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。     

强效杀菌剂ClO2水溶液制备及稳定性的研究

采用一种新的简便的方法制备了强力高效杀菌消毒剂－稳定的ClO2水溶液。研究了反应时间、酸化时间、氧化剂用量、稳定剂加入顺序等不同制备条件和方法对ClO2含量的影响;测定了使用时活化剂加入比例、储存温度和湿度对ClO2水溶液稳定性的影响。     

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。     

高浓度过氧乙酸的安全制备

提出了一种简易安全的制备高浓度过氧乙酸的实验方法,先在减压条件下,对低浓度过氧化氢提浓至70%左右,然后以此浓度的过氧化氢在常压室温下与冰乙酸反应可得到40%以上的过氧乙酸。     

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。     

固体三元稳态ClO2杀菌剂稳定性、腐蚀性及杀菌消毒特性研究

对固体三元稳态二氧化氯杀菌剂的稳定性、腐蚀性及杀菌消毒特性进行研究后发现,该杀菌剂ClO2活化得率在95.5%以上;活化酸度为pH=4.84; 于(54±1) ℃放置14 d,ClO2含量的下降率为3.1%;用ClO2质量浓度 80 mg/L的消毒液作用3～5 min,对大肠杆菌和金黄色葡萄球菌的杀灭率为100%;ClO2质量浓度 400 mg/L的消毒液作用60 min对枯草杆菌黑色变种芽孢的杀灭率为100%;ClO2质量浓度 300 mg/L的消毒液作用20 min,可以完全破坏悬液中HBsAg的抗原性;ClO2质量浓度 800 mg/L的消毒液对不锈钢基本无腐蚀,对铜片、碳钢、铝片均有中度腐蚀.     

含氯消毒剂的性能与应用

详细介绍了含氯消毒剂的组成，性能及应用范围。主要成分次氯酸钠的化学特性、杀菌作用和杀菌机理。阐述了基于次氯酸钠的不稳定性和腐蚀性，提出了解决措施。     

油田采出水处理用杀菌剂检测方法研究

对抽取的油田采出水处理用杀菌剂进行了室内分析试验,确定了产品的技术要求和检测方法,规范了杀菌剂的采购和检验。     

高稳定性硅丙乳液合成及性能的研究

介绍了一种贮存稳定的有机硅改性丙烯酸酯乳液的制备方法。讨论了软硬单体配比、有机硅单体、反应温度、乳化剂等因素对聚合稳定性和乳液性能的影响。     

不同浓度金属离子对过氧乙酸分解速度的影响

本实验考察了十种常见金属离子及其在不同浓度时对过氧乙酸分解速度的影响.同时发现通常金属离子浓度≧10~(-5)mol/l时能明显加速过氧乙酸分解速度.不同金属离子及其不同浓度对过氧乙酸分解速度的影响历程差别很大。本实验为有针对性地选择一些配位剂掩蔽这些金属离子提供实验数据,从而选择更有效的过氧乙酸稳定剂。     

高浓度过氧乙酸的实验室制备方法

提出了一种实验室条件下简便、安全制备高浓度过氧乙酸的方法.先把低质量分数的双氧水浓缩到78％左右.然后比较了用乙酸和乙酸酐分别与过氧化氢反应制备所得的过氧乙酸的质量分数.采用乙酸酐(97％)/过氧化氢反应,当过氧化氢质量分数为78.5％时,在40℃下反应4h,室温放置2h,制得过氧乙酸质量分数为48.2％.     

烷基多苷的过氧乙酸漂色及组合漂色工艺研究

对烷基多苷(APG)的过氧乙酸(CH3COOOH)漂色工艺进行了优化,优化条件是:烷基多苷(APG)水溶液的浓度为50%,CH3COOOH用量为5%,漂色时间90 m in,漂色温度80℃,初始pH 12~12.5。在此条件下漂色,可使APG水溶液的消光系数由6~7降至0.4左右;采用质量分数分别为3%的H2O2与CH3COOOH组合漂色,可使漂色效果进一步提高;对H2O2与CH3COOOH漂色前后的APG样品进行了红外光谱对比分析。     

金属离子影响过氧乙酸分解速度的探讨及对策

本文考察了部分金属离子对过氧乙酸分解速度的影响.结果发现一些金属离子(Cr3 、AL3 、Ni2 、Co2 )引起过氧乙酸快速分解,一些金属离子(Hg2 、Cu26、Zn2 、Pb26、Ag )引起过氧乙酸缓慢分解,还有一些金属离子(Mg2 、K )对过氧乙酸起稳定作用.本文探讨了金属离子对过氧乙酸分解的机理.有针对性地选择一些配位剂(8-羟基喹啉、邻二氮菲、酒石酸盐、草酸钠)作为过氧乙酸稳定剂,这些配位剂与金属离子形成稳定的配合物,从而把金属离子有效地隐蔽起来,增加过氧乙酸的稳定性.     

