Single pot sequential crystallization-distillation as a new purification procedure

A new purification procedure exploiting the simultaneous presence of a solid, liquid, and gas phase in a low surface area system is proposed and discussed. The assumptions of vanishingly low diffusion coefficients in the solid phase and that of the presence of a single “effective impurity” allow to plan the sequence of operations starting from the knowledge of just the melting and boiling points of the substance to be purified and of those of the “effective impurity”. Examples and results are presented.     

BUCHI K-370自动定氮仪蒸馏程序相关参数的试验研究

为了分析BUCHI K-370全自动定氮仪相关参数即蒸汽力度,蒸馏时间的设置使之最适合生物制品中蛋白质含量的测定。分别选用蒸汽力度90%、80%,蒸馏时间190s、170s配对进行硫酸铵回收试验同时对每次回收试验后氨的残留量进行分析比较。再将选出的测定参数对人血白蛋白国家标准品中的蛋白质进行测定。采用蒸汽力度90%,蒸馏时间190s时硫酸铵回收率为100.08%,RSD最小,为0.28%,回收试验后氨残留量最小;且测得标准品的蛋白质含量与真实值对比无显著差异。结果表明采用蒸汽力度90%,蒸馏时间190s最适合生物制品中蛋白含量的测定。     

Recovery of biologically produced 3‐hydroxypropionaldehyde and its dehydrated product acrolein

3‐Hydroxypropionaldehyde (3‐HPA), which can be derived from biomass, is an important precursor for low‐cost, large‐volume acrolein‐based chemicals like acrylic acid and acrylamide with a wide range of applications. In order to find an efficient process for isolating 3‐HPA from fermentation broth, we comparatively investigated several separation methods including precipitation with hydrazides, immobilization with amines, reactive extraction with thiols, extraction with hydrophilic solvents, and reactive distillation as acrolein. It turned out that the reactive distillation is the most efficient method for in situ recovery of 3‐HPA as acrolein. In a reactive distillation process at 37°C and Hammett acidity H₀ = –1, the aldehyde concentration was reduced to 6 ± 1 mM in the transformation medium and increased to 1866 ± 146 mM in the distillate. The yield was 96 ± 8%. These experimental results are close to the calculated ideal equilibrium results assuming total dehydration of 3‐HPA to acrolein. The main advantages of the reactive distillation process are that the recovery, purification, and concentration of acrolein are carried out in one step and the process is well suited for large‐scale production at low costs.     

Methods for recovery of ionic liquids—A review

Ionic liquids (ILs) have attracted much attention in both academics and industries as promising solvents for a diverse range of applications. However, there were little industrial processes employing ILs as current time due to the economical and efficient use of ILs. The economic efficiency can be improved by recycling and reuse of ILs. In the last few decades, several attempts have been made, by the researchers, for recovery and recycling of ILs. This review is intended to present a comprehensive summary on the methods used for recovery and recycling of ILs.     

Glycerol extracting dealcoholization for the biodiesel separation process

By means of utilizing sunflower oil and Jatropha oil as raw oil respectively, the biodiesel transesterification production and the multi-stage extracting separation were carried out experimentally. Results indicate that dealcoholized crude glycerol can be utilized as the extracting agent to achieve effective separation of methanol from the methyl ester phase, and the glycerol content in the dealcoholized methyl esters is as low as 0.02 wt.%. For the biodiesel separation process utilizing glycerol extracting dealcoholization, its technical and equipment information were acquired through the rigorous process simulation in contrast to the traditional biodiesel distillation separation process, and results show that its energy consumption decrease about 35% in contrast to that of the distillation separation process. The glycerol extracting dealcoholization has sufficient feasibility and superiority for the biodiesel separation process.     

用于高粘度易焦化基质高沸点蒸馏的新技术

进行高粘度易焦化有机基质高沸点蒸馏的最大难题,是高沸点气化物质被高粘度有机基质包裹难以气化,大大影响收率,并且结成坚硬的焦垢后无法清洗,导致无法连续生产。针对发酵法生产甘油（丙三醇）提取中的这一难题,发明了相应的载体蒸馏技术,在大生产应用中获得满意的结果。蒸馏收率大于９０％,蒸馏残渣清洗容易,可连续生产。     

Highly pure 1,3‐propanediol: Separation and purification from crude glycerol‐based fermentation

A new separation and purification process was developed for recovering 1,3‐propanediol (1,3‐PD) from crude glycerol‐based fermentation broth with high purity. The downstream process integrated chitosan flocculation, activated carbon decolorization, fixed bed cation exchange resin adsorption, and vacuum distillation. Breakthrough curves were measured considering the effect of sample concentration, flow rate, temperature, and resin stack height. Yoon–Nelson model was proposed to fit the fixed bed adsorption. The characteristic column parameters were calculated. Optimal condition for adsorption was 1,3‐PD, 30.0 g/L; flow rate, 1.00 mL/min; stacking height, 30.0 cm; and temperature, 298 K. Ethanol‐water (75%, 1 mL/min) was used as eluent to separate 1,3‐PD and glycerol with 95.3% 1,3‐PD elution rate. After vacuum distillation, the overall purity and yield of 1,3‐PD were 99.2% and 80.8% in the purification process, respectively. This is a simple and efficient downstream strategy for 1,3‐PD purification.     

A method for the solvent extraction of low-boiling-point plant volatiles

A new method has been developed for the extraction of volatiles from plant materials and tested on seedling tissue and mature leaves of Arabidopsis thaliana, pine needles and commercial mixtures of plant volatiles. Volatiles were extracted with n-pentane and then subjected to quick distillation at a moderate temperature. Under these conditions, compounds such as pigments, waxes and non-volatile compounds remained undistilled, while short-chain volatile compounds were distilled into a receiving flask using a high-efficiency condenser. Removal of the n-pentane and concentration of the volatiles in the receiving flask was carried out using a Vigreux column condenser prior to GC-MS. The method is ideal for the rapid extraction of low-boiling-point volatiles from small amounts of plant material, such as is required when conducting metabolic profiling or defining biological properties of volatile components from large numbers of mutant lines.