Bagherpour Saman, Riazi Mohsen, Riazi Masoud, Cortés Farid B, Mousavi Seyed Hamed
Enhanced Oil Recovery (EOR) Research Center, IOR/EOR Research Institute, Shiraz University, Molla Sadra Street, 7194684636 Shiraz, Iran.
Separation Processes & Nanotechnology Lab, Faculty of Caspian, College of Engineering, University of Tehran, 16 Azar Street, 1417466191 Tehran, Iran.
ACS Omega. 2020 Jun 23;5(26):16149-16164. doi: 10.1021/acsomega.0c01732. eCollection 2020 Jul 7.
In recent years, researchers have attempted to find some practical approaches for asphaltene adsorption and the prevention or postponement of asphaltene precipitation. Among different techniques, nanotechnology has attracted the researchers' attention to overcome the formation damage resulting from the deposition of asphaltenes. In this study, the application of two types of carboxylate-alumoxane nanoparticles (functionalized boehmite by methoxyacetic acid (BMA) and functionalized pseudo-boehmite by methoxyacetic acid (PBMA)) for asphaltene adsorption and precipitation was investigated. First, the synthesis of two functionalized nanoparticles was performed via the sol-gel method. For the assessment of the adsorption efficiency and adsorption capacity of these nanoparticles toward asphaltene adsorption, the batch adsorption experiments applying ultraviolet-visible (UV-Vis) spectroscopy were performed. The Langmuir and Freundlich isotherms were studied to describe the interaction between asphaltene molecules and carboxylate-alumoxane nanoparticles. For determining the "onset" point of asphaltene precipitation, the indirect method, which was based on the difference in the optical property of various solutions containing different concentrations of asphaltene, was utilized by applying UV-Vis spectroscopy. The isotherm models indicate that the adsorption of asphaltene on the surface of nanoparticles is better fitted to the Freundlich isotherm model compared with the Langmuir model. In the presence of PBMA (0.1 wt %), the onset point was delayed around 26, 20, and 17% in the asphaltene concentrations of 1000, 3000, and 5000 ppm, respectively, in comparison with their reference synthetic oils. On the other hand, these postponements for BMA nanoparticles (0.1 wt %) were 17%, 9%, and insignificant for the asphaltene concentrations of 1000, 3000, and 5000 ppm, respectively. The results reveal that two functionalized nanoparticles tend to adsorb asphaltene molecules and have a positive impact on the postponement of asphaltene precipitation due to molecular interactions between the surface of carboxylate-alumoxane nanoparticles and asphaltene molecules. However, PBMA nanoparticles exhibited better performance on the asphaltene adsorption and postponement of asphaltene precipitation, which is related to its smaller size, as well as higher surface area, compared with BMA nanoparticles.
近年来，研究人员试图找到一些实用的方法来吸附沥青质以及预防或延缓沥青质沉淀。在不同的技术中，纳米技术已引起研究人员的关注，以克服因沥青质沉积而导致的地层损害。在本研究中，研究了两种羧酸盐 - 铝氧烷纳米颗粒（用甲氧基乙酸（BMA）功能化的勃姆石和用甲氧基乙酸（PBMA）功能化的拟薄水铝石）对沥青质吸附和沉淀的应用。首先，通过溶胶 - 凝胶法合成了两种功能化纳米颗粒。为了评估这些纳米颗粒对沥青质吸附的吸附效率和吸附容量，进行了应用紫外可见（UV - Vis）光谱的批量吸附实验。研究了朗缪尔等温线和弗伦德里希等温线，以描述沥青质分子与羧酸盐 - 铝氧烷纳米颗粒之间的相互作用。为了确定沥青质沉淀的“起始”点，通过应用UV - Vis光谱，利用基于含有不同浓度沥青质的各种溶液光学性质差异的间接方法。等温线模型表明，与朗缪尔模型相比，沥青质在纳米颗粒表面的吸附更符合弗伦德里希等温线模型。在存在PBMA（0.1 wt％）的情况下，与它们的参考合成油相比，在沥青质浓度分别为1000、3000和5000 ppm时，起始点分别延迟了约26％、20％和17％。另一方面，对于BMA纳米颗粒（0.1 wt％），在沥青质浓度为1000、3000和5000 ppm时，这些延迟分别为17％、9％和不显著。结果表明，两种功能化纳米颗粒倾向于吸附沥青质分子，并且由于羧酸盐 - 铝氧烷纳米颗粒表面与沥青质分子之间的分子相互作用，对延缓沥青质沉淀有积极影响。然而，与BMA纳米颗粒相比，PBMA纳米颗粒在沥青质吸附和延缓沥青质沉淀方面表现出更好的性能，这与其较小的尺寸以及更高的表面积有关。
