UOP 733-2010 Residual Triglycerides in Deoxygenated Feedstocks by GC.pdf

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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 2010 UOP LLC. All rights reserved. Non

3、confidential 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 610.832.9585

4、 PHONE. Residual Triglycerides in Deoxygenated Feedstocks by GC UOP Method 733-10 Scope This method is for process control to quickly determine by gas chromatography (GC) the presence of residual triglycerides and partially deoxygenated intermediates in deoxygenated feedstock derived from plant oils

5、 and animal fats including but not limited to canola, jatropha, soy, palm, or algal oils. An approximate carbon distribution of product naphtha, kerosene (jet fuel), and diesel derived from the deoxygenated feedstock is also determined through carbon number 24 (C24) although there may be some interf

6、erences from partially deoxygenated feed components. The lower limit of quantitation for any individual component or grouping is 0.01 mass-%. n-Paraffin values may be biased slightly high due to non-normals eluting at n-paraffin sites. After it has been determined that there are no residual triglyce

7、rides, fatty acids, or partially deoxygenated intermediates in the sample a more detailed distribution can be determined by UOP Method 732, “Analysis of Distillate Fuels Derived from Oxygenated (Bio) Feedstocks by GC.” Reference ASTM Practice D4307, “Preparation of Liquid Blends for Use as Analytica

8、l Standards,” www.astm.org UOP Method 732, “Analysis of Distillate Fuels Derived from Oxygenated (Bio) Feedstocks by GC,” www.astm.org UOP Method 999, “Precision Statements in UOP Methods,” www.astm.org Outline of Method A diluted sample is injected into a gas chromatograph (GC) that is equipped wit

9、h a flame ionization detector (FID) and a high temperature stainless steel megabore column internally coated with 100% dimethylpolysiloxane. A quantitative blend is made from normal paraffins whose carbon number ranges extend beyond C24 and un-reacted feed material is used to determine the n-paraffi

10、n and the triglyceride sites. By utilizing these sites, an approximate carbon number distribution of the sample components can be determined as well as identifying residual feed material. The mass-% composition of the sample is obtained by the internal normalization technique, wherein the peak areas

11、 for the entire samples are first corrected for differences in response and then normalized to 100%. 2 of 10 733-10 Apparatus References to catalog numbers and suppliers are included as a convenience to the method user. Other suppliers may be used. Balance, readable to 0.1-mg Chromatographic column,

12、 15 m of 0.53-mm ID DB-ProSteel megabore capillary column, internally coated to a film thickness of 0.15 micron, DB-PS1, J do not expose to temperatures above 45C; work in a fume hood. 7. Inject 0.1 L of sample into the gas chromatograph and immediately start the integrator and the column oven progr

13、amming sequence. 4 of 10 733-10 When using an autosampler or autoinjector, the injection sequence of a GC is typically automated, performing the injection, and starting the data system and column temperature program simultaneously. If an autosampler is used, make sure fresh solvents are used: first

14、flush vial acetone, second flush vial CS2. 8. Identify the n-paraffins and carbon number groupings by comparing the resultant chromatogram with the typical chromatogram (see Figures). A quantitative blend composed of n-paraffins and triglyceride within the boiling point range of the sample to be ana

15、lyzed is to be run to determine the location of the n-paraffin and triglyceride sites. Reference paraffins used indicate a full sample range; actual paraffins used may be altered as long as n-C5 through n-C24 is present. These sites are then to be utilized in determining the approximate carbon distr

16、ibution of samples and a relative response factor for the triglycerides. The typical major product peaks from triglyceride feeds will be n-C15 through n-C18 (See Figures), but will vary depending upon the source of the feed. See Calibration for further details on determining relative factors. Other

17、available n-paraffin reference materials may also be used to identify the n-paraffin sites. For example, a GC simulated distillation mixture is shown in Figure 6. This is just an example of another reference material that could be used, and is not required for the analysis. Actual retention times of

