JOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY
·
2024
·
IF 1.9
Feng Jiang,Xinchuan Huang,Shishi Pang,Wanfen Pu
The presence of natural lipophilic emulsifiers, such as asphaltenes (A), resin (R) and petroleum acids (PA) in crude oil, plays a crucial role in stabilizing the W/O emulsions. This study primarily focuses on elucidating the influence of their interactions on the interfacial properties of the water/model oil system, as well as its emulsion stability. First, equilibrium interfacial tension (IFT), interfacial dilational modulus (IDM) and phase angle are measured. Then, emulsion stability experiments are performed. Finally, microscopic images of the emulsions were captured to evaluate droplet size and dispersity. Results show that the addition of petroleum acid to both asphaltene-only and resin-only system reduces IFT and dilational modulus, weakening the strength of the interfacial film. The inhibitory effect of petroleum acid on resins’ adsorption at the interface is more pronounced compared to asphaltenes’. A low proportion of resin and petroleum acid (A/R ≥ 5, A/PA ≥ 7) enhances emulsion stability by co-adsorbing with asphaltenes at the oil–water interface. Conversely, a high proportion of resin and petroleum acid leads to a decrease in IDM and emulsion stability. For asphaltene/petroleum acid–water system, when A/PA ≤ 5, the presence of petroleum acid decreases the droplet size but enhances droplet dispersion while decreasing emulsion stability. It can be inferred that the presence of petroleum acids contributes more to the formation rather than stabilization of emulsions. This work deepens insights into the emulsion behavior of natural surfactants, providing theoretical guidance for the formation of stable emulsions underground and efficient demulsification above ground.
研究领域:
石油工程
·
表面化学
·
胶体科学
✓ 已验证
DOI
高影响因子
JOURNAL OF CHROMATOGRAPHY A
·
2018
·
IF 3.716
Gang-Tian Zhu,Xiao-Li Hu,Sheng He,Xiao-Mei He,Shu-Kui Zhu,Yu-Qi Feng
Tailor-made chitosan fiber was prepared via hydrothermal treatment to serve as a micro-solid phase extraction (micro-SPE) sorbent for the analysis of petroleum acids (PAs) in crude oils. Chitosan fiber, which is commercial and cheap, has a diameter of about 10 μm and a length of a few centimeters. The fibrous property of the sorbent enables the micro-SPE to deal with viscous crude oil samples because of the low back-pressure during extraction, while the abundant hydroxyl groups and amino groups on the surface of chitosan fiber can provide high density of specific sites for adsorption of PAs. Moreover, it was found that hydrothermal treatment at certain conditions could tune the surface properties of chitosan fiber, leading to significant improvement of the capacity of the fiber in adsorption of PAs. Using hydrothermally treated chitosan fiber as sorbent, the micro-SPE was applied to the determination of PAs in crude oils, with the advantages of easy-operation, rapidness and high sensitivity (the limits of detection range from 0.7 ng/g to 5.4 ng/g). Furthermore, coupled with comprehensive two dimensional gas chromatography-mass spectrometry (GC × GC MS), the treated chitosan fiber packed micro-SPE method showed a great potential for comprehensive profiling of PAs in crude oils.
研究领域:
分析化学
·
材料科学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2018
·Vol. 8
·期 35
·19486-19493
·
IF 2.936
Gang-Tian Zhu,Fei Liu,Sheng He,Xiao-Mei He,Shu-Kui Zhu,Yu-Qi Feng
Magnetic aqueous ammonia (MAA) was prepared as a magnetic extractant for dispersive microextraction of petroleum acids (PAs). The amount of extractant in MAA was custom-made by a simple approach. In the MAA composed of an aqueous ammonia coating and Fe3O4@SiO2 core, the coating is a base extractant that can selectively extract acids, while the magnetic core serves as a support to achieve dispersion as well as rapid magnetic retrieval of the extractant during the extraction processes. This is the first use of reusable, stable and modifiable Fe3O4@SiO2 as a support instead of bare Fe3O4 in a magnetic particle assisted dispersive liquid–liquid microextraction technique. The parameters that affect extraction efficiency were investigated. The sampling step as well as the desorption step can be completed in 2 min. The linear ranges are 5–5000 ng g−1, while the limits of quantification range from 2.5 to 6.2 ng g−1. The recoveries in spiked crude oil samples are in the range of 79.1% to 112.1% with relative standard deviations less than 11.3% (intra-day) and 13.4% (inter-day). Finally, the proposed method was applied to the analysis of PAs in diluted crude oils with different maturities. In comparison to the existing methods for extraction of PAs, the proposed method provides superior performances including high throughput (12-well plate), high degree of sample clean-up, and low consumption of separation material, solvent and time.
