The traditional distillation method for recovery of butanol from fermentation broth is an energy-intensive process. Separation of butanol based on adsorption methodology has advantages in terms of biocompatibility and stability, as well as economy, and therefore gains much attention. However, the application of the commercial adsorbents in the integrated acetone-butanol-ethanol (ABE) fermentation process is restricted due to the low recovery (less than 85%) and the weak capability of enrichment in the eluent (3-4 times). In this study, we investigated the sorption properties of butanol onto three kinds of adsorbents with different polarities developed in our laboratory, that is, XD-41, H-511, and KA-I resin. The sorption behaviors of single component and ABE ternary mixtures presented in the fermentation broths on KA-I resin were investigated. KA-I resin had higher affinity for butanol than for acetone, ethanol, glucose, acetic acid, and butyric acid. Multicomponent ABE sorption on KA-I resin was modeled using a single site extended Langmuir isotherm model. In a desorption study, all the adsorbed components were desorbed in one bed volume of methanol, and the recovery of butanol from KA-I resin was 99.7%. The concentration of butanol in the eluent was increased by a factor of 6.13. In addition, KA-I resin was successfully regenerated by two bed volumes of water. Because of its quick sorption, high sorption capacity, low cost, and ease of desorption and regeneration, KA-I resin exhibits good potential for compatibility with future ABE fermentation coupled with in situ recovery product removal techniques.

Polyamide 56 is regarded as one of the most promising materials for the textile industry. This report gives the crystallization route of high-quality polyamide 56 monomers, and its crystal structure, transformation behaviors, and solubility.

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The solubility of adenosine 3′,5′-cyclic monophosphate sodium (cAMPNa) in mixed solvents (water+ethanol, water+methanol, and water+acetone) was measured within 293.15−313.15 K under atmospheric pressure. The (CNIBS)/ Redlich−Kister model and the modified Apelblat equation were respectively applied to correlate the solubility data to evaluate the effect of the compositional ratio of the organic solvent and the temperature on the solubility in binary solvents, and satisfactory simulation results were obtained. The solubility of cAMPNa was maximal in pure water and markedly diminished at all evaluated temperatures as the mole fraction of the organic solvent in the aqueous mixture increased. The thermodynamic functions for cAMPNa dissolution in the three solvent mixtures were obtained from the solubility data using the van't Hoff and Gibbs equations, and the dissolution behavior was discussed. Dissolution of cAMPNa was endothermic and nonspontaneous in all cases, and the enthalpy was the major contributing force to the Gibbs energy.

Separation of butanol based on sorption methodology from acetone-butanol-ethanol (ABE) fermentation broth has advantages in terms of biocompatibility and stability, as well as economy, and therefore gains much attention. In this work a chromatographic column model based on the solid film linear driving force approach and the competitive Langmuir isotherm equations was used to predict the competitive sorption behaviors of ABE single, binary, and ternary mixture. It was observed that the outlet concentration of weaker retained components exceeded the inlet concentration, which is an evidence of competitive adsorption. Butanol, the strongest retained component, could replace ethanol almost completely and also most of acetone. In the end of this work, the proposed model was validated by comparison of the experimental and predicted ABE ternary breakthrough curves using the real ABE fermentation broth as a feed solution.