UOP 732-2009 Analysis of Distillate Fuels Derived from Oxygenated (Bio) 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 2009 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. Analysis of Distillate Fuels Derived from Oxygenated (Bio) Feedstocks by GC UOP Method 732-09 Scope This method is for determining hydrocarbon distribution in petroleum naphtha, kerosene (jet fuel), and diesel derived from oxygenated feedstocks such as vegetable or tallow oils in the range o

5、f C3to C39. Specific components of a boiling point of 85C (C6) and less are identified individually. Higher boiling normal paraffins are identified individually, while the non-normals are grouped according to approximate carbon number distribution. The lower limit of quantitation for any compound or

6、 grouping is 0.01 mass-%. Due to non-normals eluting at n-paraffin sites, the lower limit of quantitation for n-paraffins may not be as low. Components of C3 and lower molecular weight should not be considered quantitative due to their volatility, see Note. This procedure is not appropriate for anal

7、yzing oxygenated feed-stocks prior to the deoxygenation stage in the EcoFining process. Residual oxygenates in feedstocks may not elute from the instrument and are not quantified by this analysis. Reference ASTM Practice D 4307, “Preparation of Liquid Blends for Use as Analytical Standards,” www.ast

8、m.org UOP Method 999, “Precision Statements in UOP Methods,” www.astm.org Outline of Method The sample is injected into a gas chromatograph (GC) that is equipped with a flame ionization detector (FID) and a fused silica capillary column internally coated with 100% dimethylpolysiloxane. A quantitativ

9、e blend composed of petroleum hydrocarbons, whose boiling points extend throughout the boiling range of the sample, is to be used to determine the n-paraffin sites. By utilizing these sites, an approximate carbon number distribution of the sample components can be determined. The mass-% composition

10、of the sample is obtained by the internal normalization technique, wherein the peak areas are normalized to 100%. 2 of 12 732-09 Apparatus References to catalog numbers and suppliers are included as a convenience to the user. Other suppliers may be used. Balance, readable to 0.1-mg. Chromatographic

11、column, 30 m of 0.25 mm ID fused silica capillary, internally coated to a film thickness of 0.25 m with 100% dimethylpolysiloxane, Restek, Cat. No. 10123 Gas chromatograph, temperature programmable, capable of constant flow, built for capillary column chromatography, utilizing a split injection syst

12、em, equipped with a deactivated glass injection port, and a flame ionization detector that will give a minimum peak height response of five times the background noise for 0.01 mass-% n-decane when operated at the recommended conditions, Agilent Technologies, Model 7890 Gas purifier, used to remove o

13、xygen from the hydrogen carrier gas, Mat/Sen, Cat. No. P-200-1 Data system, electronic, for obtaining peak areas. This device must integrate areas at a sufficiently fast rate so that narrow peaks, typically obtained from a capillary column, can be accurately measured. The data system must have progr

14、ammable parameters for controlling baseline events, and have graphics capabilities. The system must provide for integrating the detector signal and summing the peak areas between specific time intervals. Agilent Technologies, ChemStation Leak detector, gas, Restek Cat. No. 22451 Regulator, air, two-

15、stage, high purity, delivery pressure range 30-700 kPa (4-100 psi), Matheson Tri-Gas, Model 3122-590 Regulator, hydrogen, two-stage, high purity, delivery pressure range 30-700 kPa (4-100 psi), Matheson Tri-Gas, Model 3122-350 Regulator, nitrogen or helium, two-stage, high purity, delivery pressure

16、range 30-700 kPa (4-100 psi), Matheson Tri-Gas, Model 3122-580 Sample injector, syringe or injector capable of introducing a 0.5 L volume of sample. An autosampler (or autoinjector) is recommended. Agilent Technologies, Model 7683. Reagents and Materials References to catalog numbers and suppliers a

17、re included as a convenience to the user. Other suppliers may be used. Air, zero gas, total hydrocarbons less than 2.0 ppm as methane Hydrogen, zero gas, 99.95% minimum purity, total hydrocarbons less than 0.5 ppm as methane Nitrogen or helium, zero gas, total hydrocarbons less than 0.5 ppm as metha

18、ne n-Paraffins, 99% minimum purity, ChemSampCo. Obtain each individual carbon number that will be present in the sample. Procedure Chromatographic Technique The analyst is expected to be familiar with general laboratory practices, the technique of gas chromatography, and the equipment being used. 3

