Hoesch Membrane Filter Press Efficiency

[jp316]

Background: Fermentation process upstream yields extracellular product. Cool, add solvent, add filter aid, filter on MFP, wash cake with solvent (0.5 volume of feed) send filtrate to 2 stage evaporator, recover solvent in distillation column. send concentrate off evap to tank, heat, settle, decant bottoms to drain, top is product.

After solvent wash of MFP, cake is water washed (0.5 volume of feed) and squeezed with this filtrate skipping evap going straight to distillation column to recover solvent.

I am concerned about product loss in water wash / squeeze filtrate or in the cake.

Question? Is a 1:2 solvent wash / feed ratio common or is it backwards? I would think you would want to wash with more volume. What are some fundamental ideas about this ratio?

 

[jp316]

I just checked the specs and the solvent wash is 2.5 times the press volume so I may have answered my own question. We did have about 23% loss between fermentation and when we collected the concentrate from the evaporators so I am still trying to improve on that with better filtration techniques. Thanks.