Some standard content:
Chemical Industry Standard of the People's Republic of China
Test Methods for Zinc Hydrogen Desulfurizer
Subject Content and Scope of Application
HG / T 2513 -- 93
This standard specifies the test methods for sulfur capacity, particle crushing strength, abrasion rate, ignition loss and chemical composition of zinc oxide desulfurizer. This standard is applicable to zinc oxide desulfurizer used for desulfurization of industrial raw gas such as hydrocarbon steam reforming, oil refining, organic synthesis and synthetic ammonia.
2 Reference standards
GB, T601 Preparation of standard solutions for quantitative analysis (quantitative analysis) of chemical reagents GB/T603 Preparation of preparations and products used in test methods for chemical reagents GB/T3635 Determination of crushing strength of fertilizer catalysts, molecular sieves and adsorbent particles GBT3636 Determination of attrition rate of fertilizer catalysts, molecular sieves and adsorbents GB 6003 Test sieves
GB/T6682 Specifications and test methods for water used in analytical laboratories HG/T2512 Analysis method for chemical composition of zinc-supported desulfurizers ZB/TG75003 Analysis method for loss on ignition of fertilizer catalysts 3 Test method for sulfur capacity
3.1 Principle of the method
Zinc oxide reacts with sulfide oxide or part of organic sulfide to form zinc dioxide: Manganese dioxide reacts with hydrogen sulfide or part of organic sulfide in the presence of hydrogen to form manganese sulfide, which removes sulfides from the raw gas. The chemical reaction formula is as follows: COS + 4H, H,S + CH, + H,O
Zno + H,S Zns + H,O
Zno + cos zns + co,
2ZnO + CSz 2Zns + COz
Zno + CH,sH CH,OH + Zus
MnO, + H, Mno + H,0
MnO + H,S - Mns + H,O
Mno + cos - Mns + co.
3.2 Process
As shown in Figure 1:
Approved by the Ministry of Chemical Industry of the People's Republic of China on September 9, 19934
1994-07-01 Implementation
Temperature self-adjustment
Thermometer
Pressure gauge
Hydrogen sulfide
HG /T 2513-93
Electric heating
Figure 1 Flow chart of sulfur capacity test device
1-1~1-5—Filter dry explosion bottle; 2-1~2-5—Transfer flowmeter: 3—Saturator; 4—Automatic water adder; 5—Electric furnace; 6—Gas mixer; 7—Reaction tube; Name—Reaction heating furnace: 9—Condenser: 10 Gas-water separator; 11—Gas wet flowmeter 3.3 Test conditions
Reactor: This The standard adopts a three-tube (or single-tube) reactor with a tube diameter of ?11×1.5mm hard glass tube. Desulfurizer loading: 2.0mL
Desulfurizer particle size: 0.85~1.18mm
System pressure: normal pressure
Test overflow:
Dry gas space velocity:
302QT305 type 220±1c
T304-1 type 350±1C
3 000± 50 h-
Ratio of water vapor to raw gas: T302Q, T305 type 1.0±0.1T 304-1 type 0. 3± 0. 1
HG / T 2513 93
Raw gas composition: Hydrogen and nitrogen mixed gas for synthetic ammonia (H2:N2 3:1); hydrogen sulfide content 4-6 g/ Nm;
Oxygen content <0.2%
≤0.4mg/Nm2
Tail gas sulfur content:
3.4 Test steps
3.4.1 Crush the desulfurizer sample and sieve it with a test sieve with a pore size of 0.85~1.18mm. After drying at 120℃ for 1h, use a 10mL measuring tube to tightly stack 10mL of the sample and weigh it to obtain the bulk density. Then weigh a sample equivalent to 2mL of mass. 3.4.2 Use the tight stacking method to fill the pre-treated 1.40~2.00mm quartz sand or glass balls into the reaction tube to the specified height. Place a layer of glass cloth on top, then slowly pour the 2m3 sample into the reaction tube, gently tap the wall of the reaction tube with this rod while pouring, so that the sample is packed tightly, evenly and flatly, and then place another layer of glass cloth, and then fill the quartz sand or glass balls to about 10mm from the mouth of the reaction tube,
3.4.3 Place the reaction tube with the sample in the electric furnace, so that the sample is in the isothermal zone of the electric furnace, connect the system for leak test, and ensure that there is no air leakage at each joint: the thermocouple is inserted into the middle of the desulfurizer bed 3.4.4 Add appropriate amount of water (in accordance with the third-level water specification in GB/T6682) to the saturator and automatic water adder. 3.4.5 After the instruments and meters of the inspection device system are all on, the reactor is heated at a rate of about 150C/5: a. The T302Q desulfurizer is heated to 260°C and kept at this temperature for half an hour to completely reduce the manganese oxide in the sample, and then the temperature of the reactor is lowered to 220°C and kept at this temperature;
