滴流床中乙醛液相氧化合成过氧乙酸新工艺

In this paper,shorter residence time（a few minutes）with high yield in the trickle bed process for per- acetic acid synthesis by acetaldehyde liquid phase oxidation can be realized on the selected packing material SA-5118.For acetaldehyde in acetone with ferric ion as catalyst,the optimized process conditions were presented. The main factors influencing the yield,selectivity and conversion are residence time,temperature and acetaldehyde concentration,respectively.The temperature range checked is from 30 to 65℃.High yield of 81.53%with high se- lectivity of 91.84?n be obtained at higher temperature of 55℃when the residence time is 5.5min and the acet- aldehyde concentration is 9.85%（by mass）.And there is a critical acetaldehyde concentration point（Cccp）between 18%and 19.5%（by mass）.At temperature less than 55℃,the highest yield to peracetic acid at each temperature level increases with temperature when the acetaldehyde concentration is below Cccp and decreases with temperature when the acetaldehyde concentration is above Cccp.     

乙醛液相氧化合成过氧乙酸的管式填料反应器

通过填料的选择、气液流动状态的比较和反应器长径比的考察,探讨了管式填料反应器中乙醛液相氧化合成过氧乙酸的新工艺.结果表明,大比表面多孔性填料和低比表面光滑性填料都不利于过氧乙酸的合成;表面粗糙的非孔性填料SA-5118能在高转化率下获得较好的选择性和收率;下向并流的气液流动状态和大的长径比更有利于PAA的合成.其中,以SA-5118为填料,采用下向并流工艺,在长径比40的管式填料反应器内,当T=55℃,Cc=9.85%(wt),Gr=200 mL·min-1,P=8.136×105 N·m-2,可在6.87 min停留时间内,得到90.16%的转化率、84.15%的收率和93.34%的选择性.研究表明,管式填料反应器中的下向并流工艺,能在提高乙醛转化率的同时缩短反应时间,解决了提高乙醛转化率后过氧乙酸收率下降的难题,是乙醛液相氧化合成过氧乙酸并获得高收率的一条经济有效的生产工艺.     

过氧乙酸的合成研究

本文介绍了过氧乙酸在化工生产上的应用。特别是做为杀菌剂的优越性能。并且通过小试合成，探讨了其工艺路线的条件，然后转入工业品试验，最后在包头市氧气厂进行批量生产。并且投放市场，取得了一定的社会及经济效益。     

过氧乙酸的合成工艺研究

对双氧水法合成过氧乙酸的工艺进行了研究,为工业化生产提供了理论依据。     

过氧乙酸的合成及工业应用研究进展

介绍了过氧乙酸合成工艺及在环境、能源、聚合物/树脂和仿生化学领域的最新应用研究进展。分析了合成工艺的缺陷并提出了工艺改进的建议。指出过氧乙酸的重要作用除了其广谱杀菌能力外,更体现在合成化学与工业领域的各类特殊氧化反应中。建议加强过氧乙酸合成工艺尤其是乙醛液相一步氧化工艺的开发和工业领域的应用研究,以促进相关工业的发展。     

聚合硫酸铁的合成新工艺研究

以钛白粉厂副产品绿矾为原料,工业氧为氧化剂,亚硝酸钠为催化剂,采用催化氧化法合成聚合硫酸铁（PFS）,通过L9（34）正交试验优化合成工艺条件。研究结果表明了最佳工艺条件为：NaNO2用量的体积比为15%,n（SO42-）/n（Fe2＋）为1.35,反应温度为80℃,氧化反应时间为2 h时,Fe2＋转化率达76.4%,产品性能指标符合GB14591-2006国家标准。该工艺可缩短反应时间。     

过氧乙酸的合成与应用

介绍了合成过氧乙酸的5种工业生产方法。1、过氧化氢乙酰化法;2、乙醛单过氧乙酸酯法;3、气相法;4、液相法;5、酸性催化法。还介绍了该品在环氧树脂合成中及在医疗卫生与工业杀菌方面的应用。     

过氧乙酸的合成及稳定性研究

对以冰醋酸和过氧化氢为原料生产过氧乙酸过程中过氧化氢的浓度 ,催化剂和稳定剂的种类及用量等进行了研究 ,选出了能在室温下生产出符合GB1910 4 - 2 0 0 3中要求的合格产品所需的原料、催化剂及稳定剂的种类及最佳用量。     

过氧乙酸的合成和应用

介绍了过氧乙酸的性质、制备方法和应用,对开发过氧乙酸新产品、开拓过氧乙酸市场有重要意义.过氧乙酸的合成方法有很多种,主要包括醋酸(或醋酸酐)法、乙醛氧化法和乙酰基活化剂法等.过氧乙酸不仅是一种良好的氧化剂,而且是一种广谱、高效、速效、廉价的灭菌剂,应用广泛.     

