, the necessary cost, labor, and time are further increased. Therefore, it is desired to establish a method for predicting the heat foaming characteristics and the optimum firing temperature without actually producing coal gasification slag.

In addition, not only bituminous coal called high-grade coal, but also application to coal gasification combined power generation of coal type called low-grade coal is being desired. Under such circumstances, not only the heat foaming characteristics and optimum firing temperature for SiO ₂ and Al ₂ O ₃ which are the main components of bituminous coal ash, but also low-grade coal with a low content of SiO ₂ and Al ₂ O ₃ A technique for easily predicting the heat-foaming characteristics and the optimum firing temperature is desired.

  Then, an object of this invention is to provide the method and program which estimate a heating foaming characteristic and the optimal calcination temperature, without actually producing coal gasification slag.

  As a result of intensive studies by the inventors of the present invention in order to solve such problems, it has been found that coal gasification slag showing good foamability after firing has a common tendency. That is, when the carbon gasification slag after calcination is subjected to crystal structure analysis by X-ray diffraction (hereinafter referred to as XRD) analysis, in the XRD spectrum of coal gasification slag showing good foamability after calcination, FIG. It was found that the broad amorphous peak shown in FIG. Then, it discovered that if the crystal precipitation characteristic after baking of coal gasification slag could be predicted, it was possible to predict the heating foaming characteristic of coal gasification slag, and it came to this invention.

  The method for predicting the heating and foaming characteristics of coal gasification slag according to claim 1 based on such knowledge is a method for predicting the heating and foaming characteristics of coal gasification slag obtained by coal gasification treatment of coal, Perform thermodynamic equilibrium calculation based on elemental composition of ash and firing conditions of coal gasification slag, predict the crystal precipitation characteristics after firing of coal gasification slag, and from the precipitation characteristics of coal gasification slag after firing The state of foaming is predicted.

  Moreover, the heating foaming characteristic prediction program of coal gasification slag of Claim 3 based on this knowledge is a program which predicts the heating foaming characteristic of coal gasification slag obtained by coal gasification processing of coal, By storing the elemental composition of coal ash and the firing conditions of coal gasification slag, the thermodynamic equilibrium calculation based on the elemental composition of coal ash and the firing conditions of coal gasification slag was performed, and the firing of coal gasification slag The computer executes a process for predicting the subsequent crystal precipitation characteristics and a process for predicting the foaming state after burning the coal gasification slag from the crystal precipitation characteristics.

  An amorphous component is maintained in the coal gasification slag that exhibits good foamability after firing. Therefore, the components in coal gasification slag are calculated by performing thermodynamic equilibrium calculation based on the elemental composition of coal ash and the firing conditions of coal gasification slag, and predicting the crystal precipitation characteristics after firing of coal gasification slag. Can be predicted to have good heat foaming properties.

  Here, the thermodynamic equilibrium calculation in the present invention is a method of calculating an equilibrium composition that minimizes the Gibbs free energy based on the elemental composition of coal ash and the firing conditions of coal gasification slag by an optimization method. is there.

  By performing thermodynamic equilibrium calculation, the kind and amount of crystals contained in the coal gasification slag after calcination can be evaluated.

  Here, the firing conditions for coal gasification slag in the present invention mean the firing temperature of coal gasification slag and the gas composition during firing.

  Next, the optimum calcination temperature prediction method for coal gasification slag according to claim 2 is a method for predicting the optimum calcination temperature for foaming coal gasification slag obtained by coal gasification treatment of coal. The thermodynamic equilibrium calculation based on the elemental composition of coal ash and the calcination conditions of coal gasification slag was performed for multiple calcination temperatures, and the crystal precipitation characteristics of coal gasification slag at multiple calcination temperatures were predicted. The optimal firing temperature for foaming coal gasification slag is predicted from the crystal precipitation characteristics.