b. The T304-1 desulfurizer is heated to 350°C and kept at this temperature; C. The T305 desulfurizer is heated to 220°C and kept at this temperature. 3.4.6 Hydrogen and nitrogen leakage gas is introduced into the system for replacement, and the gas space velocity is controlled to be about 1500h, and the temperature of the insulation pipe is heated to about 150°C and kept at this temperature. The saturator begins to heat up to a temperature when the steam-gas ratio is 1.0 or 0.3. 3.4.7 Open the cyanogen sulfide gas source valve, add 4-6g/Nm hydrogen sulfide gas to the hydrogen-nitrogen mixture, and adjust the gas space velocity to 3000h-. Under this test condition, measure the amount of tail gas condensate once an hour, adjust the saturator water temperature, and make the ratio of water vapor to source gas within the range of 1.0 (or 0.3) ± 0.1. 3.4.8 After passing hydrogen sulfide gas for several hours (depending on the sulfur content), start to measure the sulfur content in the outlet tail gas once an hour. If the sulfur content is found to be increased, , change to 30min or 15min to set a standard. If the content exceeds 0.4mg/m3, take a sample again immediately for measurement. If it still exceeds 0.4mg/m3, it is considered that the desulfurizer has been penetrated by sulfur. Immediately cut off the hydrogen sulfide gas, stop heating the saturator, and let the hydrogen-nitrogen mixed gas enter the reactor through the bypass to replace the remaining water vapor. After half an hour, stop ventilation and turn off the reactor heating power. 3.4.9 When the reactor temperature drops below 50, unload the desulfurizer, remove the glass balls or quartz sand, grind all the desulfurizers into powder, mix well, and bake at 120℃ for 1h for standby use. 3.4.10 According to Appendix A "Sulfur content analysis method", analyze the sulfur content of the desulfurized sample and calculate the penetration sulfur content. 4 Determination of crushing strength of particles
4.1 The strength determination method shall be carried out in accordance with the provisions of GB/T3635. 4.2 The sample to be determined shall be dried at 120°C for 1 hour and then cooled to room temperature before determination. The number of particles to be determined shall be 50. The sieve of the strip sample shall be cut short to 5~7mm before determination and both sides shall be ground flat.
4.3 The measuring instrument range is 010DN and the accuracy is Class 1. 5 Determination of abrasion rate
5.1 The abrasion rate determination method shall be carried out in accordance with the provisions of GB/T3636. 5.2 The sample to be determined shall be dried at 120°C for 1 hour and then cooled to room temperature before determination. 6 Determination of loss on ignition
HG/F 13 93
The method for measuring loss on ignition shall be carried out in accordance with ZB/TG 75003 7 Chemical composition analysis
Chemical analysis method, according to the provisions of HG/T2512, A1 principle
HG/T 2313 — 93
Appendix A
Sulfur content analysis
Combustion neutralization method
Supplement)
Sulfur-containing compounds generate sulfur dioxide under high temperature and oxygen conditions, and then absorb with hydrogen peroxide solution to generate sodium peroxide. The sodium peroxide is titrated with sodium hydroxide standard solution.
2Zn +3022Zn0 +2S0,t
s + Oz so t
SO2 + H,O, H,SO,
H,SO, + 2NaOH - Na,SO, + 2H,OA2 Reagents
The purity of the reagents used in this standard, unless otherwise specified, are analytically pure reagents: Experimental water shall comply with the specifications of grade 3 water in GB/T6682.
A2.1 Sodium hydroxide (GB/T629) standard titration solution, c (NaOH) = 0.1 mol/L, prepared and calibrated according to GB/T601
A2. 2 Hydrogen peroxide (GB/T 6684) solution: 3% (V/W)A2.3. Oxycresol green (HG/T3-1220)-methyl red (HG/T3-958) indicator liquid, prepared according to GB/T603. A3. Apparatus and devices
A3.1 General laboratory apparatus
A3. 2. Bubble-jet gas absorption tube
A3.3. Magnetic boat, 70 mm, boiled with (1+1) hydrochloric acid (GB/T.622), washed with water, boiled with distilled water, dried, and burned at 950°C for 1 h.
