CN112198266A - Method for measuring chlorine content in coal and coal gasification products - Google Patents
Method for measuring chlorine content in coal and coal gasification products Download PDFInfo
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- HNSDLXPSAYFUHK-UHFFFAOYSA-N 1,4-bis(2-ethylhexyl) sulfosuccinate Chemical compound CCCCC(CC)COC(=O)CC(S(O)(=O)=O)C(=O)OCC(CC)CCCC HNSDLXPSAYFUHK-UHFFFAOYSA-N 0.000 description 2
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- HGUFODBRKLSHSI-UHFFFAOYSA-N 2,3,7,8-tetrachloro-dibenzo-p-dioxin Chemical compound O1C2=CC(Cl)=C(Cl)C=C2OC2=C1C=C(Cl)C(Cl)=C2 HGUFODBRKLSHSI-UHFFFAOYSA-N 0.000 description 1
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
- G01N30/02—Column chromatography
- G01N30/04—Preparation or injection of sample to be analysed
- G01N30/06—Preparation
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
- G01N30/02—Column chromatography
- G01N30/04—Preparation or injection of sample to be analysed
- G01N30/06—Preparation
- G01N30/08—Preparation using an enricher
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
- G01N30/02—Column chromatography
- G01N30/04—Preparation or injection of sample to be analysed
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- G01N30/14—Preparation by elimination of some components
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
- G01N30/96—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation using ion-exchange
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
- G01N30/02—Column chromatography
- G01N30/04—Preparation or injection of sample to be analysed
- G01N30/06—Preparation
- G01N2030/067—Preparation by reaction, e.g. derivatising the sample
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
- G01N30/02—Column chromatography
- G01N30/04—Preparation or injection of sample to be analysed
- G01N30/06—Preparation
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- G01N2030/143—Preparation by elimination of some components selective absorption
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- G—PHYSICS
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- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
- G01N30/02—Column chromatography
- G01N30/04—Preparation or injection of sample to be analysed
- G01N30/06—Preparation
- G01N30/14—Preparation by elimination of some components
- G01N2030/146—Preparation by elimination of some components using membranes
Abstract
The invention discloses a method for measuring chlorine content in coal and coal gasification products, which adopts a technical scheme of combining coal gasification, pressure tank digestion and ion chromatography to simultaneously measure the chlorine content in coal, coal gasification solid residues and gas products. The method mainly comprises the following steps: 1) enriching chlorine elements in the gasified gas product by utilizing a capture and collection system of the chlorine elements in the coal; 2) performing pressure tank digestion treatment on a coal sample or a gasified solid residue sample; 3) respectively measuring chlorine elements in the coal sample, the gasification residue or the gas product by using an ion chromatography; 4) calculating the chlorine content in the coal sample, the gasified solid residue sample and the gas product; 5) and checking and rechecking the balance of the chlorine element and the calculation result. The method has the advantages of simple operation method, high accuracy and precision of the measured result, good repeatability and the like.
Description
Technical Field
The invention belongs to the field of gas and solid component analysis and detection, and particularly relates to a method for determining chlorine in coal and coal gasification products.
Background
In recent years, coal gasification technology is used as clean coal utilization technology, and hundred and ten thousand-ton-level coal chemical enterprises taking coal gasification technology as a leading part are successively started in Ningxia, Shanxi and the like of China. The content of chlorine in coal has great influence on the industrial utilization of coal, the chlorine content of the coal exceeds 0.3 percent, and chlorine is partially volatilized into a gas phase mainly in the form of HCl or alkali metal chloride potassium chloride (KCl) and sodium chloride (NaCl) in the gasification process, and is condensed, slagged and even corroded on a superheater tube through various mechanisms; in the coal gasification process, a plurality of organic chlorides are generated, so that dioxin and the like are generated to pollute the environment and harm the human health. Therefore, the chlorine content in coal has attracted high attention from all societies. The mandatory national standards GB 34169 plus 2017 commercial coal quality civil loose coal and GB 34170 plus 2017 commercial coal quality civil briquette require the chlorine content in the civil loose coal and the civil briquette coal: chlorine content CldLess than or equal to 0.15 percent. The content of Cl in export coal was specified in "provisional method for commercial coal quality control": chlorine content Cld≤0.30％。
The common sample processing method for measuring the chlorine in the coal comprises a high-temperature combustion method, an oxygen bomb combustion method, an extraction method and an aldrin decomposition method, and the chlorine of the processed sample solution is measured by a precipitation titration method, a potentiometric titration method, an atomic absorption method, an inductively coupled plasma emission spectrometry method and the like. The national standard GB/T3558-. The analysis methods are long in period and complicated in operation, and the content of chlorine in the coal is calculated after titration by a silver nitrate solution. For samples with low chlorine content, the relative error of chemical titration is large, and the requirement of quick and accurate quantification is difficult to meet.
In the coal gasification process, the content and distribution of chlorine in gas products and gasification residues are determined by firstly providing a proper chlorine capturing and collecting system for analysis and detection; secondly, analyzing chlorine elements in the gasification product gas and chlorine elements in the gasification residues respectively; methodology validation was performed for the designed analytical detection method. Chinese patent CN 102914537 a discloses a method for detecting the content of chloride ions in coal gas, which has the technical defect that after absorbing chlorine elements in coal gas, chemical titration is adopted for analysis and detection, and the measurement accuracy and precision are difficult to guarantee. Chinese patent CN 101236174A discloses a method for measuring chlorine content in coal, which comprises weighing a coal sample, feeding into a cracking tube for full combustion, converting chlorine in the coal into chloride ions, carrying the chloride ions into a chlorine ion titration cell provided with 4 electrodes and forming a closed-loop automatic control system with a microcoulomb amplifier by carrier gas, carrying out chemical combination reaction between the chloride ions and silver ions in a solution, continuously electrolyzing and supplementing silver ions into the cell under the action of the electrodes and the amplifier along with the consumption of the silver ions to keep a constant value, measuring the power consumption of electrolysis by a computer, and calculating the chlorine content in the coal sample according to the Faraday's law of electrolysis. The method has the defects that the content of chlorine in the solid residue after combustion is ignored, and certain errors exist in accurate analysis and determination of the content of chlorine in the coal.
