Abstract
The purpose of this study is to convert carboxylate salts (e.g. calcium acetate, propionate, and butyrate) into carboxylic acids (e.g., acetic, propionic, and butyric acids). The carboxylate salts can be produced from wastes, such as paper fines, municipal solid wastes, sewage sludge, and industrial biosludge. Using a proprietary technology owned by Texas A&M University the wastes are first treated with lime to enhance reactivity. Then they are converted to calcium carboxylate salts using a mixed culture of microorganisms derived from cattle rumen or anaerobic waste treatment facilities. The paper fines and municipal solid waste provide energy, whereas the industrial biosludge and sewage sludge provide nutrients for the microorganisms. The calcium carboxylate salts are concentrated and reacted with a low-molecular-weight tertiary amine and carbon dioxide to precipitate calcium carbonate. In a distillation column, the low-molecular-weight amine carboxylate reacts with a high-molecular-weight tertiary amine allowing the low-molecular-weight amine to be recovered from the top of the column. The resulting high-molecular-weight amine carboxylate is converted to amine and carboxylic acid in a reactive distillation column. This project focuses on the conversion of the carboxylate salts produced via fermentation into their corresponding acids via reactive distillation. The primary objective is to determine the optimal operating conditions of the distillation. A secondary objective is to optimize the precipitation step in the recovery process.
Williamson, Shelly Ann (2000). Conversion of carboxylate salts to carboxylic acids via reactive distillation. Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -2000 -THESIS -W3543.