PONA Columns Brochure

GS-Tek, Inc. page 1 of 7 PONA Analysis on GSBP-PONA Column Naizhong Zou, Beijing Chromtech Institute, Beijing, China Zack Ji, GS-Tek. Newark, DE USA 1. Introduction Gasoline, either naphtha, cracked or reformulated, contains large number of hydrocarbons including isomers. Because of complex compositions, the analysis of individual components is a challenging technique. ASTM D 5374 and D5374-92 give methods of detailed hydrocarbon analysis (DHA) for gasoline and other petrochemical applications. This specified DHA is done on high resolution capillary column, a 100% poly(dimethylsiloxane) column. Because of its specifically important role in DHA, this column is often called PONA column. Common PONA columns are either 0.20mm x 50m x 0.5um or 0.25mm x 100m x 0.5um. Various software and methods have been developed for such PONA and DHA applications. There are two techniques for these applications. One is based on multi-dimensional GC, and other is based on high resolution chromatography. Both techniques use retention times of individual hydrocarbons to identify and quantify each composite separated. As the number of the composites of a gasoline can be as many as 500, the peak identification becomes very difficult and is very critical step for DHA. Often peak identification can be errant. Intensive labor effort is then taken to manually correct errors in peak identification. Among various softwares for ASTM D5134, the software called PONA developed by Beijing Chromtech Institute uses an algorithm of retention index to identify peaks. Because retention index is relatively insensitive to the variations from columns, instruments and methods, this software is able to automatically and correctly identify each peak with great confidence. Even though this algorithm improves accuracy of peak identification, it still requires minimum variations in column dimension, column retention time, column efficiency and column selectivity. This application note describes a FCC gasoline application on an GSBP-PONA column. This GSBP-PONA column replicates the performances of HP-PONA column, an industrial fleet column, including column selectivity, column dimension and retentions. Under the same instrumentation condition, the software PONA produces the same result as the one obtained from an HP-PONA column for this application. 2. Experimental 2.1 Column: The column used is an GSBP-PONA column, 0.20mm x 50m x 0.5um, coated with GsBP-1 stationary phase, part number 9002-PONA, obtained from GS-Tek Inc., Newark, DE 19713, USA. The column temperature limits are -60C to 325/350C. Prior to each run, column was conditioned at 280C for 4hr. GS-Tek, Inc. page 2 of 7 2.2 Instrumentation conditions: Instrumentation conditions are listed in Table I. Table I the instrumentation conditions Gas Chromatography Agilent 6890 GC with ALS Raw date acquisition HP-Chemstation Inlet 250C, s/s, split flow 140ml/min Carrier Nitrogen Column head pressure 99kpa varied Detector FID, 300C Oven 35C 10min, 0.5C/min to 60C, 2C/min to 180C, 10+min Sample A FCC gasoline sample Injection 1ul 2.3 Column retention time calibration Constant pressure mode was used for carrier flow. Column head pressure was adjusted to have n-Pentane retention time around 9.75+-0.1min as holdup time prior to sample injection. For a comparison, the analysis was repeated on an HP-PONA column at the same instrumentation conditions. 