19、of 12 732-09 1. Install the gas purifier in the supply line between the carrier gas source and the carrier gas inlet on the gas chromatograph. Column life is significantly reduced if the gas purifier is not used. 2. Install the fused silica capillary column in the gas chromatograph, according to the

20、 column and gas chromatograph manufacturers instructions. CAUTION: Hydrogen gas leakage into the confined volume of the column oven can cause a violent explosion. It is, therefore, mandatory to check for leaks each time a connection is made and periodically thereafter. 3. Establish the recommended o

21、perating conditions as given in Table 1. Other conditions may be used provided they produce the required sensitivity and chromatographic separations equivalent to those shown in the Typical Chromatograms (Figures 1-6). For samples with high concentrations of a specific component, care must be taken

22、that sample size does not allow for the major peaks to overload the column capacity or the linear range of the detector. Table 1 Recommended Operating Conditions Carrier Gas hydrogen Mode constant flow Column head pressure at 40C 44 kPa (6.4 psig) Linear velocity at 40C 28 cm/sec Equivalent flow at

23、40C 1.0 mL/min Split flow rate 250 mL/min Injection port temperature 285C Column temperature program Initial temperature 40C Initial time 8.0 min Programming rate 3C/min Final temperature 300C Final time 65 min Detector flame ionization Detector temperature 320C Hydrogen flow rate* 40 mL/min Air flo

24、w rate* 400 mL/min Makeup gas Nitrogen or Helium Makeup gas flow rate* 35 mL/min Sample size 0.5 L *Consult the manufacturers instrument manual for suggested flow rates. 4. Program the column oven to 300C and maintain this temperature until a stable baseline has been obtained at the required sensiti

25、vity. 5. Cool the column oven to a stabilized 40C. 6. Mix the sample thoroughly by shaking it vigorously. 7. Inject 0.5 L of sample into the gas chromatograph and immediately start the recorder, the integrator and the column oven programming sequence. 4 of 12 732-09 When using an autosampler or auto

26、injector, the injection sequence of a GC is typically automated, performing the injection, and starting the data system and column temperature program simultaneously. 8. Identify the n-paraffins and carbon number groupings by comparing the resultant chromatogram with the typical chromatograms, Figur

27、es 1-6, and Tables 2 and 3. Actual retention times will vary depending on the installation. Use the Figures and Tables as examples, not for absolute retention times. A quantitative blend composed of equal portions of expected n-paraffins within the boiling point range of the sample to be analyzed is

28、 to be run to determine the location of the n-paraffin sites. Reference paraffins used indicate a full sample range, actual paraffins used may be altered depending on the expected carbon range of the sample. These sites are then to be utilized in determining the approximate carbon distribution of sa

29、mples (see Figure 7). The quantitative blend can also be used to check for system linearity. See Calibration for further details on linearity and satisfactory performance. The peaks assigned a carbon number grouping are those that elute between the valley immediately following the previous n-paraffi

30、n peak and the valley immediately before the n-paraffin peak of the carbon number group (see Figure 7). Quantification of carbon number groupings are approximate. At sites with co-elution where the n-paraffin can be clearly identified (see Figure 8), a tangent line is drawn from one peak valley to a

31、nother. All of the area above the tangent line is to be considered the n-paraffin peak; all of the area below the tangent line is to be placed into the appropriate grouping (see Figure 8). At all other areas of the chromatogram, other than n-paraffin sites where co-elution exists, a common baseline

32、must be established through the chromatogram and perpendiculars from valleys dropped to the common baseline to insure all peak areas are summed. To aid in determining a common baseline, a blank run can be run and the baseline noted. Some rise in the baseline is normal at the end of the chromatogram

33、due to column bleed and is acceptable as long as it is repeatable and not integrated as peak area. If a specific n-paraffin site cannot be determined from the initial chromatogram, it may be necessary to add a few drops (spike) of the paraffin in question to 10 to 15 mL of the sample. Rerun the samp

34、le with the added paraffin and compare the two chromatograms to find the location of the n-paraffin site in question. If identification of a n-paraffin peak is unclear, do not designate it as such. Exclude the name so that only the grouping will be used for the area in question (see Figure 9). Table

35、 2 Typical Retention Times of Identified Components Typical Retention Time, Min Component Identification 1.81 1.84 1.89 1.93 2.07 2.14 2.29 2.47 2.56 2.69 2.96 3.25 3.37 Ethane Propane Isobutane n-Butane Isopentane n-Pentane 2,2-Dimethylbutane Cyclopentane +2,3-Dimethylbutane +2-Methylpentane 3-Meth

