Abstract K3PO4, K2CO3, Na3PO4 and Na2CO3 performance in biodiesel production by transesterification reaction of rapeseed oil (RO), recovery, behavior in polar alcohols (methanol, glycerol) and air during storage were studied. The catalysts were characterized by N2 sorption analysis, XRF and FE-SEM. Potassium salts and NaOH used as reference have higher solubility in reaction mixture and activity on biodiesel production process, but significantly lower catalyst recovery and stability in air during storage than sodium salts. 88.2% of Na3PO4 and 87.3% of Na2CO3 initial amounts were recovered after transesterification process by developed method. Rest of Na2CO3 (11.8%) dissolved in crude glycerol can be extracted from its ashes. The effects of molar ratio of RO to methanol (1/5–1/14), reaction temperature (40–65 °C) and catalyst amount (1–7%) on Na3PO4 and Na2CO3 catalyzed transesterification were investigated. These salts can be reused up to second and fifth run without regeneration to reach >96% of rapeseed methyl ester (RME) content in biodiesel sample under recommended conditions.

中文翻译：

---

K 3 PO 4 、K 2 CO 3 、Na 3 PO 4 和Na 2 CO 3 作为可重复使用的碱性催化剂在生物柴油生产中的实际应用的潜力

摘要 研究了K3PO4、K2CO3、Na3PO4和Na2CO3在菜籽油（RO）酯交换反应生产生物柴油中的性能、回收率、在极性醇（甲醇、甘油）和空气中储存过程中的行为。通过 N2 吸附分析、XRF 和 FE-SEM 对催化剂进行表征。用作参考的钾盐和 NaOH 在反应混合物中具有更高的溶解度和对生物柴油生产过程的活性，但与钠盐相比，在储存过程中催化剂回收率和在空气中的稳定性显着降低。在酯交换过程后，通过开发的方法回收了 88.2% 的 Na3PO4 和 87.3% 的 Na2CO3 初始量。溶解在粗甘油中的剩余 Na2CO3 (11.8%) 可以从其灰烬中提取。RO与甲醇的摩尔比（1/5-1/14）的影响，对 Na3PO4 和 Na2CO3 催化的酯交换反应温度 (40–65 °C) 和催化剂用量 (1–7%) 进行了研究。在推荐的条件下，这些盐可以重复使用至第二次和第五次运行而无需再生，以达到生物柴油样品中油菜籽甲酯 (RME) 含量的 96% 以上。