乙醇-超声波提取豆酱中大豆苷元工艺参数研究

探讨乙醇-超声波提取豆酱中大豆苷元的最佳工艺条件,在单因素试验基础上,以大豆苷元得率为响应值,采用Box-Benhnken响应面设计进行试验,得到了超声波提取大豆苷元的数学回归方程、响应曲面图及等高线图,确定了最佳提取工艺参数.结果表明,最佳提取工艺条件为超声波提取时间为61.51min,超声波提取温度为48.41℃,乙醇浓度为74.18％vol,豆酱中大豆苷元的得率为484.610μg/g.     

甜高粱茎秆汁的成分及其乙醇发酵的研究

采用原子吸收分光光度法和高效液相色谱法等技术,检测了甜高粱茎杆汁的主要成分质量浓度,包括蔗糖、果糖和葡萄糖、总氮量以及若干金属元素质量浓度;采取响应面法建立尿素、MgSO4、KH2PO4、CaCl2等的加入量最优组合的二次回归数学模型。结果表明,当尿素、MgSO4、KH2PO4和CaCl2的添加量分别为8.4228、1.0938、4.1702和4.0422g/L时,乙醇发酵得率达93.18%,比优化前乙醇质量浓度提高了9.56g/L。     

籽用南瓜果肉制备燃料乙醇发酵工艺

以籽用南瓜果肉为试材,探索了燃料乙醇的连续制备工艺.采用二次回归正交旋转组合设计,对制备工艺中的各个因素进行优化,确定了最佳燃料乙醇的制备条件,提高了产品的得率.南瓜果肉经蛋白提取后,剩余部分经液化、糖化、发酵、蒸馏等过程制备燃料乙醇.发酵最佳条件为:发酵pH4.38、酵母添加量为原料的0.063％、发酵温度为29.7℃、发酵时间为70.8h.在此条件下,乙醇最大发酵率为64.4％.     

生物质合成气发酵制取燃料乙醇研究进展

随着能源危机的日益严重,开发能够代替化石能源的可再生清洁能源已成为研究热点。燃料乙醇是一种很有应用潜力的替代能源,利用生物质合成气发酵是一种生产燃料乙醇的新技术。文章对该技术的生产工艺优势、生物质气化技术发展现状、生物质合成气发酵生产乙醇微生物、发酵基本过程和代谢机理及产业化进展进行了阐述,并提出了该领域面临的问题和建议。     

利用酸化油在超临界乙醇中制备生物柴油

以酸化油、乙醇为原料,在超临界条件下制备生物柴油。采用响应面设计和分析方法对工艺条件进行了优化,得到了最佳工艺条件：反应温度是284.8℃,醇油摩尔比30.8,反应时间43.7min,在此条件下产率达到89.7%。各因素对生物柴油产率影响的主次顺序为：反应温度〉醇油摩尔比〉反应时间,且反应温度与醇油摩尔比对生物柴油产率的交互影响效应显著,醇油摩尔比与反应时间对生物柴油产率的交互影响效应不太显著。     

利用甘蔗渣制取乙醇和低聚木糖

鉴于能源、环境、再生资源利用等问题,对甘蔗渣进行开发利用具有很好前景.本文介绍了甘蔗渣成分及总结介绍了最新利用蔗渣的方法,制备乙醇和功能性低聚木糖的研究情况.     

响应面法优化麦草酸催化乙醇法制浆工艺

因子实验研究结果表明，显著影响麦草酸催化乙醇法制浆的外界因子是乙醇体积分数、蒸煮温度、催化剂用量和保温时间。在此基础上，采用响应面建立了细浆得率的二次多项数学模型，分析了模型的有效性及各因子的交互作用和最佳水平范围；优化出细浆得率取得最大值的外界条件为：乙醇体积分数65％，蒸煮温度190℃，催化剂用量0．8％，保温时间52．5min。     

响应面法优化新疆红枣总黄酮乙醇提取工艺

以新疆红枣为原料,为优化新疆红枣中总黄酮的乙醇提取工艺,选择提取温度、乙醇浓度、液料比为自变量,总黄酮含量作为响应值,采用Box-Behnken设计方法,研究各自变量及其交互作用对总黄酮提取量的影响。采用响应面分析软件,模拟得到二次多项式回归方程的预测模型,并确定乙醇提取最佳工艺条件为提取温度66℃、乙醇浓度60%vol、液料比10.0。在此条件下,总黄酮的平均提取量为2.32mg/g,与理论预测值基本吻合,说明响应面法优化新疆红枣总黄酮乙醇提取工艺可行。     

