共查询到17条相似文献,搜索用时 125 毫秒
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吉化公司兴建千吨结晶木糖装置吉化公司木糖醇厂引进俄罗斯技术,兴建年产千吨结晶木糖生产装置,1994年10月20R举行了开工典礼,预计1995年建成。俄罗斯结晶木糖技术特点是原材料消耗低,结晶木糖纯度高,可直接生产高纯木糖醇,木糖醇含量≥98.5%,国... 相似文献
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木糖醇母液色谱分离性能优化 总被引:2,自引:0,他引:2
在实验室模拟移动床(SMB)分离设备上成功地实现了木糖醇母液中木糖和木糖醇组份的分离提纯。并在平衡理论的框架下,采用基于真实移动床(TMB)的简化数学模型,以产品纯度和收率为系统分离性能的优化指标,研究SMB分离性能与操作条件之间的关系。通过对木糖醇母液SMB色谱分离过程操作条件的寻优仿真研究,确定稳态时柱内的木糖和木糖醇浓度分布状态;计算出不同操作条件时两组分产品液各自的纯度和收率变化规律图。在阀门切换时间为15min,进料木糖醇母液中木糖浓度35gL-1,木糖醇浓度114gL-1,进料和出料总量恒定为16mLmin-1,循环洗脱剂流量恒定为18mLmin-1的操作条件下,木糖醇母液进料流量在1~2.3mLmin-1范围内都可同时获得纯净木糖醇与木糖产品。在实验室SMB分离设备上进行了验证,得到的木糖和木糖醇产品液纯度和收率均达到了100%,所有实验结果与仿真曲线基本吻合。因此采用基于TMB的简化的平衡理论模型进行仿真和优化研究可分析和预测木糖母液SMB色谱分离系统操作条件对系统分离性能的影响,有效地指导了产品分离实验、工业化放大设计和生产优化操作。 相似文献
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孙昆 《精细与专用化学品》2000,8(18):38
据<日本工业新闻>报导,日本科学家歧泽大学的高见泽一教授对乳香果皮用22个大气压进行高压处理,然后突然减压,使所含半纤维素爆裂粉碎,组织破坏,然后用酶切断半纤维素的大分子,从而提取木糖.再用转基因大肠杆菌使木糖转化为木糖醇.该技术能从乳香果皮中提取67%木糖,而从木糖中能获得82%的木糖醇.此外还对胡桃皮、花生皮和葵花籽皮也进行了研究. 相似文献
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木糖醇作为一种可作为甜味剂的糖醇具有广泛的应用前景。目前工业上酸水解法制备木糖醇的过程中需要一个脱除水解液中的残酸的工艺步骤。传统的残酸去除方法为饱和石灰水中和法,存在能耗高、消耗的化学试剂多、污染大等缺点。为实验木糖醇的清洁生产,本文采用自我组装的电渗析装置对木糖水解液中的残酸进行了选择性的去除,考察了操作电流对残酸去除及木糖得率的影响。结果表明,当操作电流为30 mA·cm-2时,电渗析过程对残酸的去除率大于99%,其木糖的得率为84.9%,电渗析工艺处理木糖水解液的能耗为179 kW·h·t-1,脱酸工序成本为每吨母液139元,具有良好的经济效益和环境效益。由此可见,电渗析工艺在木糖醇酸水解法制备过程中具有广泛的应用前景。 相似文献
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《广东化工》2021,48(12)
目的:本文以油茶果壳为原料,利用产朊假丝酵母发酵油茶果壳木糖水解液制备木糖醇,得到产朊假丝酵母发酵油茶果壳木糖水解液制备木糖醇的最佳工艺条件,为油茶果壳综合开发提供理论依据及数据参考。方法:采用稀硫酸水解油茶果壳半纤维素,利用Ca(OH)2和活性炭对水解液进行脱色脱毒,再利用产朊假丝酵母发酵水解液制备木糖醇,在单因素实验的基础上,通过响应面法设计实验优化油茶果壳木糖水解液制备木糖醇的工艺条件。结果:最佳优化结果为:初始p H值5.68,发酵温度28℃,装液量53.88 mL,接种量为10%,木糖醇得率优化值为(16.56±0.25)%。结论:方差分析结果表明,所选模型具有显著性(p0.05),相关系数R2=0.9523,验证试验木糖醇得率为(16.56±0.25)%,与预测值16.81%的误差仅为1.48%,证明所得模型可信,优化工艺参数切实可行。 相似文献
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Dbora Danielle Virgínio da Silva Maria das Graas de Almeida Felipe 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2006,81(7):1294-1300
The influence of glucose on xylose reductase (XR) and xylitol dehydrogenase (XDH) enzyme activity was evaluated from sugarcane bagasse hydrolysate fermentations with different glucose:xylose ratios (1:25, 1:12, 1:5 and 1:2.5) by employing an inoculum of Candida guilliermondii grown in media containing glucose, a mixture of glucose and xylose, or only xylose as carbon sources. According to the results, the glucose:xylose ratio affected positively this bioconversion and a correlation was not observed between the favourable conditions for xylitol production and the XR and XDH activities. Also, the results were influenced not only by the glucose:xylose ratio in the fermentation medium, but also by the carbon source employed in the growth medium of the inoculum. The optimum condition for xylitol production by C. guilliermondii in sugarcane bagasse hemicellulosic hydrolysate should use hydrolysate with a 1:5 glucose:xylose ratio and inoculum grown in medium containing xylose as the only carbon source. Copyright © 2006 Society of Chemical Industry 相似文献
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固定化酵母细胞发酵玉米芯酶解液生产木糖醇 总被引:1,自引:0,他引:1
用木聚糖酶对玉米芯的自水解液进行酶解以获得可发酵的木糖溶液。该法与直接用酶对玉米芯水解相比,水解速度快,木糖得率较高。所得酶解液发酵木糖醇的性能虽不如纯木糖,但明显优于玉米芯酸水解液。海藻酸钙/壳聚糖(ACA)微胶囊的最佳成膜时间和液化时间分别是18 min和20 min,微胶囊使用的环境pH范围是3~6。用微胶囊固定化细胞发酵玉米芯酶解液,重复培养了8批,平均木糖醇得率为61.4%。 相似文献
