Ultrasound Assisted Solid-Liquid Extraction Devices - Harnessing Active Ingredients from Plant materials – Overview and Analysis

Background: In the growing environmental concern use of natural products, efficient processes and devices are necessary. Solid-Liquid extraction of active Ingredients from Plant materials is one of the important unit operations in Chemical Engineering and need to be enhanced. Objectives: Since, these active ingredients are firmly bound to the plant cell wall membrane, which pose mass-transfer resistance and need to get detached through the use of suitable process intensification tools such as ultrasound and suitable devices. Therefore, detailed analysis and review is essential on development made in this area through Publications and Patents. Hence, the present paper illustrates the development of ultrasound assisted device for solid-liquid extraction are presented in this paper. Methods: Advantages such as % Yield, Reduction in extraction time, use of ambient conditions, better process control, avoidance or minimizing multi stage extraction could be achieved due to the use of ultrasound in extraction as compared to conventional processes. Conclusions: Use of ultrasound to provide significant improvements in the extraction of Vegetable tannins, Natural dyes for application in Leather processing has been demonstrated and reported earlier. These enhancement could be possible through various effects of ultrasound such as better flow of solvents through micro-jet formation, mass transfer enhancement due to rupture of plant cell wall membranes through acoustic cavitation, better leaching due to micro-mixing and acoustic streaming effects. This approach would minimize material wastage; thereby, leading to eco-conservation of plant materials, which is very much essential for better environment. Hence, various methods and design for application of ultrasound assisted solid-liquid extractor device are necessary.