Yeon Ki Hong

Selective extraction of succinic acid from binary mixture of succinic acid and acetic acid

In production of succinic acid by fermentation, succinic acid and acetic acid are co-produced. To purify the succinic acid from binary-acid mixture of succinic acid and acetic acid, the tertiary amine-based extraction was used. In 1-octanol, the selectivity for succinic acid was proportional to the chain length of tertiary amine. But, the distribution of acids into organic phase was low in n-heptane. These results are due to the different degree of intramolecular hydrogen bonding of succinic acid and hydrophobicity of each acid.

Bioprocessing aspects of fuels and chemicals from biomass

This review deals with a recent development of biofuels and chemicals from biomass. Some of the grainbased biofuels and chemicals have already been in commercial operation, including fuel ethanol, biodiesel, 1.3-propanediol, polylactic acid (PLA) and polyhydroxy butyric acid/alkanoates (PHB/PHA). The next generation bioproducts will be based on lignocellulosics due to their abundance and to stabilize rising food prices. However, the technologies of handling biomass are yet in their infancy and suffer from low yield, low product titer, and low productivity. This review focuses on bioprocessing technologies for biofuels production: organic raw biomaterials available in Korea; volatile fatty acids platform, multi-stage continuous high cell density culture (MSC-HCDC), enrichment of fermentation broth by forward osmosis; various purification methods of pervaporation of ethanol, solvent extraction on succinic, lactic acids and reactive separation methods.

Reactive extraction of lactic acid with mixed tertiary amine extractants

The mixture of tripropylamine (TPA) and trioctylamine (TOA) dissolved in 1-octanol/n-heptane was used in the reactive extraction of (L+)lactic acid in aqueous solution. Maximum distribution coefficients were obtained in the range from 6:4 to 8:2 weight ratio of TPA/TOA at 5% (w/w) lactic acid in aqueous phase and their extraction efficiencies were above 90%. By introducing TPA into TOA, the third phase formation could be overcome, thereby, the settling time is shorter than in the case of TOA only.

Separation Characteristics of Lactic Acid in Reactive Extraction and Stripping

Lactic acid has recently been drawing much interest as a raw material for biodegradable polymer. Various extractants for lactic acid separation were tested and TOA (trioctylamine) was found the most effective one. Lactic acid was separated by reactive extraction with TOA dissolved in various diluents. The effect of temperature on the extraction efficiency was smaller than that of composition for the system studied in this work.

Removal of bovine serum albumin using solid-phase extraction with in-situ polymerized stationary phase in a microfluidic device.

Serum albumin, one of the most abundant serum proteins, blocks the expression of other important biomarkers. The objective of this study is to remove serum albumin effectively by using solid-phase extraction (SPE) in microfluidic devices. Photo-polymerized adsorbent as a stationary phase of SPE was used to remove bovine serum albumin (BSA). The adsorption capacity was examined with the effect of pH and concentration in BSA solution, and adjustment of monomer concentration such as hydrophilic 2-acrylamido-2-methyl-1-propanesulfonic acid and acrylamide in the adsorbent. The effect of hydrophobic butyl methacylate on BSA adsorption was also studied. Selective removal in a bicomponent with BSA and bovine gamma-globulin was performed by adjusting the pH as required.

Effect of pH on the extraction characteristics of succinic and formic acids with Tri-n-octylamine dissolved in 1-octanol

A study was made on the extraction equilibria of succinic and formic acids from aqueous solutions using tri-n-octylamine (TOA) in 1-octanol. It was shown that the loading values of TOA decreased with increasing pH values. The apparent equilibrium constants for each acid-amine complex were determined by an equilibrium model. In the case of succinic acid, the formation of a bisuccinate anion played an important role in the stoichiometry of the acid-amine complex.

Water Enhanced Solubilities of Succinic Acid in Reactive Extraction Using Tertiary Amines/Alcohols Systems

Tertiary amines were used as the extradants for reactive extraction in alcohol diluents. Equilibrium and hydration data for various alcohol diluents and tertiary amines were obtained. From these data, the effect of coextracted water on extractability was investigated. For the measurement of the water-enhanced solubilities of succinic acid, the sensitivity index was introduced. The amount of coextracted water into organic phase was increased with the chain length of alcohol diluents. However, the water-enhanced solubility of succinic acid was almost constant with the chain length of alcohol diluents. The sensitivity indices were proportional to the chain length of tertiary amines; thus, the water-enhanced solubilities of succinic acid were increased.

Kinetics of the Extraction of Succinic Acid with Tri-n-octylamine in 1-Octanol Solution

Kinetic studies for the extraction of succinic acid from aqueous solution with 1‐octanol solutions of tri‐n‐octylamine (TOA) were carried out using a stirred cell with a microporous hydrophobic membrane. The interfacial concentrations of species were correlated and thus the intrinsic kinetics was obtained. The overall extraction process was controlled by the chemical reaction at or near the interface between the aqueous and organic phases. The formation reaction of succinic acid‐TOA complex was found to be first order with respect to the concentration of succinic acid in the aqueous phase and the order of 0.5 with respect to that of TOA in the organic phase with a rate constant of (3.14 ± 0.6) × 10−8 m2.5·mol−0.5·s−1. The dissociation reaction of succinic acid‐TOA complex was found to be the second‐order with respect to that of succinic acid‐TOA complex in the organic phase and the order of –2 with respect to that of TOA in the organic phase with a rate constant of (1.44 ± 1.4) × 10−4 mol·m−2·s−1.

Influence of chain length of tertiary amines on extractability and chemical interactions in reactive extraction of succinic acid

Reactive extraction of succinic acid from aqueous solutions with various tertiary amines dissolved in 1-octanol and in n-heptane has been studied as a function of the chain length of the tertiary amine. In the tertiary amine extractants in 1-octanol, the extractabilities of tertiary amines were proportional to their chain length. But, in n-heptane, the extractabilities of tertiary amines decreased with their chain length. In order to analyze chemical interactions involved in the complexation of succinic acid with amine extractants in 1-octanol and n-heptane, infrared (IR) spectroscopy was used. From IR spectroscopy, it was found that the difference of extractability in 1-octanol and in n-heptane was mainly due to the different degree of intramolecular hydrogen bonding of succinic acid with the polarity of diluents. And the possible stoichiometry of acid-amine-diluent complex was predicted as (1,1), (2,1), (1,1,1).

Effect of salts on the extraction characteristics of succinic acid by predispersed solvent extraction

Predispersed solvent extraction (PDSE) of succinic acid with Tri-n-octylamine (TOA) dissolved in 1-octanol from aqueous solutions of 50 g/L succinic acid was examined. It was found that the equilibrium data in PDSE was equal to that in conventional solvent extraction in spite of the lack of mechanical mixing in PDSE. The influence of salts on succinic acid extraction and the stability of colloidal liquid aphrons (CLAs) were also investigated. Results indicated that in the presence of sodium chloride, less succinic acid was extracted by CLAs and the stability of CLAs decreased. However, the stability of CLAs was sufficient to make PDSE practically applicable to real fermentation broth, considering the concentration range of salts in the fermentation process for succinic acid.