  Moreover, the optimal calcination temperature prediction program of coal gasification slag of Claim 4 is a program which estimates the optimal calcination temperature for foaming the coal gasification slag obtained by coal gasification processing of coal, The thermodynamic equilibrium calculation based on the elemental composition of coal ash and the calcination conditions of coal gasification slag is performed for multiple calcination temperatures. , Which causes the computer to execute the process of predicting the crystal precipitation characteristics of coal gasification slag at multiple firing temperatures and the process of predicting the optimal firing temperature for foaming coal gasification slag from the crystal precipitation characteristics is there.

  An amorphous component is maintained in the coal gasification slag that exhibits good foamability after firing. Therefore, the crystallization characteristics after calcination of coal gasification slag were calculated for multiple calcination temperatures by performing thermodynamic equilibrium calculation based on the elemental composition of coal ash and the calcination conditions of coal gasification slag. By predicting the crystal precipitation characteristics of coal gasification slag, it is possible to determine the firing temperature range in which the components in the coal gasification slag are predicted not to be controlled by the crystalline, and to set the highest firing temperature within that range. The optimum firing temperature can be predicted.

  According to the first aspect of the present invention, the foaming characteristics after calcination of coal gasification slag can be predicted from the elemental composition of coal ash and the firing conditions of coal gasification slag without actually producing coal gasification slag. Therefore, it is possible to save the operating cost of the high pressure gasification furnace for performing the coal gasification treatment, and the labor and time for measuring the absolute dry density by firing the coal gasification slag. Moreover, when applying not only bituminous coal called high-grade coal but also a new coal type called low-grade coal to coal gasification combined power generation, it becomes possible to easily predict these heating and foaming characteristics.

  According to the second aspect of the present invention, it is possible to predict a firing temperature suitable for foaming from the elemental composition of coal ash and the firing conditions of the coal gasification slag without actually producing the coal gasification slag. Therefore, it is possible to save the operating cost of the high-pressure gasification furnace for performing the coal gasification process, and the time and labor for calcining the coal gasification slag and measuring the absolute dry density. In addition, not only bituminous coal called high-grade coal but also a new coal type called low-grade coal can be used for coal gasification combined power generation, and it becomes possible to easily predict the firing temperature suitable for foaming.

  According to the third aspect of the present invention, it is possible to predict foaming characteristics after calcination of coal gasification slag only by inputting the elemental composition of ash content of coal and the firing conditions of coal gasification slag. Therefore, it can be obtained from various coal types without the operating cost of the high pressure gasification furnace for performing the coal gasification treatment and the labor and time for measuring the absolute dry density by firing the coal gasification slag. It becomes possible to predict the heating and foaming characteristics of coal gasification slag.

  According to the fourth aspect of the present invention, it is possible to predict a firing temperature suitable for foaming of coal gasified slag simply by inputting the elemental composition of coal ash and the firing conditions of coal gasified slag. . Therefore, it can be obtained from various coal types without the operating cost of the high pressure gasification furnace for performing the coal gasification treatment and the labor and time for measuring the absolute dry density by firing the coal gasification slag. It becomes possible to predict a firing temperature suitable for foaming of coal gasification slag.

  The best mode for carrying out the present invention will be described below in detail with reference to the drawings.

  The method for predicting the heating and foaming characteristics of coal gasification slag according to the present invention is a method for predicting the heating and foaming characteristics of coal gasification slag obtained by coal gasification treatment, wherein the elemental composition of coal ash and coal gas The thermodynamic equilibrium calculation is performed based on the calcination conditions of gasified slag, the crystal precipitation characteristics after calcination of coal gasification slag are predicted, and the foaming state after calcination of coal gasification slag is predicted from the crystal precipitation characteristics I have to.

  The inventors of the present application have a common tendency in coal gasification slag showing good foamability after firing, that is, in the XRD spectrum obtained by XRD analysis of the coal gasification slag after firing, As shown in FIG. 1, it was found that the coal gasification slag showing good foamability tends to maintain a broad amorphous peak observed in the vicinity of 20 ° to 38 ° at the baseline.