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基于遗传算法的木糖醇发酵培养基优化研究 总被引:6,自引:1,他引:5
运用遗传算法,对利用莫格假丝酵母由木糖生产木糖醇的发酵培养基优化进行研究,用40个实验样本完成了6种培养基成份,50个浓度水平的优化任务。实验结果表明:利用遗传算法可优化培养基成份富量,取得更好的发酵效果。按照优化后的培养基组成,由50g/L木糖获得了29.7g/L木糖醇,比优化前提高5.7%。 相似文献
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玉米秸秆半纤维素制备木糖醇的研究 总被引:5,自引:1,他引:4
首先采用无污染的碱性过氧化氢法研究了半纤维素的分离与提取,然后对提取的半纤维素分别进行化学水解和酶水解比较,最后研究了水解液发酵制备木糖醇。结果表明,半纤维素分离提取的优化参数为:2%过氧化氢,2%氢氧化钠,加热时间4 h,反应温度75℃。使用CF3COOH水解半纤维素所得木糖含量为67%~73%,水解率为76%~84%,稀盐酸预处理半纤维素再化学水解所得木糖含量高达88%,水解率上升至大约90%。半纤维素的酶水解实验表明,木聚糖酶的水解专一性高于半纤维素酶,木聚糖酶水解率为38%~60%。在水解液发酵实验中,酶水解液的木糖醇转化率高于化学水解液。另外,通过浓缩半纤维素水解液,提高发酵液的木糖初始浓度,有利于菌株生长,可以提高木糖醇转化率。研究对于玉米秸秆半纤维素制备化学品具有一定的指导意义。 相似文献
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Sarote Sirisansaneeyakul Rittikorn Chainoy Wirat Vanichsriratana Thongchai Srinophakun Yusuf Chisti 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2009,84(8):1218-1228
BACKGROUND: Liquid emulsion membrane (LEM)‐encapsulated live cells can be used to produce various products. This work reports on LEM‐encapsulated cells for producing xylitol and models the production process. RESULTS: Encapsulated cells of Candida mogii ATCC 18364 were used to produce xylitol from xylose. Soybean oil LEM consisting of 5% (w/v) lanolin and microwaxes was found most suitable for this process. The LEM‐encapsulated cells were immobilized in a tubular biocatalytic loop. Xylitol was produced under oxygen‐limited and aerobic conditions. Xylitol productivity and yield were 0.005 g L?1 h?1 and 0.52 g g?1, respectively, for oxygen‐limited operation. Under aerobic conditions, xylitol productivity increased greatly to 0.022 g L?1 h?1, but yield on xylose declined to 0.49 g g?1. A mathematical model successfully described substrate consumption and product formation in the LEM‐immobilized cell system. CONCLUSION: Potentially, immobilized cell LEM systems are useful for certain fermentations and they can be successfully modeled, as shown by the example of xylitol from xylose process. Copyright © 2009 Society of Chemical Industry 相似文献
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Xylitol recovery by crystallization from synthetic solutions and fermented hemicellulose hydrolyzates 总被引:3,自引:0,他引:3
D. De Faveri P. Perego A. Converti M. Del Borghi 《Chemical engineering journal (Lausanne, Switzerland : 1996)》2002,90(3):266-298
Preliminary xylitol separation tests were carried out using solutions with relativity high concentrations of xylose and xylitol to simulate the actual composition of hemicellulose hydrolyzates. Xylitol was recovered by a crystallization methodology consisting of dilute solution evaporation up to supersaturation, supersaturated solutions cooling, separation of crystals by centrifugation, and final filtration. Two sets of tests were performed on xylitol–xylose synthetic solutions and an additional one on fermented hardwood hemicellulose hydrolyzate. The best results in terms either of crystallization yield (0.56) or purity degree (1.00) were obtained with quite concentrated solutions (730 g/l) at relatively high temperature (−5 °C). Besides, xylitol solubility limits in the solution, which are very important for future scale-up of the process, were estimated at different crystallization temperatures. Product yields and crystal purity were calculated and crystallization kinetics were investigated. 相似文献