3. Software 3.1 DHA and PONA analysis PONA software from Beijing Chromtech Institute, Beijing, China was used in a PC with OS Microsoft 95 or above. It uses the following formula (1) to calculate the retention index of all individual peaks. RIi = ((RTi-Rtref_Cn)/(Rtref_Cn+1-Rtref_Cn)+ Cn)*100 (1) RIi: Retention index of composite i RTi: Retention time of composite i Cn : Reference peak of carbon n Cn+1: Reference peak of carbon n+1 Rtref_Cn :Retention time of reference peak Cn Rtref_Cn+1:Retention time of reference peak Cn+1 GS-Tek, Inc. page 3 of 7 Retention time of reference peaks can be searched automatically based on empirical database built-in the PONA software 3.2 Calculation of Octane Number: Two octane values defined by RON and MON are calculated as i=N RON = Cr + Fr ? Ai Wi (2) i=1 i=N MON = Cm + Fm ? Bi Wi (3) i=1 Cr : given constant, RON Fr : given correlation factor, ROM Cm : given constant, MON Fm : given correlation factor, MON Ai : correlation coefficient of ith hydrocarbon, RON, listed in calibration table Bi : correlation coefficient of ith hydrocarbon, MON, listed in calibration table Wi : weight percentage of ith , measured by DHA N : total number of peaks measured by DHA 3.3 Calculation of Carbon/Hydrogen(C:H)ratio: i=N C:H = ? (C:H)i Wi (4) i=1 (C:H)i : Carbon/Hydrogen of ith hydrocarbon Wi : weight percentage of ith , measured by DHA N : total number of peaks measured by DHA 3.4 Calculation of Specific Gravity (D): i=N D = ? Di Wi (5) i=1 Di : Specific Gravity of ith hydrocarbon Wi : Weight percentage of ith , measured by DHA N : Total number of peaks measured by DHA 3.5 Data Analysis: GS-Tek, Inc. page 4 of 7 Once the separation of each composite in a gasoline sample is completed, the raw data of DHA was generated by HP Chemstation or similar data acquisition software. The raw data includes peak retention time, area and/or area percentage. The file format of the raw data file used in this PONA software is .D. After completion of the chromatography run, the PONA reads the raw data file, and automatically identify the reference peaks (as many as to 13) from assigned one of three databases for three types of gasoline. Manual correction of the reference peaks is only as needed for the first run. Once the reference peaks are correctly identified, the software can automatically calculate all physically and chemically values described in 3.1 to 3.4. The report file can be either printed or transferred for a customized report. 4. Result Fig 1 shows the comparable chromatograms of a FCC gasoline sample on GSBP-PONA and HP-PONA columns. It is clearly that the GSBP-PONA exhibits a small retention time difference from the HP-PONA column, however, the peak elution order and relative peak height ratios are essentially same. Even for this retention time difference, the PONA software is able to identify all peaks in both chromatograms. The physical properties calculated are listed in table II for the results from two PONA columns. Table II Calculated physical properties Column GSBP-PONA HP-PONA No. of peaks identified 300 301 Calculated RON 87.26 87.15 Calculated MON 78.18 78.07 C:H 7.33 7.34 Specific density 0.8064 0.8062 All other calculated values are listed in the table III. Table III PONA analysis report of a FCC gasoline sample PONA Columns GsBP HP GsBP HP Compositions Wt% Wt% V % V % P (Normal Paraffin) 3.29 3.28 3.68 3.67 I (Iso Paraffin) 25.81 25.69 28.37 28.20 O (Olefin) 9.14 9.40 10.08 