1、 IT IS THE USERS RESPONSIBILITY TO ESTABLISH APPROPRIATE PRECAUTIONARY PRACTICES AND TO DETERMINE THE APPLICABILITY OF REGULATORY LIMITATIONS PRIOR TO USE. EFFECTIVE HEALTH AND SAFETY PRACTICES ARE TO BE FOLLOWED WHEN UTILIZING THIS PROCEDURE. FAILURE TO UTILIZE THIS PROCEDURE IN THE MANNER PRESCRIB
2、ED HEREIN CAN BE HAZARDOUS. MATERIAL SAFETY DATA SHEETS (MSDS) OR EXPERIMENTAL MATERIAL SAFETY DATA SHEETS (EMSDS) FOR ALL OF THE MATERIALS USED IN THIS PROCEDURE SHOULD BE REVIEWED FOR SELECTION OF THE APPROPRIATE PERSONAL PROTECTION EQUIPMENT (PPE). COPYRIGHT 1980, 1990, 2008 UOP LLC. All rights r
3、eserved. Nonconfidential UOP Methods are available from ASTM International, 100 Barr Harbor Drive, P.O. Box C700, West Conshohocken, PA 19428-2959, USA. The UOP Methods may be obtained through the ASTM website, www.astm.org, or by contacting Customer Service at serviceastm.org, 610.832.9555 FAX, or
4、610.832.9585 PHONE. Analysis of Hydrogen Fluoride Alkylation Catalysts and Regenerator Bottoms UOP Method 629-08 Scope This 4-part procedure is for the sampling of liquid hydrogen fluoride (HF) streams and the analysis of these streams for acidity, water content and acid-soluble oil. The method is a
5、pplicable to fresh acid and alkylation process system acid. The acid-soluble oil determination is also applicable to regenerator bottoms samples. However, acidity and water determinations on regenerator bottoms samples must be conducted according to UOP Methods 379 and 382, respectively. The Appendi
6、x provides information about an online instrumental option that could significantly reduce the number of samples that are brought into the lab for analysis. Caution! HF is toxic and may be fatal if inhaled, absorbed through skin or swallowed. It is extremely corrosive and destructive to tissue, and
7、specialized medical treatment is required for all exposures. All appropriate safety procedures, including those listed in the HF MSDS, must be read, understood, and followed. Appropriate protective equipment must be worn throughout the procedure and all laboratory work must be performed in an approp
8、riate fume hood. References MSDS, Hydrofluoric Acid, available from the supplier of the chemical. UOP Method 379, “Hydrogen Fluoride in HF Alkylation Regenerator Bottoms,” www.astm.org UOP Method 382, “Water in Regenerator Bottoms from Hydrogen Fluoride Alkylation,” www.astm.org Outline of Method A
9、cleaned and dried sample cylinder is used to take a plant sample of liquid HF. The cylinder containing the sample is taken to the laboratory, where 3 portions of the sample are transferred to respective polypropylene bottles and analyses for acidity, water, and acid-soluble oil are made. To determin
10、e acidity, the sample is diluted with neutralized 2-propanol. An aliquot is titrated with standard 1-M sodium hydroxide. 2 of 17 To determine water, the HF is allowed to volatilize from the sample and any remaining acid is neutralized with dried pyridine. The neutralized sample is transferred to a m
11、oisture analyzer and titrated coulometrically. To determine oil in liquid HF, pentane is added to the oil residue after all the excess HF has been volatilized. The pentane-oil mixture is warmed until a constant mass is achieved. The mass of the oil residue is calculated. Oil in regenerator bottoms i
12、s determined in a similar fashion to the liquid HF. Part I Plant and Laboratory Sampling Apparatus References to catalog numbers and suppliers are included as a convenience to the method user. Other suppliers may be used. Balance, readability 0.01-g, 1800 g capacity Beaker, 150-mL, Griffin, borosili
13、cate glass, VWR, Cat. No. 89000-202 Beaker, polypropylene, 4-L, VWR, Cat. No. 13890-181 (3 required) Bottles, polypropylene, narrow mouth, with screw caps, 125-mL (2 required) and 500-mL, VWR, Cat. Nos. 16067-066 and 16067-102, respectively Bottle, polyethylene, 1000-mL, VWR, Cat. No. 16129-704 (use
14、d for waste) Bottles, polyethylene, wash, 500-mL, VWR, Cat. No. 16651-493 Box, wood, with hinged cover and 2 hasp-type locks, large enough to accommodate several sampling cylinders Bucket, polypropylene, 7.6-L, VWR, Cat. No. 73470-016 Clamp, 3-prong, utility, VWR, Cat. No. 21573-265 Cylinder samplin
