| n-Heptyl-p-hydroxybenzoate, as an excellent antiseptic, especially in beers, has a wide market prospect. In this thesis, the analysis method of n-heptyl-p-hydroxybenzoate was established, but the synthesis of n-heptyl-p-hydroxybenzoate by immobilized candida sp. lipase was failed, the conversion was no more than5%.Caprylic glycerides is a kind of medium-chain glycerides, having many advantages which traditional lipids don’t have. In this thesis, the synthesis of caprylic glycerides from caprylic acid and glycerol by immobilized candida sp. lipase was investigated. It is approved that a solvent-free system is more efficiency than organic solvent system.The influences of the different lipases, the molar ratio of substrates, reaction temperature, the amount of immobilized lipase and reaction time on the reaction were also investigated. The optimum reaction condition was obtained by esterification from0.69g glycerol and2.16g caprilic acid, with0.5g immobilized lipase at40℃for24hr. In this condition, the conversion of caprilic acid could reach94%.It was discovered that adding0.54g caprylic acid after24hr was helpful to increase the yield of triglyceride. The total conversion of caprylic acid could reach91%, the content of triglyceride in the product was over44%.Stability of the immobilized candida sp. lipase was also studied. The lipase could be reused for4batches after simple treatment.Scale-up of the reaction was studied. Batch stired tank reactor (BSTR) was used for the scale-up of the reaction in a solvent-free system, but the conversion was far below the small reaction above. Packed bed reactor (PBR) was used for the scale-up of the reaction in organic solvent system, the effect was same as the small reaction. |
