微波协同萃取射干异黄酮的研究

Microwave-assisted extraction （MAE） of isoflavones from Belamcanda chinensis was studied using ethanol as the solvent. The single factor experiment and the orthogonal method were used to optimize the MAE condition. It was concluded that two doses of intermittent microwave power radiation, 300 W each for 4 rain, were needed for extraction. The mass ratio of solvent to material was 8：1 and the alcohol mass fraction was 80%. The extracted liquor was then concentrated under vacuum and degreased with petroleum ether. The yield of total isofiavones was about 8.8% and the contents of tectoridin and iridin were 67.6% and 16.3% respectively. Compared with direct-heating extraction （DHE）, MAE may shorten extracting duration, reduce solvent consumption, and improve yield and purity of isoflavones from Belamcanda chinensis.     

用于乙醇脱水的生物质吸附性能

The adsorption capability of paddy flour and maize flour for gaseous phase selective adsorption for ethanol dehydration was investigated via a bench-test fixed-bed adsorber at constant temperature. Ethanol concentration in the feed was 93.4% (mass) and each of the dried biomass was used as adsorbent, and breakthrough curves and temperature distribution in adsorptive bed were obtained for different bed depths,superficial velocities, granularities of adsorbent and temperatures. Bed pressure drop curves for different bed depths and superficial velocities were also measured. A product of ethanol purity of 99.5% (mass) could be obtained through both kinds of biomass adsorbent. When 99.5% (mass) of ethanol purity is defined as the breakthrough point, the production capacity for either adsorbent was within 0.0915-0.2256 (gram product/gram adsorbent). Tests on pure ethanol adsorption were also performed to extrapolate the selectivity of both adsorbents.     

酒精-沼气双发酵耦联工艺中丙酸对酿酒酵母酒精发酵的影响(英文)

Propanoic acid accumulated in an ethanol-methane coupled fermentation process affects the ethanol fermentation by Saccharomyces cerevisiae. The effects of propanoic acid on ethanol production were examined in cassava mash under different pH conditions. Final ethanol concentrations increased when undissociated propanoic acid was <30.0 mmol·L-1 . Propanoic acid, however, stimulated ethanol production, as much as 7.6% under proper conditions, but ethanol fermentation was completely inhibited when undissociated acid was >53.2 mmol·L-1 . Therefore, the potential inhibitory effect of propanoic acid on ethanol fermentation may be avoided by controlling the undissociated acid concentrations through elevated medium pH. Biomass and glycerol production decreased with propanoic acid in the medium, partly contributing to increased ethanol concentration.     

生物油中乙酸和乙醇共裂化获取汽油产物的研究简

Abstract Acetic acid was selected as the model compound representing the carboxylic acids present in bio-oil. This work focuses the co-cracking of acetic acid with ethanol for bio-gasoline production. The influences of reaction temperature and pressure on the conversion of reactants as well as the selectivity and Conaposition of the crudegasoline phase were investigated. It was found that increasing reaction temperature benefited the conversion of reactants and pressurized cracking produced a higher crude gasoline yield. At 400 ℃ and 1 MPa, the conversion of the reactants reached over 99% and the selectivity of the gasoline phase reached 42.79% （by mass）. The gasoline phase shows outstanding quality, with a hydrocarbon content of 100%.     

Influences of operating conditions on biocatalytic activity and reusability of Novozym 435 for esterification of free fatty acids with short-chain alcohols:A case study of palm fatty acid distillate

In the present study, the effects of operating conditions on biocatalytic activity and stability of Novozym 435 for repeated-batch biodiesel production from free fatty acid (FFA) were investigated. Thermal deactivation caused by increased operating temperature from 45 to 50 °C could seriously affect the reusability of Novozym 435. The deactivation of Novozym 435 during the esterification of oleic acid with ethanol tended to be stronger than that in the system with methanol. Under the optimal conditions, considering both biocatalytic activity and stability of the enzyme, Novozym 435 could be reused for 13 cycles for biodiesel productions from oleic acid and absolute alcohols (methanol and ethanol) with FFA conversions of at least 90%. The presence of 4%–5%water in ethanol significantly affected the reusability of Novozym 435. Changes in the surface morphology of Novozym 435 during the esterification with various conditions were observed. It was revealed that the reduc-tion in catalytic activity was related to the swel ing degree of the catalyst surface. Additionally, biodiesel produc-tion from low cost renewable feedstocks, such as palm fatty acid distillate (PFAD) and 95%ethanol was examined. The esterification of PFAD with 95%ethanol catalyzed by Novozym 435 in 10-repeated batch operation showed the similar results in FFA conversion as compared to those using oleic acid. Novozym 435 remained active and could maintain 97.6%of its initial conversion after being used for 10 batches.     

