Stabilizing Triglyceride in Methanol Emulsions via a Magnetic Pickering Interfacial Catalyst for Efficient Transesterification under Static Conditions
作者：Hao Zhang, Siyang Yu, Shixiong Cao, Xiaobo Liu, Jun Tang, Lingyu Zhu, Jianbing Ji, and Jianli Wang
關鍵字：pickering emulsion, pickering interfacial catalysts
論文來源：期刊
具體來源：ACS Omega
發表時間：2021年
Pickering乳液體系為在靜態條件下同時強化和催化甘油三酯與甲醇的酯交換提供了潛在的平臺。然而，由于乳化液在反應溫度下的穩定性較低，實現具有高生物柴油收率的靜態酯交換仍然具有挑戰性。本文構建了一系列表面親和性相似但密度不同的磁性可回收皮克林界面催化劑(PICs)作為大豆油/甲醇乳液的穩定劑。從液滴沉降和催化劑顆粒脫落的角度，對乳化液體積分數和液滴尺寸的變化進行了對比研究和分析。研究發現，除了表面親和力外，由于重力對催化劑在甘油三酯/甲醇乳液中的吸附有不可忽視的影響(特別是在高溫下)，PIC密度對乳液的穩定性也起著關鍵作用。通過降低密度，精細改善親油性，優化PIC的加入量，得到的大豆油/甲醇乳液在60℃下能保持穩定至少12 h，實現靜態酯交換，生物柴油收率高達95.6%。此外，性能最好的PIC可以重復使用至少7個周期。這種高效的靜態酯交換系統為生物柴油生產提供了一種綠色策略。
Pickering emulsion systems provide potential platforms for simultaneously intensifying and catalyzing transesterification between triglyceride and methanol under static conditions. However, realizing static transesterification with high biodiesel yield is still challenging due to low emulsion stability at the reaction temperature. Here, a series of magnetically recyclable Pickering interfacial catalysts (PICs) with similar surface affinities but diferent densities were constructed as stabilizers of a soybean oil/methanol emulsion. The variations in the emulsion volume fraction and viewpoint of droplet settling and catalyst particle shedding. It is found that, expect for surface affinity, PIC density also plays a pivotal role in emulsion stability owing to the non-negligible effect of gravity on catalyst adsorption in triglyceride/methanol emulsion (especially at elevated temperature ). By reducing the density, finely improving the lipophilicity, and optimizing the addition amount of PIC, the obtained soybean oil/methanol emulsion can remain stable for at least 12h at 60℃, enabling static transesterification with a high biodiesel yield of 95.6%. Moreover, the best performing PIC can be reused for at least 7 cycles. This efficient static transesterification system offers a green strategy for biodiesel production.
DOI: 10.1021/acsomega.1c00629
浙江省自然科學基金項目(LY18B040004)和中國博士后科學基金項目(2020M671790)資助。