【作者】 洪诗群；

【导师】 蓝伟光； 何旭敏；

【作者基本信息】 厦门大学 ， 高分子化学与物理， 2009， 硕士

【摘要】 木糖醇是时兴的功能型添加剂,我国是木糖醇生产大国,然而大部分企业的生产方法仍然采用传统的木糖化学合成法,生产和提纯的节能及环保压力大。因此研究生物发酵新工艺,采用膜分离和色谱分离等技术,进一步提高产品的纯度和质量,是行业发展与整合的必经之路。目前生物发酵法生产木糖醇已经取得突破,虽然该工艺可以省去木糖纯化步骤,并可以简化木糖醇的分离步骤,但寻找有效分离发酵液的工艺路线,是半纤维素水解物发酵木糖醇工艺中,提高最终产品收率和品质的重要课题。本论文在获取木糖醇发酵液的前提下,研究了一套完整的发酵液分离工艺,并开展了一系列目的在于将数据放大应用到工业生产的中试实验,通过膜分离发酵细胞,树脂脱盐脱色,连续移动床分离三步骤,连续高效获得高纯度的木糖醇料液。首先选用FLOW-CEL超滤膜系统将发酵液中的细胞截留,高收率的获得发酵液的透析液;接着使用典型的阴、阳离子交换树脂柱层析工艺进行脱盐脱色,提高产品品质,并减少盐分和色素对移动床使用周期的影响;然后选择对木糖醇发酵液有良好分离效果的某钙型树脂,经单柱脉冲实验和“三角理论”指导连续移动床的参数确定;最后通过实际连续移动床的运行,验证并优化运行参数。实验最终确定了连续移动床运行参数,依据该参数运行设备可连续高效获得高纯度木糖醇料液。在连续移动床参数确定过程中,本文在“三角理论”的基础上,提出了一个简便实用的计算方法,简化了连续移动床分离参数确定的过程。更多还原

【Abstract】 Xylitol is widely used as a functional additive,China is playing an important role in xylitol production,and more than 60%xylitol is produced in China. Unfortunately,most of the manufacturers are still applying the traditional synthesis process,which converts xylose to xylitol in high temperature as well as high pressure conditions,so it is not an energy-efficient and environmental-friendly process.Therefore,it is an interesting and exciting work to develop a new type xylitol production process based on biotransformation with innovative separation and purification technology based on membrane and chrotographic techniques, which would reduce resources consumption,improve product quality,increase production yield and minimize pollution.In this dissertation,a series of pilot-scae experiments have been carried out to obtain the optimized operation parameters and conditions,which are suitable for enlarging the pilot-scale results to industrial one,after separating cells by membrane, desalting and deeolorizing by resins,separating using continuous moving bed, xylitol solution in high purity can be continuously product.Firstly,choosing Flow-eel ultrafiltration system to reusing the cells,also getting the dialysate in high yield;secondly,using the typical ion exchange resin chromagraphy to desalting and decoloring,this process can improve the quality of xylitol and reduce the effects on the cycle of simulated moving bed for less salinity and pigments;then getting a high performance resin for separating xylitol fermentation,and directing how to get the operation parameters by pulse experiment and the "Triangle theory";finally, opetating the continuous moving bed actually to verify and optimize the operation parameters.At last,an integrated separation and purification process based on membrane and chromatography has been studied and the results have been successfully applied by a famous industrial enterprise in China.In the process of determinating operation parameters,this dissertation proposes a useful and simple calculation method which simplifies the process of parameters determination.更多还原