  Therefore, in the XRD spectrum obtained by XRD analysis of the coal gasified slag after calcination, when the amorphous peak is maintained at the baseline, the heating and foaming characteristics of the coal gasified slag are good. Can be evaluated. That is, the foamability can be evaluated by evaluating the crystallinity of the coal gasified slag after firing. The evaluation of crystallinity is not limited to the XRD analysis, and for example, it can be easily evaluated by observing the appearance of the fracture surface and gloss of the coal gasification slag. Therefore, when the purpose is to easily evaluate the heating and foaming characteristics of the actually produced coal gasification slag, the crystallinity of the coal gasification slag after firing is evaluated by XRD analysis or appearance observation. This object can be achieved, and it is a very effective means as a method for evaluating the heat foaming characteristics. Moreover, if it is a calcination temperature range in which an amorphous peak is maintained in the XRD spectrum, it can be judged that the coal gasified slag after calcination has good foaming properties, and therefore the highest calcination temperature within the calcination temperature range. Can be determined as the optimum firing temperature.

  Here, the crystallinity of the coal gasified slag after calcination can be evaluated by thermodynamic equilibrium calculation. In other words, without actually producing coal gasification slag, by predicting crystal precipitation characteristics by performing thermodynamic equilibrium calculation based on the elemental composition of coal ash and the firing conditions of coal gasification slag, The crystallinity of the coal gasified slag after firing can be evaluated.

  The elemental composition of the ash content of coal can be easily obtained as the specifications at the time of purchasing the coal, but if not known, it can be determined based on the ash composition analyzed according to JIS-M8815.

  Here, the thermodynamic equilibrium calculation in the present invention is a method of calculating an equilibrium composition that minimizes the Gibbs free energy based on the elemental composition of coal ash and the firing conditions of coal gasification slag by an optimization method. is there.

  The coal gasification slag firing conditions mean the coal gasification slag firing temperature and the gas composition during firing.

  By performing thermodynamic equilibrium calculation, the kind and amount of crystals contained in the coal gasification slag after calcination can be evaluated.

  The thermodynamic equilibrium calculation can be performed using commercially available software such as FactSage (GTT Technologies GmbH), Malt2 (Science & Technology), Thermocalc (Thermotech), HSC Chemistry (Outokumpu Research). In addition, if the crystal seed | species and crystal content (crystal content rate) of coal gasification slag can be calculated, it will not be limited to the calculation method using these software. In addition, it is also possible to evaluate the chemical composition and amount of the molten liquid phase by performing thermodynamic equilibrium calculation.

  When the crystal precipitation characteristics are predicted by thermodynamic equilibrium calculation, and it is judged that the amorphous component is hardly maintained in the coal gasification slag after calcination, the heating foaming characteristic is Can be predicted as bad. On the contrary, when it is judged that the amorphous component is maintained in the coal gasification slag, it can be predicted that the heat foaming characteristic is good.

  In addition, perform thermodynamic equilibrium calculations for multiple firing temperatures to predict crystal precipitation characteristics and determine the firing temperature range in which it is determined that amorphous components are maintained in the coal gasified slag after firing. In addition, the maximum temperature within the range can be predicted as the optimum firing temperature.

Here, the method of judging the quality of the heating foaming property from the amount of crystals (crystal content) contained in the coal gasification slag will be specifically described based on FIG. In FIG. 2, the horizontal axis represents the firing temperature, and the vertical axis represents the crystal content obtained for various firing temperatures by thermodynamic equilibrium calculation. Moreover, the broken line has shown the crystal content rate threshold value (alpha). The threshold value α can be obtained experimentally. An example of how to determine the threshold value α is as follows. That is, for various coals, the crystal content of the coal gasification slag after firing by performing a thermodynamic equilibrium calculation for various firing temperatures based on the elemental composition of the ash of these coals and the firing conditions of the coal gasification slag Ask for. Next, the coal gasification slag obtained from each type of coal is fired at the firing temperature under the same conditions as the thermodynamic equilibrium calculation, and the absolutely dry density of the fired coal gasification slag is measured. Then, for each coal type, the crystal content obtained by thermodynamic equilibrium calculation is compared with the measured absolute dry density, which is suitable for use as a desired absolute dry density, for example, as a light bone material for concrete. A firing temperature range in which the absolute dry density is 1.6 g / m ³ or less is determined. The crystal content at the highest calcination temperature within this calcination temperature range is the threshold for the crystal content at which the amorphous component is maintained in the coal type and the good foaming characteristics are maintained. The threshold value α is determined by determining this threshold value for various types of coal and taking the average of these values.

