Example 1
Fermentation/Concentration
In some embodiments, whey permeate, concentrated permeate, and/or ultrafiltration permeate is pasteurized and then fermented with Lactic acid bacteria for 20 to 30 hours at 10-130° F. with injection of NH4(OH) to maintain pH at 5.5 to 5.6 during fermentation. The resulting fermented liquid is concentrated by mechanical vapor recompression (MVR) to achieve a solids content of about 58%-64%. The concentrated fermented liquid is then sent to a pH balance tank where it is injected with NH4(OH) to achieve a pH of about 6.5 to 6.7.
Crystallization
The concentrated fermented liquid is then sent to a plate heat exchanger (PHE) to bring the temperature of the liquid to about 130° F. The concentrated fermented liquid is then sent to a crystallization tank where the concentrated fermented liquid is agitated and allowed to cool to about 110° F. to 115° F., during which crystal formation occurs. In some embodiments, once the temperature of the concentrated fermented liquid reaches about 90° F. to 115° F. the concentrated fermented liquid is sent to a decanter centrifuge to separate the solid crystals from the liquid. Across 12 fermentation batches from production, the average yield of solid crystals was 1,744 lb.
Across multiple processing trials the following crystal yields were achieved:
Example 2
Fermentation/Concentration
In some embodiments, whey permeate, concentrated permeate, and/or ultrafiltration permeate is pasteurized and then fermented with Lactic acid bacteria for 20 to 30 hours at 100-120° F. with injection of NH4(OH) to maintain pH at 5.5 to 5.6. The resulting fermented liquid is concentrated by mechanical vapor recompression (MVR) to achieve a solids content of about 61%-64%.
Crystallization
The concentrated fermented liquid is then sent directly to a crystallizer tank with continuous agitation. In this example, the liquid is not sent to pH balance tank or chiller plate heat exchanger. To achieve higher crystal yield, a 3000 (w/w) CaOH slurry is added to the concentrated fermented liquid in the crystallization tank to achieve a calcium concentration of 0.9-2.0% (w/w) in the combined mixture. The CaOH slurry is added to the concentrated fermented liquid in the crystallizer tank slowly to allow thorough mixing. The mixture is then allowed to stand in the crystallization tank for 6 to 18 hours, during which time the temperature is allowed to cool to about 90 to 115° F. and crystals are formed. Once the temperature of the concentrated fermented liquid reaches about 90 to 115° F. the concentrated fermented liquid is sent to a decanter to separate the solid crystals from the liquid.
Across multiple processing trials the following crystal yields were achieved with a calcium concentration of 3.33% (non-seeded data from Example 1 is included for comparison):
