Jiawen Zhu

Synthesis of Epichlorohydrin from Dichloropropanols: Kinetic Aspects of the Process

The reactions involved in the industrial production of epichlorohydrin from dichloropropanols (DCP, including 1,3-dichloro-2-propanol and 2-3-dichloro-1-propanlol) have been kinetically investigated. The kinetics of dehydrochlorination of DCP has been studied in the presence of caustic soda, by potentiometric techniques. The kinetic parameters of the reactions have been determined. The epichlorohydrin hydrolysis has been studied by measuring the decrease of the reagents during the time using titration. The whole study indicate that both dehydrochlorination and hydrolysis reaction can be considered as second order kinetic reaction. It is also indicated that the kinetic constant for dehydrochlorination reaction is far bigger than that for hydrolysis reaction in the same conditions.

Reactive extraction of 2,3-butanediol from fermentation broth

Biochemical 2,3-butanediol is a renewable material, but the lack of an effective separation process limits its industrial application. We developed an effective separation process to recover 2,3-butanediol from fermentation broth by reactive-extraction with ion-exchange resin HZ732 as catalyst. n-Butylaldehyde was used as both reactant and extractant. Feasible operation conditions were obtained as follows: room temperature, Ccat=200 g·L−1, three-stage cross-current extraction, with reactant ratio (VButylaldehyde: Vfermentation broth) 0.05 for each stage. Reactive-extraction can recover over 98% of 2,3-butanediol in the form of 2-propyl-4,5-dimethyl-1,3-dioxolane from fermentation broth. Then 2,3-butanediol was obtained by hydrolyzing 2-propyl-4,5-dimethyl-1,3-dioxolane and purified by vacuum distillation. The total yield rate of 2,3-butanediol through the process was over 94% and purity of final product reached 99%.

Reactive-extraction of 2,3-butanediol from fermentation broth by propionaldehyde: Equilibrium and kinetic study

An effective process was developed to separate 2,3-butanediol (2,3-BD) from fermentation broth (FB) by reactive-extraction. Propionaldehyde (PRA) was used as reactant and reaction product 2-ethyl-4,5-dimethyl-1,3-dioxolane (EDD) acted as extractant. HCl was selected as catalyst. Appropriate conditions were obtained by experiment as follows: 10 °C, CHCl=0.2mol·L−1, two-stage cross-current extraction, reactant volume ratio (VPRA: VFB) for first stage and second stage is 0.10 and 0.05, respectively. The yield rate of 2,3-butanediol for the whole process can reach 90% w/w, and 2,3-butanediol in the final product can be more than 99% w/w. The novel process required less solution and especially had advantages in treating dilute fermentation broth. Furthermore, equilibrium and kinetic study were investigated on the reaction of propionaldehyde and 2,3-butanediol to provide basic data for process development. The results reveal that reaction enthalpy and activation energy of the reaction were −21.84±2.38 KJ·mol−1 and 51.97±2.84 KJ·mol−1, respectively. Kinetics was well described by pseudo-homogeneous model.

Use of Long-chain Alcohol in Extraction and Purification of Lincomycin from Fermentation Broth

Low selectivity for lincomycin in butanol extraction process leads to relatively higher content of impurities. A novel process for extraction of lincomycin from fermentation broth was studied in this work. Mixture of n-octanol and n-decanol is used as extradant to replace n-butanol in extraction of lincomycin. Optimal operation conditions for the process have been studied. Due to higher extraction selectivity for lincomycin A by long-chain alcohol, content of impurity (lincomycin B) in the final product is much lower than that in product by butanol process. Furthermore, the practicability for combination of long-chain alcohol and butanol in purification of lincomycin was investigated.

The Distillation Process Design for the Ternary System 1,2-Butanediol + 1,4-Butanediol + 2,3-Butanediol

The isobaric vapor-liquid equilibrium data for distillation have been measured for three binary systems of (1,2-butanediol(BD)+1,4-BD), (1,2-BD+2,3-BD), and (1,4-BD+2,3-BD) and for the ternary system of (1,2+BD+1,4-BD+2,3-BD) at 101.3 kPa. The thermodynamic properties of the vapor phase have been calculated with the Hayden-O’Connell equation in consideration of nonideality. The liquid activity coefficients have been satisfactorily correlated with the Wilson, NRTL and UNIQUAC models. The corresponding binary interaction parameters of the three models were calculated. Based on all the preceding results, a two-column distillation process was designed to obtain the required products with purity of 98% for industrial use.