Disclosure of Invention
According to the invention, through a self-made simple and efficient system for capturing and collecting chlorine in the coal gasification process and by utilizing the system to measure the chlorine content in coal gasification products (including gasification residues and gas products), the problems of large error and low efficiency of the detection method of the chlorine in coal and coal gasification products in the prior art are solved.
The invention relates to a method for measuring the content of chlorine in coal and coal gasification products, which adopts the following technical scheme.
A method for measuring the chlorine content in coal and coal gasification products is characterized by comprising the following steps:
1) enriching chlorine elements in the gasified gas product by utilizing a capture and collection system of the chlorine elements in the coal;
2) performing pressure tank digestion treatment on a coal sample or a gasified solid residue sample;
3) respectively measuring chlorine elements in the coal sample, the gasification residue or the gas product by using an ion chromatography;
4) calculating the chlorine content in the coal sample, the gasified solid residue sample and the gas product;
5) and checking and rechecking the balance of the chlorine element and the calculation result.
In the technical scheme, the system for capturing and collecting the chlorine element in the coal adopts a self-made experimental device, and the experimental device consists of four operation units, namely a sample gasification unit, a fly ash capture unit, a tar condensation unit and a chlorine element capture and collection unit which are sequentially connected; the sample gasification unit enables a coal sample to be subjected to gasification reaction at high temperature and converted into a gaseous product and solid residues, so that chlorine in the coal sample is released in a gaseous form; the fly ash collecting unit and the tar condensing unit sequentially remove fly ash and tar in the gaseous product; the chlorine element capturing and collecting unit transfers all the chlorine elements in the gaseous products without fly ash and tar into the chlorine element absorption liquid, thereby realizing the capturing and collecting of the chlorine elements in the coal and facilitating the further quantitative analysis of the chlorine elements in the coal.
Preferably, in the method for measuring the chlorine content in the coal and the coal gasification product, the coal gasification temperature is 500-1200 ℃, and the gasification reaction time is 8-30 min.
Preferably, in the method for measuring the chlorine content in coal and coal gasification products, the operation of enriching chlorine in the gasified gas products is to use a 0.1mol/L NaOH solution as an absorption solution, wherein the NaOH solution is prepared by ultrapure water with the resistivity of 18.2M omega cm.
In the above technical solution, in the method for determining the chlorine content in coal and coal gasification products, the method for pressure tank digestion treatment of a coal sample or a gasified solid residue sample comprises:
a. digestion of coal samples
With mass M1Placing the coal sample in a beaker with a polytetrafluoroethylene lining according to the volume of 8-13 mlDigestion liquid/0.05gSample to be testedAdding a certain volume of digestion solution into the added amount, uniformly mixing, putting the beaker into a matched high-pressure reaction kettle, screwing a kettle cover, putting the kettle cover into a constant-temperature drying box, and digesting for 4 hours at 170 ℃. And after digestion is finished and the reaction kettle is cooled, taking out the polytetrafluoroethylene lining, slowly opening the tank cover in a fume hood, and fully exhausting to obtain clear and transparent coal sample digestion solution after digestion. In the process, the digestion solution is prepared from 7-10 parts by volume of 68 wt.% of superior pure nitric acid solution and 1-2 parts by volume of 30 wt.% of hydrogen peroxide solution.
b. Digestion of gasification residues
With mass M2The gasification residue sample is placed in a beaker with a polytetrafluoroethylene lining, a certain volume of digestion solution is added according to the addition amount of (8-13 ml digestion solution)/(0.05 g sample to be detected), after uniform mixing, the beaker is placed in a matched high-pressure reaction kettle, a kettle cover is screwed, then the beaker is placed in a constant-temperature drying oven, and digestion is carried out for 5-6h at 170 ℃. And after the digestion is finished and the reaction kettle is cooled, taking out the polytetrafluoroethylene beaker with the lining, slowly opening the tank cover in a fume hood, and fully exhausting to obtain a clear and transparent coal gasification residue digestion solution after digestion. In the process, the digestion solution is prepared from 7-10 parts by volume of 68 wt.% of high-grade pure nitric acid solution, 1-2 parts by volume of 30 wt.% of hydrogen peroxide solution and 0.1-0.5 part by volume of hydrofluoric acid.
Preferably, in the process of digesting the coal sample or the gasified solid residue sample in the pressure tank, the digestion temperature is 150-170 ℃ and the digestion time is 4-6 h.
Further, step 3) is implemented by obtaining a chloride ion standard curve in advance, and the specific method comprises the following steps: the national standard sample chlorine ion standard solution (GSB 04-1770-2004) is used for preparing a series of standard solutions with different concentrations. Then, under the set ion chromatography working conditions, the concentration of the chloride ions in the standard solution is measured by using ion chromatography, and finally, a standard curve of the chloride ions is obtained according to the peak area and the ion concentration.
The chlorine element in the coal sample, the gasification residue and the gas product is respectively measured by using the ion chromatographic analyzer and the working conditions which are the same in the process of measuring the concentration of the chloride ions in the chloride ion standard solution, and the operation method is as follows:
a. determination of chlorine content in coal sample
Using ultrapure water to fix the volume of the coal sample digestion solution obtained in the step 2) to V1And obtaining the liquid 1 to be detected. And (3) repeating the steps under the condition of not adding a coal sample to obtain a liquid 2 to be detected as a blank sample. Measuring the volume concentration C of chloride ions in the solutions 1 and 2 by using the same ion chromatographic analyzer, working conditions and test methodcoal-ClAnd Cblank-Cl。
b. Determination of chlorine content in gasification residue
Weighing M as mass by using analytical balance2The gasification residue sample is placed in a polytetrafluoroethylene beaker, 68 wt.% of high-grade pure nitric acid solution, 30 wt.% of hydrogen peroxide solution and hydrofluoric acid with a certain volume are added, the mixture is uniformly mixed, the beaker is placed in a matched high-pressure reaction kettle, a kettle cover is screwed, the kettle cover is placed in a constant-temperature drying box, and digestion is carried out for 5-6 hours at 170 ℃. After digestion is finished and the reaction kettle is cooled, taking out the polytetrafluoroethylene beaker with the lining, slowly opening the tank cover in a fume hood, and fully exhausting to obtain a clear and transparent coal gasification residue digestion solution after digestion; the digested solution of the coal gasification residue is subjected to constant volume to V by using ultrapure water2And obtaining the liquid 3 to be detected. And repeating the steps under the condition of not adding the coal gasification residue sample to obtain the liquid to be detected 4 as a blank sample. Measuring the volume concentration C of chlorine element in the solutions 3 and 4 to be measured by using the same ion chromatographic analyzer, working conditions and test methodresidue-ClAnd C'blank-Cl.