10.40 N (Naphtha) 15.74 15.72 16.20 16.19 A (Aromatic) 46.02 45.91 41.67 41.54 GS-Tek, Inc. page 5 of 7 5. Conclusion Based on the above results and same instrumentation conditions used, it can conclude that both GSBP-PONA and HP-PONA are essential identical. GSBP-PONA column has produced almost same result as HP-PONA has. 6. Order Guild Table IV lists the suggested parts for PONA application. Table IV Suggested parts for PONA analysis Item Description P/N 1 PONA software 9001-PONA 2 GSBP-PONA 9002-PONA 3 Gasoline Reference Sample, 1ml 9003-PONA 7. Other applications of GSBP-PONA column The other applications of GSBP-PONA column would be the separations of natural gas, pesticides, and VOC. GS-Tek, Inc. page 6 of 7 min40 42 44 46 48 50 52 54 56 58pA0102030405060708090 FID1 A, (PONA 2006-12-01 13-54-09\\\\PONA12011.D) 39.973 40.369 40.802 40.989 41.277 41.519 41.726 42.452 42.794 43.701 44.237 44.441 44.876 45.444 45.792 46.188 47.141 47.673 47.982 48.235 48.716 49.175 49.546 50.265 50.630 51.004 51.984 52.405 52.824 53.397 54.092 54.374 54.777 55.264 55.639 56.049 56.727 57.196 57.426 58.043 58.650 58.998 59.266 59.645 60.008min40 42 44 46 48 50 52 54 56 58pA0102030405060708090 FID1 A, (PONA 2006-12-08 10-37-35\\\\PONA12082.D) 40.085 40.478 40.922 41.120 41.401 41.645 41.857 42.594 42.937 43.858 44.395 44.608 44.784 45.048 45.602 45.970 46.377 47.333 47.868 48.178 48.413 48.900 49.372 49.735 50.466 50.846 51.219 52.191 52.628 53.046 53.620 54.317 54.611 55.014 55.514 55.900 56.297 56.979 57.477 57.677 58.318 58.930 59.269 59.538 59.932min20 22 24 26 28 30 32 34 36 38pA0102030405060708090 FID1 A, (PONA 2006-12-01 13-54-09\\\\PONA12011.D) 20.207 20.363 20.731 21.043 21.150 21.459 21.803 22.057 22.348 22.561 22.792 23.036 23.359 23.568 23.805 24.212 24.530 24.827 25.350 25.778 26.207 26.389 26.639 26.818 26.944 27.580 27.844 28.456 28.759 29.097 29.285 29.590 29.878 30.442 31.065 31.786 32.121 32.260 32.872 33.586 33.998 34.545 34.845 35.213 35.507 36.335 36.893 37.424 37.890 38.299 38.651 38.953 39.281 39.734 39.973min20 22 24 26 28 30 32 34 36 38pA0102030405060708090 FID1 A, (PONA 2006-12-08 10-37-35\\\\PONA12082.D) 20.053 20.212 20.585 20.766 20.903 21.004 21.147 21.324 21.671 21.932 22.236 22.442 22.682 22.799 22.928 23.256 23.475 23.715 24.126 24.447 24.753 25.276 25.719 26.155 26.335 26.592 26.766 26.895 27.541 27.803 28.425 28.739 29.077 29.265 29.574 29.866 30.443 31.071 31.802 32.152 32.296 32.913 33.623 34.045 34.602 34.905 35.282 35.576 36.415 36.948 37.506 37.991 38.383 38.748 39.054 39.382 39.838 40.085min0 2 4 6 8 10 12 14 16 18pA0102030405060708090 FID1 A, (PONA 2006-12-01 13-54-09\\\\PONA12011.D) 7.721 9.232 10.047 10.314 10.628 10.832 12.521 12.688 12.788 13.267 13.394 13.516 14.529 14.885 14.958 15.810 15.896 16.055 16.165 16.300 16.508 16.818 17.032 17.171 17.774 18.327 18.479 18.871 19.274 19.468 19.693min0 2 4 6 8 10 12 14 16 18pA0102030405060708090 FID1 A, (PONA 2006-12-08 10-37-35\\\\PONA12082.D) 8.874 9.977 10.297 10.504 12.226 12.398 12.500 12.989 13.114 13.243 14.275 14.634 14.711 15.575 15.668 15.826 15.937 16.075 16.287 16.533 16.605 16.824 16.963 17.576 18.141 18.300 18.697 19.099 19.308 19.523 20.053GS-Tek, Inc. page 7 of 7 Fig. 1, Chromatograms of a FCC gasoline sample on an GSBP-PONA column and an HP-PONA column. Top, GSBP-PONA; bottom, HP-PONA. Instrumentation condition is shown in Table I. min100 102 104 106 108 110 112 114 116 118pA0102030405060708090 FID1 