鸡毛水解液活性炭脱色工艺条件研究

采用活性炭对鸡毛水解液进行脱色处理,考察水解液稀释倍数、活性炭用量、脱色时间和温度等工艺条件对脱色效果以及溶液中L-亮氨酸保留量的影响.结果表明:最佳工艺条件为,将水解液稀释2倍后,在60℃下加入6g/100mL的活性炭,脱色20min.     

凹凸棒土热改性对玉米秸秆稀酸水解液脱色的研究

采用焙烧酸化法对凹凸棒土进行了改性,通过单因素实验对凹凸棒土的热改性条件进行了优化,且采用N2吸附-脱附、X射线衍射、扫描电镜等表征手段对其脱色机理进行了研究。结果表明,对玉米秸秆稀酸水解液的脱色效果最佳的凹凸棒土热改性条件:450℃焙烧2 h、酸浓度10%。酸化作用使凹土内粒间杂质胶结物和碳酸盐矿物分解,疏通内部孔道,H+与凹土结构内阳离子置换,增大比表面积,改善其表面特性;焙烧活化可除去不同状态的水,改变其结构,增大孔容和比表面积;两者结合处理使颗粒白土的吸附脱色能力提高。     

油松花粉水解液的脱色研究

以活性炭为吸附剂,对油松花粉水解液进行脱色,研究了影响花粉水解液脱色的主要影响因素.实验结果表明,活性炭脱色最佳工艺条件如下:脱色时间30min,脱色温度70℃,加入活性炭量1.0g,pH值5.所得油松花粉水解液无色,氨基氮损失率为2.4%,表明活性炭对花粉水解液有着较强的脱色效果.     

肌醇生产水解液脱色工艺研究

对肌醇的水解液脱色工艺进行了研究。通过改进，实现了安全生产，解决了粉状活性炭的二次污染，改善了工作环境：消除了生产中的安全质量隐患，保障了操作工人的人身安全；提高了单位时间装置生产能力。     

Glucobacter oxydans全细胞直接催化秸秆稀酸预处理水解液产木糖酸

以长期驯化选育得到的耐抑制物氧化葡萄糖酸杆菌Glucobacter oxydans NL71为催化菌株,对全细胞直接催化木质纤维(麦秆)稀酸预处理水解液产木糖酸的工艺进行研究。结果表明:未脱毒水解液对催化反应生产木糖酸具有抑制作用,且随浓度提高,抑制作用增强。提高细胞浓度和提高供氧能力可以有效抵抗麦杆稀水解液的抑制效应。在摇瓶体系中以2 g/L细胞接种量直接催化未经脱毒的麦秆稀酸水解浓缩液,当初始木糖质量浓度超过100 g/L时,细胞的催化性能受到严重抑制,木糖酸得率均低于50%;当细胞接种量提升至8 g/L时,木糖酸得率可以达到85.7%;在机械搅拌式通氧加压反应体系中,采用密封加氧技术对100 g/L木糖浓度的麦秸稀酸水解浓缩液全细胞催化24 h的细胞接种量8 g/L,木糖酸终质量浓度达到103.1 g/L,木糖酸得率可达到93.1%,产生速率为摇瓶体系的1.6倍。     

木质纤维素稀水解液脱毒研究进展

稀酸水解作为一种广泛使用的木质纤维原料的预处殚方法,已在生产中得到广泛应用,但由于木质纤维素经稀酸水解预处理后,水解液中会产生大量的对发酵有毒的物质如乙酸、糠醛、酚类物质等,从而影响进一步发酵.主要综述了木质纤维素稀酸水解的原理、发酵抑制物的产生及种类、发酵抑制物抑制发酵的原因及发酵液中发酵抑制物的脱毒方法进行了综述,并对脱毒发展前景做了展望.     

磷酸法麦秆活性炭的研制

本文就以麦秆为木质原料,以磷酸为活化剂制备活性炭的工艺过程进行了研究,得出了优化的工艺条件,同时对该工艺的环保及推广前景进行了分析。     

近临界水中鱼蛋白水解及水解液脱色研究

鱼类蛋白包括鱼肉及鱼类加工过程中产生的废弃物,文中采用近临界水技术,在反应温度180—320℃,反应压力5—26 MPa,反应时间5—60 min,无催化剂条件下将其制备成氨基酸,不但能提高附加值,而且有利于环境保护。实验结果发现,水解物含17种氨基酸,水解物中不同种类氨基酸的产率随反应温度、反应压力和反应时间的变化规律各不相同。对其中8种含量高、用途广、附加值高的氨基酸,分别得到了最佳水解工艺。以颗粒状活性炭为脱色剂,对水解液在不同pH值、活性炭用量、吸附温度和吸附时间条件下进行脱色实验,并考察脱色率和氨基酸损失率,结果表明,较好的脱色工艺条件为:pH=4.0,活性炭用量为0.020 g/mL,吸附温度45℃,吸附时间25 min,脱色率90%。被活性炭吸附的氨基酸,可以通过解吸附得到回收。     

