Evaluation of a Prototype for Electrochemical pH-Shift Crystallization of Succinic Acid

Abstract

Downstream processing of biotechnologically produced carboxylic acids, such as succinic acid, poses environmental and economic challenges. Conventional downstream processes cause large amounts of waste salts, which have to be purified or disposed of. Therefore, lean and waste-free downstream processes are necessary for the biotechnological production of succinic acid. Electrochemical downstream processes gain especially significant attention due to low chemical consumption and waste reduction. This work presents the pH-dependent solid-liquid equilibrium of succinic acid, a prototype for electrochemical pH-shift crystallization processes, and its characterization. Based on the supersaturation, energy consumption, and electrochemical protonation efficiency the proposed electrochemical pH-shift crystallization is evaluated. This evaluation highlights the potential of the proposed electrochemical crystallization processes as waste-free and economically attractive processes for bio-based succinic acid production.

From Microbial Succinic Acid Production to Polybutylene Bio‐Succinate Synthesis

“…The final concentration was measured to be 620 mmol L -1 bio-SA, which resulted in 9.9 g of crystalline bio-SA and a theoretical yield of 31 %. The pH in the cathode was increased from 2 to 13.8 and thus, could be used for pH buffering of fermentation, as discussed by Kocks et al [39]. To further improve the yield, additional process steps to increase the concentration of the bio-SA like reactive extraction [18,40] or evaporation [41] have to be applied.…”