A 3. 4 High temperature carbonization furnace
A3.5 Device
As shown in Figure A1:
Figure A1 Schematic diagram of the combustion method analysis bowl installation process 1 oxygen cylinder:
2-pressure reducing gauge: 3-rotameter; 4-quartz glass: 5-high temperature carbonization furnace, 6 absorption tube HG/T2513-93
A 4 Analysis stepsbZxz.net
Weigh 0.1~0.2g of the sample after sulfur absorption and treatment [accurate to 0.0001g) and mix them evenly in the magnetic boat. Heat the high temperature carbonization furnace to 1050~1100℃, adjust the oxygen flow rate to 100mL/min, pour 1.15mL of hydrogen peroxide solution into each of the two absorption tubes and connect them to the outlet of the quartz tube. Quickly put the magnetic boat into the middle of the quartz tube, and then plug the rubber stopper. After 15-20 minutes, remove the two absorption tubes, pour the absorption liquid into a 250mL conical flask and wash the absorption tubes. Add 2-3 fulls of mixed indicator solution and use sodium hydroxide standard titration solution until the red color changes to light green as the end point. A5 Selection of analysis results
The sulfur content of the desulfurizer X is expressed as mass fraction (%) and calculated according to formula (A1): X
c × V × 0. 016
C × V× 0.016
Where: c——the actual concentration of sodium hydroxide standard titration solution, mol/L; V-the volume of sodium hydroxide standard titration solution used for titration. L; m-the mass of the sample, more
0.016——the mass of sulfur expressed in grams equivalent to 1.00mL sodium hydroxide standard titration solution [r(Na0H)=1.000mol/L).
A6 Allowable error
The absolute difference of parallel analysis results shall not exceed 0.3%. The arithmetic mean of the parallel analysis results shall be taken as the analysis result. Appendix B
Analysis of Sulfur Ions in Gases—Agmercury Sulfate Method
(Supplement)
B1 Principle
When hydrogen sulfide in the gas sample is absorbed by the sodium hydroxide solution, it becomes sulfide ions that easily react with mercury ions. Dithiothione (diphenylthiobatide) is used as the indicator liquid and directly titrated with mercury ion standard titration solution. When the titration reaches the endpoint, under the action of alkali, a slightly excess of mercury ions and dithiol form a slightly reddish complex. Reagent B2
The purity of the reagents used in this standard, unless otherwise specified, are all analytically pure reagents: The water used in the experiment should meet the specifications of Grade 3 water in GB/T6682.
B2.1 Standard titration solution for mercury ions
Weigh 68.0 mg of red mercuric oxide (calculated based on a mercuric oxide content of 99.6%) in a 100 mL beaker, add 6 mL of mineral acid (GB/T626) to completely dissolve it, add an appropriate amount of distilled water and transfer to a 500 mL brown volumetric flask, dilute to the scale with distilled water, and shake well. Each liter of this solution is equivalent to 20 sulfide ions, and the storage period is half a year. B2.2 Sodium hydroxide (GB/T629) absorption liquid: C (NaOH) = 0.25 mol/L, first prepared into 1 mal/L according to GB/T601, and diluted to 0.25 mal/L when used. B2.3 Disulfide chloroform (GB/T682) indicator liquid: prepared according to GB/T603. B3 Apparatus
B3.1 General laboratory apparatus
B3.2 Medical syringe: 2mL, 5mL50mLB3.3 Impact-type gas sampling bottle
B3.4 Wet gas flowmeter, 2L
B4 Analysis steps
B4.1 Raw gas analysis
HG/T2513-93
Add 10mL of sodium hydroxide absorption solution to a 50mL conical flask: plug it tightly with a rubber stopper and evacuate it, use a syringe to directly draw a certain volume (mL) of gas sample and inject it into the bottle and shake it thoroughly to make the hydrogen sulfide be absorbed by the sodium hydroxide solution, add one-tenth of indicator solution, and then use mercury ion standard titration solution (each milliliter is equivalent to 4 sulfur ions), and titrate until it turns slightly red as the end point. At the same time, perform a blank test. If the concentration of sulfide oxygen in the raw gas is low, a mercury ion standard solution equivalent to 1 liter of sulfur can be used for titration. B4.2 Tail gas analysis
Put 10 mL of sodium hydroxide absorption liquid in the absorption tube, and make the hydrogen sulfide be absorbed by sodium hydroxide at a gas trace rate of 100 mL/mi. The remaining gas is measured by a wet gas flow meter (the general gas volume is 1L). Transfer the absorption liquid to a 100mL conical flask, add a drop of indicator liquid, and use a standard titration solution of mercury ions equivalent to 0.5 sulfur ions per liter. Drop until it turns slightly red, which is the end point. At the same time, perform a blank test. B5 Expression of analysis results
The sulfur content X in the raw gas and tail gas is expressed in / m and, m/ respectively. According to formula (B1), the sulfur content of high/m is calculated by cx(v,-v,)
wherein: c—concentration of standard titration solution for mercury ion, mL; V—volume of standard titration solution for mercury ion removal used in titration, mL; V——volume of gas sample taken, L.
