Downstream processing of 1,3‐propanediol fermentation broth

Abstract

The downstream processing of 1,3-propanediol fermentation broth using flocculation, reactive extraction, and reactive distillation was studied. Cellular debris and soluble protein in the broth were flocculated by combined use of chitosan and polyacrylamide at optimal concentrations of 150 ppm and 70 ppm, respectively; the soluble protein in the broth decreased to 0.06 g L −1 , and the recovery ratio of the supernatant liquor to broth was greater than 99%. 1,3-Propanediol and other alcohols were extracted from the supernatant liquor by reacting with butyraldehyde. In a four-stage countercurrent extraction with the volume ratio of the extraction solvent to the aqueous phase being 20:100, more than 99% 1,3-propanediol acetal (2-propyl-1,3-dioxane) and 2,3-butanediol acetal (2-propyl-4,5-dimethyl-1,3-dioxolane) were recovered from the aqueous phase; 35% of the glycerol acetals were recovered. The acetals produced were hydrolyzed in a reactive distillation column using the strongly acidic cation-exchange resin as catalyst, the bottom product obtained was a mixture of 1,3-propanediol (407 g L −1 ), 2,3-butanediol (252 g L −1 ), glycerol (277 g L −1 ), and glycerol acetals (146 g L −1 ).

Microbial 1,3-Propanediol, Its Copolymerization with Terephthalate, and Applications

“…Chitosan and polyacrylamide have been tested for this purpose. By combined use of chitosan and polyacrylamide at optimal concentrations of 150 and 70 ppm, respectively, the soluble protein in the broth decreased to 0.06 g/L, and the recovery ratio of the supernatant liquor to the broth was greater than 99% (Hao et al 2006). The second step is the removal of impurities and primary separation of PDO from the fermentative broth.…”

Organic Chemicals from Bioprocesses in China

“…Chen et al studied 1,3-PDD fermentation with immobilized cells [40,41]. Scientists in Tsinghua University [42,43] and Dalian University of Technology [44] are working hard to develop new 1,3-PDD production lines in China. A group of scientists in Tsinghua University developed a two-step fermentation process to produce 1,3-PDD from low-grade starch such as cassava.…”

Reactive Extraction of 1,3-Propanediol with Aldehydes in the Presence of a Hydrophobic Acidic Ionic Liquid as a Catalyst

“…Pervaporation [4], extraction [5,10,14], reactive extraction [6][7][8][9]11,13,15,19,27], vacuum distillation [16], aqueous two phase extraction [12,17,18,20,[22][23][24][25][26] and adsorption [21] have been proposed as separation methods. Compared with other separation techniques, extraction is considered to possess several advantages, such as large throughput and low energy consumption.…”

“…However, in aqueous two-phase extraction, recovery of the product from the extracted phase is an issue that often arises. Alternatively, reactive extraction methods using a reversible reaction such as esterification with boronates [27] and acetalization with aldehydes in the presence of an acid catalyst, as shown in Scheme 1, [6][7][8][9]11,13,15,19] were proposed to selectively separate 1,3-propanediol. In our previous paper [27], reactive extraction with boronates gave a low partition coefficient due to poor reactivity.…”

“…Recently Boonoun et al [15] developed a low-cost sulfonated carbon-based catalyst. Furthermore, use of water-soluble catalysts such as sulfuric acid [9] 4 ], have been proposed. [30,32] If an oil-soluble acidic ionic liquid plays a catalytic role for acetalization, it may remain in the organic solution after the acetal products of 1,3-propanediol were removed by stripping or distillation from the organic solution and then may be reused as catalyst .…”