Enrichment of nervonic acid in Acer truncatum Bunge oil by combination of two-stage molecular distillation,one-stage urea complexation and five-stage solvent crystallization

Nervonic acid is the world’s first and only potent substance that can repair damaged nerve fibers and promote nerve cell regeneration with high nutritional value.The wide variety of fatty acids in plant oils and fats with similar structures makes the large-scale separation and purification of high-purity nervonic acid very difficult.A new combined process of molecular distillation,urea inclusion and solvent crystallization was established to prepare high-purity nervonic acid with the mixed fatty acids obtained after saponification and acidification of Acer truncatum Bunge oil as raw materials.First,according to the difference in the mean free path of fatty acids,molecular distillation was used to separate and remove C16 saturated fatty acid of palmitic acid and four C18-C20 fatty acids of stearic,oleic,linoleic,and linolenic acids.The content of C16-C20 fatty acids decreased from 72.92% to 19.22% after two-stage molecular distillation processes,in which the contents of saturated fatty acid of palmitic acid decreased to about 0.5%.Then,according to the difference in carbon chain length and saturation of fatty acid,the contents of C22-C24 saturated fatty acids of tetracosanoic and docosanoic acids decreased to 0.21% and 0.07% by urea inclusion with urea/free fatty acid preparation by saponification(SPOMFs)ratio as 0.6.In addition,all saturated fatty acids were basically separated.Finally,according to the difference in the solubility of fatty acids in solvents,the C18-C20 unsaturated fatty acids of oleic,linoleic,and linolenic acids and C22 unsaturated fatty acid of erucic acid were removed by solvent crystallization.The content of C18-C20 unsaturated fatty acids decreased to less than 5% with pentanol as the solvent after the first stage solvent crystallization.The content of erucic acid decreased to 3.47% with anhydrous ethanol as the solvent after the second to fifth stage solvent crystallization.The combined process of molecular distillation,urea inclusion and low temperature crystallization innovatively adopted an efficient,simple and easy-toindustrial solvent crystallization method to separate erucic and nervonic acids,obtaining nervonic acid with purity of 96.53% and final yield of 47.99%.

Volatile Components and Antitumor Activity of Ganoderma lucidum Spore Oil and Its Molecular Distillation Components

[Objectives]To compare the effects of molecular distillation on the flavor and antitumor activity of Ganoderma lucidum spore oil.[Methods]G.lucidum spore oil was separated and purified by molecular distillation technology,and the volatile components of different components of molecular distillation were analyzed by gas chromatography-ion mobility spectrometry(GC-IMS)technology.Human liver carcinoma cells(HepG2),human breast cancer cells(MCF-7),and human cervical cancer cells(Hela)were selected as the tumor cell lines to be tested,and the cell viability was detected by the MTT assay.[Results]Molecular distillation effectively reduced small molecular substances produced by oil oxidation in G.lucidum spore oil,such as heptanal,octanal,linalool,hexanal,E-2-octanal,3-ethylpyridine,etc.Among the heavy components,the content of esters was relatively high,mainly including ethyl levulinate,ethyl crotonate,and amyl butyrate.The MTT cytotoxicity test indicated that G.lucidum spore oil and its molecular distillation components had certain inhibitory effects on the growth of three tumor cells,and G.lucidum spore oil crude oil had the most significant antitumor activity.G.lucidum spore oil crude oil,heavy component,and light component had the most significant antitumor activity on HepG2 cells,followed by MCF-7 cells,and the weakest antitumor activity on Hela cells.The quality of G.lucidum spore oil became higher after molecular distillation,and the rancid smell was reduced,and molecular distillation had little effect on the antitumor activity of G.lucidum spores.[Conclusions]Molecular distillation technology can be applied to the refining of G.lucidum spore oil to improve product quality.

Determination of Thermal Properties of Cuts and Residue Streams Obtained in the Molecular Distillation Process

A real-time sensing of the molecular distillation process temperature by a FLUKE brand thermograph Ti50 IR FlexCam and thermography technique was realized. After completion of the molecular distillation, three properties of heat transport chain cuts and residues obtained in the process were estimated by Differential Scanning Calorimetry （DSC） （specific heat, enthalpy, thermal conductivity）. These properties are of great importance for improving oil characterization and for future modeling and simulation of the molecular distillation process. The results show that through the method of Differential Scanning Calorimetry, profiles have been obtained from the variation of specific heat, enthalpy and thermal condutivity as a function of temperature for samples of cuts from the distillation （ASTM D-2892） and fractions of distillate and residue from the process of molecular distillation.

