Thermal hazard characteristic evaluation of two low-temperature-reactive azo compounds under adiabatic process conditions

• Published in: Process safety and environmental protection 2019-10, Vol.130, p.231-237
• Main Authors: Cao, Chen-Rui, Liu, Shang-Hao
• Format: Article
• Language: English
• Subjects: Adiabatic; Adiabatic calorimeter; Adiabatic flow; Azo compounds; Boundary conditions; Chemical reactions; Computer simulation; Environmental assessment; Hazard assessment; Hazard mitigation; Initiators; Kinetic models; Low temperature; Mitigation; Organic chemistry; Parameter estimation; Polymerization; Process hazard; Propionic acid; Safety; Thermal safety; Transportation
• ISSN: 0957-5820; 1744-3598
• DOI: 10.1016/j.psep.2019.08.020

•Used the results of laboratory scale analysis to confirm thermal hazards in plant.•The kinetics of two azo compounds by thermal analysis was investigated.•Kinetic-based simulations were applied for evaluation of SADT for two azos.•Kinetic model on process condition was determined based on adiabatic data.•Thermal stability, such as TMRad and SADT have been found using analytical models. As a key initiator of polymerization, azo compounds (azos) can supply abundant energy to the polymerization process. Although polymerization can be implemented more smoothly and the product can be modified, the use of azos also increases the probability of process hazards caused by high heat accumulation and release. To preserve the thermal safety of using azo initiators in the synthesis process, the frequently used azo initiators dimethyl 2,2′-azobis(2-methyl propionate) (AIBME) and 2,2′-azobis(2,4-dimethylvaleronitrile) (ABVN) were chosen for investigation. Under process conditions, initiators are essential for evolving and monitoring chemical reactions on both the laboratory scale and process environment. The assessment, control, and mitigation of reaction hazards are primarily based on kinetic models, which are used to estimate multiple critical safety parameters, such as TMRad in process safety and TCL and SADT in storage and transportation operation. The data from the adiabatic calorimeter correspond to real process situations are combined with the nonlinear adiabatic kinetic model, which is rarely applied to analyze the thermal hazard properties of azos. The results indicated that the kinetic model of azos in the actual process, the thermal hazard characteristics, and simulation of the runaway mode of azos in setting boundary conditions should also be investigated.