توليد رزين نفتي از بنزين پيروليز توسط نانوكاتاليست مغناطيسي هسته-پوسته Fe₃O₄@SiO₂@AlCl₃ و بهينه سازي پارامترهاي تأثيرگذار بر واكنش توليد

Petroleum resins are one of the key materials in the adhesive, paint, printing ink, an‎d rubber industries. Despite the global advancement of this technology, the industrial production of petroleum resins has not yet been realized in Iran, making the country reliant on their importation. In this study, the laboratory-scale production of petroleum resin from pyrolysis gasoline feed using an aluminum chloride (AlCl₃) catalyst in a batch reactor was investigated. In this regard, the effects of the most important operating parameters—namely temperature, residence time, an‎d catalyst weight percentage—on the reaction yield an‎d the properties of the produced resin, including molecular weight, softening point, an‎d color, were examined, an‎d the optimal conditions were determined. To optimize the parameters, experimental design an‎d the response surface methodology based on a central composite design were employed. In the next step, for the first time, a magnetic nanocatalyst with an iron oxide core–silica shell structure modified with aluminum chloride (Fe₃O₄@SiO₂@AlCl₃), featuring magnetic separability an‎d reusability, was synthesized an‎d applied in the petroleum resin production reaction. At this stage, the polymerization reaction was carried out using a modified feed (the 35–65°C cut of pyrolysis gasoline) under the optimal conditions obtained from the previous step. The properties an‎d characteristics of the synthesized nanocatalyst were determined using BET, DLS, EDAX, FESEM, FT-IR, ICP, TEM, TGA, VSM, an‎d XRD analyses. Furthermore, the kinetics of the polymerization reaction for petroleum resin production were studied. The results indicated that the optimal conditions were a temperature of 20°C, a catalyst loading of 1.13 wt%, an‎d a residence time of 86 minutes, under which the maximum yield, maximum softening point, an‎d minimum color were 22.5%, 152°C, an‎d 3.7 Gardner, respectively. A comparison of the performance of the AlCl₃ catalyst an‎d the Fe₃O₄@SiO₂@AlCl₃ nanocatalyst showed that, although the molecular weight an‎d softening point of the resin did not change significantly, the use of the nanocatalyst led to a substantial increase in yield from 22.1% to 40.8% (approximately double), while the resin color increased by an average of about 1.5 Gardner units (from 4 to 5.4). Moreover, the use of the modified feed resulted in increased yield, molecular weight, an‎d softening point, as well as reduced resin color, indicating improved stability an‎d quality of the produced resin. The reusability study of the nanocatalyst revealed that after six cycles of recovery an‎d reuse, the polymerization reaction yield decreased by only about 7% (from 98% to 91%), with no significant changes observed in the responses, particularly yield, over these six cycles. These results indicate high catalytic activity an‎d adequate stability of the synthesized nanocatalyst. Additionally, the kinetic study demonstrated that feed modification plays an effective role in improving the petroleum resin production process, such that the reaction rate constant increased from 0.0040 min⁻¹ to 0.0158 min⁻¹ (approximately fourfold), an‎d the final conversion percentage increased from 58% to 98% (about 40%). Finally, a comparison of the method presented in this study with some previous methods showed that conducting the reaction under solvent-free conditions, reducing the reaction time, an‎d the ability to reuse the catalyst for at least six cycles without significant loss of activity are among the outstan‎ding advantages of this research.

حميدرضا شاه وردي , وحيد جوانبخت

عليرضا نجفي چرمهيني , افسانه فخار

نسرين اعتصامي , عليرضا علافچيان , كيومرث زرگوش , اميرحسين نوارچيان