18、 components can shift due to concentration or composition of the products vs. the reference blend but retention times can be confirmed by overlaying chromatograms or spiking the subsequent product sample with the reference blend. The peaks assigned a carbon number grouping, tg (timed group), are tho

19、se that elute between the valley immediately following the previous n-paraffin peak and the corresponding valley following the next n-paraffin peak. Quantification of carbon number groupings is approximate. If identification of a n-paraffin peak is unclear, do not designate it as such. Exclude the n

20、ame so that only the grouping will be called for the area in question. The composition of the intermediates is largely unknown but could consist of hydrocarbons, fatty acids, partially hydrogenated fatty acids, hydrogenated sterols, monoglycerides, diglycerides, etc. Table 1 Recommended Operating Co

21、nditions Carrier Gas hydrogen Mode constant flow Column head pressure at 25C 1.8 psig Linear velocity at 25C 82 cm/sec Equivalent flow at 25C 11.2 mL/min Split flow rate 60 mL/min Injection port temperature 250C Column temperature program Initial temperature 25C Initial time 1.0 min Programming rate

22、 15 C/min Final temperature 345C Final time 14 min Detector flame ionization Detector temperature 360C Hydrogen flow rate* 20 mL/min Air flow rate* 400 mL/min Makeup gas helium or nitrogen Makeup gas flow rate* 30 mL/min Sample size 0.1 L *Consult the manufacturers instrument manual for suggested fl

23、ow rates. 5 of 10 733-10 Calibration This analysis uses internal normalization of the total sample, not including the CS2 diluent, for quantitation. All components in the sample which elute from the column under the specified conditions are measured. Any components which do not elute from the column

24、 under the specified conditions are not measured. In order to accurately measure the total sample, triglycerides beyond the intermediate range must be calibrated. This is necessary because glycerides components that may be present in the sample do not have the same detector response as the hydrocarb

25、on components. All expected paraffinic hydrocarbon components have essentially the same FID detector response. Table 2 Typical Retention Times of n-Paraffin and Timed Carbon Number Groupings Typical Retention Time, Min tg = Timed Group Component Identification tg = Timed Group Typical Retention Time

26、, Min tg = Timed Group Component Identification tg = Timed Group 0.0 0.4 tg Unknown C5- tg* 7.22 n-C15 0.41 n-C5 7.22 7.95 tg i-C16 tg 0.41 - 0.59 tg i-C6 tg 7.95 n-C16 0.59 n-C6 7.95 8.68 tg i-C17 tg 0.59 0.68 tg i-C7 tg 8.68 n-C17 0.68 n-C7 8.68 9.37 tg i-C18 tg 0.68 1.17 tg i-C8 tg 9.37 n-C18 1.1

27、7 n-C8 9.37 9.86 tg i-C19 tg 1.17 2.01 tg i-C9 tg 9.86 n-C19 2.01 n-C9 9.86 10.44 tg i-C20 tg 2.01 2.98 tg i-C10 tg 10.44 n-C20 2.98 n-C10 10.44 11.00 tg i-C21 tg 2.98 3.93 tg i-C11 tg 11.00 n-C21 3.93 n-C11 11.54 n-C22 3.93 4.82 tg i-C12 tg 12.06 n-C23 4.82 n-C12 12.56 n-C24 4.82 5.66 tg i-C13 tg 1

28、1.00 18.00 tg Intermediates tg 5.66 n-C13 18.00 26.00 tg Glycerides tg 5.66 6.45 tg i-C14 tg 22.36 Triglycerides A 6.45 n-C14 22.82 Triglycerides B 6.45 7.22 tg i-C15 tg 23.44 Triglycerides C 26.00 end of analysis tg Heavies tg *Not including the CS2 peak Since all paraffinic components have essenti

29、ally the same detector response on a mass basis in a flame ionization detector, the same relative response factor calibration is used for the C24 and lower hydrocarbon sites. Intermediates use the relative response factor of the hydrocarbons. Components in 6 of 10 733-10 the glycerides and heavies r

