Preparation Of Glycerol Phosphatidylcholine By Hydrotalcite Solid Base Catalyzed Transesterification Of Soybean Phospholipid

As a water-soluble phospholipid,L-a-Glycerophosphocholine is naturally exist in the body of animals and plants.It can be used for treating brain mental illness such as alzheimer's disease and dysthymia.Therefore,it can be widely used in healthcare and food industries.In this paper,the process for production of GPC by hydrotalcites solid base catalyzed transesterification using natural phospholipids(phosphatidyl choline,PC for short)as raw materials was developed.The effects of the preparation conditions on the catalytic activity,stability as well as the reaction results were investigated,in order to accumulate basic data for scale-up progress and practical application.The calcined U-LDH and T-LDH hydrotalcites catalyst was characterized by Hmmett indicator method,XRD,FT-IR,DSC,SEM.The results showed the optimum U-LDO catalyst was obtained by calcined on 773 K and Mg/Al ratio is 3.The optimal reaction condition of the Mg/Al hydrotalcites catalysts system is as follows:10.5 mmol/L of PC concentration;9%of catalyst amount;350 rpm of stirring speed;65?of reaction temperature and 280 min of reaction time.94.4%of PC conversion and 92.3%of GPC yield were achieved under the optimized conditions.The results of stability test showed that U-LDO catalysts can reused four times.After loss of activity of U-LDO hydrotalcite catalyst,it can be recovered by regeneration calcined at 773 K to supply activated components.Hydrotalcite-like compounds containing Mg2+,Al3+and Fe3+ layered double hydroxide were synthesized by co-precipitation method.The calcined Mg/Al/Fe hydrotalcites catalyst was characterized by BET,SEM,XRD,TGA,FT-IR.The results showed that optimum Mg/Al/Fe catalyst was obtained by calcined at 773 K with 15:8:1 of Mg/Al/Fe ratio.The optimal reaction condition of the MgAlFe 15 hydrotalcites catalysts system is as follows:10.5 mmol/L of PC concentration;7%of catalyst amount;350 rmp of stirring speed;60 ? of reaction temperature and 120 min of reaction time.97.4%of PC conversion and 93.3%of GPC yield were obtained.The reasons for loss of activity of MgAlFe 15 hydrotalcites catalysts weread sorption of H2O and CO2 in atmosphere.The regeneration method was confirmed as calcined the catalyst at 773 K to supply activated components.Kinetics of PC transesterification by U-RLDO catalytic was analyzed.The experimental data regression showed that the reaction complied with the pseudo-first order kinetic model.The whole process is divided into mass transfer rate control stage and the reaction rate control stage.Combined with Arrhenius equation and experimental data regression,0.00408min-1 of mass transfer parameter,0.04575mim-1 of the reaction rate constant under 65? and 71.5kJ/mol of the activation energy on U-RLDO were obtained.