  The threshold value α is a criterion for determining whether the heat foaming characteristics of the coal gasified slag after firing are good or bad. That is, when the crystal content of the coal gasification slag after calcination by the thermodynamic equilibrium calculation is equal to or less than the threshold value α, it can be determined that the heating foaming property is good. Furthermore, it can also be a standard for determining the optimum firing temperature. For example, for coal gasification slag obtained from the same coal type, a thermodynamic equilibrium calculation is performed at various firing temperatures, the crystal content is plotted against various firing temperatures, and a straight line obtained by fitting the plotted data The firing temperature at the intersection of the (curve) and the threshold value α can be determined to be a temperature at which foaming proceeds sufficiently while the amorphous component is maintained to such an extent that the heat-foaming characteristics are good. For fitting, a known method such as a least square method can be used.

  A more specific description will be given based on FIG. The coal gasification slag obtained from the coal types c and d in FIG. 2 has a crystal content smaller than the threshold value α even when the firing temperature is 1100 ° C. Therefore, it is judged that the coal gasification slag obtained from the coal types c and d has good foaming characteristics even at 1100 ° C. As for the coal gasification slag obtained from the coal type b, when the firing temperature exceeds T ° C., the crystal content exceeds the threshold value α, and good heat foaming characteristics cannot be obtained. Therefore, in order to obtain good heat-foaming characteristics, it is judged that baking should be performed at T ° C. or less, most preferably at T ° C.

  The temperature at which the coal gasification slag is fired is preferably as low as possible as long as good heat foaming characteristics can be maintained. The coal types c and d shown in FIG. 2 can be fired even at about 1100 ° C., but if the firing temperature exceeds 1000 ° C., the coal gasification slag may be fused in the rotary kiln. Further, some kilns cannot be fired at a temperature exceeding 1000 ° C., and it is preferable to fire at 1000 ° C. or less from the viewpoint of reducing fuel costs and manufacturing costs.

  In addition, although there are coal types with good heating and foaming characteristics even at a firing temperature of 900 ° C. or less, in general coal types, when the firing temperature is 900 ° C. or less, the heating and foaming properties of coal gasification slag are not good. In some cases, firing at a temperature exceeding 900 ° C. is preferable. For example, since the coal type a in FIG. 2 is less than 900 ° C. and exceeds the threshold value α, it cannot be fired at a temperature at which the coal gasification slag is sufficiently foamed, and the heating and foaming characteristics are determined to be poor.

  In other words, thermodynamic equilibrium calculation can be performed over a wide range of firing temperatures, but considering the firing temperature necessary to sufficiently foam coal gasification slag and the above problems when using a kiln, It is preferable to perform the thermodynamic equilibrium calculation in the firing temperature range of more than 900 ° C. to 1000 ° C.

  As described above, according to the method for predicting the heating and foaming characteristics of the present invention, it is possible to reliably foam with a general rotary kiln without predicting the firing temperature range where coal gasification slag can be reliably foamed or using a special rotary kiln. The firing temperature range can be predicted.

  Next, the program of this invention is demonstrated based on FIGS.

  The heating and foaming prediction program of the present invention is executed by, for example, the heating and foaming property prediction apparatus 1. FIG. 3 shows an example of the configuration of the heating and foaming characteristic prediction apparatus 1. The heating and foaming characteristic prediction device 1 stores an output device 2 such as a display, an input device 3 such as a keyboard and a mouse, a central processing arithmetic device (CPU) 4 that performs arithmetic processing, and data and parameters being calculated. A main storage device (RAM) 5, a hard disk 6 as an auxiliary storage device in which calculation results and the like are recorded, and a communication interface 7 for communicating with the outside. The main storage device 5 and the auxiliary storage device 6 are collectively referred to simply as a storage device. The above hardware resources are electrically connected through the bus 8, for example.