B6 Allows for whole
When the sulfur ion content in the titrated solution is above 1g and the solvent volume is not more than 10 mL, the relative error of titration is not more than 3%. B7. Precautions
U.S. 7.1 When the endpoint color changes abnormally, the indicator solution should be re-prepared. B7.2 Carbon dioxide is absorbed by the sodium hydroxide solution. High concentration of carbon dioxide will affect the endpoint test. It must be controlled below 0.3 mol/L. Otherwise, concentrated sodium hydroxide should be added during titration to reach the required alkalinity. B7.3 Some heavy metal ions in the sodium hydroxide absorption solution can cause interference. Adding 4g of disodium ethylenediaminetetraacetate (EDTA) (GB/T 1401) to every 1000mL of the solution can eliminate it.
Appendix C
Generation of hydrogen sulfide and preparation of raw gas
(reference)
C1 Principle
Na,s + H,PO, Na,HPO, + H,st C2 Apparatus
As shown in Figure 1:
HG / T 2513 Figure C 1 Schematic diagram of hydrogen sulfide generating device
1- flask: 2- cock: 3 dropping funnel: 4- iron stand: 5 air bag; 6- three-way cock; 7 absorption bottle; B- hydrogen chlorine gas cylinder: 9- hydrogen sulfide gas cylinder: 10- vacuum system: 11, 12, 13, 14, 15-- cut-off incubator: 16-- vacuum coat C3 Operation steps
C3.1 100mL phosphoric acid (GB/T1282) is measured in the dropping funnel, 350g sodium sulfide (NazS9H,0) is placed in the distillation flask, the filling is connected according to Figure C1, and there must be no leakage at each connection part. C3.2 Replace the air in the airbag and pipeline with hydrogen-nitrogen mixed gas, then start the vacuum pump, evacuate the aluminum alloy gas cylinder (or the fiberglass gas cylinder with aluminum alloy liner) to -0.1MP, close valves 12 and 15C3.3 Rotate the filter funnel cock, start dripping phosphoric acid, adjust the full speed to make the hydrogen sulfide production amount about 200mL/min, rotate the three-way cock 6 to the effective empty disk, replace for a few minutes, and then rotate cock 6 to allow the generated hydrogen sulfide to enter the gas sleeve, C3. 4 After the air bag is full, stop adding acid, rotate three-way cock 6 to the venting position, and open valve 11 to allow hydrogen sulfide to enter the aluminum alloy gas cylinder.
