| Investigating the Radical Interaction of Asphaltene with TEMPO and Propyl Gallate |
| کد مقاله : 1267-ICOC |
| نویسندگان |
|
لقمان الباجی *1، بابک مختاری2، الهام رئیسی2، شیرین باقرسایی2 1دانشجوی دکترا، گروه شیمی، دانشکده علوم، دانشگاه شهید چمران اهواز، اهواز، ایران 2گروه شیمی، دانشکده علوم، دانشگاه شهید چمران اهواز، اهواز، ایران |
| چکیده مقاله |
| Asphaltenes are the most polar and heaviest components of crude oil. They have an aromatic structure and contain heteroatoms such as sulfur, oxygen, and nitrogen, as well as metals like nickel and vanadium. During self-assembly and precipitation, asphaltenes create challenges in the production, transportation, and refining of crude oil, leading to decreased production and higher costs [1]. Among the various methods developed to control asphaltene deposition, chemical methods are more attractive due to their operational simplicity, low cost, and effectiveness [2]. Since 10 to 20 percent of asphaltene molecules contain free radicals that contribute to the aggregation and precipitation of asphaltenes, the use of antioxidants could be a novel approach to stabilize and prevent their self-assembly [3]. In continuation of our studies [4], this study aimed to assess the effectiveness of two antioxidants, 2,2,6,6-Tetramethylpiperidine 1-oxyl (TEMPO) and 3,4,5-trihydroxy-benzoic acid (propyl gallate), in a synthetic oil (asphaltene-toluene solution) through UV–Vis Spectroscopy to determine the asphaltene dispersion index, measurement of the precipitation onset point, and FT-IR spectroscopy. The UV-Vis results indicated that both additives increased the stability of asphaltene compared to the sample without antioxidants. The maximum asphaltene dispersion index was achieved at a concentration of 4000 ppm of TEMPO, reaching 79.72%, and at a concentration of 1000 ppm of propyl gallate, reaching 59.36%. Furthermore, both antioxidants shifted the precipitation onset point of asphaltene from a volume ratio of 40% n-hexane to toluene (without additive) to 60%, demonstrating an effective delay in the precipitation process. FT-IR spectra also revealed the emergence of new bands and changes in the OH and NH peaks of the asphaltene spectrum, confirming the interaction of antioxidants with asphaltene. It seems that TEMPO and propyl gallate interact with free radicals on the aromatic structure of asphaltene through radical interactions. Additionally, propyl gallate interacts with asphaltene through π–π stacking and hydrogen bonding. |
| کلیدواژه ها |
| Asphaltene Aggregation, Tempo, Propyl Gallate, Radical Interactions |
| وضعیت: پذیرفته شده |