Sonochemically enhanced extraction

Increased efficiency in extraction leads directly to a reduction in material wastage and power ultrasound has been shown to improve systems as diverse as coal slurry benefication on a tonne scale to medicinal compound extraction from plant materials. The classical techniques for extraction are mainly liquid-solid extraction by means of steam and/or organic solvents. All such techniques use relatively high temperatures and thus the energy consumption is very high and decomposition of some compounds may also occur. The use of ultrasound avoids these high temperatures and can result in enhanced component extraction at lower temperatures and in a faster time. 

Chendke and Fogler [59] examined the rate of ultrasonic extraction of sugar from sugar beets and discovered that the disruption of cells via cavitation enhanced the release of cell contents into the bulk medium. This combined with enhanced mass transfer, due to the effects of microstreaming, resulted in a more efficient method for sugar extraction. 

Another example is to be found in the extraction of tea solids from dried leaves using water under the influence of ultrasound [60]. Sonication improved the extraction at 60°C by nearly 20%, close to the efficiency of that of conventional thermal extraction at 100°C. 

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