30、egions, other than the identified triglycerides, may include glycols, other glycerides, fatty acids or sterols. Use the response factor for triglycerides for any of these components remaining in the deoxygenated feedstock. 1. Prepare a quantitative blend, as described in ASTM Method D4307, containin

31、g 95% of the expected hydrocarbons, and 5% of the triglyceride feed being used in the process. The hydrocarbons in the blend should be high in n-paraffins through C24, but the hydrocarbons must not interfere with the triglyceride feed used in the process. Use the blend to identify the expected n-par

32、affin peak retention times and the three largest triglyceride peaks, which are to be simply identified as A, B & C. 2. Analyze the blend in triplicate, diluting the blend in CS2 and analyzing as described under Chromatographic Technique. The peak areas from each of the three runs should not deviate

33、from the average by more than 3% relative. If greater deviations occur, make certain that there are no problems with the equipment or technique, and then make additional runs until the required repeatability is obtained on three consecutive runs. A calibration blend is run when the method is initial

34、ly set up and thereafter when changes have been made to the equipment, or periodically, to verify proper calibration. 3. Based upon 3 replicate runs of the blend, determine the average response factor for triglycerides relative to hydrocarbons to four significant figures using Equation 1 and hydroca

35、rbon-range peaks as reference: Relative response factor for triglycerides = DC BA (1) where: A = feed triglycerides, mass-% B = total peak area of hydrocarbon peaks C = hydrocarbons, mass-% D = total peak area of feed triglycerides Calculations Calculate the composition of samples, to the nearest 0.

36、01 mass-% using Equation 2: Concentration of each specific component or group components, mass-% = G FE100 (2) where: E = relative response factor of the individual component or group of components, 1.0000 for all hydrocarbons, determined in Equation 1 for triglycerides F = peak area of the individu

37、al component or group of components G = sum of products, EF, of all the components and groups of components in the sample 100 = factor to convert to percent Report each component or group of components to the nearest 0.01 mass-%. Precision Precision statements were determined using UOP Method 999, “

38、Precision Statements in UOP Methods,”from data obtained using an autosampler. 7 of 10 733-10 Repeatability A nested design was carried out for determining components in one sample with four analysts in one laboratory. Each analyst carried out tests on two separate days, performing four tests each da

39、y. The total number of tests for each component was 32. The precision data are summarized in Table 4. Two tests performed by the same analyst on the same day should not differ by more than the repeatable allowable difference with 95% confidence. Two tests performed in one laboratory by different ana

40、lysts on different days should not differ by more than the site precision allowable difference with 95% confidence. The data in Table 4 are a short-term estimate of repeatability. When the test is run routinely, a control standard and chart should be used to develop a better estimate of long-term pr

41、ecision. Table 4 Repeatability and Site Precision, mass-% Repeatability Site Precision Sample Component or Region Mean Within-Day esd Allowable Difference Within-Lab esd Allowable Difference Total Hydrocarbons 97.13 0.037 0.15 0.045 0.22 Intermediates 0.81 0.014 0.05 0.017 0.08 Glycerides 0.09 0.004

42、 0.01 0.006 0.02 Triglycerides A 0.07 0.001 0.01 0.001 0.01 Triglycerides B 0.57 0.010 0.04 0.012 0.05 Triglycerides C 1.34 0.028 0.11 0.035 0.13 Heavies 0.01 0.001 0.01 0.001 0.01 Reproducibility There is insufficient data to calculate reproducibility at this time. Time for Analysis The elapsed tim

43、e for one analysis is 1.0 hour. The labor requirement is 0.5 hour. Suggested Suppliers AccuStandard, 125 Market St., New Haven, CT 06513 USA (203-786-5290) Agilent, 2850 Centerville Road, Wilmington, DE 19808 USA (302-633-8000) ChemSampCo, 1880 Ryan Road, Dallas, TX 75220 USA (609-656-2440) Mathe

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