Explosion in a Chemical Plant Producing Methyltris(methylethylketoxime)silane and Vinyltris(methylethylketoxime)silane from 2-Butanone Oxime

Abstract

On August 3, 2020, a disastrous explosion demolished the Lanhua Organosilicone Ltd. plant in Xiantao county, China, causing six deaths, four injuries, and a loss exceeding US$2 million. We performed an extensive case study with differential scanning calorimetry (DSC) and accelerating rate calorimetry (ARC). The calorimetric methodology can obtain thermal hazard data, such as the exothermic onset temperature, enthalpy change, maximum temperature, maximum self-heat rate, maximum pressure, maximum pressure-rising rate, adiabatic temperature rise, and time-to-maximum rate. The ARC assessed a simulation of the incident vessel by storing the product solution of vinyltris(methylethylketoxime)silane with a thermal inertia of 1.87. The thermal runaway phenomena can be scaled up directly to an industrial vessel with good adiabaticity under such low thermal inertia. An official report announced the time of explosion as 33.2 h, which agreed with the ARC-determined time-to-maximum-rate (TMR) of 28.7 h. A (dT dt^–1)_max is as high as 801.4 °C min^–1, revealing that once the decomposition goes through the critical point, the severe thermal runaway cannot be mitigated or hindered effectively. Therefore, the explosion of the process vessel shows that the maximum pressure under thermal decomposition largely exceeded the design pressure of static tank #1 without adequate relief under overpressure. This paper not only provides a lesson learned for producing chemical products using 2-butanone oxime and alkyl silane but also stands as a guide for an inherently safer processes in similar chemical industries.