Detoxification and concentration of corn stover hydrolysate and its fermentation for ethanol production

Environmental and energy concerns have increased interest in renewable energy sources, particularly biofuels. Thus the fermentation of glucose from sulfuric acid-hydrolyzed corn stover for the production of bioethanol has been explored using a combined acid retardation and continuous-effect membrane distillation treatment process. This process resulted in the separation of the sugars and acids from the acid-catalyzed hydrolysate, the removal of most of the fermentation inhibitors from the hydrolysate and the concentration of the detoxified hydrolysate. The recovery rate of glucose from the sugar-acid mixture using acid retardation was greater than 99.12% and the sulfuric acid was completely recovered from the hydrolysate. When the treated com stover hydrolysate, containing 100 g/L glucose, was used as a carbon source, 43.06 g/L of ethanol was produced with a productivity of 1.79 g/(L· h) and a yield of 86.31 %, In the control experiment, where glucose was used as the carbon source these values were 1.97 g/(L·h) and 93.10% respectively. Thus the integration of acid retardation and a continuous-effect membrane distillation process are effective for the production of fuel ethanol from com stover.     

Design of reactive distillation processes for the production of butyl acrylate:Impact of bio-based raw materials☆

The chemical industry is nowadays predominantly using fossil raw materials, but the alternative use of bio-based resources is investigated to account for the foreseeable scarcity of fossil feedstocks. A main challenge of using bio-based feedstocks is the complexity of the impurity profile. For an economic production of bio-based chemicals, the use of intensified processes is inevitable and approaches are needed for the various process intensification techniques to identify their applicability to be used for the production of bio-based components. In the presented study, an approach is shown for the reactive distil ation (RD) technology to identify the most critical bio-based impurities and their impact on the reactive distillation process. The investigated case-study is the production of n-butyl acrylate from acrylic acid and n-butanol. Among al initially identified impurities, the key impurities, having the biggest impact on the product purity in the reactive distil ation process, are found. These impurities are then studied in more detail and an operating window depending on the impurity concentration is identified for the reactive distil ation column. Furthermore, an integrated design of upstream and downstream processes is facilitated, as the presented results can be used in the development of the fermentation processes for the produc-tion of the bio-based reactants by decreasing the concentration of the critical impurities.     

有机溶剂原位萃取法提高悬浮培养中国红豆杉细胞紫杉醇产量

The production of paclitaxel from suspension culture of Taxus chinensis var,mairei was improved by in situ extraction with organic solvents to avoid feedback repression and product degradation.Oleic acid and dibutyl phthalate were proved to be suitable solvents .The optimal volumetric percentage of organic solvents in the culture medium was found to be around 8%,and the favorable time for their introduction was at the exponential phase of cell growth,Paclitaxel production with the in situ extraction was ca 3-fold of that without extraction.     

反应精馏合成乙酸丁酯的实验和模拟(英文)

In this paper, a reactive distillation (RD) column was applied for synthesis n-butyl acetate from n-butanol and acetic acid. The Langmuir-Hinshelwood-Hougen-Watson (LHHW) kinetic model and an equilibrium stage model for separation were employed to study the RD process. The results obtained from the equilibrium stage model agreed well with the experiments. The effects of operating variables on the n-butanol conversion and n-butyl acetate purity were further investigated. The optimal column configuration for the production of n-butyl acetate was designed with 5 rectifying stages, 8 reaction stages and 13 stripping stages by the simulation study. According to the simulation results, n-butanol conversion and n-butyl acetate purity all reached greater than 96%.     

固定化Candida sp. 99-125脂肪酶催化合成蜡酯(英文)

Wax esters were synthesized in a solvent free system catalyzed by immobilized lipase from Candida sp. 99-125, with oleic acid and cetyl alcohol. The effects of substrate molar ratio, lipase dosage and water removal were investigated in a 50 ml flask incubated in a thermostatic cultivation cabinet. The optimized conditions were: temperature 40 ℃, shaking at 170 r·min-1, acid/alcohol molar ratio 1:0.9, lipase dosage in 10% (by mass) of oleic acid, and open reaction for water removal. As a result, the conversion rate reached 98% for reaction of 8 h. The volume of reactor was scaled up to 1 L three-neck flask. The optimized parameters were: 200 r·min-1 agitation speed, 2.5% (by mass) lipase dosage, others were the same as the parameters described above. The conversion rate reached 95% for reaction of 24 h. The lipase retained 46% conversion rate after reuse for 6, 7 batches. The products were purified by removing remained cetyl alcohol and fatty acids with ethanol and saturated sodium carbonate so-lution, respectively. The purity of the wax ester, cetyl oleate, was 96%. The physical and chemical properties of cetyl oleate were tested and compared with those of jojoba oil. The results show that the product cetyl oleate has great potential to use as the substitute of natural jojoba oil.     