  Moreover, the heating foaming characteristic prediction program of the present invention is recorded in the auxiliary storage device 6, and the computer functions as the heating foaming characteristic prediction apparatus 1 by being read and executed by the CPU 4. Data necessary for the execution is loaded into the RAM 5. The above-described hardware configuration is an example, and the present invention is not limited to this.

  The coal gasification slag heat foaming characteristic prediction program of the present invention shown in FIG. 4 is a program for predicting the heat foaming characteristic of coal gasification slag obtained by coal gasification treatment of coal, and is an element of coal ash content. Thermodynamic equilibrium calculation based on the elemental composition of coal ash and calcining conditions of coal gasification slag was performed by memorizing the composition and calcining conditions of coal gasification slag, and crystal precipitation characteristics after calcination of coal gasification slag And a process for predicting the foamed state after firing of the coal gasification slag from the crystal precipitation characteristics. Specifically, the thermodynamics based on the step (S1) of inputting the elemental composition of coal ash and the firing conditions of coal gasification slag, and the elemental composition of coal ash and the firing conditions of coal gasification slag. At least a step (S2) of performing equilibrium calculation to predict the crystal precipitation characteristics after firing of coal gasification slag and a step (S3) of predicting a foaming state after firing of coal gasification slag from the crystal precipitation characteristics Contains.

  In executing the program, the elemental composition of the ash content of coal supplied to the coal gasification furnace and the firing conditions for firing the coal gasification slag are acquired and input as initial data (S1). This initial data is stored in the auxiliary storage device 6 or the like.

  The firing conditions for firing the coal gasification slag are the firing temperature of the coal gasification slag and the gas composition during firing.

  Next, thermodynamic equilibrium calculation is executed based on the initial data, and the computer is caused to execute a process (S2) for predicting the crystal precipitation characteristics after calcination of the coal gasification slag. The thermodynamic equilibrium calculation is performed by the same method as described above.

  Next, the computer is caused to execute a process (S3) for predicting the foaming state after firing the coal gasification slag from the crystal precipitation characteristics. When it is predicted that the components in the coal gasification slag are not controlled by the crystallinity, it can be predicted that the heat foaming characteristics are good. The determination as to whether the heating and foaming characteristics are good or not is made by previously storing the above-described threshold value α in a storage device and using this threshold value α as a reference. That is, when the crystal content, which is the crystal precipitation characteristic obtained from the thermodynamic equilibrium calculation in S2, exceeds the threshold value α (S3; Yes), it is determined that the heating foaming characteristic is poor (S5), and the threshold value α or less. In the case (S3; No), it is determined that the heating and foaming characteristics are good (S4), and the determination result is output to the output device 2.

  Here, the heating foaming characteristic prediction apparatus 1 shown in FIG. 3 can also be used as an optimum firing temperature prediction apparatus for foaming coal gasification slag.

  The optimum firing temperature prediction program is executed by, for example, an optimum firing temperature prediction device. The configuration of the optimum firing temperature predicting device is the same as that of the above-described heating foaming property predicting device 1, and the description thereof is omitted.

  The optimum firing temperature prediction program of the present invention is recorded in the auxiliary storage device 6, and the computer functions as the maximum firing temperature prediction device 1 when the program is read and executed by the CPU 4. Data necessary for the execution is loaded into the RAM 5. The above-described hardware configuration is an example, and the present invention is not limited to this.

  The optimum firing temperature prediction program shown in FIG. 5 is a program for predicting the optimum firing temperature for foaming coal gasification slag obtained by coal gasification treatment of coal. The thermodynamic equilibrium calculation based on the ash slag element composition and the coal gasification slag calcination condition is performed for multiple calcination temperatures, and the coal gas at multiple calcination temperatures is stored. The computer executes a process for predicting the crystallization slag crystal precipitation characteristics and a process for predicting the optimum firing temperature for foaming the coal gasification slag from the crystal precipitation characteristics. Specifically, the step (S11) of inputting the elemental composition of coal ash and the firing conditions of coal gasification slag, and the thermodynamics based on the elemental composition of coal ash and the firing conditions of coal gasification slag. A step of performing equilibrium calculation for a plurality of calcination temperatures to predict crystal precipitation characteristics after calcination of coal gasification slag (S12), and a step of determining a function F representing a crystal content with respect to the calcination temperature (S13) And a step (S14) of calculating the firing temperature at the threshold value α from the function F and a step (S15) of outputting the calculation processing result as the optimum firing temperature. S13 to S15 are processes for predicting the optimum firing temperature for foaming the coal gasification slag from the crystal precipitation characteristics.

