The mutual solubilities of multiple components in the transesterification reaction are among the key factors affecting biodiesel production. In the experiments, refined palm oil (RPO) and fatty acid methyl ester (FAME) were the main reactants, and methanol was added. Sodium methoxide and sulfuric acid were used as alkaline and acid catalysts, respectively. The co-solvent, tetrahydrofuran (THF), was used to improve solubility. Visual observations with an LCD digital microscope were done at room temperature to eliminate methanol loss. A concave slide glass was employed as a micro-reactor for observing mass transport in the reaction zone. The imaging results showed that the multi-component reactions in biodiesel production were of heterogeneous liquid-liquid type. The by-products glycerol and soap play significant roles as reaction barrier and suspension component in the system, while the added THF did not induce complete solubility. The kinetics of heterogeneous liquid-liquid transesterification or esterification reactions should be revised to properly account for both mass transfer and chemical reactions. Multistage combinations of separation of the alcohol phase and of new alcohol intake should be employed to reduce mass transfer resistances by glycerol and soap, to speed up overall kinetics.

酯交换反应中多种组分的互溶性是影响生物柴油生产的关键因素之一。在实验中，精炼棕榈油（RPO）和脂肪酸甲酯（FAME）是主要反应物，并添加了甲醇。甲醇钠和硫酸分别用作碱性和酸性催化剂。助溶剂四氢呋喃（THF）用于提高溶解度。在室温下使用LCD数字显微镜进行目视观察，以消除甲醇损失。使用凹面载玻片作为微反应器，以观察反应区中的传质。成像结果表明，生物柴油生产中的多组分反应是异质液-液型的。副产物甘油和肥皂在系统中作为反应屏障和悬浮液组分起着重要作用，而添加的THF则不会引起完全溶解。应当修改异质液-液酯交换或酯化反应的动力学，以适当考虑传质和化学反应。应当采用分离醇相和新引入醇的多级组合，以减少甘油和肥皂对传质的阻力，以加快整体动力学。