The molecular transformations of carboxylic acids in heavy acidic SL crude before and after true boiling point distillation were examined by ultra-high resolution negative-ion electrospray ionization(ESI) Fourier tran...The molecular transformations of carboxylic acids in heavy acidic SL crude before and after true boiling point distillation were examined by ultra-high resolution negative-ion electrospray ionization(ESI) Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR MS). The acid class(heteroatom number), type(z numbers) and carbon number distributions were positively characterized. It was found out that the total acid number(TAN) of SL crude decreased after true boiling point distillation, and the abundance of O2 class in mass spectra was also found to be reduced from 67.6% to 34.5% in SL TBP mixed crude as measured by MS spectra, indicating to a potential carboxylic acid decomposition. However, it was interesting that the carboxylic acids type distribution in both oils was almost the same although their relative abundance in SL TBP mixed crude turned to be much lower, suggesting that various petroleum carboxylic acid types have the similar thermal decomposition reaction behavior. Furthermore, for each O2 type of acids in SL TBP mixed crude, the abundance of carboxylic acids with carbon number higher than 35 was reduced greatly, especially for those with carbon number higher than 60, the mass peaks of which were nearly totally removed, indicating that the large carboxylic acid molecules in heavy fractions decomposed more significantly because of longer heating time during the true boiling point distillation process. As a result, the reduction of TAN may be caused by the thermal decomposition of carboxylic acids especially those with high carbon number, suggesting that quick distillation or much lower pressure is required to avoid the thermal decomposition.展开更多
High acidity crude oils have an advantage over normal oils in terms of their price,but can cause corrosion and refinery problems.They are the so-called opportunity crudes and likely to be important reserved resources ...High acidity crude oils have an advantage over normal oils in terms of their price,but can cause corrosion and refinery problems.They are the so-called opportunity crudes and likely to be important reserved resources in the 21st century.Researches on high acidity crude oils are becoming more and more profound.Based on the existing research achievements,this article has given an overview of the chemical composition and acid distribution of high acidity oils,and also analyzed their origin types and potential influence factors.展开更多
采用Brookfield DV-ⅢUltra流变仪,对高酸原油降黏规律进行了研究。结果表明:在磁感应强度为80 m T,磁化时间为30 min,处理温度为50℃和搅拌转速为600 r/min的优化磁场处理条件下,高酸原油表观黏度由53.9 m Pa·s降低到45.9 m Pa...采用Brookfield DV-ⅢUltra流变仪,对高酸原油降黏规律进行了研究。结果表明:在磁感应强度为80 m T,磁化时间为30 min,处理温度为50℃和搅拌转速为600 r/min的优化磁场处理条件下,高酸原油表观黏度由53.9 m Pa·s降低到45.9 m Pa·s,降黏率达到14.8%;处理后的高酸值原油经50℃恒温静置12 h,其表观黏度基本恢复。展开更多
基金financially supported by the National Key Basic Research Development Program "973" Project (2006CB202501)
文摘The molecular transformations of carboxylic acids in heavy acidic SL crude before and after true boiling point distillation were examined by ultra-high resolution negative-ion electrospray ionization(ESI) Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR MS). The acid class(heteroatom number), type(z numbers) and carbon number distributions were positively characterized. It was found out that the total acid number(TAN) of SL crude decreased after true boiling point distillation, and the abundance of O2 class in mass spectra was also found to be reduced from 67.6% to 34.5% in SL TBP mixed crude as measured by MS spectra, indicating to a potential carboxylic acid decomposition. However, it was interesting that the carboxylic acids type distribution in both oils was almost the same although their relative abundance in SL TBP mixed crude turned to be much lower, suggesting that various petroleum carboxylic acid types have the similar thermal decomposition reaction behavior. Furthermore, for each O2 type of acids in SL TBP mixed crude, the abundance of carboxylic acids with carbon number higher than 35 was reduced greatly, especially for those with carbon number higher than 60, the mass peaks of which were nearly totally removed, indicating that the large carboxylic acid molecules in heavy fractions decomposed more significantly because of longer heating time during the true boiling point distillation process. As a result, the reduction of TAN may be caused by the thermal decomposition of carboxylic acids especially those with high carbon number, suggesting that quick distillation or much lower pressure is required to avoid the thermal decomposition.
文摘High acidity crude oils have an advantage over normal oils in terms of their price,but can cause corrosion and refinery problems.They are the so-called opportunity crudes and likely to be important reserved resources in the 21st century.Researches on high acidity crude oils are becoming more and more profound.Based on the existing research achievements,this article has given an overview of the chemical composition and acid distribution of high acidity oils,and also analyzed their origin types and potential influence factors.
文摘采用Brookfield DV-ⅢUltra流变仪,对高酸原油降黏规律进行了研究。结果表明:在磁感应强度为80 m T,磁化时间为30 min,处理温度为50℃和搅拌转速为600 r/min的优化磁场处理条件下,高酸原油表观黏度由53.9 m Pa·s降低到45.9 m Pa·s,降黏率达到14.8%;处理后的高酸值原油经50℃恒温静置12 h,其表观黏度基本恢复。
