异辛醇硝化制备硝酸异辛酯合成工艺热危险性的初步研究

【作者】 刘婷婷；

【导师】 陈网桦； 陈利平；

【作者基本信息】 南京理工大学 ， 工程力学， 2010， 硕士

【摘要】 向硝硫混酸中滴加异辛醇硝化制备硝酸异辛酯(EHN)的过程具有较大的热危险性,国内类似工艺曾经发生两起爆炸事故,有必要对此工艺过程的热危险性开展系统分析、测试、评估和安全控制方向的研究。本文主要通过实验室全自动反应量热仪(RCle)测试了这一半间歇硝化反应的热力学数据,同时利用差示扫描量热仪(DSC)以及用加速度量热仪(ARC)研究了产物的二次分解特性,从而对反应的热危险性进行评估分级。首先采用DSC对反应体系及产物在动态升温过程下的热分解特性进行了研究和分析；再采用RCle研究不同的反应温度、加料速率等参数对反应放热特性的影响,计算出间歇式反应失控条件下的绝热温升(△Tad)、反应所能达到的最高温度(MTSR)等参数；用ARC对反应产物体系在绝热状态下的热分解特性进行了研究,得出诱导期与温度的关系曲线,同时得到诱导期为24h所对应的温度TD24等参数；最后结合ARC数据和RCle数据,根据热失控危险等级分类标准进行热失控危险等级划分。结果表明：对硝酸异辛酯(EHN)与混酸的混合物,混酸含量越大,EHN的起始分解温度越低；对合成EHN反应的工艺条件条件严格控制,尤其是反应温度,当温度超过20℃时,反应的热失控危险等级为第5级,非常危险；另外,通过对不同反应条件下的产物浓度测试得到温度较低时,产率也较低。因此应在保证生产安全的基础上对反应的工艺条件进行进一步的优化,使其经济效益达到最佳。更多还原

【Abstract】 The nitrification process of producing 2-Ethylhexyl nitrate(EHN)by dosing isooctyl alcohol to nitric-sulfuric acid mixture is with greater risk of heat, and domestic similar process has been two explosions occurred.So,about the thermal hazard of this process, it is necessary to carry out the systems analysis, testing, evaluation and investigation on the direction of security control.In this paper, Reaction Calorimeter(RCle) was used to measure the thermodynamics parameters of this nitration in semi-batch reactor, additionally, Differential Scanning Calorimeter(DSC) and Accelerating Rate Calorimeter (ARC) were used to study the secondary decomposition characterizations of the product, thereby, evaluating the thermal runaway criticality of the reaction. First of all,the thermodynamics behaviors of products and reaction system under non-isothermal mode were studied by DSC.Then a series of experiments were carried out with RCle to study the influence of several parameter, such as reaction temperature and dosing time on the exothermic character of the reaction; Some parameters such as adiabatic temperature increase of batch reaction(△Tad),maximum temperature of synthetic reaction(MTSR) were obtained here. After that, ARC was used to study the thermal decomposition of the product, the relation curve of the induction period and temperature can be fitted. Also the temperature when the explosion happened on 24h(TD24) were analyzed. Finally, combining the datum from ARC and RCle, the risk class of thermal runaway criticality is studied.The results indicate that about the mixture of the mix acid and the 2-Ethylhexyl nitrate, the more the content of the mix acid was, the lower was the onset of the secondary decomposition of 2-Ethylhexyl nitrate. The process conditions of the synthetic reaction should be severely controlled, especially the reaction temperature. When the temperature is above 20℃,its risk class of thermal runaway reaction is class 5,which is very dangerous. Through the purity test of several reaction products under different conditions, it is found that the rate of production is lower if the reaction temperature blew 30℃.So, further optimizing the processing condition on assuring the security of the process of producting should be developed, to reach the best economic benefit.更多还原