Separation of Vanillin and Syringaldehyde from Oxygen Delignification Spent Liquor by Macroporous Resin Adsorption     

Zhaojiang Wang  Kefu Chen  Jun Li  Qianqian Wang  Jie Guo 《洁净——土壤、空气、水》2010,38(11):1074-1079

This paper reports on an approach for separating vanillin and syringaldehyde (VSA) from oxygen delignification spent liquor using non‐polar macroporous resin. The effects of temperature and pH on the adsorption isotherms were studied. The adsorption capacity and adsorption equilibrium constant were obtained using the Langmuir adsorption model at pH<4.5, where the ionization of the VSA to ionic forms was negligible. The standard enthalpy change was calculated using the van't Hoff equation and clearly showed that the adsorption is an exothermic process. The effect of pH on the adsorption isotherm is well‐described by a modified Langmuir model and shows that the adsorption equilibrium constant decreases significantly with the increasing pH. The VSA adsorbed on macroporous resin was eluted by ethyl ether. The separated VSA contained 37.51% vanillin, 31.88% syringaldehyde. The recoveries of VSA were 96.2 and 94.7%, respectively.  相似文献   

Separation of Vanillin from Oil Palm Empty Fruit Bunch Lignin     

Mohamad Nasir Mohamad Ibrahim  Mohamad Yusof Nor Nadiah  Mohd Salleh Norliyana  Coswald Stephen Sipaut  Sollehuddin Shuib 《洁净——土壤、空气、水》2008,36(3):287-291

The separation of vanillin from the lignin of empty fruit bunch oil palm is presented in this study. The lignin was extracted from soda black liquor derived from oil palm empty fruit bunches (EFB) using 20% sulfuric acid. Nitrobenzene oxidation was carried out by adding 50 mg of dry EFB lignin into a mixture of 7 mL of 2 M NaOH and 4 mL of nitrobenzene in a 15 mL steel autoclave. The autoclave was sealed tightly with a screw cap fitted with a Teflon gasket and heated to 165°C for 3 h in a preheated thermostatic oil bath. High performance liquid chromatography (HPLC) was used to determine the concentration of each compound present in the lignin. There were eight compounds detected in the HPLC chromatogram. The crystallization process was then used as a method to separate vanillin from other compounds. Based on the solubility of vanillin in acetone, 15 mL of acetone was added to the residue of the oxidized products and heated to 60°C for 10 min. A yield of 1.6% vanillin was isolated from a 50 mg lignin sample. The isolated compound was analyzed with HPLC, Fourier transform infrared spectrophotometry (FT‐IR) and nuclear magnetic resonance (¹³C‐NMR) for structural verification. The results of the characterization studies proved that the isolated compound is vanillin.  相似文献