15、g tube, U-tube, 316 stainless steel, form as shown in Figure 1, EG includes Valve Stem, “K” Monel; Valve Gland, “R” Monel; Valve Body, “R” Monel; pressure test to 1.72x104kPa (2500 psi) hydrostatic. Stirring rod, fluoropolymer, 20-cm long, Fisher Scientific, Cat. No. 14-518-10C 629-08 3 of 17 Suppor
16、t stand, 61-cm rod length, 15- x 23-cm base, VWR, Cat. No. 60110-244 Tubing, FEP fluoropolymer, 5.0-mm ID, VWR Scientific, Cat. No. 63014-714 Tubing, rubber or flexible plastic Vacuum system, house vacuum or vacuum pump Reagents and Materials References to catalog numbers and suppliers are included
17、as a convenience to the method user. Other suppliers may be used. Unless otherwise specified, references to water mean deionized or distilled water. Acetone (2-propanone), 99.5% minimum purity, VWR, Cat. No. BJ010-1 Air, compressed Ice, crushed Phenolphthalein, 1% solution, VWR, Cat. No. VW3341-2 So
18、dium hydroxide, 50% solution, VWR, Cat. No. VW3246-1 Tags, with string, white and red Water, deionized or distilled Water, tap, cold and hot Procedure CAUTION: HF is a highly hazardous material. All appropriate safety procedures, as well as those listed in the HF MSDS, must be read, understood, and
19、followed. Appropriate protective equipment must be worn throughout the analysis and all laboratory work must be performed in an appropriate fume hood. Cylinder Preparation 1. Remove any previous sample by emptying the cylinder into a polypropylene bucket containing crushed ice. Open the valve slowly
20、 at first to prevent splashing. If the cylinder is new, begin the cleaning procedure with Step 7. 2. Add several mL of phenolphthalein indicator solution to the crushed ice-HF mixture. 3. Neutralize the HF by slowly adding 50% sodium hydroxide solution, while stirring with a Teflon rod, until a pers
21、istent pink color is obtained. 4. Squirt approximately 25 to 30 mL of acetone from a wash bottle into the cylinder. 5. Close the valve on the cylinder and place the cylinder in hot (approximately 50C) tap water. 6. Shake the cylinder, invert it and release the acetone into the bucket containing the
22、previously neutralized sample. This bucket is used to temporarily contain neutralized samples and acetone washes. Dispose of the waste material following local safety practices and in an environmentally safe manner. 7. Attach the cylinder sampling tube to the cylinder and evacuate the cylinder with
23、a vacuum pump protected by a filtering flask. 8. Close the valve on the cylinder and disconnect it from the vacuum system. 629-08 4 of 17 9. Cool the cylinder in cold (approximately 15C) tap water. If local tap water is warm, fill a container with tap water; add sufficient ice to cool to approximate
24、ly 15C; and place the cylinder in the container. 10. Place the tip of the cylinder sampling tube into a 150-mL beaker containing approximately 125 mL of acetone. 11. Open the valve on the cylinder and draw acetone into the cylinder. 12. Close the valve and heat the cylinder under hot (approximately
25、50C) running tap water. 13. Remove the cylinder from the hot water and shake. 14. Invert the cylinder and open the valve to discharge the acetone into the bucket containing the previously neutralized sample. If cleaning a new cylinder, dispose of the acetone according to locally appropriate procedur
26、es. 15. Repeat Steps 7 through 14 two more times. 16. Evacuate the cylinder one final time (Step 7). 17. Disconnect the HF cylinder sampling tube and place the cylinder in an oven at 65C for 20 minutes with the valve open. 18. Remove the cylinder from the oven and, with the valve still open, allow i
27、t to cool to room temperature. 19. Close the valve on the cylinder and cap it. 20. Weigh the cylinder to the nearest 0.5 g with the valve cap on the cylinder and record the weight. Obtaining the Sample at the Plant 1. Remove the valve cap from the cylinder. 2. Open and close the valve to make certai
28、n that the cylinder is filled with air. 3. Connect the cylinder vertically to the sample connection, using an acid sampling manifold, with the valve-end down. This creates an air pocket in the cylinder that prevents overfilling. 4. Collect the sample from the plant. Follow all safety procedures. 5.