燃料乙醇脱水工艺的研究与展望

探讨燃料乙醇的多种生产工艺,主要包括精馏、膜分离和吸附。综述了精馏工艺中萃取精馏、溶盐精馏、加盐萃取精馏及共沸精馏的研究现状,展望新技术在其中的应用,包括离子液体萃取和热泵共沸精馏。简述膜分离技术中渗透汽化和蒸汽渗透工艺,分析膜分离技术中最关键的膜性能研究进展。总结吸附工艺的优越性,分析分子筛吸附生产燃料乙醇,着重介绍新兴的生物质吸附法,探索燃料乙醇工业走向节能环保的绿色之路。      

利用响应面法优化乳酮糖制取工艺的研究

采用响应分析法较系统地研究了碱性条件下乳糖异构生产乳酮糖的工艺条件,得到了在一定条件范围内异构率随反应温度、时间、ＰＨ值的变化规律（回归方程）及相应的ＲＳＡ等高图,可用于对异构率的预测及生产中工艺条件的优化。     

堆积糖化对玉米秸秆同步糖化固态发酵生产乙醇的影响

该文以玉米秸秆为原料,经蒸汽爆破预处理后接入Trichoderma reesei Rut C-40培养纤维素酶曲,将纤维素酶曲与汽爆秸秆混合堆积糖化后,接入酵母菌进行同步糖化固态发酵生产乙醇,通过Box-Behnken设计实验得到最适酶解工艺条件:酶曲/汽爆秸秆为1.2,温度46℃,pH值4.4,堆积糖化48h后酶解率可达到32.50%。将酶解糖化48h后的底物接入酵母菌,发酵96h后乙醇产率可达0.15g/g底物,较直接同步糖化发酵乙醇产率提高了9.3%。     

木薯半连续同步糖化发酵乙醇

研究了用木薯为原料,半连续同步糖化发酵生产乙醇的工艺。工艺条件为:原料粉碎粒度:Φ1.5mm,料水比:1∶2.3,α-淀粉酶、糖化酶的添加量分别为9U/g木薯粉,120U/g木薯粉,95℃下蒸煮90min～110min,60℃下前糖化35min～40min。前期发酵温度28℃,中后期发酵温度32℃,总发酵时间69h。在此条件下酒精度达到13.5%vol,半连续发酵17d,为进一步研究以木薯为原料生产乙醇工业化提供了依据。     

混合菌同步糖化共发酵造纸污泥产乙醇

对酿酒酵母（Saccharomyces cerevisiae）与重组大肠杆菌K011（Escherichia coli）混合菌同步糖化共发酵造纸污泥产乙醇进行了初步研究。在底物浓度为50g／L时,通过单因素实验和正交实验获得乙醇发酵的最佳条件：纤维素酶添加量25FPU／g底物,接种量为6％,酿酒酵母与重组大肠杆菌K011接种比例为1：1（细胞干重初始浓度分别为1．0g／L和0．3g／L左右）。发酵72h后,乙醇浓度为5．71g／L,产率达到0．114g乙醇／g污泥,达到理论值的42．5％。分别用酿酒酵母、K011单菌种发酵与双菌株组合发酵对比结果表明,混合菌发酵效果明显优于单菌种发酵。     

马铃薯渣同步糖化发酵生产酒精工艺研究

以马铃薯渣为原料,采用同步糖化发酵技术生产酒精。考察料液比、α-淀粉酶用量、糖化酶用量、纤维素酶用量、酵母添加量、pH值、发酵温度、发酵时间等因素对发酵的影响,确定生产工艺。结果表明,料液比1∶5,α-淀粉酶用量15U/g,糖化酶用量200U/g,纤维素酶用量12U/g,酵母用量0.8%,pH值为4,发酵温度为32℃,发酵时间72h为最佳工艺。     

马铃薯渣生料同步糖化发酵生产乙醇工艺研究

采用生料同步糖化发酵法,将马铃薯提取淀粉后的废渣进行发酵制备乙醇,对各影响因素进行了探讨,获得了最佳发酵工艺条件.结果显示:适宜发酵条件为水料比3.5∶1.0、初始pH4.5、酵母接种量0.4％、发酵温度32℃、糖化酶添加量160U/g,α-淀粉酶添加量10U/g、纤维素酶添加量10U/g、原料粒度0.40mm.     

