Dear Syriac Palackal,

There exist several ways in which a product can be washed or extracted.

In the attached .pdf file I worked out the equations and a graph to calculate a multi-stage cross flow solid/liquid extraction (see attached .pdf file, including worked examples). In the presented multi-stage cross flow solid/liquid extraction, a mass of L kg of the product is washed (“extracted”) with a fixed mass V kg of solvent; the spent product then is drained to obtain the original mass of L kg and an extract 1 of V kg. The L kg spent solid is again washed with V kg of fresh solvent, drained, etc. This can be repeated N times; N = the number of extraction steps. Sometimes at the end all extracts are mixed to get a TOTAL extract, which will be very dilute.

I could also have worked out equations and a graph on a multi-stage counter current extraction.

Or even on a multi-stage counter current extraction in which the product increases in mass after the first extraction step.

If the multi-stage cross flow solid/liquid extraction attached was not what you asked for, could you please specify the required extraction (wash) process in more details?

Yours sincerely,

Janwillem Rouweler

[email protected]

At the link there is a description of the computation methods for solvent extraction.

http://www.google.it/url?sa=t&rct=j&q=&esrc=s&source=web&cd=6&cad=rja&uact=8&ved=0CEsQFjAF&url=http%3A%2F%2Fstudenti.di3.units.it%2FImpianti%2520chimici%2F02%2520Script%2520Extraction.pdf&ei=Wj1uVIu-AYeqywO5nYFI&usg=AFQjCNHA_bncYGbbTpeyPGIDUZFj78P4aQ&bvm=bv.80185997,d.bGQ

Dear Janwillem Rouweler and Guido Sassi,

I really appreciate that you both provided lot of detailed the information on extraction. As this is a new filed for me, I had no idea where to start. Your information will help me to get started.

Best regards,

Syriac

Dear Syriac Palackal,

Thank you for your feedback.

In addition to my previous contribution of 6 days ago, I now also have included equations and worked examples regarding washing/extraction/leaching for products which increase in mass during extraction. This is frequently the case with dried foods such as tea leaves, ground coffee, etc. By the simple soaking action to increase the mass (swelling) prior to the first extraction step, all Kremser equations and graph can be applied, assuming that the swollen mass of the product is the mass to be extracted.

Best wishes with your reserach,

Janwillem Rouweler

[email protected]

Dear Syriac Palackal,

Following my reply of November 18, and November 25, 2014 regarding calculation of cascade/washing extractions, I put the Kremser calculation approach in 2 different Excel spreadsheets. Both can be downloaded from my Researchgate page:

"Multi-stage CROSS FLOW extraction-leaching-washing of non-swelling or pre-soaked solids, calculated by Kremser's rapid estimation equations.xlsx"

and

"Multi-stage COUNTER CURRENT extraction-leaching-washing of non-swelling or pre-soaked solids, calculated by Kremser's rapid estimation equations.xlsx".

I have outlined the restrictions in the use of the Excel spreadsheets: to be used only for non-swelling products, or for pre-soaked products. Both Excel documents list the Kremser theory and show the Kremser graphs. To each spreadsheet I added some 5 worked examples: the answers are found by the Kremser Excel sections, by calculations with the Kremser graphs, and by manual calculations with the Kremser equations 

Best wishes with your research,

Janwillem Rouweler

[email protected]