稻壳灰二氧化硅(RHAS)的制备、表征及在菜籽油脱胶中的应用

利用农业生产的副产物稻壳为原料,制备了比表面积大、结构细的稻壳灰SiO2(RHAS),同时采用EDX、FTIR、XRD、SEM、N2吸附-脱附对RHAS进行了表征与分析,并以RHAS为脱胶剂,考察RHAS对菜籽油的脱胶效果。结果表明:RHAS颗粒大小均匀、结构疏松,BET比表面积达149cm2/g;RHAS对菜籽油中的磷脂有较强的吸附脱除作用,在脱胶温度50℃、脱胶剂用量4.5%、脱胶时间40 min条件下,脱胶率可达57.8%,且再生循环6次脱胶,脱胶率仍达35%左右。RHAS可作为一种良好的新型植物油吸附脱胶剂。

硅胶在米糠毛油脱胶中的应用

利用硅胶对米糠毛油进行吸附脱胶,研究柠檬酸添加量、硅胶添加量、吸附温度及吸附时间对脱胶效果的影响,通过单因素及正交实验得到硅胶吸附脱胶的最佳条件:柠檬酸添加量0.20%、硅胶添加量6%、吸附温度50℃、吸附时间30 min,此条件下,米糠油脱磷率可达82.26%,谷维素含量无明显变化,总生育酚含量有少量损失,总甾醇含量保留80%以上。

专用硅胶在油脂精炼生产中的应用研究

利用专用硅胶对油脂进行吸附脱胶、吸附脱皂、吸附脱色及脱除氯离子,通过对工艺条件和脱除效果的研究,评价其在油脂精炼生产中应用的可行性。结果表明:利用SORBSIL R92硅胶对浓香花生油进行吸附脱胶,在硅胶添加量0. 5%、吸附温度80℃、吸附时间15 min条件下,磷脂脱除率为96. 2%,且脱胶油色泽清亮、风味保留好;利用SORBSIL R92硅胶对碱炼脱酸后的大豆油进行脱皂处理,可使大豆油含皂量从130. 7 mg/kg降至未检出,与水洗脱皂相比,不仅能明显降低含皂量,还实现了脱皂过程的废水零排放,减少了脱皂过程的油脂损耗;利用SORBSIL R40F在优化条件下对大豆油脱色(先向待脱色油中添加0. 08%的SORBSIL R40F硅胶,吸附反应后再添加1. 57%的活性白土)后,其含磷量明显低于单纯活性白土脱色油,并且脱臭油的色泽、氧化稳定性也优于单纯活性白土脱色脱臭油;利用SORBISIL R40F硅胶和SORBSIL R92硅胶在100℃、20 min条件下对大豆油进行吸附处理,大豆油中氯离子含量分别降低28. 47%和18. 98%,这对防范和降低油脂脱臭过程3-氯丙醇酯和缩水甘油酯的形成是有利的。综上,专用硅胶SORBSIL R92和SORBSIL R40F在油脂精炼工艺技术的改进发展方面具有很好的应用前景。

Removal of Chromium from Chromium（VI） Solutions by Adsorption and Reduction Using Immobilized Persimmon Gel

The removal of chromium（Vl） from an aqueous solution using persimmon gel was examined. The amount of chromium（VI） removed was strongly affected by the pH of the solution, with all ehromium（VI） being removed at pH 2 or lower. However, in a solution containing, 15 mg dry weight of immobilized persimmon gel, the amount of removed chromium（VI） decreased as the pH increased. A part of chromium（VI） was reduced another oxidation stage, mainly chromium（III）, by immobilized persimmon gel. The amount of reduced chromium（III） in the solution was increased with decreasing the pH of the solution. As a result, the amount of total chromium removed was maximal at pH 2. The amount of chromium removed were affected by the chromium concentration and the amount of gel. The maximal amount of chromium removed by the column system was also discussed.