c. Determination of chlorine content in gas products
After the gasification reaction is finished, respectively transferring 1mL of liquid absorbing chlorine element from four gas washing bottles, and respectively metering the volume to V by using ultrapure water3And obtaining the solutions to be detected in four different gas-phase products, and respectively marking the solutions. And (3) in the NaOH solution which does not absorb the chlorine element, repeating the steps to obtain a solution to be detected 5 as a blank sample. Measuring the volume concentration C of the solution chloride ions to be measured in the gas-phase product by using the same ion chromatographic analyzer, working conditions and test methodgas-ClAnd Cgas-blank。
All samples were filtered through 0.45 μm microporous membranes before ion chromatography measurements were performed on the chlorine in the coal samples, gasification residues and gas products.
In the technical scheme, the calculation formula of the chlorine content in the coal sample, the gasified solid residue sample and the gas product is as follows:
a. mass concentration W of chlorine element in coal samplecoal-Cl(μ g/g) is:
in the formula, Ccoal-Cl(ug/mL) -the concentration of chloride ions in the coal sample digestion solution; cblank-Cl(ug/mL) -the concentration of chloride ion in the corresponding blank; v1(mL) -the volume of the coal sample digestion solution after constant volume; m1(g) Resolving the quality of the coal sample;
b. mass concentration W of chlorine in gasification residueresidue-Cl(μ g/g) is:
in the formula, Cresidue-Cl(ug/mL) -concentration of chloride ions in gasification residue digestion solution; c'blank-Cl(ug/mL) -the concentration of chloride ion in the corresponding blank; v2(mL) -the volume of the gasified residue digestion solution after constant volume; m2(g) -resolving the quality of the gasification residue;
c. mass M of chlorine element in gas productgas-ClThe formula for calculation of (ug) is:
Mgas-Cl＝(Cgas-Cl1+Cgas-Cl2+Cgas-Cl3+Cgas-Cl4-4*Cgas-blank)*V3*VX (3)
in the formula, Cgas-Cl1，Cgas-Cl2，Cgas-Cl3，Cgas-Cl4(ug/mL) -the concentration of chloride ions in the gas products absorbed in the NaOH absorption solutions of the four gas washing bottles respectively; cgas-blank(ug/mL) -the concentration of chloride ion in the corresponding blank; v3(mL) -the volume of the gas product absorption liquid after constant volume; vX(mL) -the volume of NaOH solution absorbed in the gas-washing bottle.
In the technical scheme, the checking and rechecking process of the balance and the calculation result of the chlorine element comprises the following specific operation processes:
carrying out gasification reaction on a coal sample under different coal gasification temperature conditions, such as 700 ℃, 800 ℃ and 900 ℃, and then respectively detecting the distribution of chlorine in the coal gasification product under the temperature conditions by adopting the same measuring method to carry out material balance of chlorine; taking coal samples and coal gasification solid samples of the same batch, and carrying out parallel determination of the content of chloride ions to check the repeatability of the calculated result; and (5) taking a coal sample to measure the standard recovery rate, and verifying the accuracy of the measurement result.
The technical progress and beneficial technical effects of the method for measuring the chlorine content in the coal and coal gasification products claimed by the invention are as follows.
The invention discloses a method for measuring chlorine content in coal and coal gasification products, which adopts a technical means of coal gasification-pressure tank digestion-ion chromatography combination to simultaneously measure the chlorine content in coal, coal gasification solid residues and gas products. Compared with the prior art, its advantage lies in:
(1) according to the method, the capture and collection device of the chlorine element in the coal gasification product is improved, so that the chlorine element in the coal gasification product is enriched completely, the capture and collection accuracy of the chlorine element in the coal gasification product is improved, and the material balance calculation of the chlorine element in the capture and collection device can reach more than 90%.
(2) The method adopts a pressure tank digestion method to treat the coal sample and the coal gasification residues, has the advantages of strong decomposition capability, low price of equipment required for pretreatment, easy pollution control, small acid consumption and the like, and can further thoroughly transfer trace chlorine elements in the coal sample and the coal gasification residues into the digestion solution.
(3) The method has the advantages of high sensitivity, good selectivity, good stability, large capacity, rapidness and convenience in measurement by adopting the ion chromatograph, combines the steps of accurate calculation, balance calculation of chlorine element and check and recheck of the calculation result, and further ensures the scientificity and accuracy of the method.
Therefore, compared with the prior art, the overall technical scheme of the method has the advantages of simple operation method, high accuracy and precision of the measured result and good repeatability.
Drawings
FIG. 1 is a schematic flow chart of the method for measuring chlorine content in coal and coal gasification products according to the present invention.
FIG. 2 is a schematic diagram of a device for capturing and collecting chlorine element in self-made coal adopted by the invention, wherein in FIG. 1: 1-a gas cylinder; 2-a valve; 3-a gas flow meter; 4-stainless steel tube; 5-high temperature resistant silicon rubber plug; 6-high temperature generating equipment; 7-corundum ark; 8-a tubular reactor; 9-a thermocouple; 10-heating a belt; 11-aluminosilicate cotton; 12-a tubular high temperature ceramic filter; 13-silicone tube; 14-ice salt mixture; 15-tar absorption bottle; 16-a cold trap; 17-glass pull ring; 18-gas washing bottle.