响应面法优化马铃薯渣生料同步糖化发酵生产乙醇工艺

采用生料同步糖化发酵法,将马铃薯废渣发酵生产乙醇,对各个影响因素进行了研究,并通过响应面法优化发酵工艺。结果显示:最佳发酵条件为水料比3.5∶1、初始pH值4.5、酵母接种量0.42%、发酵温度32℃、糖化酶添加量165U/g、α-淀粉酶添加量11U/g、纤维素酶添加量12U/g、原料粒度0.40mm。该方法工艺简单,能耗小,成本低,可用于马铃薯废渣工业化处理。     

Lactic acid production by simultaneous saccharification and fermentation of alfalfa fiber

Lactic acid was produced by simultaneous saccharification and fermentation (SSF) of liquid hot water (LHW)-pretreated and non-LHW-pretreated alfalfa fibers. The Lactobacillus plantarum and L. delbrueckii strains produced 0.464 and 0.354 g of lactic acid per g of dry matter of alfalfa fiber, respectively, by non-LHW pretreatment. L. xylosus and L. pentoaceticus produced lower yields of lactic acid from the same amount of alfalfa fiber, however, their acetic acid production was higher. These Lactobacillus strains did not require any additional nutrients during SSF of non-LHW-pretreated alfalfa fiber. After LHW pretreatment, the "raffinate" cellulosic fraction of alfalfa required additional nutrients for lactic acid production by SSF. Both L. plantarum and L. delbrueckii produced 0.606 and 0.59 g of lactic acid per g of dry matter of fiber, respectively. However, the "extract" soluble hemicellulosic fraction of alfalfa produced 0.38 to 0.62 g of lactic acid per g of dry matter extract during SSF and did not require nutrient supplementation. These results suggest that during the LHW pretreatment, alfalfa fiber nutrients are lost in cellulosic fractions but retained in hemicellulosic extract fractions.     

Ultrasound-assisted production of bioethanol by simultaneous saccharification and fermentation of corn meal

An ultrasound-assisted liquefaction as a pretreatment for bioethanol production by simultaneous saccharification and fermentation (SSF) of corn meal using Saccharomyces cerevisiae var. ellipsoideus yeast in a batch system was studied. Ultrasound pretreatment (at a frequency of 40 kHz) was performed at different sonication times and temperatures, before addition of liquefying enzyme. An optimal duration of the treatment of 5 min and sonication temperature of 60 °C were selected, taking into account glucose concentration after the liquefaction step. Under the optimum conditions an increase of glucose concentration of 6.82% over untreated control sample was achieved. Furthermore, the SSF process kinetics was assessed and determined, and the effect of ultrasound pretreatment on an increase of ethanol productivity was investigated. The obtained results indicated that the ultrasound pretreatment could increase the ethanol concentration by 11.15% (compared to the control sample) as well as other significant process parameters. In this case, the maximum ethanol concentration of 9.67% w/w (which corresponded to percentage of the theoretical ethanol yield of 88.96%) was achieved after 32 h of the SSF process. A comparison of scanning electron micrographs of the ultrasound-pretreated and untreated samples of corn meal suspensions showed that the ultrasound stimulated degradation of starch granules and release of glucose, and thereby accelerated the starch hydrolysis due to the cavitation and acoustic streaming caused by the ultrasonic action.     

Effective enzyme saccharification and ethanol production from Japanese cedar using various pretreatment methods

We investigated an effective method for the pretreatment of Japanese cedar for efficient enzymatic saccharification and ethanol production. A 45-atm steam explosion provided a comparatively large amount of glucose and reducing sugars. Addition of polyethylene glycol (PEG) influenced the digestibility of holocellulose in a 35-atm steam-exploded sample. However, we observed a negative effect on enzymatic saccharification when sodium hydroxide was used in the pretreatment. The maximum values of glucose and reducing sugars produced using consecutive pretreatments with a 25-atm steam explosion and an ionic liquid were 408 and 462 mg/(g initial dry sample), respectively. The most positive effects on the enzymatic saccharification kinetics were observed when the above consecutive pretreatment methods were used. However, using the organosolv treatment of wood chips without the steam explosion is a more cost-effective pretreatment method for the enzymatic saccharification of Japanese cedar, and this results in 386 and 426 mg/(g initial dry sample) of glucose and reducing sugars, respectively.     

氧化去木质素玉米芯同步糖化发酵产2,3-丁二醇

2,3-丁二醇是一种重要的平台化合物。选取经过碱性高锰酸钾(APP)预处理后的玉米芯为底物,采用阴沟肠杆菌Enterobacter cloacae CICC10011通过同步糖化发酵工艺(SSF)发酵产2,3-丁二醇。通过对SSF主要工艺参数进行优化,确定最适宜工艺条件为:底物浓度120 g/L,纤维素酶添加量40 FPU/g,木聚糖酶添加量12 000 U/g,发酵温度35℃,初始发酵p H 5.5,转速180 r/min。在最优发酵条件下,以APP预处理后的玉米芯为底物连续发酵36 h,2,3-丁二醇的浓度为21.5 g/L,转化率为0.27 g/g(以纤维素和半纤维素为参照);分别是未处理的玉米芯为底物时的8.41倍和8.71倍。