  In executing the program, the element composition of the ash content of coal supplied to the coal gasification furnace and the firing conditions for firing the coal gasification slag are acquired and input as initial data (S11). This initial data is stored in the auxiliary storage device 6 or the like.

  The firing conditions for firing the coal gasification slag are the firing temperature of the coal gasification slag and the gas composition during firing. When the optimum firing temperature prediction program is executed, a plurality of firing temperatures are input as initial data.

  Here, in the optimum calcining temperature prediction program, the thermodynamic equilibrium calculation can be executed over a wide range of calcining temperatures. However, as described above, in general coal types, when the calcining temperature is 900 ° C. or less, coal gas There is a risk that the heat-foaming characteristics of the slag will be poor, and considering the case where the coal gasification slag is actually fired by a rotary kiln, it is preferable to set the firing temperature to 1000 ° C. or lower. The temperature is preferably selected in the range of more than 900 ° C to 1000 ° C.

  Next, thermodynamic equilibrium calculation is executed based on the initial data, and the computer is caused to execute processing (S12) for predicting the crystal precipitation characteristics of coal gasification slag for a plurality of firing temperatures. The thermodynamic equilibrium calculation is performed by the same method as described above.

  Next, the computer is caused to execute processing (S13 to S15) for predicting the optimum firing temperature for foaming the coal gasification slag from the crystal precipitation characteristics. Specifically, the firing temperature range in which the amorphous component is sufficiently maintained in the fired coal gasification slag and the heating foaming property is judged to be good is determined, and the maximum temperature within that range is determined. Predict the optimum firing temperature. The determination as to whether the heating and foaming characteristics are good or not is made by previously storing the above-described threshold value α in a storage device and using this threshold value α as a reference. That is, a function F representing the crystal content with respect to the firing temperature is determined from the crystal content data for a plurality of firing temperatures (S13), and the firing temperature at the threshold α is calculated from the function F (S14), and the temperature is optimal. The firing temperature is output to the output device 2 (S15). The function F can be obtained by fitting from a crystal content data for a plurality of firing temperatures by a known method such as a least square method.

  As described above, according to the present invention, it is possible to predict the heating and foaming characteristics and optimum firing temperature of coal gasification slag without actually producing coal gasification slag. And from this prediction result, it is possible to select a coal type that provides good coal gasification slag foaming ability and use it for coal gasification combined power generation. However, by adding additives to the coal gasification furnace so as to approach the elemental composition of coal ash with good foaming properties, it is possible to improve the heat foaming characteristics of the final product, coal gasification slag. It can be. Therefore, the present invention increases applicability of all types of coal to combined coal gasification combined power generation, and greatly contributes to its early practical application.

  The above-described embodiment is an example of a preferred embodiment of the present invention, but is not limited thereto, and various modifications can be made without departing from the scope of the present invention.

  EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

(Example 1)
(1) Sample preparation Coal A, B, C and D, which are bituminous coals commonly used in domestic thermal power plants, are processed in a coal gasifier (Electric Power Research Laboratory), and A coal slag B charcoal slag, C charcoal slag and D charcoal slag were obtained. Table 1 shows the composition of these coal ash contents.

  For firing A coal slag, B coal slag, C coal slag, and D coal slag, a muffle furnace capable of accurate temperature setting was used and heated at 700 ° C. to 1100 ° C. in an air atmosphere.