同步合成过氧化氢和过氧乙酸

研究了同步合成过氧化氢与过氧乙酸的方法,讨论了磷酸、溴离子质量分数和溶剂配比对合成反应的影响。过低或过高的磷酸或溴离子质量分数对生成目标产物均是不利的。在Pd催化剂存在下,氢与氧反应生成过氧化氢,同时,氢、氧与乙酸生成过氧乙酸。在特定条件下,催化剂活性(反应氢总量)达123.1 mol(/kg.h),催化剂选择性达95.5%,过氧化氢质量分数达15.5%,过氧乙酸质量分数达4.1%,氢气转化率达69%。     

过氧乙酸的合成与杀生作用研究

以乙酸和过氧化氢为原料合成了新型水处理杀生剂——过氧乙酸．并考察了过氧乙酸的贮存稳定性及稳定剂8-羟基喹啉的影响。通过细菌测试瓶法测细菌总数,研究了过氧乙酸杀生效果与投加浓度、pH值和作用时间之间的关系。结果表明：过氧乙酸作为水处理剂具有杀生速度快、杀生效果好的特点,是一种具有良好应用前景的水处理杀生剂。     

过氧乙酸制备及稳定性研究

过氧乙酸是强氧化剂,具有广泛用途,但其化学性质不稳定,易分解。通过过氧乙酸制备的条件选择试验,考察了反应物料比、催化剂用量、温度等对过氧乙酸产率的影响;通过稳定性试验,揭示了温度、稀释用水水质和某些稳定剂对过氧乙酸分解的影响。提出了过氧乙酸制备、贮存、稀释和使用的优化条件。     

过氧乙酸稳定方法研究进展

通过对国内取得过氧乙酸卫生许可证单位的统计与分析,介绍了国内目前过氧乙酸的制备方法与发展现状,过氧乙酸的生产方法以过氧化氢法为主,由过氧化氢和乙酸加催化剂合成,分析了在保持过氧乙酸稳定性上采取的措施,并对过氧乙酸的发展方向作了展望。     

Factors affecting production of nonaqueous peracetic acid in tubular packed reactors

The synthesis of nonaqueous peracetic acid in acetone by acetaldehyde oxidation was carried out in a tubular packed reactor. The influencing factors of the reacting system including packing material, oxygen carrier, and reactor configuration were investigated. The results show that porous materials are inappropriate for peracetic acid synthesis and only non porous material with appropriate surface area can provide good peracetic acid selectivity and yield. Among the six kinds of packing material investigated, SA-5118 is the best one. As oxidizing gas, pure oxygen is superior to air. The optimum length-to-inner diameter ratio of the reactor is about 40. Under the proper reaction conditions, the highest peracetic acid yield of 84.15% and the highest selectivity of 93.34% can be achieved which indicates that the novel reacting system is effective and economical for nonaqueous peracetic acid production.     

Peracetic acid pretreatment of sugarcane bagasse for enzymatic hydrolysis: a continued work

Previous work has shown that the enzymatic hydrolysis of sugarcane bagasse could be greatly enhanced by peracetic acid (PAA) pretreatment. There are several factors affecting the enzymatic digestibility of the biomass, including lignin and hemicelluloses content, cellulose crystallinity, acetyl group content, accessible surface area and so on. The objective of this work is to analyze the mechanism of the enhancement of enzymatic digestibility caused by PAA pretreatment. Delignification resulted in an increase of the surface area and reduction of the irreversible absorption of cellulase, which helped to increase the enzymatic digestibility. The Fourier transform infrared (FTIR) spectrum showed that the absorption peaks of aromatic skeletal vibrations were weakened or disappeared after PAA pretreatment. However, the infrared crystallization index (N.O'KI) was increased. X‐ray diffraction (XRD) analysis indicated that the crystallinity of PAA‐treated samples was increased owing to the partial removal of amorphous lignin and hemicelluloses and probable physical change of cellulose. The effect of acetyl group content on enzymatic digestibility is negligible compared with the degree of delignification and crystallinity. The results indicate that enhancement of enzymatic digestibility of sugarcane bagasse by PAA pretreatment is achieved mainly by delignification and an increase in the surface area and exposure of cellulose fibers. Copyright © 2008 Society of Chemical Industry     

1,2,3,5-O-四乙酰-β-D-呋喃核糖的合成新工艺

通过对三氮唑核苷合成工艺中乙酰化反应机理的分析 ,研究了采用肌苷 80 g、醋酐 32 0g为原料 ,固体酸PMB -Ⅱ 0 5 g为催化剂的乙酰化新工艺 ,制得 1,2 ,3,5 O 四乙酰 β D 呋喃核糖 82 6 g ,最高产率为 87% ,熔点为 83 5℃