In this study, the main factors influencing the measurements by means of the off-line low-field 1H NMR in the lab were discussed base on a robust calibration model established by the PLS algorithm using 255 crude oil ...In this study, the main factors influencing the measurements by means of the off-line low-field 1H NMR in the lab were discussed base on a robust calibration model established by the PLS algorithm using 255 crude oil samples. The preheating temperature had a great influence on the viscosity of oil samples and the resolution of spectral analysis. The repeatability of spectral measurements was impacted by the metal and wax content of the oil samples. For the case of high wax content oils, the wax species began to crystallize in the course of determination that could affect the repeatability of spectral measurements. These factors have evidenced why the preheating devices and filter unit are necessary when low field NMR system is used in the online analysis process. The investigation is very important for the on-line application of the low field NMR.展开更多
This study investigates the effects of sampling conditions on volatile organic compound(VOC)compositions including different flow restrictors,SUMMA volumes,sampling heights,and wind speeds.Results show that at the six...This study investigates the effects of sampling conditions on volatile organic compound(VOC)compositions including different flow restrictors,SUMMA volumes,sampling heights,and wind speeds.Results show that at the six sampling heights the concentrations of main VOC species were slightly different,while the wind speed had a greater impact on the VOC composition of source profiles.With the increase of wind speed,the weighted percentage of high-carbon aromatic hydrocarbons was higher.Besides,there was an extremely different profile between the normal production and shutdown conditions of the delayed coking unit.To compare the emission characteristics of VOCs in various process units of the S and the C refineries,the samples were collected from the catalytic cracking unit,the continuous catalytic reforming unit,and the delayed coking unit.In the continuous catalytic reforming unit,C3-C5 alkanes and low-carbon aromatic hydrocarbons were the main components collected from the S and the C refineries,accounting for 67.1%and 34.9%,respectively.For the delayed coking unit,the total weighted percentage of high carbon C6-C12 alkanes was significantly higher than other units in the S and the C refineries,accounting for 30.5%and 24.4%,respectively.In the catalytic cracking unit,the low-carbon C2-C5 alkanes were abundant,and the weighted percentage of propylene was higher.The emission characteristics obtained were consistent with the processing technology of production units.The results indicate that the VOC emission characteristics from the same production unit in different refineries have similarities and significant differences which are related to the technological process.The emission characteristics of VOCs could provide the data support for source apportionment work in the production units.展开更多
基金the financial support from the SINOPEC (ST 13028)
文摘In this study, the main factors influencing the measurements by means of the off-line low-field 1H NMR in the lab were discussed base on a robust calibration model established by the PLS algorithm using 255 crude oil samples. The preheating temperature had a great influence on the viscosity of oil samples and the resolution of spectral analysis. The repeatability of spectral measurements was impacted by the metal and wax content of the oil samples. For the case of high wax content oils, the wax species began to crystallize in the course of determination that could affect the repeatability of spectral measurements. These factors have evidenced why the preheating devices and filter unit are necessary when low field NMR system is used in the online analysis process. The investigation is very important for the on-line application of the low field NMR.
基金This study was funded by the Natural Key Research and Development Program(Grant No.2016YFC0801301)the SINOPEC Program(Grant No.319022-10).
文摘This study investigates the effects of sampling conditions on volatile organic compound(VOC)compositions including different flow restrictors,SUMMA volumes,sampling heights,and wind speeds.Results show that at the six sampling heights the concentrations of main VOC species were slightly different,while the wind speed had a greater impact on the VOC composition of source profiles.With the increase of wind speed,the weighted percentage of high-carbon aromatic hydrocarbons was higher.Besides,there was an extremely different profile between the normal production and shutdown conditions of the delayed coking unit.To compare the emission characteristics of VOCs in various process units of the S and the C refineries,the samples were collected from the catalytic cracking unit,the continuous catalytic reforming unit,and the delayed coking unit.In the continuous catalytic reforming unit,C3-C5 alkanes and low-carbon aromatic hydrocarbons were the main components collected from the S and the C refineries,accounting for 67.1%and 34.9%,respectively.For the delayed coking unit,the total weighted percentage of high carbon C6-C12 alkanes was significantly higher than other units in the S and the C refineries,accounting for 30.5%and 24.4%,respectively.In the catalytic cracking unit,the low-carbon C2-C5 alkanes were abundant,and the weighted percentage of propylene was higher.The emission characteristics obtained were consistent with the processing technology of production units.The results indicate that the VOC emission characteristics from the same production unit in different refineries have similarities and significant differences which are related to the technological process.The emission characteristics of VOCs could provide the data support for source apportionment work in the production units.