36、ylpentane n-Hexane Methylcyclopentane Benzene Cyclohexane 5 of 12 732-09 Table 3 Typical Retention Times of n-Paraffins and Timed Carbon Number Groupings Typical Retention Time, Min Component Identification Typical Retention Time, Min Component Identification 0-2.69 2.69-4.07 4.07 4.07-7.49 7.49 7.4

37、9-13.42 13.42 13.42-19.28 19.28 19.28-24.61 24.61 24.61-29.48 29.48 29.48-33.98 33.98 33.98-38.19 38.19 38.19-42.55 42.55 42.55-45.99 45.99 45.99-49.68 49.68 49.68-53.04 53.04 53.04-56.10 56.10 56.10-59.18 59.18 59.18-62.08 62.08 62.08-64.91 64.91 64.91-67.61 Unknown C6- C7group n-C7C8group n-C8C9gr

38、oup n-C9C10group n-C10C11group n-C11C12group n-C12C13group n-C13C14group n-C14C15group n-C15C16group n-C16C17group n-C17C18group n-C18C19group n-C19C20group n-C20C21group n-C21C22group n-C22C23group 67.61 67.61-70.22 70.22 70.22-72.71 72.71 72.71-75.13 75.13 75.13-77.46 77.46 77.46-79.71 79.71 79.71

39、-81.88 81.88 81.88-83.95 83.95 83.95-86.03 86.03 86.03-87.81 87.81 87.81-89.92 89.92 89.92-92.32 92.32 92.32-94.93 94.93 94.93-97.39 97.39 97.39-100.06 100.06 100.06-117.23 117.23 117.23-123.71 123.71 n-C23C24group n-C24C25group n-C25C26group n-C26C27group n-C27C28group n-C28C29group n-C29C30group n

40、-C30C31group n-C31C32group n-C32C33group n-C33C34group n-C34C35group n-C35C36group n-C36C37group n-C37C38group n-C38C39group n-C39Calibration Since all paraffinic components have essentially the same detector response on a mass basis in a flame ionization detector, no relative response factor calibr

41、ation is required (area-% is equivalent to mass-%). Prepare a quantitative blend as described in ASTM Method D4307 to obtain the target values of the following n-paraffin blend. A quantitative blend composed of equal portions of expected n-paraffins within the boiling point range of the sample is th

42、en analyzed to check for instrument linearity. 6 of 12 732-09 o Use the blend to identify the expected n-paraffin peak retention times o Each n-paraffin within the blend should be within 3% of the expected value not to exceed +/- 0.3 mass-%. Calculations Calculate the composition of samples, to the

43、nearest 0.01% mass-% using Equation 1: BA100C = (1) where: A = peak area of the individual component or group of components. The area included in each group does not include the area of the individual component. B = sum of all the peak areas C = concentration of all specific component or group compo

44、nents, mass-% 100 = factor to convert to percent Report each component or group of components to the nearest 0.01 mass-%. Note Components of C3 and lower molecular weight may be partially lost before analysis due to their volatility. Due to the nature of the internal normalization technique, a reduc

45、tion of one group of components will result in the increase of the other components, thereby keeping the sum of all the components at 100%. However, for practical purposes, the loss of a portion of the light components, when spread across the balance of the sample, results in a negligible difference

46、 in the quantitation of the heavier components. Precision Precision statements were determined using UOP Method 999 from data obtained using an autosampler. Repeatability A nested design was carried out for determining components in one sample with four analysts in one laboratory. Each analyst carri

47、ed out tests on two separate days, performing two tests each day. The total number of tests for each component was 16. 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% con

48、fidence. Two tests performed in one laboratory by different analysts 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 ch

49、art should be used to develop a better estimate of long-term precision. Reproducibility There is insufficient data to calculate reproducibility at this time. Time for Analysis The elapsed time for one analysis is 3 hours. The labor requirement is 1.0 hour. 7 of 12 732-09 Table 4 Repeatability and Site Precision, mass-% Repeatability Site Precision Sample Component or Region Mean Within-Day esd Allowable DifferenceWithin-Lab esd Allowable Differencen-Butane 0.09 0.001 0.01 0.006 0.03 Isopentane 0.07 0.001 0.01 0.00