Application of Molecular Distillation Process to Extend the True Boiling Point Curve of Petroleum Residues 400 ℃ ＋

True Boiling Point （TBP） distillation is one of the most common experimental techniques for determination of petroleum properties. The methods for performing TBP distillation experiments are described by ASTM D2892 and by ASTM D5236. However, these methods are established for petroleum fractions that reach temperatures up to 565 ~C. In this work, two petroleum residues were distilled in a falling film molecular distillation prototype and the data were used to obtain the extension of the TBP curve above a temperature of 565 ~C. It was possible to extend the TBP curve of both petroleum up to temperatures close to 700 ~C with consistency and continuity in comparison to the standard curve. In addition, an amount of raw material that was been treated as residue could be reused.

A novel purification process for dodecanedioic acid by molecular distillation

A novel purification process is involved to obtain the high purity[>99%(by mass)]dodecanedioic acid(DC_(12)).It involves a re-crystallization followed by molecular distillation from the crude product.The objective of this study is to investigate general conditions,feed rate,distilling temperature and vacuum,necessary for centrifugal distillation of DC_(12).Under the optimum conditions,distilling temperature 180℃,pressure 30 Pa and feed flow rate700 ml·h^(-1),the purity of DC_(12) in the residence reached 97.55%with a yield of 53.18%by the analysis of gas chromatography.Multiple-pass distillation made a considerable contribution by improving the purity to99.22%.Additionally,the effect of pretreatment(re-crystallization) on distillation process was revealed through a series of comparative experiments.

Wiped-Film Molecular Distillation Process

Based on the Bhatnagar-Gross-Krook distillation for two components in the presence equation, a new scheme of wiped-film molecular of inert gas is developed. The equations in the scheme are solved numerically by the method of finite difference and iteration. The new scheme is used to simulate the molecular distillation of dibutyl phthalate and dibutyl sebacate （ DBP-DBS ） mixture. The effects of the inert gas pressure, the distance between the evaporation surface and condensation surface, the rotation rate of blade, and the number of blades on the distillation rate and separation factor are discussed.

Optimization of Molecular Distillation for Removal of Limonene from Ponkan Essential Oil Using Response Surface Methodology

Ponkan (Citrus reticulate Blanco) is one of the most popular citrus fruits for daily consumption and processing in China. In this study, limonene was removed from ponkan essential oil (PEO) by using an effective methodology to estimate the optimum levels of three independent variables of molecular distillation (MD) in order to minimize the limonene content and (b) maximize the removal rate. A three-factor Box-Behnken design (BBD) was employed to evaluate the effect of distilling temperature (45.00~55.00 ℃), wiper rolling speed (150.00~250.00 r/ min) and distilling pressure (25.00~35.00 Pa). The optimum parameters within the experimental range of the variables were extrapolated to be: distilling temperature 47.00℃, wiper rolling speed 203.00 r/min and distilling pressure 30.00 Pa. Optimal values extrapolated by response surface methodology (RSM) for the limonene content and removal rate of the desirable PEO were 47.82% and 84.67%, respectively.

Modeling of Molecular Distillation Parameters： Case Study of Green Coffee Oil （Coffea arabica）

In principle, the free fatty acids, diterpene fatty acid esters and triglycerides from green coffee oil can be separated effectively, by a suitable separation process, due to the differences between molar mass and vapor pressures. In addition, in the case of component separation by molecular distillation, boiling point is replaced by evaporation rate at a given temperature. Several experiments and theoretical analyses have been carried out to identify the impact of important parameters （mean free path, evaporation rate, relative volatility and Knudsen number）, which determine the performance of these processes and degree of separation. In this work, a process development based on molecular distillation, for the enrichment of coffee diterpenes from green coffee oil is presented. The distillates were enriched in diterpene fatty acid esters and free fatty acids, while the residues were enriched in high molar mass triglycerides.

Simulation of Molecular Distillation Process for Lactic Acid

In this work, a procedure to simulate the MD （molecular distillation） process for lactic acid purification was developed. The simulation was carried out with the aid of the Aspen Plus Process Simulator. Flash vessel was used to represent the MD process since the software does not present this unit operation. The simulation results with efficiency factors were in agreement with previously reported experimental data.

Recycling and Reuse of Ionic Liquid in Homogeneous Cellulose Acetylation

Molecular distillation was used to recover ionic liquid(IL) 1-allyl-3-methylimidazolium chloride(AmimCl) in homogeneous cellulose acetylation.The five factors that affect the separation efficiency of molecular distillation,namely,feed flow rate,distillation temperature,feed temperature,wiper rotating speed,and distillation pressure,are discussed.The optimal recovery condition was determined via orthogonal experiments using an OA9(34) design.The IL was recycled and reused 5 times in the homogeneous cellulose acetylation system under optimal conditions.The purity of recycled IL the 5th time reached 99.56%.FT-IR(Fourier transform infrared spectroscopy) and 1H NMR(nuclear magnetic resonance) spectroscopy showed that the structure of the recovered IL is not changed.This work proves that AmimCl has excellent reusability,and that molecular distillation is an effective method for recovering IL in homogeneous cellulose acetylation.