电点火头蘸药过程反应失效分析

为解决某电点火头在蘸药过程发生反应导致点火药失效问题,采用化学分析、DSC热分析、红外光谱分析、X衍射分析技术对影响点火头生产工艺的因素进行综合分析,设计DSC方法模拟反应程度与材料的关系.结果表明,点火药与配漆溶剂丙酮在室温较高时,易发生放热反应,放出的热量加剧反应,从而引起点火药被反应消耗而失效.可通过降低工房温度、缩短蘸药时间、改变配漆溶剂、控制铬酸铅原材料质量等方面改进,以避免点火药失效.     

Diisopropyl ether one-step generation from acetone-rich feedstocks

A one-step integrated process for the generation of the high-octane fuel ether, diisopropyl ether (DIPE), from acetone-rich feedstocks has been demonstrated. Three continuous, downflow, reactor configurations have been considered, including a two-bed catalyst design separated by inerts, gradient multicatalyst combinations, and an integrated two-zone layout with differing catalyst compositions. The bifunctional catalysts have both hydrogenation and etherification/dehydration capabilities and may comprise groups IB, VIB, and VIII metals incorporated into acidic, large and medium-pore zeolites, groups III or IV metal oxides, as well as heteropoly acid structures. DIPE syntheses are typically conducted at 100–165°C, under hydrogen pressure. The gradient reactor design, with careful choice of hydrogenation and etherification catalysts, allows DIPE to be generated in high selectivity and productivity. This revised version was published online in July 2006 with corrections to the Cover Date.     

Use of Sodium Alginate-Poly(vinyl pyrrolidone) Membranes for Pervaporation Separation of Acetone/Water Mixtures

Pervaporative separation of acetone from water at a concentration range of 0–100 wt% were studied using sodium alginate (NaAlg)/Poly vinyl pyrrolidone (PVP) membranes. Membranes were prepared in different ratios (w/w) (100/0, 95/5, 90/10, 85/15, 80/20, 75/25) of NaAlg/PVP by crosslinking with CaCl₂. Experimental studies were carried out to investigate the effects of the operating temperature, feed composition, and membrane thickness on the pervaporation performance. The optimum operating temperature, membrane thickness, NaAlg/PVP ratio, and feed composition were determined as 40°C, 70 µm, 75/25 (w/w), and 20 wt% acetone, respectively. The effect of PVP content in the membranes was investigated on pervaporation performance. The permeation rate was increased with increasing the PVP content; however, there was no appreciable change about the separation factor. The permeation rate and separation factor values were found to be in the range of 0.304–1.023 kg/m² h and 16–57, respectively. In addition, the sorption-diffusion properties of the alginate membranes were investigated at the operating temperature and the feed composition. It was found that the sorption selectivity was the dominant factor for the separation of acetone/water mixtures.     

Effect of organic solvents on growth of freshwater algae

The impact of acetone, methanol, ethanol and dimethyl sulfoxide (DMSO) as carrier solvents on two species of algae was investigated. Scenedesmus quadricauda of green algae and Anabaena flos‐aquae of blue green algae were subjected to different concentrations of the studied solvents which ranged from 0.01 to 7.29 mL/L for 10 days in batch studies. The data recommended the use of acetone, ethanol and methanol than dimethyl sulfoxide in this order as a carrier solvent for chemical toxicity tests using a maximum concentration of 7.29 mL/L which represents 0.729% (volume/volume) in the algal bioassay test.     

2-甲氧基丙烯生产中有关体系的共沸点研究

利用基于精馏原理的加压共沸点测定装置，测定了2-甲氧基丙烯(MPP)与甲醇或丙酮二元体系在减压、常压及加压条件下的共沸点数据，并对数据进行了关联。从关联的结果可知，该体系共沸组成与共沸温度、压力的对数及共沸温度的倒数均呈良好的线性关系，计算结果与实验值符合良好。随着压力的降低，这两个二元体系中MPP的含量都增加，说明在减压条件下更利于MPP的分离和提纯。特别是MPP-丙酮体系，在49．7kPa下，其MPP的摩尔分数已达到0．997。这项研究为MPP工业化过程中共沸混合物的分离、提纯，以及共沸精馏、反应精馏等工艺与装置的研究与设计提供了重要的基础数据和参考依据。     

微波快速合成1,5-二芳基-1,4-戊二烯-3-酮

以芳醛、丙酮为原料，在碱性条件下经微波辐射快速合成了一系列1，5-二芳基-1，4-戊二烯-3-酮，反应在1min左右完成，得率61％—86％。     

以活性炭纤维为载体催化剂降解丙酮的研究

以活性炭纤维为载体，用TiOSO4为原料自制催化剂与P25光催化降解丙酮进行比较。实验结果表明，以TiOSO4为原料自制催化剂降解丙酮效率比以P25为催化剂降解丙酮效率高。由于工业用硫酸氧钛易得且价格便宜，工业化前景看好，这有可能为制备TiO2光催化剂提供一条合适的工业化生产途径。     

Antioxidant Activity of Mycelia from Aspergillus candidus

The antioxidant activity of mycelia extracts produced from the submerged cultures of Aspergillus candidus CCRC 31543 was investigated. Inhibition of peroxidation (IP%) of mycelia acetone extracts (MAE) in linoleic acid peroxidation was equal to that of BHA and significantly (p < 0.05) higher than that of α-tocopherol. As measured by the Rancimat method in lard, MAE showed marked antioxidant activity with an induction time of 8.4 h at a concentration of 200 μg/mL. MAE also exhibited strong scavenging effect on α,α-diphenyl-β-picrylhydrazyl radicals and marked reducing power. HPLC-DAD analysis suggested that MAE possessed the antioxidant components 3,3"-dihydroxyterphenyllin, 3-hydroxyterphenyllin, and candidusin B.     

活性炭负载纳米TiO2光催化降解气相丙酮

以钛酸四丁酯为前驱体,采用溶胶-凝胶法制得Fe、N离子共掺杂的以活性炭(AC)为载体的光催化剂(TiO2/AC),在紫外光照射下进行了气相丙酮的光催化降解研究。探讨了丙酮初始质量浓度、紫外光光强、催化剂用量、反应器内湿度等因素对其降解率的影响。结果表明,活性炭与TiO2的协同作用大大提高了对丙酮的降解效果;紫外光光强的增加对丙酮降解率有一定提高;使用3g光催化剂,丙酮的初始质量浓度为39.40mg/L;反应器内相对湿度为63%时,丙酮的降解效果最好,降解反应155min后丙酮的降解率达92.63%;催化剂循环使用6次后丙酮的降解率为83.91%。     

丙酮一步法合成甲基异丁基酮催化剂的失活机理

为研究丙酮一步法合成甲基异丁基酮Pd/Al2O3催化剂的失活机理,采用BET,XRD,SEM,O2-TPO等方法,对反应前后的催化剂进行了表征。表征结果表明,反应前后催化剂中的Pd含量没有明显变化,而反应后的催化剂表面织构变化较大,反应后的催化剂孔体积减小、平均孔径增大,Al2O3载体形态由γ型转化为羟基氧化铝的形态;同时,反应后的催化剂表面存在一定的高沸物。因此,催化剂加氢能力降低的主要原因是载体Al2O3形态的变化和催化剂表面包覆的高沸物,造成加氢活性中心减少。