FIG. 3 is a standard curve of chloride ion obtained by using a national standard sample of chloride ion standard solution (GSB 04-1770-2004) under a set chromatographic condition; FIG. 3 shows: the linear correlation between the peak area and the chloride ion concentration is good, R2＝0.9996。
Detailed Description
All the ultrapure water mentioned in the following embodiments or examples is ultrapure water having a resistivity of 18.2. omega. cm, which can be prepared by a Milli-Q A2 ultrapure water system. All the embodiments or examples the ion chromatography used to determine the chlorine content of the sample was performed using an ion chromatograph "Sammer Feideran ICS-2100" equipped with a Dionex IonPac AS19-4 mm analytical column and a AG19-4mm protective column, a Dionex AERS suppressor, the operating conditions and parameters of the chromatograph were set AS: the column temperature was 30 ℃, the suppressor current was 50mA, the pump flow rate was 1mL/min, and the sample ion separation was carried out using 17mmol/L KOH AS the eluent, using an AS-DV autosampler, at a sample volume of 25. mu.L.
The flow schematic diagram of the method for measuring the chlorine content in the coal and coal gasification products is shown in figure 1.
The self-made system for capturing and collecting the chlorine element in the coal, which is adopted by the method, is suitable for the situation that the accuracy of the chlorine element test in the subsequent coal gasification products is improved through the efficient capture and collection of the chlorine element in the gas products after the coal is gasified, wherein the coal gasification products comprise gasification residues and gas products.
The following will describe in detail the method of the present invention with reference to fig. 1, which is a schematic flow chart of the method of the present invention for measuring chlorine content in coal and coal gasification products, and fig. 2, which is a schematic diagram of a system for capturing and collecting chlorine element in self-made coal used in the present invention. It should be noted that, in fig. 1, the method steps are simplified or summarized, and the flow of the method for determining the chlorine content in coal and coal gasification products according to the present invention is summarized as five steps, namely, "enriching chlorine in a gasified gas product", "performing pressure tank digestion treatment on a solid residue sample", "determining chlorine in a detected sample by using ion chromatography", "calculating chlorine content in a detected sample", and "balance calculation of chlorine and check and recheck of calculation result", but the essence of the method is completely consistent with the five steps described below.
As shown in FIG. 1, the method for measuring the chlorine content in coal and coal gasification products of the present invention comprises the following steps:
enriching chlorine elements in a gasified gas product by utilizing a capture and collection system of chlorine elements in coal;
as shown in figure 2, the self-made experimental system for capturing and collecting chlorine element in coal comprises four operation units, namely a sample gasification unit, a fly ash capture unit, a tar condensation unit and a chlorine element capture and collection unit, which are sequentially connected. The sample gasification unit consists of a tubular reactor 8 and a gas cylinder 1, wherein the gas cylinder 1 supplies a gasification agent to the tubular reactor 8, and then gasification reaction is carried out under a high-temperature condition. A gas flowmeter 3 is arranged between a gas cylinder 1 and a tubular reactor 8 in the sample gasification unit, the gas flowmeter 3 is communicated with the tubular reactor 8 through a stainless steel gas guide tube 4, and a high-temperature-resistant silicon rubber plug 5 is arranged at the tube orifice of the stainless steel gas guide tube 4.
The specific operation method for carrying out the coal gasification experiment by using the self-made coal chlorine element capturing and collecting system shown in FIG. 2 comprises the following steps: firstly, weighing the mass of a corundum boat by using an analytical balance, putting the corundum boat into a muffle furnace, heating to 815 ℃, and carrying out heat preservation and ignition until the weight of the corundum boat is constant. Then, a certain amount of shenmu coal powder is taken, ground to 80-100 meshes, 1g of coal powder sample is weighed and evenly paved in a corundum boat which is fired to constant weight, the total mass of the corundum boat and the coal powder sample is weighed by an analytical balance, and the mass of the corundum boat is subtracted, so that the accurate mass of the coal sample for gasification is obtained. Then, when the temperature of the high-temperature tube furnace is stabilized at 800 ℃, the corundum ark is placed in a constant-temperature area of the high-temperature tube furnace by using a stainless steel push rod, and the corundum ark is gasified for 12 min. And after the gasification experiment is finished, taking the corundum square boat out of the tube furnace by using a stainless steel push rod, quenching for 1min, quickly transferring the corundum square boat containing gasification residues after quenching into a dryer, cooling to room temperature, and weighing.
The step is carried out in a tubular reactor 8 of a sample gasification unit, the length of the tubular reactor 8 is 600 mm-1000 mm, and the inner diameter is 40 mm-60 mm. In the experimental process, the tubular reactor 8 is provided with two high-temperature distribution areas, wherein one high-temperature distribution area is positioned in the middle of the high-temperature tubular furnace 6, and the temperature of the part in the quartz tube is maintained to be 500-1200 ℃ through real-time monitoring by a thermocouple arranged in the high-temperature tubular furnace 6, so that the coal sample is completely gasified; one side part of the quartz tube close to the fly ash trapping unit is wrapped by a heating belt 10, the outer layer of the heating belt 10 is wrapped by an insulating material 11, a thermocouple 9 is arranged on the inner layer of the heating belt 10, and the temperature of the part in the quartz tube is kept between 260 and 300 ℃ in the working process, so that tar is prevented from being condensed on the inner wall of the part of the quartz tube to cause interference on subsequent chlorine element trapping.
In the whole experiment process, the flow rate of the gasification agent compressed air is controlled to be 200mL/min through the gas flowmeter 3. After the gasification reaction is finished, the residual gasification agent in the reaction is used as carrier gas, and the gasification product is brought into a subsequent fly ash trapping unit, a tar condensing unit and a chlorine element capturing and collecting unit.
As shown in figure 2, in the self-made coal chlorine element capturing and collecting experiment system adopted by the invention, the chlorine element capturing and collecting unit consists of 4 gas washing cylinders 18 which are mutually connected in series, and a proper amount of chlorine element absorbing liquid and a glass pull ring 17 are respectively arranged in the gas washing cylinders 18. The chlorine element absorption solution is a NaOH solution with the concentration of 0.1mol/L, and the NaOH solution is prepared by ultrapure water with the resistivity of 18.2M omega cm; the loading capacity of the chlorine element absorption liquid is 1/3-2/3 of the volume of the gas washing bottle 18.
