Chemical Engineering Department, Institute of Chemical Technology, Matunga, Mumbai 400019, India.
Chemical Engineering Department, Institute of Chemical Technology, Matunga, Mumbai 400019, India.
Ultrason Sonochem. 2017 May;36:309-318. doi: 10.1016/j.ultsonch.2016.11.040. Epub 2016 Dec 1.
Using sustainable feed stock such as non-edible oil for the biodiesel production can be one of the cost effective approaches considering the ever growing interest towards renewable energy and problems in existing approaches for production. However, due to the high free fatty acid content, non-edible oils require considerable preprocessing before the actual transesterification reaction for biodiesel production. The present work focuses on intensification of the esterification reaction used as preprocessing step based on acoustic and hydrodynamic cavitation also presenting the comparison with the conventional approach. Karanja oil with initial acid value as 14.15mg of KOH/g of oil has been used as a sustainable feedstock. Effect of operating parameters such as molar ratio, catalyst loading, temperature and type of catalyst (sulfuric acid and Amberlyst-15) on the acid value reduction has been investigated. The maximum reduction in the acid value (final acid value as 2.7mg of KOH/g of oil) was obtained using acoustic cavitation at optimum molar ratio of oil to methanol as 1:5 and 2% sulfuric acid loading at ambient temperature. In the case of hydrodynamic cavitation, acid value reduced upto 4.2mg of KOH under optimized conditions of first stage processing. In the second stage esterification using hydrodynamic cavitation and conventional approach, the final acid value was 3.6 and 3.8mg of KOH/g of oil respectively. Energy requirement analysis for ultrasound and conventional approaches clearly established the superiority of the ultrasound based approach. The present study clearly demonstrated that significant intensification benefits can be obtained in terms of the reduction in the molar ratio and operating temperature for the case of acoustic cavitation as compared to the conventional approach with somewhat lower effects for the hydrodynamic cavitation.
使用可持续的原料，如非食用油脂，来生产生物柴油，考虑到人们对可再生能源日益增长的兴趣和现有生产方法存在的问题，这可能是一种具有成本效益的方法。然而，由于非食用油脂的游离脂肪酸含量较高，在进行实际的酯交换反应生产生物柴油之前，需要进行相当多的预处理。本工作基于声空化和空化水力旋流，集中研究了作为预处理步骤的酯化反应的强化，同时也对其与传统方法进行了比较。以初始酸值为 14.15mg KOH/g 油的麻疯树油为可持续原料。考察了操作参数（如摩尔比、催化剂用量、温度和催化剂类型（硫酸和 Amberlyst-15））对酸值降低的影响。在最佳摩尔比为油：甲醇=1:5，环境温度下硫酸用量为 2%的条件下，采用声空化可使酸值最大降低（最终酸值为 2.7mg KOH/g 油）。在空化水力旋流的情况下，在第一级处理的最佳条件下，酸值降低到 4.2mg KOH。在第二级酯化反应中，采用空化水力旋流和传统方法，最终酸值分别为 3.6mg 和 3.8mg KOH/g 油。超声和传统方法的能量需求分析清楚地确立了基于超声的方法的优越性。本研究清楚地表明，与传统方法相比，在声空化的情况下，酯化反应的摩尔比和操作温度都可以显著降低，而空化水力旋流的效果略低。