活性炭纤维用于苦卤脱色的研究

采用活性炭纤维（ACF）对海盐苦卤进行吸附脱色实验.通过动态吸附实验,探讨了活性炭用量、溶液流速、温度、浓度、pH对脱色率的影响.确定活性炭纤维对苦卤溶液脱色的最佳工艺条件为：温度20 ℃,苦卤溶液浓度（以溶液中X-计）为2 mol/L,溶液pH＝6,动态吸附流速为6 mL/min.在此条件下,苦卤脱色率大于98%.活性炭纤维对海盐苦卤的饱和吸附量比颗粒活性炭大10倍.吸附后的活性炭纤维加热到120 ℃并抽真空进行脱附,可循环使用18次以上.     

分步脱色法处理苯酐酸水研究

就粉末活性炭和大孔树脂对苯酐酸水的脱色效果进行了研究。首先考察了活性炭种类、脱色时间、活性炭用量等因素对脱色效果的影响,结果表明在优化后的条件下其对苯酐酸水的脱色率仍难以达到90%。此后通过试验筛选了4种脱色用大孔树脂,发现SXD-11树脂具有较好的脱色效果。在实验条件下,流出液体积为5 BV时的酸水脱色率在95%以上,10 BV时的脱色率85%。针对工业应用,最后在活性炭脱色基础上构建了与树脂脱色相联合的分步脱色法。该分步脱色法不仅保证了流出液体积20 BV时总的脱色率保持在91%以上,还提高了树脂单批处理量和使用寿命,降低了脱色成本。     

Wheat straw acid hydrolysate as a potential cost‐effective feedstock for production of bacterial cellulose

BACKGROUND: Bacterial cellulose (BC) is an extracellular biopolymer product of vinegar bacteria, which is widely used in many areas. However, problems of high production cost have prevented widescale extension of BC applications. In this work, BC was produced using wheat straw hydrolysates prepared by dilute acid hydrolysis instead of the usual carbon sources, with the aim of decreasing the production costs of BC. RESULTS: In order to remove microbial growth inhibitors, wheat straw hydrolysates were detoxified by treatment with various alkalis including calcium hydroxide, sodium hydroxide and ammonia, and their combination with activated charcoal or laccase. Results showed that the detoxification effect using calcium hydroxide was much better than that with the other alkalis. The BC yield using hydrolysate treated with Ca(OH)₂ and activated charcoal was at least 50% higher than that using routine carbon sources. Additionally, the ions of Ca²⁺ and Na⁺ in the hydrolysates had important and positive effects on BC production while Cl^? exhibited negative effects. CONCLUSION: Wheat straw was shown to be a suitable feedstock for BC production, and a process was established for BC production from lignocellulosic feedstocks using a detoxification treatment. Copyright © 2011 Society of Chemical Industry     

抗真菌活性物质的活性炭法脱色过程研究

研究了活性炭对链霉菌182-2发酵液中抗真菌活性物质的脱色作用,讨论了实验条件对活性炭脱色能力的影响.实验结果表明,在28℃下,炭-液质量比1.0:2.5、脱色4 h时,1.5mm圆柱状活性炭对182-2发酵液具有良好的脱色效果,脱色率为77%.     

活性炭脱除湿法磷酸色素的研究

在采用溶剂萃取法净化湿法磷酸时,磷酸中的有色杂质会与萃取剂作用,干扰萃取过程,因此有必要事先对磷酸进行脱色处理.对4种活性炭的脱色及再生性能进行了研究,用间歇实验筛选出了一种脱色性能好、磷损失小的活性炭.并用玻璃吸附柱进行连续吸附实验,测定了其初始脱色率和最佳用量,以及经过1次再生和2次再生的再生率和最大脱色率.实验结果表明,新炭的最佳用量为1 kg原酸用12.9 g新炭,脱色率为72%;1次再生的活性炭再生率为99.5%,脱色率达到新炭的95%.适用于湿法磷酸脱色的活性炭是颗粒状、比表面积大、孔隙体积大和平均孔径大的一类产品.     