A, (PONA 2006-12-01 13-54-09\\\\PONA12011.D) 99.950 100.164 100.615 100.809 100.967 101.213 101.426 101.781 102.065 102.270 102.459 102.636 103.533 103.701 103.891 104.177 104.317 104.550 104.929 105.504 105.813 106.232 106.382 106.641 107.038 107.430 107.654 107.859 108.256 108.428 108.856 109.190 109.367 109.574 109.704 110.185 110.352 110.661 110.795 110.978 111.136 111.626 111.905 112.245 112.437 112.589 112.856 113.289 113.840 114.100 114.257 114.613 114.737 115.027 115.316 115.657 115.876 116.235 116.582 116.811 117.016 117.372 117.570 117.812 118.364 118.519 118.696 118.906 119.048 119.357 119.719 119.975 120.134min100 102 104 106 108 110 112 114 116 118pA0102030405060708090 FID1 A, (PONA 2006-12-08 10-37-35\\\\PONA12082.D) 99.961 100.181 100.630 100.799 100.949 101.211 101.437 101.791 102.067 102.252 102.467 102.616 102.723 103.001 103.542 103.879 104.161 104.307 104.555 104.920 105.446 105.568 105.797 106.220 106.368 106.607 106.772 107.012 107.431 107.616 107.846 108.241 108.414 108.845 109.172 109.344 109.534 109.674 110.146 110.317 110.643 110.778 110.937 111.070 111.571 111.850 112.212 112.411 112.545 112.814 113.241 113.370 113.642 113.802 114.065 114.210 114.578 114.840 114.994 115.239 115.596 115.831 116.173 116.541 116.967 117.337 117.523 117.764 118.320 118.438 118.659 118.997 119.670 119.915min80 82 84 86 88 90 92 94 96 98pA0102030405060708090 FID1 A, (PONA 2006-12-01 13-54-09\\\\PONA12011.D) 79.922 80.097 80.654 81.301 81.547 81.737 81.914 82.154 82.490 82.765 83.328 83.603 83.826 84.114 84.221 84.436 84.679 84.954 85.258 85.486 85.962 86.331 86.674 87.078 87.301 87.486 87.707 87.900 88.256 88.535 89.076 89.444 89.628 89.990 90.211 90.545 90.740 90.975 91.148 91.344 91.509 91.927 92.240 92.585 93.191 93.466 93.758 93.979 94.290 94.722 95.050 95.333 95.529 95.862 96.045 96.437 96.603 96.770 97.167 97.384 97.841 98.028 98.402 98.688 98.899 99.274 99.410 99.685 99.950min80 82 84 86 88 90 92 94 96 98pA0102030405060708090 FID1 A, (PONA 2006-12-08 10-37-35\\\\PONA12082.D) 80.057 80.229 80.780 81.430 81.669 81.860 82.050 82.273 82.610 82.884 83.125 83.427 83.714 83.924 84.197 84.535 84.773 85.064 85.353 85.583 86.048 86.777 87.170 87.397 87.555 87.789 87.990 88.343 88.596 89.144 89.524 89.686 90.067 90.292 90.621 90.802 91.024 91.209 91.417 91.559 91.999 92.281 92.621 93.214 93.339 93.518 93.801 94.023 94.333 94.765 95.086 95.377 95.543 95.888 96.081 96.453 96.615 96.785 97.190 97.407 97.850 98.056 98.408 98.713 98.887 99.288 99.429 99.688 99.961min60 62 64 66 68 70 72 74 76 78pA0102030405060708090 FID1 A, (PONA 2006-12-01 13-54-09\\\\PONA12011.D) 60.008 61.073 61.662 61.952 62.336 62.897 63.126 63.452 64.057 64.569 65.057 65.598 65.823 66.114 66.540 66.743 67.252 67.605 67.910 68.139 68.583 69.225 69.531 69.743 70.059 70.342 70.653 70.982 71.597 71.831 72.237 72.535 72.746 73.046 73.694 74.040 74.361 74.860 75.308 75.579 75.821 76.541 76.740 77.004 77.456 77.775 78.142 78.910 79.249 79.922 80.097min60 62 64 66 68 70 72 74 76 78pA0102030405060708090 FID1 A, (PONA 2006-12-08 10-37-35\\\\PONA12082.D) 59.932 60.269 61.339 61.932 62.225 62.601 63.148 63.373 63.699 63.982 64.313 64.818 65.327 65.833 66.056 66.350 66.777 66.988 67.473 67.817 68.131 68.359 68.576 68.827 69.443 69.744 69.957 70.277 70.552 70.881 71.806 72.049 72.436 72.708 72.927 73.246 73.868 74.207 74.526 74.680 75.030 75.240 75.500 75.736 75.996 76.700 76.891 77.158 77.326 77.628 77.923 78.291 79.081 79.393 80.057