夏枯草降糖成分提取工艺的优化

文章介绍夏枯草中降糖成分提取条件的优化研究,以熊果酸为指标物。采用乙醇加热回流法,检测方法采用紫外分光光度法,检测波长为206nm。用石油醚洗涤去除大部分杂质。选择乙醇浓度,料液比,提取温度,提取时间为考察因素。确定夏枯草中熊果酸最佳工艺条件为80%乙醇为溶剂,料液比1︰20,在80℃恒温下,水浴回流110min。该方法简单易行。     

微波辅助法提取辣椒红色素的探讨

文章对辣椒红色素的提取进行了较为详尽的研究。结果表明,适宜选用乙醇作为提取剂,提取液的最大吸收波长为471 nm;佳工艺条件是提取温度为55℃;提取时间2.5 h;物料比(g/ml)为1∶6.5。对微波辅助提取辣椒红色素的工艺进行了研究,最佳工艺条件:即微波功率为大火(600 W),微波作用12 min。该工艺具有溶剂用量少,提取周期较短,提取率较高等特点。且验证实验表明,该工艺条件操作稳定,有较好的重复性。     

离子液体中结晶分离熊果酸和齐墩果酸研究

为拓展结晶溶剂的范围和提高结晶分离熊果酸和齐墩果酸的性能，引入离子液体作为结晶溶剂。测定了熊果酸和齐墩果酸在六种离子液体+乙醇溶液中的溶解度数据，根据该数据，选取1-辛基-3-甲基咪唑六氟磷酸+乙醇混合溶液作为溶剂对熊果酸和齐墩果酸进行了结晶分离，并采用单因素实验对结晶工艺进行了初步优化。结果表明：在1-辛基-3-甲基咪唑六氟磷酸质量分数5%，熊果酸和齐墩果酸质量比1.5∶1，结晶温度30℃，结晶时间14 h的条件下，结晶产物中齐墩果酸的质量分数可以达到85%左右。     

Microwave-Assisted Extraction of Oleanolic Acid and Ursolic Acid from Ligustrum lucidum Ait

Oleanolic acid and ursolic acid are the main active components in fruit of Ligustrum lucidum Ait, and possess anticancer, antimutagenic, anti-inflammatory, antioxidative and antiprotozoal activities. In this study, microwave-assisted extraction of oleanolic acid and ursolic acid from Ligustrum lucidum was investigated with HPLC-photodiode array detection. Effects of several experimental parameters, such as type and concentration of extraction solvent, ratio of liquid to material, microwave power, extraction temperature and microwave time, on the extraction efficiencies of oleanolic acid and ursolic acid from Ligustrum lucidum were evaluated. The influence of experimental parameters on the extraction efficiency of ursolic acid was more significant than that of oleanolic acid (p < 0.05). The optimal extraction conditions were 80% ethanol aqueous solution, the ratio of material to liquid was 1:15, and extraction for 30 min at 70 °C under microwave irradiation of 500 W. Under optimal conditions, the yields of oleanolic acid and ursolic acid were 4.4 ± 0.20 mg/g and 5.8 ± 0.15 mg/g, respectively. The results obtained are helpful for the full utilization of Ligustrum lucidum, which also indicated that microwave-assisted extraction is a very useful method for extraction of oleanolic acid and ursolic acid from plant materials.     

结晶法提纯工业磷酸的数学模型与实验研究

为了制备电子级磷酸,采用了悬浮结晶法对工业磷酸进行提纯。分析了结晶法提纯工业磷酸的原理,并基于结晶过程中杂质的有效分配系数对多次结晶后杂质的分布建立了晶体纯度预测模型,同时考察了酸浓度、结晶次数和磷酸原料杂质初始含量对磷酸提纯效果的影响。研究结果表明,采用结晶法提纯磷酸具有良好的效果,能有效地脱除所考察的五种杂质(Li、Mg、Al、Cr、Mn);以一次晶体为原料,在磷酸浓度为84%的条件下,经过3次结晶,和在磷酸浓度为88%的条件下,经过4次结晶,均可以达到美国典型半导体磷酸要求。所建立的晶体纯度预测模型能很好地预测杂质浓度随结晶次数的变化。     