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.     

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。     

Effect of several factors on peracetic acid pretreatment of sugarcane bagasse for enzymatic hydrolysis

BACKGROUND: Lignocellulose should undergo pretreatment to enhance its enzymatic digestibility before being saccharified. Peracetic acid (PAA) is a strong oxidant that can remove lignin under mild conditions. The sulfuric acid in the PAA solution also can cause degradation of hemicelluloses. The objective of the present work is to investigate the effect of several factors on peracetic acid pretreatment of sugarcane bagasse. RESULTS: It was found that PAA charge, liquid/solid (l/s) ratio, temperature, time, interactions between PAA charge and l/s ratio, temperature and time, all had a very significant effect on the enzymatic conversion ratio of cellulose. The relative optimum condition was obtained as follows: PAA charge 50%, l/s ratio 6:1, temperature 80 °C and time 2 h. More than 80% of the cellulose in bagasse treated under the above conditions was converted to glucose by cellulase of 20 FPU g^?1 cellulose. Compared with H₂SO₄ and NaOH pretreatments under the same mild conditions, PAA pretreatment was the most effective for enhancement of enzymatic digestibility. CONCLUSION: PAA pretreatment could greatly enhance the enzymatic digestibility of sugarcane bagasse by removing hemicelluloses and lignin, but removal of lignin was more helpful. This study can serve as a step to further optimization of PAA pretreatment and understanding the mechanism of enhancement of enzymatic digestibility. Copyright © 2007 Society of Chemical Industry     

Kinetics of peracetic acid decomposition: Part I: Spontaneous decomposition at typical pulp bleaching conditions

Peracetic acid may become one of alternative non-chlorine bleaching chemicals in the production of fully bleached chemical pulps. In this paper, the stability of peracetic acid was studied in an aqueous solution under conditions most likely encountered in the industrial processes. It was found that three potential reactions, namely i) the spontaneous decomposition, ii) the hydrolysis and iii) the transition metal catalyzed decomposition, are responsible for the consumption of peracetic acid. Furthermore, the kinetics of the spontaneous decomposition was developed. It was found that the reaction follows a second-order kinetics with the maximum rate at pH 8.2, which is the pK_a of peracetic acid. Finally, the developed kinetic equation can describe very well the experimental results obtained in this study as well as the earlier data from Koubek (1964).     

Generation of electron accepting surface sites in carbon blacks by peracetic acid oxidation

Surface oxidation of three different carbon blacks was carried out using peracetic acid. An electron spin resonance investigation of these oxidized blacks revealed that a significant number of surface sites were generated. These surface sites were in equilibrium with the bulk conduction electrons as evidenced by the large deviation from the Curie Law. Electrochemical reduction of these blacks also resulted in electron transfer to these surface sites as evidenced by ESR. The ESR results on the reduced and oxidized carbon blacks correlated with the measured contact potentials. This is consistent with a mechanism of electron acceptance by surface sites during contact electrification in a xerographic developer system.     

Kinetics of the peracetic acid decomposition: Part II: pH effect and alkaline hydrolysis

The effect of pH on the decomposition of peracetic acid in an aqueous solution was studied. It was found that three potential reactions, namely i) the spontaneous decomposition, ii) the hydrolysis and iii) the transition metal catalysed decomposition, are responsible for the consumption of peracetic acid. The spontaneous decomposition reaches its maximum at pH 8.2, while both the hydrolysis and metal ion catalysed decomposition increase as the pH increases. At pH 10.5 and higher, the hydrolysis becomes dominant when the metal ion catalysed decomposition is minimized by the addition of DTMPA. The kinetics of the peracetic acid hydrolysis was developed, which can very well predict the development of peracetic acid and hydrogen peroxide during the decomposition reaction.