We have optimized the extraction some phytochemicals in laboratory scale.How can I contend that our optimization should work at a larger scale?
What are the factors or aspects influence the difference in the productivity and selectivity of phyochemical extraction in laboratory scale compared to the same in industrial scale?
Dear Mahesha
I do not have experience in this field, but my phytochemistry friends who developed bench-scale laboratory technologies for a number of medicinal and aromatic plants' products informed me that scaling up of technologies requires fine-tuning of almost all the process parameters based on the scale of up-gradation i.e. if it is 10 kg to 100 kg to 1000 kg to 10000 kg the process parameters need to be reworked.
I have experience of eight series of 0.5 kg - 5 kg laboratory-pilot technological scaling and I concluded that the extraction of the vegetal materials at the pilot level may also be less effective as more effective than the extraction at the laboratory level, the final products generaly being in limit of (+ / -) 5 -10 % (w/w) active compounds. Also, I have observed that the extraction at the pilot level is less efective in terms of polysaccharides content/extraction and more effective as concerning polyphenols level/extraction.
In laboratory scale extraction or fractionation of extracts one can use solvents such as acetone or hexane with relatively few problems. Someone once said that a spark in a laboratory can become an explosion in a pilot plant and a catastrophe in a factory. Even if acetone is a much better extractant than ethanol for many of our applications, the cost of protecting a factory against explosions may make it worthwhile to use a safer extractant even if it is less efficient.
We once applied a novel extraction system to yield a grape seed extract with very high antioxidant activity. When the process was licensed and applied in a factory, the activity was very disappointing until we brought a vacuum oven into the process. Drying the final product under a vacuum reduced oxidative changes by air oxygen tremendously and yielded a product that was marketed by a big pharmaceutical company.
For laboratory scaling you can adopt and use any methods that shows an yield and quality of product up to 90%, but for laboratory-pilot technological scaling one should need a method that can show both values above 99%. Further in laboratory one can do work with 500 mg-1 gm of phytoconstituent but for laboratory scaling product is synthesized from kgs to tonnes in weight. That is only possible by technological development and higher scaling of project, market value and production cost and taxes. Hence, material should be row and low cost. Technology may be the best one to enhance the quality of the product.
Dear Mahesha,
That depends very much on the technology you are using for extraction. For example, in supercritical fluid extraction, yield tends to be higher at pilot and industrial scales than at lab scale.
If you are using ultrasounds, it is difficult to make the waves reach all the extractor at industrial scale, and thus the yield decreases.
If you tell me the type of extraction you are using maybe I can help you.
You can find some extra information in the book: Natural product extraction: principles and applications, by RSC.
Dear Dr. Ravi and Dr. Juliana, thanks for your valuable suggestions.
@ Dr. Juliana, I am extraction carotenoids from vegetables.
Dear Mahesha,
What kind of technique are you using (low pressure, high pressure, ultrasounds, microwave)?
It is just solvent extraction at room temperature. I am not using other extreme conditions so as to minimize degradation.
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