US 12,281,346 B2
Advanced anaerobic digestion to carboxylic acids
Violeta Sanchez Nogue, Manlleu (ES); Eric M. Karp, Denver, CO (US); Patrick Owen Saboe, Golden, CO (US); Lucas Hans Loetscher, Broomfield, CO (US); and Sybil Sharvelle, Fort Collins, CO (US)
Assigned to Alliance for Sustainable Energy, LLC, Golden, CO (US); and Colorado State University Research Foundation, Fort Collins, CO (US)
Filed by Alliance for Sustainable Energy, LLC, Golden, CO (US); and Colorado State University Research Foundation, Fort Collins, CO (US)
Filed on May 3, 2021, as Appl. No. 17/306,251.
Claims priority of provisional application 63/020,598, filed on May 6, 2020.
Prior Publication US 2021/0348201 A1, Nov. 11, 2021
Int. Cl. C12P 7/40 (2006.01); B01D 61/24 (2006.01); B01D 63/02 (2006.01); B01D 71/26 (2006.01); C12P 7/52 (2006.01); C12P 7/54 (2006.01); C12P 39/00 (2006.01)
CPC C12P 7/40 (2013.01) [B01D 61/2461 (2022.08); B01D 63/02 (2013.01); B01D 71/261 (2022.08); B01D 71/262 (2022.08); C12P 7/52 (2013.01); C12P 7/54 (2013.01); C12P 39/00 (2013.01)] 15 Claims
 
1. A method comprising:
converting, utilizing a microorganism, a substrate into a carboxylic acid contained in a fermentation stream comprising the carboxylic acid, water, and solids;
removing the solids from the fermentation stream to form a substantially solids-free permeate comprising the carboxylic acid and water;
treating the permeate with a first stream comprising a phosphine oxide by directing the permeate to a first side of a membrane having a thickness defined by a first side and a second side, and directing the first stream to the second side of the membrane; and
maintaining a pH of the permeate between greater than 2.5 and less than 5 without the addition of an acid or a base; wherein:
a concentration of the solids in the fermentation stream is between greater than 12 wt % and less than or equal to 30 wt %,
the removing is performed using a rotating ceramic disk filter,
the treating is performed using a volumetric ratio of the permeate to the first stream between 1:100 and 1:10,
the carboxylic acid is present as a water-soluble species in the permeate,
the treating results in the transferring of the carboxylic acid from the permeate, through the membrane thickness, to the first stream,
the transferring results in the maintaining of the pH range,
the treating results in the forming of a water stream and a second stream comprising the phosphine oxide and the carboxylic acid, and
the membrane is not a hollow fiber membrane.