Kelkar Mandar A, Gogate Parag R, Pandit Aniruddha B
Chemical Engineering Department, Institute of Chemical Technology, University of Mumbai, Matunga, Mumbai 400 019, India.
Ultrason Sonochem. 2008 Mar;15(3):188-94. doi: 10.1016/j.ultsonch.2007.04.003. Epub 2007 Apr 29.
Cavitation results in conditions of turbulence and liquid circulation in the reactor which can aid in eliminating mass transfer resistances. The present work illustrates the use of cavitation for intensification of biodiesel synthesis (esterification) reaction, which is mass transfer limited reaction considering the immiscible nature of the reactants, i.e., fatty acids and alcohol. Esterification of fatty acid (FA) odour cut (C(8)-C(10)) with methanol in the presence of concentrated H(2)SO(4) as a catalyst has been studied in hydrodynamic cavitation reactor as well as in the sonochemical reactor. The different reaction operating parameters such as molar ratio of acid to alcohol, catalyst quantity have been optimized under acoustic as well as hydrodynamic cavitating conditions in addition to the optimization of the geometry of the orifice plate in the case of hydrodynamic cavitation reactors. Few experiments have also been carried out with other acid (lower and higher)/methanol combination viz. caprylic acid and capric acids with methanol with an aim of investigating the efficacy of cavitation for giving the desired yields and also to quantify the degree of process intensification that can be achieved using the same. It has been observed that ambient operating conditions of temperature and pressure and reaction times of <3h, for all the different combinations of acid (lower and higher)/methanol studied in the present work, was sufficient for giving >90% conversion (mol%). This clearly establishes the efficacy of cavitation as an excellent way to achieve process intensification of the biodiesel synthesis process.
空化作用会在反应器中产生湍流和液体循环，有助于消除传质阻力。本研究阐述了利用空化作用强化生物柴油合成（酯化）反应，鉴于反应物脂肪酸和醇互不相溶的性质，该反应受传质限制。在浓硫酸作为催化剂的情况下，研究了在流体动力空化反应器以及声化学反应器中脂肪酸（FA）气味馏分（C(8)-C(10)）与甲醇的酯化反应。除了在流体动力空化反应器中对孔板几何形状进行优化外，还在声学和流体动力空化条件下对酸与醇的摩尔比、催化剂用量等不同反应操作参数进行了优化。还对其他酸（低级和高级）/甲醇组合，即辛酸和癸酸与甲醇进行了一些实验，目的是研究空化作用在获得所需产率方面的效果，并量化使用空化作用可实现的过程强化程度。据观察，对于本研究中所研究的所有不同酸（低级和高级）/甲醇组合，在温度和压力的环境操作条件以及反应时间<3小时的情况下，足以实现>90%的转化率（摩尔%）。这清楚地证明了空化作用作为实现生物柴油合成过程强化的一种极佳方式的有效性。