29、Close the valve and carefully disconnect the cylinder from the plant. 6. Replace the valve cap. Document the sample location and time of sampling. 7. Place the cylinder in a wood box and transport the box to the analytical laboratory. 8. Weigh the cylinder to the nearest 0.5 g immediately; subtract
30、the previously recorded tare weight to obtain the mass of the sample in the cylinder. The sample mass should be at least 40 g in order to have enough sample for all the analyses, but should not exceed 100 g. 629-08 5 of 17 Preparation of Laboratory Apparatus 1. Fill the three 4-L polypropylene beake
31、rs approximately 1/2 full with crushed ice and place the 1000-mL polyethylene waste bottle in one of them. Add sufficient cold tap water to the other two beakers to just cover the ice. 2. Clean two 125-mL and one 500-mL polypropylene screw cap bottles with deionized or distilled water, rinse with ac
32、etone, and dry with air. As an aid in estimating sample volumes, the 125-mL bottles may be marked at 5 and 15 mL, and the 500-mL bottle at 100 and 115 mL. 3. Identify one of the 125-mL bottles, cap included, to be used for the sample for the determination of acid-soluble oil in HF. This is to preven
33、t the possibility of switching the cap of the bottle used for the determination of water in liquid HF. 4. Weigh each of the the sample bottles with caps to the nearest 0.01 g. 5. Pipet 100 mL of deionized or distilled water into the tared 500-mL polypropylene bottle and cap it. Take care to exclude
34、any water from the upper portion of the neck of the bottle. 6. Reweigh the capped 500-mL polypropylene bottle containing the water to the nearest 0.01 g. 7. Arrange the apparatus, as illustrated in Figure 1, in a fume hood. Confirm that the fume hood is operating according to specifications. 8. Remo
35、ve the cylinder from the wood box. Perform all cylinder handling in a fume hood while wearing appropriate protective clothing. 9. Invert the cylinder several times to ensure complete mixing of the sample. 10. Remove the valve cap and attach the cylinder sampling tube. 11. Immerse the U-shaped portio
36、n of the cylinder sampling tube to at least 1/2 its depth in a 4-L beaker containing crushed ice. 12. Clamp the cylinder to the stand with the valve end down. 13. Place the end of the Teflon tubing from the cylinder sampling tube into the 1000-mL polyethylene waste bottle, which is in a 4-L beaker c
37、ontaining crushed ice. 14. Place all three of the tared bottles in another of the 4-L beakers containing crushed ice. Take the samples before the ice has melted significantly and it can no longer stabilize the bottles. Laboratory Sampling for Analysis 1. Open the cylinder valve slowly and allow appr
38、oximately 5 g of sample to flow into the waste bottle. Steps 1 through 7 must be performed as rapidly as possible to minimize losses of HF through volatilization. 2. Close the valve and remove the tubing from the waste bottle. 3. Remove the screw caps from the sample bottles. 629-08 6 of 17 4. Inser
39、t the Teflon tubing into the 125-mL polypropylene bottle designated for the acid-soluble oil determination. The end of the tubing should be approximately 5 cm above the bottom of the bottle. 5. Slowly open the valve of the sample cylinder. Transfer approximately 5 g of sample into the bottle, close
40、the cylinder valve and cap the bottle. Markings previously placed on the bottles may be used as an aid in estimating the correct amount of sample to be transferred. 6. Insert the FEP tubing into the second 125-mL bottle. Transfer approximately 15 g of sample for the water determination and cap the b
41、ottle. The end of the tube should be approximately 5 cm above the bottom of the bottle. 7. Insert the tubing into the 500-mL bottle. Transfer 10 to 15 g of sample for the acidity measurement and cap the bottle. Do not allow the sampling tube to contact the water. 8. Place the end of the Teflon tubin
42、g in the waste bottle. Make certain the cylinder valve is fully closed. 9. Allow the bottles to remain in the ice until the analyses are performed. Disposal of Sampling Waste 1. Loosen, but do not remove, the lock nut on the cylinder sampling tube. CAUTION: Since some of the condensed HF still remai
43、ns in the iced part of the stainless steel tubing, care must be used in its removal. 2. Position the tip of the Teflon tubing so that the flow is down and away from the analyst. 3. Direct the expelled HF into the 1000-mL waste bottle. 4. Hold an air line (rubber or flexible plastic tubing) tightly a
44、gainst the hole in the lock nut (Detail “A”, Figure 1), and allow a moderate flow of air to blow through the tubing until no more HF can be observed coming from the tubing. 5. Remove the lock nut from the cylinder, immediately rinse it and the cylinder threads with acetone and blow them dry using ai
45、r. The rinsings are collected in the waste bottle. 6. Remove the “U” portion of the cylinder sampling tube from the 4-L beaker containing the crushed ice. 7. Clean the cylinder sampling tubing using a stream of acetone from a wash bottle to flush the residue into the waste bottle. 8. Dry the tube us
46、ing a stream of air. 9. Replace the valve cap on the cylinder. 10. Remove the cylinder from the stand and place it in a wood storage box. 11. Add crushed ice and neutralize the waste material contained in the 1000-mL waste bottle as described under Cylinder Preparation, Steps 2 and 3. 12. Dispose of
47、 the neutralized mixture according to local safety practices and in an environmentally safe manner. 629-08 7 of 17 Part II Analysis for Total Acidity of HF Apparatus The apparatus listed are in addition to those listed in Part I. References to catalog numbers and suppliers are included as a convenie
48、nce to the method user. Other suppliers may be used. Beaker, Teflon, 250-mL, VWR, Cat. No. 13917-540 Buret, 50-mL, PTFE stopcock, 0.1-mL subdivisions, VWR, Cat. No. 89001-624 Stirrer, magnetic, with fluoropolymer-covered stirring bar, VWR, Cat. No. 12365-380 Reagents and Materials The reagents and m
49、aterials listed are in addition to those listed in Part I. References to catalog numbers and suppliers are included as a convenience to the method user. Other suppliers may be used. 2-Propanol (isopropyl alcohol), 99.9% minimum purity, VWR, Cat. No. BJAH323-4. Neutralize to a faint pink phenolphthalein endpoint by adding, dropwise, 0.1-M sodium hydroxide, to a quantity of the 2-propanol. Sodium hydroxide solution, aqueous, 0.1-M, standardized, VWR, Cat. No. VW3219-2 Towels, paper Procedure CAUTION: HF is a highly hazardous material. A