In the self-made coal chlorine element capturing and collecting experiment system adopted by the invention, the fly ash capturing unit and the tar condensing unit are arranged, so that more than 95% of fly ash and tar in a gasified gas product can be removed compared with the prior detection technology, and the accuracy of a coal gasification subsequent measurement result is ensured. The fly ash trapping unit is a tubular high-temperature ceramic filter 12 filled with porous high-temperature ceramic filter materials; the tar condensing unit consists of 3 tar absorption bottles 15 which are connected in series and are arranged in a cold trap 16 with the temperature maintained between 20 ℃ below zero and 15 ℃ below zero. One tar absorption bottle 15 is connected with the tubular high-temperature ceramic filter 12 through a silicone tube 13, the other tar absorption bottle 15 is connected with 1 gas washing bottle 18 filled with NaOH solution in the chlorine element capturing and collecting unit, and the tar absorption bottle 15 is filled with a steel wire mesh; the chlorine element capturing and collecting unit transfers all the chlorine elements in the gaseous product without fly ash and tar into the chlorine element absorption liquid in the gas washing bottle 18, thereby realizing the capturing and collecting of the chlorine elements in the coal or biomass and facilitating the further quantitative analysis of the chlorine elements in the coal gasification products.
Step two, performing pressure tank digestion treatment on the coal sample or the gasified solid residue sample:
a. digestion of coal samples
Weighing the coal sample M prepared in the preparation stage by using an analytical balance1(g) Placing the mixture into a beaker with a polytetrafluoroethylene lining, adding 68 wt.% of superior pure nitric acid solution and 30 wt.% of hydrogen peroxide solution with a certain volume, uniformly mixing, placing the beaker into a matched high-pressure reaction kettle, screwing a kettle cover, placing the kettle into a constant-temperature drying box, and digesting for 4 hours at 170 ℃. And after digestion is finished and the reaction kettle is cooled, taking out the polytetrafluoroethylene lining, slowly opening the tank cover in a fume hood, and fully exhausting to obtain clear and transparent coal sample digestion solution after digestion.
b. Digestion of gasification residues
Weighing a gasification residue sample M obtained in the coal sample gasification experimental process in the step 1) by using an analytical balance2(g) Placing the mixture into a beaker with a polytetrafluoroethylene lining, adding a certain volume of digestion solution according to the addition amount of (8-13 ml digestion solution)/(0.05 g sample to be detected), uniformly mixing, placing the beaker into a matched high-pressure reaction kettle, screwing a kettle cover, placing the beaker into a constant-temperature drying oven, and digesting for 5 hours at 170 ℃. And after the digestion is finished and the reaction kettle is cooled, taking out the polytetrafluoroethylene beaker with the lining, slowly opening the tank cover in a fume hood, and fully exhausting to obtain a clear and transparent coal gasification residue digestion solution after digestion.
Step three, respectively measuring chlorine elements in the coal sample, the gasification residue or the gas product by using an ion chromatography:
first, a chloride ion chromatography standard curve was obtained in advance. The specific method is that the national standard sample chloride ion standard solution (GSB 04-1770-2004) is used to prepare a series of standard solutions with different concentrations, such as 0.02 mu g/mL, 0.1 mu g/mL, 0.3 mu g/mL, 0.5 mu g/mL, 1.0 mu g/mL, etc. Then, under the set chromatographic working conditions, the chloride ion concentration in the standard solution is measured by ion chromatography, and finally, a standard curve of the chloride ion is obtained according to the peak area and the ion concentration.
Then, the method comprises the following steps of:
the same ion chromatographic analyzer and working conditions are utilized to respectively measure the chlorine elements in the coal sample, the gasification residue and the gas product, and the operation method is as follows:
a. determination of chlorine content in coal sample
Using ultrapure water to fix the volume of the coal sample digestion solution obtained in the step 2) to V1(in this example V)150mL) to obtain a solution 1 to be tested. And (3) repeating the steps under the condition of not adding a coal sample to obtain a liquid 2 to be detected as a blank sample. Measuring the volume concentration C of chlorine element in the liquid 1 and the liquid 2 to be measured by using the ion chromatographic analyzer, the working condition and the measuring method which are the same in the step 3)coal-ClAnd Cblank-Cl。
In the above measurement, all samples were filtered through a 0.45 μm microfiltration membrane before ion chromatography.
b. Determination of chlorine content in gasification residue
The digested solution of the coal gasification residue is subjected to constant volume to V by using ultrapure water2(in this example V)250mL) to obtain a solution to be detected 3. And repeating the steps under the condition of not adding the coal gasification residue sample to obtain the liquid to be detected 4 as a blank sample. Measuring the volume concentration C of chlorine element in the solutions 3 and 4 to be measured by using the ion chromatographic analyzer, the working condition and the measuring method which are the same in the step 4)residue-ClAnd C'blank-Cl。
In the above measurement, all samples were filtered through a 0.45 μm microfiltration membrane before ion chromatography.
c. Determination of chlorine content in gas products
After the completion of the gasification reaction, 1mL of the chlorine-absorbed liquid was taken from each of the four gas washing bottles (in this example, 250mL capacity scale gas washing bottles were used), and the volume was adjusted to V with ultrapure water3(in this example V)310 mL). Thereby obtaining the products to be in four different gas phasesAnd (5) detecting the solution and marking respectively. And (3) in the NaOH solution which does not absorb the chlorine element, repeating the steps to obtain a solution to be detected 5 as a blank sample.
According to the working conditions and the testing method set by the ion chromatography, the volume concentration C of the chlorine element in the solution to be tested in the four different gas phase products is respectively measuredgas-Cl(ug/mL), and volume concentration of blank sample (ug/mL) Cgas-blank。
In the above measurement, all samples were filtered through a 0.45 μm microfiltration membrane before ion chromatography.
