Naphthenic acids in petroleum are considered a class of biological markers. Their potential use i... more Naphthenic acids in petroleum are considered a class of biological markers. Their potential use in source correlation and as an indicator of biodegradation was reported in the past (Dzidic et al., 1988; Behar and Albrecht, 1984). Due to their highly complicated properties, detailed characterization of the acids is difficult. A method based on positive ion CI (chemical ionization) mass spectrometry using isobutane reagent gas to produce (M+15)+ ions was applied to the analysis of naphthenic acid esters. Since the complex mixture of naphthenic acids cannot be separated into individual components, only the determination of relative distribution of acids classified in terms of hydrogen deficiency was possible. The identities and relative distribution of fatty and mono-, di-, tri-, and higher polycyclic acids were obtained from the intensities of the (M+15)+ ions according to z-series formula Cn H2n+z O2 of naphthenic acids. The components are characterized on the basis of group type and carbon number distributions. A comparison of the FAB and CI results showed that the group type distributions obtained by both methods agree surprisingly well. The results indicated this method is simple, rapid and easy to operate. The geochemical implication of naphthenic acids was investigated by using a set of well-characterized crude oil samples. It is found that the naphthenic acid distribution can be used as a fingerprint for oil-oil and oil-source correlations.
The thermal decomposition of four alkanethiols was investigated in this paper. The test was proce... more The thermal decomposition of four alkanethiols was investigated in this paper. The test was processed in a pressure reactor at 200 -400 -C. GC/ MS and GC/SCD were used to detect the products of thermal decomposition. The result indicates that the alkane groups of alkanethiols have great influence on the thermal stability of alkanethiols. N-butylthiol, isobutylthiol and n-hexylthiol begin to pyrolyse at about 250 -C and more than 75% decomposes at 400 -C after being maintained for 4 h. However, tert-octylthiol can be broken down at lower temperature below 200 -C and almost 75% decomposes at 250 -C after 4 h. The main product of thermal decomposition is H 2 S and a free radical reaction is used to explain the decomposition mechanism. D
ABSTRACT The presence of petroleum acids in crude oils is a key problem in refineries due to corr... more ABSTRACT The presence of petroleum acids in crude oils is a key problem in refineries due to corrosion to industrial units. To economically and effectively remove the petroleum acids from high acid crude oils is an urgent project. A theoretical and experimental study to develop a catalytic decarboxylation process to remove petroleum acids from high acid crude oils was conducted. By using the molecular simulation technology, a solid acid catalyst was constructed for removing petroleum acids. The experimental results indicated that the acid removal rate of a high acid crude oil with a total acid number (TAN) of 12.52 over the solid acid catalyst of MLC500 was up to 97% at a volume space velocity of 8 h(-1), ratio of catalyst to oil of 7.5, and temperature of 460 degrees C in the fixed fluid bed reactor.
A new ternary complex system was described. At pH 4.8 diphenylcarbazon formed ternary complexes w... more A new ternary complex system was described. At pH 4.8 diphenylcarbazon formed ternary complexes with metal ions (Cr(VI) and V(V)) and hexadecyltrimethyl ammonium bromide (cetyltrimethyl ammonium bromide, CTAB). The ternary complex of chromate was separated from that of vanadate by means of liquid chromatography using a mobile phase of acetonitrile-acetone-water (85520, v/v) containing 0.002 M CTAFL The analytical sensitivity of the complex of chromate could be raised further if the medium of the injection solution is transferred in methanol by solid-phase extraction.
The thermal decomposition of four alkanethiols was investigated in this paper. The test was proce... more The thermal decomposition of four alkanethiols was investigated in this paper. The test was processed in a pressure reactor at 200 -400 -C. GC/ MS and GC/SCD were used to detect the products of thermal decomposition. The result indicates that the alkane groups of alkanethiols have great influence on the thermal stability of alkanethiols. N-butylthiol, isobutylthiol and n-hexylthiol begin to pyrolyse at about 250 -C and more than 75% decomposes at 400 -C after being maintained for 4 h. However, tert-octylthiol can be broken down at lower temperature below 200 -C and almost 75% decomposes at 250 -C after 4 h. The main product of thermal decomposition is H 2 S and a free radical reaction is used to explain the decomposition mechanism. D
We collect a total of 330 crude oil samples. We presented a fast analytical tool for rapid identi... more We collect a total of 330 crude oil samples. We presented a fast analytical tool for rapid identification of crude oil type. Compared with NIR, IR method can distinguish highly similar mixed crude oils given in the study. We study parameters of the moving window correlation coefficient method in the paper. g r a p h i c a l a b s t r a c t 0.93 0.94 0.95 0.96 0.97 0.98 0.99 1.00 690 740 790 840 890 940 990 Correlation coefficient Wavenumber/cm -1 a b
Naphthenic acids in petroleum are considered a class of biological markers. Their potential use i... more Naphthenic acids in petroleum are considered a class of biological markers. Their potential use in source correlation and as an indicator of biodegradation was reported in the past (Dzidic et al., 1988; Behar and Albrecht, 1984). Due to their highly complicated properties, detailed characterization of the acids is difficult. A method based on positive ion CI (chemical ionization) mass spectrometry using isobutane reagent gas to produce (M+15)+ ions was applied to the analysis of naphthenic acid esters. Since the complex mixture of naphthenic acids cannot be separated into individual components, only the determination of relative distribution of acids classified in terms of hydrogen deficiency was possible. The identities and relative distribution of fatty and mono-, di-, tri-, and higher polycyclic acids were obtained from the intensities of the (M+15)+ ions according to z-series formula Cn H2n+z O2 of naphthenic acids. The components are characterized on the basis of group type and carbon number distributions. A comparison of the FAB and CI results showed that the group type distributions obtained by both methods agree surprisingly well. The results indicated this method is simple, rapid and easy to operate. The geochemical implication of naphthenic acids was investigated by using a set of well-characterized crude oil samples. It is found that the naphthenic acid distribution can be used as a fingerprint for oil-oil and oil-source correlations.
