丙酮-丁醇精馏工艺中丁醇塔的优化模拟

针对发酵法的丙酮-丁醇精馏工艺中能耗较高的问题,提出一个优化方案:在醪塔增加一个侧线出料,醪塔的侧线与塔顶出料分别从不同位置进入丁醇塔,并增加丁醇塔的塔高,同时将丁醇塔内的分相罐移至塔外。采用PRO/Ⅱ化工流程模拟软件对优化后的丁醇塔进行模拟计算,考察了理论塔板数、进料位置、回流比对分离性能的影响。优化的丁醇塔为40块理论塔板,两股进料位置分别为第8块和第14块理论塔板,回流比为4。在此条件下,丁醇塔塔顶馏出物中水的质量分数由8.56%降为2.18%,丁醇的质量分数由2.71%降为微量,蒸汽消耗量与原丁醇塔相比降低了52.6%。工业试运行结果与优化结果吻合良好。     

MgFe2O4纳米复合氧化物的制备和气敏性能

用反滴定化学共沉淀法制备了纳米尺寸尖晶石型的复合金属氧化物MgFe2O4粉体.用X射线粉末衍射分析、透射电镜等手段研究了其结构特性.MgFe2O4粉体颗粒均匀,700℃煅烧1 h粉体平均粒径约为20 nm.研究表明煅烧温度对材料的结构及性能有较大的影响.以MgFe2O4纳米粉体为原料制备了旁热式气敏元件,测试了元件的敏感特性和响应恢复特性.结果显示,MgFe2O4是一种良好的n型半导体气敏材料,700℃煅烧1 h所得纳米粉体制作的元件在300℃工作温度时对CH3COCH3有较高灵敏度和良好的选择性,对体积分数为1 000×10-6的CH3COCH3的灵敏度可达36.87.并对气敏机理给予了解释.     

花状ZnO纳米棒的合成及丙酮敏感特性的研究

利用水热法合成花状的ZnO纳米棒,并对其进行X射线衍射（X-ray diffraction, XRD)与扫描电子显微镜（scanning electron microscope, SEM) 表征.以该ZnO为敏感材料制成了旁热式结构气体传感器,测试了样品在不同温度下对丙酮气体的灵敏度.结果表明样品在290℃下对于丙酮气体具有高的灵敏度、快的响应恢复速度等特点.测试了传感器对于常见干扰气体的灵敏度,表明器件具有良好的选择性.     

一种从红辣素中制备高品质红辣素的方法

对红辣素中丙酮不溶物进行了研究,选取了脱胶剂、物料比、搅拌时间、搅拌温度作为参数,以红辣素中丙酮不溶物作为评价指标,优化了红辣素脱胶工艺,并由正交试验确定了除去红辣素中丙酮不溶物的最优条件:物料比5∶3 (g/mL),硫酸钾水溶液为40%、,搅拌时间为3h,搅拌温度为50℃。     

基于喷墨打印的可实现敏感材料原位沉积和高温检测的柔性丙酮气体传感器

通过离子交换技术对衬底表面改性,然后喷墨打印掩膜图形,在聚酰亚胺衬底两面分别制备了银叉指电极和加热电阻.通过调节电阻加热器两端的直流偏压,实现25 ℃~280 ℃的控温加热.集成的加热器具有双重功能:纳米ZnO敏感薄膜原位沉积和高温检测.结果表明,该传感器对丙酮气体的灵敏度随温度单调增加(<150 ℃).此外,加热器促进了ZnO敏感薄膜表面丙酮气体分子的解吸,缩短了传感器响应和恢复时间,并减小了初始电阻的漂移.此外,在丙酮检测中,加热器能有效地减少湿度干扰.     

Electrophysiological and Behavioral Responses of <Emphasis Type="Italic">Ips subelongatus</Emphasis> to Semiochemicals from Its Hosts,Non-hosts,and Conspecifics in China

Volatiles from hosts, non-hosts, interspecifics, and conspecifics of the Asian larch bark beetle, Ips subelongatus Motsch., were analyzed using both gas chromatographic-electroantennographic detection (GC-EAD) and gas chromatography/mass spectrometry (GC-MS) techniques, and field trapping bioassays in Inner Mongolia, China. GC-EAD experiments indicated that I. subelongatus antennae (both sexes) strongly responded not only to the major male-produced conspecific components, ipsenol, and ipsdienol, but also to other bark beetle compounds (cis-verbenol and verbenone), host monoterpenes (α-pinene, β-pinene, and para-cymene) from Larix sp. logs, and non-host leaf (green leaf volatiles and geranyl acetone) and bark (C₈-alcohols and trans-conophthorin) volatiles. Repeatable EAD responses were also found to two compounds from hindgut extracts that are undetectable by GC. One of these minor compounds was identified as amitinol. Field trapping experiments showed that the EAD-active, major male-hindgut component, racemic ipsenol, is the only individual compound that significantly attracted both sexes of I. subelongatus, whereas all other compounds, including previously reported pheromone components of European Ips cembrae, ipsdienol and 3-methyl-3-buten-1-ol, were unattractive. Ipsdienol, 3-methyl-3-buten-1-ol, or their binary blend had no synergistic or antagonistic effects on I. subelongatus attraction when combined with ipsenol, whereas cis-verbenol (a synomone) and verbenone (the antiaggregation semiochemical) inhibited its attraction to the ipsenol-containing attractive blend. A mixture of three EAD-active host monoterpenes, α-pinene, β-pinene, and para-cymene, was unattractive, but interrupted the pheromone response of I. subelongatus. Geranyl acetone, one of the strong EAD-active non-host volatiles also significantly reduced the number of I. subelongatus captured in traps baited with ipsenol-containing attractive blend. Our results add support to the recent phylogenetic finding that European and Asian larch bark beetles should be regarded as two distinct species: I. cembrae infecting larch in Europe and I. subelongatus infesting larch in Asia.     

丙酮汽提塔系统的工艺改造

原醋酸回收系统脱除丙酮的丙酮汽提塔效率很低,损失大量己烷。经改造后的脱丙酮系统脱丙酮的效率提高,己烷损失减少。每年可节约成本４０多万元,延长了设备的使用寿命。介绍了对丙酮汽提塔系统的工艺改造过程。     

工艺条件对丙酮高选择性一氯化反应的影响

采用填料塔作为氯化反应器,在塔内全回流的丙酮与氯气进行反应,实现了丙酮的高选择性一氯化。研究了水量及气速对一氯化选择性反应的影响。结果表明：水与丙酮体积比为１∶１５０时,产物中一氯丙酮的含量达到最大值;尽量低的通氯速率对避免重复氯化反应有利,在１７ｇ／ｈＣｌ２的条件下,所得产品中一氯丙酮的质量分数高达９３．８５％。另外,反应速度随氯气气速的增大而增大     

丙酮一步法合成甲基异丁基酮

综述了丙酮一步法合成甲基异丁基酮的生产与研究现状。     

Poisoning of aldol condensation reaction with H2O on acid catalysts

The effect of chemisorbing water on three catalysts previously evaluated in the acetone condensation reaction has been studied. The active sites in that reaction are Lewis acid sites present either on the surface of alumina or of nonframework alumina in zeolites. These sites are poisoned by water and the reaction rate decreases at the pace of the loss of Lewis sites. The stoichiometry of the poisoning reactions is one water molecule per site on alumina and two water molecules per site on nonframework alumina. This revised version was published online in July 2006 with corrections to the Cover Date.