Step four, calculating the chlorine content in the coal sample, the gasified solid residue sample and the gas product:
the calculation formula of the chlorine content in the coal sample, the gasification residue and the gas product is as follows:
a. mass fraction W of chlorine element in coal samplecoal-Cl(μ g/g) is:
in the formula, Ccoal-Cl(ug/mL) -the concentration of chloride ions in the coal sample digestion solution; cblank-Cl(ug/mL) -the concentration of chloride ion in the corresponding blank; v1(mL) -the volume of the coal sample digestion solution after constant volume; m1(g) -the mass of the digested coal sample;
b. mass fraction W of chlorine element in gasification residueresidue-Cl(μ g/g) is:
in the formula, Cresidue-Cl(ug/mL) -concentration of chloride ions in gasification residue digestion solution; c'blank-Cl(ug/mL) -the concentration of chloride ion in the corresponding blank; v2(mL) -the volume of the gasified residue digestion solution after constant volume; m2(g) -the quality of the digested gasification residue;
c. mass M of chlorine element in gas productgas-ClThe formula for calculation of (ug) is:
Mgas-Cl＝(Cgas-Cl1+Cgas-Cl2+Cgas-Cl3+Cgas-Cl4-4*Cgas-blank)*V3*VX (3)
in the formula, Cgas-Cl1，Cgas-Cl2，Cgas-Cl3，Cgas-Cl4(ug/mL) -the concentration of chloride ions in the gas products absorbed in the NaOH absorption solutions of the four gas washing bottles respectively; cgas-blank(ug/mL) -the concentration of chloride ion in the corresponding blank; v3(mL) -the volume of the gasified residue digestion solution after constant volume; vx(mL) -volume of sodium hydroxide absorption solution in the scrubber bottle;
step five, checking and rechecking the balance of the chlorine element and the calculation result:
the purpose of this step is to ensure the accuracy and scientificity of the measurement method. Therefore, the capture and collection device is required to calculate the capture and absorption efficiency of the capture and collection device on chlorine in the gas-phase product, and the calculation formula is as follows:
the chlorine element trapping and absorption efficiencies (. eta.) of the experimental system used in the present invention can be calculated by substituting the data calculated by the formulae (1), (2) and (3) into the respective dataCl)。
And (3) carrying out gasification reaction on the coal sample at 700 ℃, 800 ℃ and 900 ℃, and then respectively detecting the distribution of the chlorine element in the coal gasification product under the three temperature conditions by adopting the same measuring method to carry out material balance of the chlorine element. Then, taking the same batch of the Shenmu gasified coal samples, and carrying out parallel measurement on the content of the chloride ions to check the repeatability of the calculation result. And finally, taking a coal sample to measure the standard recovery rate, and verifying the accuracy of the measurement result.
The following description will further explain the technical effects of the present invention obtained in comparison with the prior art by way of specific embodiments in conjunction with the above description of the method for measuring chlorine content in coal and coal gasification products according to the present invention.
Example 1
The gasification system is prepared before the experiment. Before the start of the experiment, the entire reaction system was purged with air and the tube furnace was heated to 700 ℃. The fly ash collecting device, the tar condensing device and the gas collecting device are connected in sequence, wherein the fly ash collecting device is made of a tubular high-temperature ceramic filter; the tar condensation is realized by additionally arranging a cold trap, namely 3 tar bottles filled with a steel wire mesh are connected in series in the experiment and placed in an ice-salt bath heat-preservation barrel with ice and sodium chloride uniformly mixed in a ratio of 3:1, so that the temperature of the cold trap is maintained at about-18 ℃. The steel wire mesh is plugged in the tar bottle, and the effects of tar condensation and fly ash capture are achieved. The outlet of the heating tube furnace is heated by a heating belt, and insulation materials such as aluminosilicate cotton are coated outside the heating tube furnace, so that the temperature of the heating tube furnace is maintained at 260-300 ℃, and tar is prevented from being condensed at the outlet of the heating tube furnace. And a gas collecting device is connected behind the tar condensing device, namely 4 gas washing bottles filled with 150mL of NaOH solution are connected in series.
The experimental process of gasification. Weighing 1g of shenmu gasified coal, uniformly spreading the shenmu gasified coal in a corundum ark with constant weight, and putting the corundum ark in a constant-temperature area of a high-temperature tube furnace for gasification for 12min by using a stainless steel push rod after the gasification temperature is stable. The flow rate of air in the gasification experiment was controlled using a gas mass flow meter. And after the gasification experiment is finished, taking the corundum square boat out of the tubular furnace by using a stainless steel push rod, immediately quenching for 1min, quickly transferring the corundum square boat containing the solid gasification residues after quenching into a dryer, cooling to room temperature, weighing, then filling the corundum square boat into a sample bag, sealing and storing in the dryer to obtain a gasification solid residue sample to be digested.
And preparing a sample to be tested. Sampling the liquid in the absorption device in a brown reagent bottle, and processing according to the third step to obtain a sample to be detected of the gas product; and weighing 0.05g of the gasified solid residue sample, and digesting according to the third step to obtain the gasified solid residue sample to be detected.
And (4) measuring chloride ions in the sample. Under the set working conditions, the concentrations of chloride ions in the gas product and the gasified solid residue of the sample to be measured are determined by ion chromatography, and the measurement is repeated for 2 times to obtain the average value. According to the calculation formula in step four, 863.54 μ g of chloride ions in the gas product and 153.66 μ g of chloride ions in the gasified solid product were calculated.
The balance of chlorine and the checking and rechecking results of the calculation results are shown in tables 1 and 2.
Example 2
The gasification system is prepared before the experiment. Before the start of the experiment, the entire reaction system was purged with air and the tube furnace was heated to 800 ℃. The fly ash collecting device, the tar condensing device and the gas collecting device are connected in sequence, wherein the fly ash collecting device is made of a tubular high-temperature ceramic filter; the tar condensation is realized by additionally arranging a cold trap, namely 3 tar bottles filled with a steel wire mesh are connected in series in the experiment and placed in an ice-salt bath heat-preservation barrel with ice and sodium chloride uniformly mixed in a ratio of 3:1, so that the temperature of the cold trap is maintained at about-18 ℃. The steel wire mesh is plugged in the tar bottle, and the effects of tar condensation and fly ash capture are achieved. The outlet of the heating tube furnace is heated by a heating belt, and insulation materials such as aluminosilicate cotton are coated outside the heating tube furnace, so that the temperature of the heating tube furnace is maintained at 260-300 ℃, and tar is prevented from being condensed at the outlet of the heating tube furnace. And a gas collecting device is connected behind the tar condensing device, namely 4 gas washing bottles filled with 150mL of NaOH solution are connected in series.
