摘要
为了系统研究环氧乙烷水溶液失控反应热动力学参数的变化规律,采用等温扫描量热仪C600和绝热量热仪VSP-2分别对环氧乙烷水溶液进行了量热试验研究,得到了纯环氧乙烷的热稳定性数据,以及不同质量分数环氧乙烷水溶液的起始放热温度、最高放热温度和压力、放热量、绝热温升及失控反应过程的温度、压力变化等。结果表明,纯环氧乙烷发生失控反应的起始温度接近360℃,其放热量高达2 600 k J/kg。水加入环氧乙烷能够显著降低体系的起始放热温度至200℃以下。随环氧乙烷水溶液质量分数升高,失控反应致灾后果的严重程度明显提高。最高温度和压力、温升和压升速率、放热量及绝热温升随环氧乙烷质量分数升高而增大,而达到最大反应速率的时间减小。
The given paper has done an investigation and analysis of the thermodynamic parameters of EO aqueous solution through isothermal scanning calorimeter C600 and the adiabatic calorimeter VSP-2,respectively,so as to identify and fully experiment the conditions and consequences of the thermal runaway reactions for ethylene oxide（ EO） aqueous solution. For this purpose,we have managed to obtain the thermal stability data for pure EO and the thermodynamic parameters at various weight concentrations of EO aqueous solutions,for instance,the onset temperature,the maximum temperature,the maximum pressure,the temperature increasing rate,the pressurization rate and the exothermic heat,etc. The above mentioned data and parameters we have gained from the above experiments can be used to compare with that of pure EO and the data available provided in literature concerned.The above study shows that it is necessary for pure ethylene oxide to initiate a runaway reaction at least at a temperature of 360 ℃,and the exothermic heat has to be made to reach 2 600 k J/kg.For EO aqueous solution,in comparison to pure ethylene oxide,water can significantly reduce the onset temperature of EO runaway reaction to 200 ℃. Under the adiabatic conditions,the EO aqueous solutions can keep a minimum onset temperature at about80 ℃ for the weight concentration in a range from 10% to 30%,whereas no dramatic over-temperature or overpressure can be observed. With the increase of the weight concentration of EO aqueous solutions,the consequence due to runaway reaction would become much severe. The maximum temperature and maximum pressure in the runaway reaction may likely exceed 400 ℃ and 12 MPa when the EO weight concentration exceeds 90%. Under such a condition,the exothermic heat would increase with the EO concentration,and the maximum adiabatic temperature could rise by 300 ℃. The time length for the maximum reaction rate to reach may then begin to decrease with the increase of EO concentration to the minimum of 37 min,whereas the variation of temperature and pressure during the runaway reaction would show that there would no non-condensable gases be resulted. The temperature rise rate and pressurization rate may increase rapidly in the runaway reaction process,with the maximum rates exceeding 275℃/min and 7 MPa/min,respectively. Thus,the basic experimental data and information support on the runaway reaction of EO aqueous solutions prove to be helpful for the engineering design and safety operation of EO facilities.
出处
《安全与环境学报》
CAS
CSCD
北大核心
2017年第6期2234-2239,共6页
Journal of Safety and Environment
关键词
安全工程
环氧乙烷
热稳定性
失控反应
反应量热
safety engineering
ethylene oxide
thermal stability
runway reaction
reaction calorimetry
