Recovery of Organic Acids From Fermentation Broths
Recovery of Organic Acids From Fermentation Broths
Recovery of Organic Acids From Fermentation Broths
Fermentation Broths
O O O
RCR RCOH RCOR
Organic Ester
Ketone
Acid
O
RCH RCH2OH R CH2
Aldehyde Alcohol Olefin
C2 Platform
O O O
CH3CCH3 CH3COH CH3COCH2CH3
Acetone Acetic Ethyl
Acid Acetate
O
CH3CH CH3CH2OH CH2 CH2
Acetaldehdye Ethanol Ethylene
Issues in Recovery
pH of Broth
Unreactive Species at Near Neutral pH
Commodity Scale Production is Constrained by
Need to Avoid Salt Coproduction
Dilute Broths
Evaporating Water is Expensive
Prefer Selective Methods for Removing
Organic Acids from Water
Effect of pH
O O
CH3COH CH3CO- + H+
Protonated Dissociated
Acid Acid
100
90
80 pKa = 4.75
70
% Dissociation
60
30
20
10
0
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
pH
Acidic Basic
Neutral
pH Options
Low pH Fermentation
Neutral pH Fermentation
Direct Acidification
Amine Complex Formation
Other
Bipolar Electrodialysis
Esterases
Lactic Acid - Traditional
Alcohol
Water
Sulfuric Hydrolysis
Ester
Lime Acid
Lactic
Acid
Fermentation Direct Esterification
Sugars Acidification
Water
Gypsum
Direct Acidification
Sulfuric
Acid Water
Calcium
Citrate
Gypsum
Citric Acid Amine Extraction
Water
Water
Forward Extraction
Back Extraction
Sugars Fermentation Crystallization Citric
Acid
Residue
Formic Acid
Water
CO Formic
Carbonylation Methyl Formate Hydrolysis Acid
Methanol
Methanol
O
Carbonylation: CO + CH3OH HCOCH3
O O
Hydrolysis: HCOCH3 + H2 O HCOH
O
Net: CO + H2O HCOH
Some Common Themes
Eliminating Salt Coproduction is Difficult
Microbiology
Careful Selection of Cations and Recovery
Scheme
Direct Fermentation
Dextrose 2 Ethanol + 2 CO2
Lab Status - Fermentation
Batch Results
First Run: 28 g/l acetate
Goal: 35-50 g/l acetate, yield = 85+% of theoretical
Lab Status - Recovery
Lab Scale
Amine Complex Formation
w/ CaCO3 Precipitation
Extraction of Amine
Complex
Esterification
Results to Date
97+% CaCO3 Recovery
Excellent Extraction
(KD > 2)
Ester Yield: 75% of
Theoretical
Conclusions
Technical Issues
pH and Avoidance of Salt Coproduction
Dilute Broths