The experimental process of gasification. Weighing 1g of shenmu gasified coal, uniformly spreading the shenmu gasified coal in a corundum ark with constant weight, and putting the corundum ark in a constant-temperature area of a high-temperature tube furnace for gasification for 12min by using a stainless steel push rod after the gasification temperature is stable. The flow rate of air in the gasification experiment was controlled using a gas mass flow meter. And after the gasification experiment is finished, taking the corundum square boat out of the tubular furnace by using a stainless steel push rod, immediately quenching for 1min, quickly transferring the corundum square boat containing the solid gasification residues after quenching into a dryer, cooling to room temperature, weighing, then filling the corundum square boat into a sample bag, sealing and storing in the dryer to obtain a gasification solid residue sample to be digested.
And preparing a sample to be tested. Sampling the liquid in the absorption device in a brown reagent bottle, and processing according to the third step to obtain a sample to be detected of the gas product; and weighing 0.05g of the gasified solid residue sample, and digesting according to the third step to obtain the gasified solid residue sample to be detected.
And (4) measuring chloride ions in the sample. Under the set working conditions, the concentrations of chloride ions in the gas product and the gasified solid residue of the sample to be tested were measured by ion chromatography, and the measurement was repeated 2 times to obtain the average value. According to the calculation formula in the fourth step, 964.13 mu g of chloride ions in the gas product and 156.20 mu g of chloride ions in the gasified solid product are calculated.
The balance of chlorine and the checking and rechecking results of the calculation results are shown in tables 1 and 2.
Example 3
The gasification system is prepared before the experiment. Before the start of the experiment, the entire reaction system was purged with air and the tube furnace was heated to 900 ℃. The fly ash collecting device, the tar condensing device and the gas collecting device are connected in sequence, wherein the fly ash collecting device is made of a tubular high-temperature ceramic filter; the tar condensation is realized by additionally arranging a cold trap, namely 3 tar bottles filled with a steel wire mesh are connected in series in the experiment and placed in an ice-salt bath heat-preservation barrel with ice and sodium chloride uniformly mixed in a ratio of 3:1, so that the temperature of the cold trap is maintained at about-18 ℃. The steel wire mesh is plugged in the tar bottle, and the effects of tar condensation and fly ash capture are achieved. The outlet of the heating tube furnace is heated by a heating belt, and insulation materials such as aluminosilicate cotton are coated outside the heating tube furnace, so that the temperature of the heating tube furnace is maintained at 260-300 ℃, and tar is prevented from being condensed at the outlet of the heating tube furnace. And a gas collecting device is connected behind the tar condensing device, namely 4 gas washing bottles filled with 150mL of NaOH solution are connected in series.
The experimental process of gasification. Weighing 1g of shenmu gasified coal, uniformly spreading the shenmu gasified coal in a corundum ark with constant weight, and putting the corundum ark in a constant-temperature area of a high-temperature tube furnace for gasification for 12min by using a stainless steel push rod after the gasification temperature is stable. The flow rate of air in the gasification experiment was controlled using a gas mass flow meter. And after the gasification experiment is finished, taking the corundum square boat out of the tubular furnace by using a stainless steel push rod, immediately quenching for 1min, quickly transferring the corundum square boat containing the solid gasification residues after quenching into a dryer, cooling to room temperature, weighing, then filling the corundum square boat into a sample bag, sealing and storing in the dryer to obtain a gasification solid residue sample to be digested.
And preparing a sample to be tested. Sampling the liquid in the absorption device in a brown reagent bottle, and processing according to the third step to obtain a sample to be detected of the gas product; and weighing 0.05g of the gasified solid residue sample, and digesting according to the third step to obtain the gasified solid residue sample to be detected.
And (4) measuring chloride ions in the sample. Under the set working conditions, the concentrations of chloride ions in the gas product and the gasified solid residue of the sample to be measured are determined by ion chromatography, and the measurement is repeated for 2 times to obtain the average value. According to the calculation formula in the fourth step, 1010.26 mu g of chloride ions in the gas product and 92.15 mu g of chloride ions in the gasified solid product are calculated.
The balance of chlorine and the checking and rechecking results of the calculation results are shown in tables 1 and 2.
The efficiency of the self-made capturing and collecting device for capturing and absorbing the chlorine element in the gas-phase product is calculated as follows:
the data obtained by the above analysis are substituted respectively to obtain the chlorine element capturing efficiency (. eta.) of the collecting and capturing system used in the present inventionCl)。
The experimental results of examples 1, 2 and 3 are detailed in table 1. The experimental data in the table 1 show that the method has high repeatability for measuring the chloride ions in the coal sample gasification product and is simple to operate.
TABLE 1 distribution of chlorine in gasified products of shenmu coal after gasification at different temperatures
The chlorine ion content of the same batch of the shenmuo gasified coal was measured in parallel (blank was subtracted), and the results are shown in table 2.
TABLE 2 parallel determination of chloride ions in the gasified coal of Neem
As can be seen from Table 2, the relative standard deviation of the parallel measurement is less than 5%, which shows that the method of the invention can effectively measure the concentration of chloride ions in the gasified coal sample, and has the advantages of good repeatability, high accuracy, simple steps, convenient operation and the like.
Selecting a coal sample with known chloride ion concentration to measure the standard recovery rate, wherein the specific method comprises the following steps: 6 parts of 0.05g coal sample are respectively weighed and subjected to pressure tank digestion treatment, then chloride ion standard solutions with high, medium and low concentration levels shown in the table 3 are added (namely, the added standard sample amounts are 2.00 mu g/mL, 1.00 mu g/mL, 0.50 mu g/mL and 0.50 mu g/mL in sequence), then the 6 samples are respectively subjected to chloride ion detection according to the same detection method in the embodiments 1-3, the analysis and calculation results are shown in the table 3 and are between 92.43% and 105.32%, the recovery rate is good, and the determination result is high in accuracy and is suitable for determining the content of chlorine in coal and coal gasification products.
TABLE 3 determination of chloride ion content in the gasified coal of Pistacia chinensis by adding standard recovery
From the measurement results of examples 1 to 3, it can be seen that the method for measuring the content of chlorine in coal and coal gasification products claimed by the present invention is based on the accurate capture and collection of chlorine in coal gasification products, and compared with the prior art, the overall method has the advantages of simple steps, convenient operation, high capture efficiency and accuracy, good repeatability, etc. The self-made coal chlorine element capturing and collecting system adopted by the method has the advantages of cheap and easily-obtained instruments, convenient operation of the whole experiment system, simple method and high chlorine element capturing and collecting rate, and can meet the subsequent requirements of accurate and efficient detection of chlorine element in coal or biomass.