Partition behavior of spiramycin in an aqueous two-phase system based on polyethylene glycol and sulfates

ABSTRACT A polymer–salt aqueous two-phase system based on polyethylene glycol and sulfates was applied to explore the partition behavior of spiramycin. Binodal curves were measured by the turbidimetric titration method. The influence of temperature, salt concentration, and pH on the distribution behavior was investigated in detail by determining the partition coefficient and extraction efficiency. As pH and salt concentration increase, the partition coefficients increase accordingly. It was found that pH displays a significant influence on the partition behavior. The partition coefficient and extraction efficiency can reach 42.46 and 97.8%, respectively, at pH 9.0 and 15.80% (w/w) salt concentration.

Study on the crystal transformation of ammonium polyphosphate crystalline form V

GRAPHICAL ABSTRACT ABSTRACT The crystal transformation of ammonium polyphosphate crystalline form V (APPv) was studied. The effects of heating time and water content in the reactor were explored. The results showed that APPv underwent complete conversion to crystalline form II (APPii) when heated at 200°C. The pure and water-insoluble APPii was obtained under the alternate wet ammonia and dry ammonia atmosphere. Then, the thermal behavior of APPv and APPii was investigated. The TG analysis showed APPv had high thermal stability over the range of 300°C to 580°C, which was possibly due to its highly cross-linked structures.

Isobaric Vapor-Liquid-Liquid Equilibria for 1-Butanol + Water + 2,3-Butanediol at 101.3 kPa

Vapor-liquid-liquid equilibria (VLLE) data were determined for the ternary system 1-butanol + water + 2,3-butanediol at 101.3 kPa. A binary heterogeneous minimum boiling azeotrope was found at 365.95 K with mass fractions of 0.526 and 0.474 for 1-butanol and water, respectively. A modified UNIQUAC model was used to predict VLLE by using experimental data, including VLE of 1-butanol + 2,3-butanediol, VLE of water + 2,3-butanediol, LLE of 1-butanol + water, and one LLE tie-line of 1-butanol + water + 2,3-butanediol. The experimental data were compared with the calculated values. The absolute average relative deviations (AARD) are 1.65%, 1.72%, and 2.22% for organic liquid phase, aqueous liquid phase, and vapor phase, respectively. It demonstrates an appropriate fit of the modified UNIQUAC model.

ENRICHMENT AND PURIFICATION OF BITESPIRAMYCIN USING MACROPOROUS RESIN

Bitespiramycin was purified by selective adsorption. The adsorption and desorption properties of bitespiramycin on six different macroporous resins (HZ806, HZ816, HZ820, HZ830, XAD16, and SP207) were compared systematically. According to the adsorption capacity and selectivity towards 4″-O-isovalerylspiramycin, HZ820 was chosen as the most suitable resin for bitespiramycin purification. The equilibrium data on HZ820 in a batch system were well described by Langmuir and Freundlich models. The film and pore diffusion model was successfully measured in batch adsorption kinetics. Dynamic adsorption and desorption experiments were also performed using a packed column of HZ820 to optimize the separation process of 4″-O-isovalerylspiramycin from aqueous solution. After being treated with HZ820, the 4″-O-isovalerylspiramycin content increased from 80.4% to 91.7%, and the 4″-O-isovalerylspiramycin III content increased from 41.7% to 64.4%.

Separation of ternary system (1,2-ethanediol + 1,3-butanediol +1,3-propanediol) by distillation

ABSTRACT A study on separation of system (1,2-ethanediol (1,2-EG) + 1,3-butanediol (1,3-BD) + 1,3-propanediol (1,3-PG)) was conducted in the article. Vapor–liquid equilibria (VLE) behaviors of systems (1,2-EG + 1,3-BD), (1,2-EG +1,3-PG), (1,2-EG + 1,3-BD + 1,3-PG) were studied at 101.3 kPa . A two-column (column C1 and column C2) sequence distillation process at normal pressure was designed and optimized to separate the ternary mixture. The results have shown Wilson model is the most appropriate one to describe the ternary system; product amounts of 1,2-EG, 1,3-BD, and 1,3-PG can be up to 0.970, 0.945, and 0.980, respectively, under optimized conditions.