研究领域:
分析化学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 64
·40608-40614
·
IF 3.108
Gang-Tian Zhu,Sheng He,Xiao-Mei He,Shu-Kui Zhu,Yu-Qi Feng
In this work, a micro-solid phase extraction (micro-SPE) method was developed for the analysis of petroleum acids in crude oils. Plastic vessels were found to be unsuitable as the micro-SPE vessel, because of the plasticizer interferences and the serious adhesion of oil samples on vessel surfaces. To reduce or eliminate these influences, a glass pipette was selected as the micro-SPE vessel. With the glass pipette micro-SPE format, amino-functionalized silica was chosen as the sorbent for extraction of petroleum acids based on mix-mode hydrogen bonding/ion-exchange interactions. The conditions of the micro-SPE were carefully optimized. Under the optimized conditions, no evaporation was needed, which can save time and reduce losses of analytes. By coupling with gas chromatography-mass spectrometry (GC-MS), the proposed micro-SPE method for analysis of petroleum acids was proved to be easily operated, fast (the micro-SPE can be accomplished within 5 min), solvent-saving (3 mL of solvent), reproducible and sensitive (the limits of detection range from 2 ng g−1 to 6 ng g−1).
研究领域:
分析化学
·
石油化学
✓ 已验证
DOI
高影响因子
FUEL
·
2024
·
IF 6.7
Haojie Hu,Shuofan Li,Yuanfeng Wang,Ruochen Yang,Jianxun Wu,Weilai Zhang,Chen He,Han Li,Yahe Zhang,Di Zhu,Quan Shi
Petroleum acids are widely present in crude oil and are important indicators of generation and preservation of the crude oil. However, it is difficult to analyze these compounds using gas chromatography due to their strong polarity and low volatility. In this work, we established a method to reduce petroleum acids into corresponding hydrocarbons using n -butylsilane as the reducing agent. The reduced products of the acids from three crude oils with different geological origin were analyzed by gas chromatography-mass spectrometry and high resolution Orbitrap mass spectrometry coupled with electrospray ionization. Various hydrocarbons with specific biomarker carbon skeletons were identified in the reduced products and compared to the corresponding compounds in the saturates of the crude oils, which provides molecular clues for the understanding of the geochemical formation mechanism of petroleum acids. The results show large difference in molecular composition of petroleum acids in different crude oils. The Liaohe acids were composed of fatty acids which should be primary acids in source rock or derived from low-maturity kerogen. In contrast, the Xinjiang and Shengli acids were dominated with naphthenic acids. Xinjiang naphthenic acids showed good consistency in carbon skeleton and carbon number with the saturates. This indicates that these naphthenic acids originate from the bio-oxidation and degradation of cycloalkanes, which can also be further decarboxylated and degraded to generate cycloalkanes. Abundant 8,14-secohopanes and 25-norhopanes and corresponding acids were detected in Shengli crude oil. The compositional differences between the acids and corresponding hydrocarbons suggests that biodegradation occurs preferentially on large molecules with long side chains and has structural selectivity on the isomers. The results implies that 25-norhopanic acids seems to be the intermediates for the biodegradation of hopanes to 25-norhopanes.
研究领域:
石油化学
·
地球化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）