Claims (9)
1. A method for measuring the chlorine content in coal and coal gasification products is characterized by comprising the following steps:
1) enriching chlorine elements in the gasified gas product by utilizing a capture and collection system of the chlorine elements in the coal;
2) performing pressure tank digestion treatment on a coal sample or a gasified solid residue sample;
3) respectively measuring chlorine elements in the coal sample, the gasification residue or the gas product by using an ion chromatography;
4) calculating the chlorine content in the coal sample, the gasified solid residue sample and the gas product;
5) and checking and rechecking the balance of the chlorine element and the calculation result.
2. The method for determining the chlorine content in the coal and the coal gasification product according to claim 1, wherein the system for capturing and collecting the chlorine element in the coal adopts a self-made experimental device, and the experimental device comprises a sample gasification unit, a fly ash capture unit, a tar condensation unit and a chlorine element capture and collection unit which are sequentially connected; the sample gasification unit enables a coal sample to be subjected to gasification reaction at high temperature and converted into a gaseous product and solid residues, so that chlorine in the coal sample is released in a gaseous form; the fly ash collecting unit and the tar condensing unit sequentially remove fly ash and tar in the gaseous product; the chlorine element capturing and collecting unit transfers all the chlorine elements in the gaseous products without fly ash and tar into the chlorine element absorption liquid, thereby realizing the capturing and collecting of the chlorine elements in the coal and facilitating the further quantitative analysis of the chlorine elements in the coal.
3. The method for measuring the chlorine content in coal and coal gasification products according to claim 1 or 2, wherein in the step 1), the coal gasification temperature is 500 ℃ to 1200 ℃, and the gasification reaction time is 8min to 30 min.
4. The method according to claim 1, wherein the concentration of chlorine in the gasified gas in the step 1) is carried out by using an absorption solution of 0.1mol/L NaOH solution prepared from ultrapure water having a resistivity of 18.2M Ω -cm.
5. The method for measuring the chlorine content in the coal and coal gasification product according to claim 1, wherein the method for performing pressure tank digestion treatment on the coal sample or the gasified solid residue sample in the step 2) comprises the following steps:
placing a coal sample or a gasified solid-phase residue sample to be detected in a beaker with a polytetrafluoroethylene lining, and placing 8-13 ml of the sampleDigestion liquid/0.05gSample to be testedAdding a certain volume of digestion solution into the added amount, uniformly mixing, putting the beaker into a matched high-pressure reaction kettle, screwing a kettle cover, putting the kettle cover into a constant-temperature drying box, digesting for a period of time under certain pressure and temperature conditions, taking out the polytetrafluoroethylene lining after digestion is finished and the reaction kettle is cooled, slowly opening the tank cover in a fume hood, fully exhausting, and obtaining clear and transparent digestion solution of the sample to be measured after digestion.
6. The method for determining the chlorine content in the coal and coal gasification product according to claim 5, wherein when the sample to be measured is a coal sample, the digestion solution is prepared from 7-10 parts by volume of 68 wt.% of high-grade pure nitric acid solution and 1-2 parts by volume of 30 wt.% of hydrogen peroxide solution; when the sample to be detected is a gasified solid-phase residue sample, the digestion solution is prepared from 7-10 parts by volume of 68 wt.% of high-grade pure nitric acid solution, 1-2 parts by volume of 30 wt.% of hydrogen peroxide solution and 0.1-0.5 part by volume of hydrofluoric acid.
7. The method for measuring the chlorine content in the coal and coal gasification product according to claim 5, wherein in the step 3), the digestion temperature is 150-170 ℃ and the digestion time is 4-6 h.
8. The method according to claim 1, wherein in the step 4),
the mass concentration of the chlorine element in the coal sample is Wcoal-Cl(μ g/g) is:
in the formula, Ccoal-Cl(ug/mL) -the concentration of chloride ions in the coal sample digestion solution; cblank-Cl(ug/mL) -the concentration of chloride ion in the corresponding blank; v1(mL) -the volume of the coal sample digestion solution after constant volume; m1(g) Resolving the quality of the coal sample;
mass concentration W of chlorine element in gasification residueresidue-Cl(μ g/g) is:
in the formula, Cresidue-Cl(ug/mL) -concentration of chloride ions in gasification residue digestion solution; c'blank-Cl(ug/mL) -the concentration of chloride ion in the corresponding blank; v2(mL) -the volume of the gasified residue digestion solution after constant volume; m2(g) -resolving the quality of the gasification residue;
mass M of chlorine element in gas productgas-ClThe formula for calculation of (ug) is:
Mgas-Cl＝(Cgas-Cl1+Cgas-Cl2+Cgas-Cl3+Cgas-Cl4-4*Cgas-blank)*V3*VX (3)
in the formula, Cgas-Cl1，Cgas-Cl2，Cgas-Cl3，Cgas-Cl4(ug/mL) -the concentration of chloride ions in the gas products absorbed in the NaOH absorption solutions of the four gas washing bottles respectively; cgas-blank(ug/mL) -correspondingThe concentration of chloride ions in the blank sample; v3(mL) -the volume of the gas product absorption liquid after constant volume; vX(mL) -the volume of NaOH solution absorbed in the gas-washing bottle.
9. The method for determining the content of chlorine in coal and coal gasification products according to claim 1, wherein in the step 5), the checking and rechecking process of the balance of chlorine and the calculation result comprises the following specific operation processes:
under different coal gasification temperature conditions, carrying out gasification reaction on a coal sample, and then respectively detecting the distribution of chlorine elements in the coal gasification products under the temperature conditions by adopting the same measuring method to carry out material balance of the chlorine elements;
taking the same batch of the shenmu gasified coal samples, and carrying out parallel determination on the content of chloride ions to check the repeatability of the calculated result;
and (5) taking a coal sample to measure the standard recovery rate, and verifying the accuracy of the measurement result.
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