As mentioned above, sample A-7 was obtained from sample A-1 shown below from A coal slag, B coal slag, C coal slag, and D coal slag.
Sample A-1: Unfired A charcoal slag sample A-2: 1000 ° C calcined A charcoal slag sample B-1: 700 ° C calcined B charcoal slag sample B-2: 800 ° C calcined B charcoal slag sample B-3: 900 ° C Calcined B charcoal slag sample B-4: 1000 ° C calcined B charcoal slag sample B-5: 1100 ° C calcined B charcoal slag sample C-1: 700 ° C calcined C charcoal slag sample C-2: 800 ° C calcined C charcoal slag sample C -3: 900 ° C calcined C charcoal slag sample C-4: 1000 ° C calcined C charcoal slag sample C-5: 1100 ° C calcined C charcoal slag sample D-1: Unfired D charcoal slag sample D-2: 800 ° C calcined D Charcoal slag sample D-3: 900 ° C calcined D charcoal slag sample D-4: 950 ° C calcined D charcoal slag sample D-5: 1000 ° C calcined D charcoal slag sample D-6: 1050 ° C calcined D charcoal slag sample D-7 : 1100 ℃ calcined D charcoal slag

(2) Heat-foaming property evaluation The absolute dry density of sample A-1 to sample D-7 was measured, and the quality of the heat-foaming property was judged. The quality of the heat-foaming property was based on the absolute dry density (1.6 g / cm ³ or less) judged to be suitable when used as a light bone material for concrete. That is, when the absolute dry density of the slag is 1.6 g / cm ³ or less, the heating foaming characteristic is judged as “good”, and when it exceeds 1.6 g / cm ³ , the heating foaming characteristic is judged as “bad”. I decided.

(3) XRD measurement JDX-8030 made from JEOL was used for the XRD measurement of the sample A-1 to the sample D-7. Measurement conditions are: tube voltage 40 kV, tube current 30 A, step angle 0.04 °, counting time 10 seconds, measurement angle 5 to 70 °, diverging slit 2 °, light receiving slit 0.04 mm, scattering The slit was 2 °. Note that the XRD measurement apparatus and measurement conditions are not limited to those shown in the present embodiment, and can be appropriately implemented according to commonly used XRD measurement apparatuses and measurement conditions.

(4) XRD measurement result and heating foamability evaluation result (4-1) A charcoal slag The result of XRD measurement of sample A-1 and sample A-2 is shown in FIG. In sample A-1, a broad amorphous peak was observed at 20 ° to 38 °. This amorphous peak was maintained also in sample A-2. Moreover, the heat foamability of sample A-2 was determined to be “good”.

(4-2) B charcoal slag The results of XRD measurement of Sample B-1 to Sample B-5 are shown in FIG. In Sample B-4 and Sample B-5, a sharp crystalline peak was observed, but a broad amorphous peak observed at 20 ° to 38 ° was maintained in all samples. Moreover, the heat foamability of sample B-4 and sample B-5 was determined to be “good”. In addition, about sample B-1, sample B-2, and sample B-3, since the calcination temperature was low, the heat foaming property was judged to be "poor".

(4-3) C charcoal slag FIG. 8 shows the results of XRD measurement of samples C-1 to C-5. In Sample C-4 and Sample C-5, a sharp crystalline peak was observed, but a broad amorphous peak observed at 20 ° to 38 ° was maintained in all samples. Moreover, the heat foamability of sample C-4 and sample C-5 was determined to be “good”. In addition, about sample C-1, sample C-2, and sample C-3, since the calcination temperature was low, the heat foaming property was judged to be "poor".

(4-4) D charcoal slag The results of XRD measurement of Sample D-1 to Sample D-7 are shown in FIG. In Sample D-1, Sample D-2, and Sample D-3, a broad amorphous peak was observed at 20 ° to 38 °, but Sample D-4, Sample D-5, Sample D-6, and Sample D In D-7, this broad amorphous peak was not observed, but only a sharp crystalline peak was observed, and the heat foamability was judged to be “poor”. In addition, about the sample D-2 and the sample D-3, since the calcination temperature was low, the heat foamability was judged to be "poor".

From the above results, it was shown that there is a correlation between the amorphous peak of slag measured by XRD and the heat foaming characteristics. That is, if the amorphous peak of slag is maintained even when heated at a temperature exceeding 900 ° C., the heat foaming characteristics are good, that is, it is judged to be suitable for use as a light bone material for concrete. It was revealed that the dry density was 1.6 g / cm ³ or less.

