反应失控条件下过氧化二叔丁基-甲苯体系的安全泄放研究

Vent sizing of DTBP-toluene runaway reactions based on Phi-TEC Ⅱ calorimeter test

安全泄放是在失控条件下降低反应体系风险最为经济有效的技术措施。为了研究泄放口的设计,利用高性能绝热量热仪PhiTEC II对质量分数20%的过氧化二叔丁基(DTBP)-甲苯(C7H8)体系进行了测试,得到热惯量1.06条件下温升速率、压升速率随温度变化的数据。结果表明:该DTBP体系的起始分解温度为148℃,其反应体系属蒸汽和气体共同作用的混合体系;采用Leung方法和OMEGA方法对该体系的安全泄放量和泄放装置的泄放能力进行了计算,求得当泄放压力为0.25 MPa时的泄放面积为0.001 4 m2;低热惯量的绝热量热仪Phi-TEC II可以为失控反应的压力泄放设计提供基础数据,有利于提高安全泄放设计的可靠性。

The paper is to take it as its main objective to build up an emergency relief system to prevent over-pressurization of the reactor and associated equipment. Therefore, in order to design the pressure relief system sizing, we have carried out a research on a 20% di-tert- butyl peroxide （Toluene as solvent） based on Phi- TEC II calorime- ter, which is a bench-scale experimental apparatus, data of tempera- ture rising rate and pressure rising rate various with the temperature with thermal inertia 1.06. By means of the 110 mL thin-walled test cells, the thermal inertia could be made much lower so as to be made close to the value of a large-scale plant, which implies that the data could be directly used in the industrial production process. The re- suits of our study have shown that the onset temperature of the reac- tive system tends to be around 148 ~C, with its maximum temperature rising rate being 41.5 ~C/min and the maximum pressure rising rate being 2.86 MPa/min. According to the relationship between the tem- perature and the pressure, the reactive system can be identified as a hybrid system, for the pressure varies both with the evolution of the gas and the increase of the vapor pressure with the increase of tem- perature. It is just based on the calorimetric data of runaway reaction that it would be possible for us to find that the relief set pressure is 0.25 MPa and the maximum accumulated pressure is 0.88 MPa, so that we can work out the required relief rate by Leung＇s method, the mass flow capacity and the average two-dimensional flowing capacity per cross-section unit area of the vent-line by OMEGA method re- spectively. Thus, we can determine the required relief area 0.001 4 m2, that is, the vent area for an ideal nozzle, with no interference of overpressure above the set value. Thus, we can prove that the Phi - TEC II calorimeter can be used to supply the basic runaway chemical reaction data and in turn provide technical supports for the emergency relief system, which is helpful to improve the reliability of the safety relief design.