稻草水解液与乙腈的双水相分配特性

研究了稻草水解液中的糖在乙腈-水双水相体系中的分配行为,首先重点考察了双水相的形成,分析了乙腈与稻草水解浓缩液的体积比和温度等对糖的分配系数影响。乙腈体积分数低于50%时不能形成双水相。当V乙腈:V样品等于2或者3时,在25℃下实验,上层富含乙腈相中有葡萄糖、还原糖以及多糖同时存在,特别是当V乙腈:V样品等于3时,81.56%的葡萄糖提取到乙腈相中。在0℃下实验,上层富含乙腈相中都只检测到多糖。     

湿法磷酸一步法脱色脱氟工艺中磷酸损失率的研究

分别以活性炭和碳酸钠为脱色剂和脱氟剂,一步法脱色脱氟净化湿法磷酸,研究该工艺中影响磷酸损失率的因素。以Gore膜为过滤介质,确定了一步法脱色脱氟净化湿法磷酸的最佳工艺条件为：反应温度70℃,反应时间90min,活性炭与碳酸钠添加量分别为湿法磷酸处理质量的0.3％和2％,静置时间为1d。在此条件下,磷酸损失率在6％以内。     

Sugarcane bagasse hydrolysis with phosphoric and sulfuric acids and hydrolysate detoxification for xylitol production

The effectiveness of phosphoric acid to release xylose from sugarcane bagasse hemicellulose was assessed through a 2³ full factorial design. The maximum xylose concentration in the hydrolysate (17.1 g dm^?3) was attained when the bagasse was treated at 160 °C for 60 min, using 70 mg of phosphoric acid per gram of dry‐bagasse. Hydrolysis carried out with sulfuric acid, under optimum conditions previously determined, provided a hydrolysate with a similar xylose concentration (17.2 g dm^?3). After vacuum concentration, these hydrolysates were detoxified and used for xylitol production with the yeast Candida guilliermondii. Two different detoxification strategies, which consisted of adjusting the pH of the hydrolysates to 5.5 with either calcium oxide or ammonium hydroxide, both followed by active charcoal adsorption, were tested. The best xylitol productions (18.1 and 19.2 g dm^?3) were observed when calcium oxide was used to adjust the pH of both the phosphoric and the sulfuric acid hydrolysates, respectively. Copyright © 2004 Society of Chemical Industry     

湿法磷酸脱色脱氟实验研究

以活性炭为脱色剂、碳酸钠为脱氟剂,对净化湿法磷酸工艺中的影响因素进行研究,确定了湿法磷酸脱色脱氟同步进行的最佳工艺条件:采用1.0%湿法磷酸用量的活性炭,并添加1.1倍理论脱氟用量的Na2CO3,在50℃下反应120 min,处理后的湿法磷酸透光率达到80%以上,脱氟率也高于70%。     

L-乳酸脱色工艺研究

本试验采用活性炭对L-乳酸进行了脱色实验,从而达到L-乳酸的提纯与精制。在活性炭脱色工艺中,采用三因素三水平的正交实验方法,考察了反应温度、反应时间和活性炭用量对脱色率的影响。实验结果表明,在活性炭脱色工艺中,三个因素对脱色率影响的大小的顺序为：活性炭用量〉反应温度〉反应时间;最适工艺条件为：活性炭用量15g／L,反应时间30min,反应温度为50℃,此时的脱色效果最好。     

Effect of pH and activated charcoal adsorption on hemicellulosic hydrolysate detoxification for xylitol production

Biotechnological conversion of xylose into xylitol using hydrolysates obtained from the hemicellulosic fraction of lignocellulosic materials is compromised by the presence of compounds released or formed during the hydrolysis process, some of them being toxic to microorganisms. In order to improve the bioconversion of these hydrolysates it is necessary to find methods to reduce their toxicity. In the present work, rice straw hemicellulosic hydrolysate was treated by six different procedures (all of them involving pH adjustment, with or without activated charcoal adsorption), before being used as a fermentation medium for xylitol production. The most effective method of treatment was to increase the initial pH (0.4) to 2.0 using solid NaOH, followed by the addition of activated charcoal (25 g kg^?1) and increase in the pH to 6.5 using solid NaOH. Lignin degradation products were the most inhibitory compounds present in the hydrolysate; their removal was selective and strongly dependent on the pH employed in the treatment. The highest yield of xylitol was 0.72 g g^?1 xylose, with a productivity of 0.55 g dm^?3 h^?1. Copyright © 2004 Society of Chemical Industry