  Accordingly, if there is an amorphous component in an amount detectable by XRD measurement in the coal gasified slag component after calcination, it can be determined that the heat-foaming characteristics are good. It is possible to easily determine the heat-foaming characteristics by evaluating whether or not an amorphous component is present. For example, by visually observing the fracture surface and gloss of the slag, it is possible to confirm the presence of the amorphous component and determine the heat foaming characteristics. Moreover, the crystal precipitation characteristics of coal gasified slag after firing can be determined based on the elemental composition of coal ash and the firing conditions of coal gasified slag by known thermodynamic equilibrium calculations. Can be predicted.

  Also, the coal gasification slag fired at various firing temperatures is subjected to XRD measurement to determine the firing temperature range in which an amount of amorphous component detectable by XRD measurement can be present, and the maximum temperature within that range is optimized. The firing temperature can be determined. Therefore, a thermodynamic equilibrium calculation is performed for a plurality of firing temperatures to predict crystal precipitation characteristics, and a firing temperature range in which it is determined that the amorphous component is sufficiently maintained in the coal gasification slag after firing. And the maximum temperature within the range can be predicted as the optimum firing temperature.

It is a figure which shows the amorphous peak of coal gasification slag. It is a schematic diagram which shows the method of performing heating foaming characteristic prediction and optimal baking temperature prediction on the basis of threshold value (alpha). It is an example of the hardware block diagram of a heating foaming characteristic prediction apparatus. It is a figure which shows the flowchart of the heating foam prediction program of this invention. It is a figure which shows the flowchart of the optimal baking temperature prediction program of this invention. It is a figure which shows the XRD analysis result of the slag produced from A charcoal. It is a figure which shows the XRD analysis result of the slag produced from B charcoal. It is a figure which shows the XRD analysis result of the slag produced from C charcoal. It is a figure which shows the XRD analysis result of the slag produced from D charcoal.

Claims (4)

  A method for predicting the heating and foaming characteristics of coal gasification slag obtained by coal gasification treatment, wherein thermodynamic equilibrium calculation is performed based on the elemental composition of ash in the coal and the firing conditions of the coal gasification slag. Predicting the crystal precipitation characteristics after firing of the coal gasification slag, and predicting the foaming state after firing of the coal gasification slag from the crystal precipitation characteristics, heating the coal gasification slag Foaming property prediction method.   A method for predicting an optimum firing temperature for foaming coal gasification slag obtained by coal gasification treatment of coal, wherein the heat is based on the elemental composition of the coal ash and the firing conditions of the coal gasification slag. Optimal for foaming the coal gasification slag from the crystal precipitation characteristics by performing dynamic equilibrium calculation for a plurality of firing temperatures and predicting the crystal precipitation characteristics of the coal gasification slag at the plurality of firing temperatures. A method for predicting the optimum firing temperature of coal gasification slag characterized by predicting a suitable firing temperature.   A program for predicting the heating and foaming characteristics of coal gasification slag obtained by coal gasification treatment, comprising storing the elemental composition of ash in the coal and the firing conditions of the coal gasification slag and storing the coal A thermodynamic equilibrium calculation based on the elemental composition of ash and the firing conditions of the coal gasification slag is performed, and a process for predicting the crystal precipitation characteristics after firing the coal gasification slag, and the coal gas from the crystal precipitation characteristics A program for predicting the heating and foaming characteristics of coal gasification slag, which causes a computer to execute a process for predicting the foaming state after calcination of slag.   A program for predicting the optimum firing temperature for foaming coal gasification slag obtained by coal gasification treatment, and storing the elemental composition of the ash content of coal and the firing conditions of the coal gasification slag A thermodynamic equilibrium calculation based on the elemental composition of the coal ash and the firing conditions of the coal gasification slag is performed for a plurality of firing temperatures, and the coal gasification slag is crystallized at the firing temperatures. A process for predicting characteristics, and a process for predicting an optimum firing temperature for foaming the coal gasification slag from the crystal precipitation characteristics. program.