The thermal decomposition of four alkanethiols was investigated in this paper. The test was proce... more The thermal decomposition of four alkanethiols was investigated in this paper. The test was processed in a pressure reactor at 200 -400 -C. GC/ MS and GC/SCD were used to detect the products of thermal decomposition. The result indicates that the alkane groups of alkanethiols have great influence on the thermal stability of alkanethiols. N-butylthiol, isobutylthiol and n-hexylthiol begin to pyrolyse at about 250 -C and more than 75% decomposes at 400 -C after being maintained for 4 h. However, tert-octylthiol can be broken down at lower temperature below 200 -C and almost 75% decomposes at 250 -C after 4 h. The main product of thermal decomposition is H 2 S and a free radical reaction is used to explain the decomposition mechanism. D
ABSTRACT The presence of petroleum acids in crude oils is a key problem in refineries due to corr... more ABSTRACT The presence of petroleum acids in crude oils is a key problem in refineries due to corrosion to industrial units. To economically and effectively remove the petroleum acids from high acid crude oils is an urgent project. A theoretical and experimental study to develop a catalytic decarboxylation process to remove petroleum acids from high acid crude oils was conducted. By using the molecular simulation technology, a solid acid catalyst was constructed for removing petroleum acids. The experimental results indicated that the acid removal rate of a high acid crude oil with a total acid number (TAN) of 12.52 over the solid acid catalyst of MLC500 was up to 97% at a volume space velocity of 8 h(-1), ratio of catalyst to oil of 7.5, and temperature of 460 degrees C in the fixed fluid bed reactor.
A new ternary complex system was described. At pH 4.8 diphenylcarbazon formed ternary complexes w... more A new ternary complex system was described. At pH 4.8 diphenylcarbazon formed ternary complexes with metal ions (Cr(VI) and V(V)) and hexadecyltrimethyl ammonium bromide (cetyltrimethyl ammonium bromide, CTAB). The ternary complex of chromate was separated from that of vanadate by means of liquid chromatography using a mobile phase of acetonitrile-acetone-water (85520, v/v) containing 0.002 M CTAFL The analytical sensitivity of the complex of chromate could be raised further if the medium of the injection solution is transferred in methanol by solid-phase extraction.
The thermal decomposition of four alkanethiols was investigated in this paper. The test was proce... more The thermal decomposition of four alkanethiols was investigated in this paper. The test was processed in a pressure reactor at 200 -400 -C. GC/ MS and GC/SCD were used to detect the products of thermal decomposition. The result indicates that the alkane groups of alkanethiols have great influence on the thermal stability of alkanethiols. N-butylthiol, isobutylthiol and n-hexylthiol begin to pyrolyse at about 250 -C and more than 75% decomposes at 400 -C after being maintained for 4 h. However, tert-octylthiol can be broken down at lower temperature below 200 -C and almost 75% decomposes at 250 -C after 4 h. The main product of thermal decomposition is H 2 S and a free radical reaction is used to explain the decomposition mechanism. D
We collect a total of 330 crude oil samples. We presented a fast analytical tool for rapid identi... more We collect a total of 330 crude oil samples. We presented a fast analytical tool for rapid identification of crude oil type. Compared with NIR, IR method can distinguish highly similar mixed crude oils given in the study. We study parameters of the moving window correlation coefficient method in the paper. g r a p h i c a l a b s t r a c t 0.93 0.94 0.95 0.96 0.97 0.98 0.99 1.00 690 740 790 840 890 940 990 Correlation coefficient Wavenumber/cm -1 a b
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