Investigation of a Polymeric Resin Deflagration Using Advanced Calorimetric Techniques

2019 AIChE Global Congress Process Safety Abstract Submission- FINAL

Title: Investigation of a Deflagration Incident using Adiabatic Calorimetric Experiments Coupled to GC/MS and Thermogravimetric Analysis

Authors: Katie Mulligan, Robert Bellair, Steven Horsch, Don Huether, Amy Koziol, Kevin Simmons, Kefu Sun, Praveen Boopalachandran

In 2018, a Process Safety incident occurred during loading operations for a polymeric resin, resulting in a deflagration inside the shipping container and an investigation was conducted to determine the cause of the event. During the extrusion operation, an organic solid additive is added to base polymer resin at ppm levels to protect resin quality at elevated temperatures, and some additive degradation is expected. After the event, it was learned that a zone of the extruder had reached a higher-than-normal temperature shortly before the event, although it was unclear at the time whether this observation was connected to the event. Through the application of laboratory-scale thermo-analytical testing, it was subsequently determined that the higher operating temperature resulted in a higher percentage of additive decomposition than had been expected, creating the conditions that led to the event. Despite the maturity of this technology, the potential to accumulate a sufficient quantity of flammable additive degradation components during a non-routine operating mode had not been previously identified as a potential hazard scenario.

This paper will illustrate how reactive chemicals knowledge was combined with analytical expertise to determine the cause of the event. This investigative work included the use of Thermogravimetric Analysis (TGA) as well as an innovative adiabatic Accelerating Rate Calorimetry (ARC) unit coupled to an online gas chromatograph/mass spectrometer (GC/MS). As a result of this reactive chemicals evaluation and design of key experiments, the root cause of the event was identified, enabling stakeholders to define mitigations that would permit safe return to operations and prevent a future reoccurrence.