C3.5 After all the hydrogen sulfide in the air bag enters the aluminum alloy gas cylinder, close valve 11, open the hydrogen and nitrogen cylinder valves and valve 13, and slowly fill the hydrogen and nitrogen mixture into the aluminum alloy gas cylinder. After the pressure is balanced, close the valves of the two gas cylinders, and then place the aluminum alloy gas cylinder flat on the ground, roll it dozens of times, and let it stand for 12 hours. C4 can be used after the sampling and analysis data are stable. Notes
Strictly control the oxygen content in the raw gas to be less than 0.2%, otherwise it should be re-prepared. 11
HG/T2513-93
Determination of the isothermal zone of the reactor
(reference)
D1 In order to eliminate the influence of temperature difference on the test results of the sulfur capacity of the desulfurizer, all test samples must be placed in the isothermal zone of the reaction tube. Therefore, the newly made or replaced electric furnace reactor must be measured in the isothermal zone. D2 The reaction tube is fully filled with 1.18-1.40mm quartz sand or glass balls, and then connected to the system. The bed temperature thermocouple is inserted into the middle of the reaction tube. Hydrogen and nitrogen mixed gas is introduced at a dry gas space velocity of 3000h-, the system is at normal pressure, and the ratio of water vapor to raw gas is 1.0. Raise the temperature to 220℃ at a rate of 120～50℃/h and keep the temperature constant for 1h.\3 Insert the marked thermocouple into the furnace, and record the temperature and the length of the thermocouple after 10mm of insertion for 23min of temperature stabilization. Measure them in sequence until the temperature changes significantly. Pull the thermocouple outwards and repeat the above method until the temperature changes significantly. To verify the correctness of the measurement results, repeat the measurement according to the above method. D4 Raise the temperature of the reactor to 350℃. After stabilization for 1h, measure the isothermal zone at 350℃ according to the method in D3. Take the isothermal zone of 220℃ and 350℃ as the isothermal zone of the reactor. D5 Sometimes the measured temperature does not show the isothermal zone. The reactor should be dismantled, the density of the electric furnace wire should be adjusted, and then the isothermal zone should be remeasured. The temperature difference in the isothermal zone is not greater than 1°C, and the length of the isothermal zone is greater than 50mm. D6 According to the measured length of the isothermal zone, determine the height of the quartz sand or glass ball filled at the bottom of the reaction tube and the filling position of the desulfurizer, calculate the length of the thermocouple insertion and make positioning marks. Appendix E
Determination of the ratio of water vapor to raw gas
(reference)
E1 The volume ratio of water vapor to raw gas has a certain influence on the sulfur capacity of zinc oxide desulfurizer. In order to ensure that the ratio is continuously and stably within the specified range, the ratio of water vapor to raw gas is briefly determined. E2 According to the characteristics of the process flow and the test conditions, a part of the hydrogen-nitrogen-hydrogen sulfide mixed gas enters the reaction tube without passing through the saturator. Therefore, the ratio of water vapor to raw gas is measured during the sulfur capacity test. E3 According to the test conditions: the temperature of each point in the system rises to the specified index, the system is filled with raw gas, and the condenser is filled with cooling water. After the temperature of the saturator stabilizes, release the condensed water accumulated in the gas-water separator (condensate collector), and record the initial reading of the wet gas flow meter. The raw gas is measured by the wet gas flow meter and then released. After 1 hour, release the condensed water in the gas-water separator, weigh it accurately with a balance (to one decimal place) and record the volume of the raw gas passing through the wet gas flow meter (to one decimal place). E4 The ratio of water vapor to raw gas (n) is calculated according to the following formula: m
Wherein: m—condensed water amount, g:
273 + t
P-Ph,o
The volume of raw gas passing through the wet gas flowmeter, L;-atmospheric pressure under standard conditions, Pl;
Atmospheric pressure at time, Pa:
Partial pressure of saturated water vapor at room temperature t, Pa; (E)
-Room temperature at the time of measurement,,
HG /T 2513— 93
Appendix F
Rotameter flow calibration
(reference)
F1 The rotor flowmeter only plays a regulating role in this device. In actual use, the rotor indication position of the rotor flowmeter is required to be between 1/3 and 3/4 of the full scale. The calibration method uses the wet gas flowmeter measurement method. 2. Adjust the level of the wet gas flowmeter, open the overflow valve of the water level, add distilled water to the wet gas flowmeter, stop adding water when water overflows from the overflow hole, close the overflow valve when the overflow hole does not overflow, F3. Pass hydrogen and nitrogen mixed gas, adjust the rotor of the rotor flowmeter to 20 grids (scale), record the starting reading of the wet gas flowmeter, and start the stopwatch. After 5 to 10 minutes, calculate the gas flow through the wet gas flowmeter. F4. Measure the flow of the gas passing through other scales (30 grids, 40 grids, 50 grids, and 60 grids), then draw the scale-flow calibration curve, and indicate the calibration date and room temperature.
Additional instructions:
This standard is proposed by the Science and Technology Department of the Ministry of Chemical Industry of the People's Republic of China. This standard is under the technical supervision of Nanjing Chemical Industry (Group) Corporation Research Institute, and was drafted by the Chemical Fertilizer Industry Research Institute of the Ministry of Chemical Industry. The main drafters of this standard are Zhai Jikun, Liu Yun, Hongyi, Fang Kunli, Xue Yongsheng, 13
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