乙醇提取-丙酮沉淀法提取分离茶皂素的工艺研究

以油茶饼粕为原料，采用乙醇提取-丙酮沉淀法对茶皂素进行提取分离。以茶皂素纯度和得率为考察指标，对乙醇体积分数、液料比、提取温度、提取时间、提取次数、提取液浓缩程度和丙酮用量等工艺参数进行了单因素优化。结果表明：体积分数95%的乙醇为提取溶剂，乙醇与预处理过的油茶饼粕液料比为9：1（mL：g），提取温度为70℃，提取时间为4 h，提取次数为2次，提取液浓缩至刚好有固体析出，丙酮用量为4倍浓缩液体积量时提取分离效果较佳，得到的茶皂素纯度为85.17%，得率为9.82%。不同溶剂打浆对产品纯化效果的比较发现：丙酮、乙酸乙酯、无水乙醇、体积分数95%的乙醇作为打浆纯化溶剂用于提高茶皂素纯度效果均不明显。     

鸡爪槭等8种植物提取物对萝卜蚜的毒杀作用

[目的]从植物中筛选对萝卜蚜有生物活性的物质。[方法]用冷浸提取法,以萝卜蚜为供试昆虫,采用浸叶法测定了8种植物乙醇提取物的杀虫活性,并对鸡爪槭等3种植物提取物进行了毒力测定。[结果]在质量浓度为500 mg/L时,鸡爪槭乙醇提取物24、48 h校正死亡率分别为62.34%和81.61%;陆英和棕榈48 h校正死亡率分别为78.88%和83.65%。鸡爪槭、棕榈和陆英48 h对萝卜蚜的致死中浓度(LC50值)分别为26.08、147.96、159.53 mg/L。相对毒力顺序为鸡爪槭>棕榈>陆英。[结论]鸡爪槭叶具有潜在的杀虫活性。     

红枣中熊果酸的微波提取工艺研究

以红枣为原料,利用微波技术提取红枣中熊果酸。通过单因素实验和正交实验,考察φ(乙醇)、液料比、提取温度、微波功率、微波提取时间对熊果酸提取率的影响。结果表明,微波法提取红枣熊果酸的最佳工艺条件为:φ(乙醇)=90%、液料比20∶1(mL/g)、提取温度60℃、微波功率300 W、微波提取时间90 s。在此工艺条件下,熊果酸的提取率为2.412 7 mg/g。     

钛-二氧化铅阳极电解次磷酸钠制备高纯次磷酸

以六室电解槽为反应槽,分别以石墨电极、钛-二氧化铅电极和钛涂钌电极为阳极,不锈钢为阴极电极,研究了电解法制备成本低、纯度高且环境友好的次磷酸新工艺。结果表明：六室电解槽制得的次磷酸杂质少;与国内外常用石墨和钛涂钌阳极材料相比,钛-二氧化铅电极作为阳极材料在阳极电位、产品浓度及产品室电流效率方面性能优良。钛-二氧化铅电极没有固体沉淀,无其他杂质离子产生,阳极液不必更换,只需定期补充电解消耗的水,属于清洁生产。在最佳电解电流、电解温度、原料浓度和电解时间条件下制得次磷酸产品,经减压富集后其杂质含量能够满足电容器生产的要求。     

螯合剂对湿法磷酸制备磷酸二氢钾结晶过程影响

湿法磷酸生产成本低,但杂质含量高,以湿法磷酸为原料制得的磷酸二氢钾(KDP)产品质量低。研究利用中和法,以杂质含量高的工业湿法磷酸为原料,制备柱状大颗粒磷酸二氢钾晶体。研究了螯合剂用量、降温速率和搅拌速率对磷酸二氢钾结晶过程的影响,考察了磷酸二氢钾的质量分数、收率、结晶速率和晶体形貌等指标,并进行了母液循环实验。研究结果表明：螯合剂能有效消除杂质离子对结晶过程的抑制作用。结晶的最适宜工艺条件为螯合剂用量0.70%、搅拌速率100 r·min^-1、降温速率0.1℃·min^-1。在此条件下得到的磷酸二氢钾晶体外观为柱状大颗粒,质量分数99.91%,平均粒度1.38 mm,结晶速率0.128 g·min^-1,达到肥料级磷酸二氢钾优等品标准(HG/T 2321—2016);其中磷的单次收率49.86%。母液循环生产的磷酸二氢钾晶体质量分数、晶型和收率等指标全部达标。