2024 Spring Meeting and 20th Global Congress on Process Safety

(41m) Compressed Natural Gas Safety: Investigation Findings and Lessons Learned from an Explosion in a CNG Vehicle Assembly Facility

Authors

Tom DeBold, GexCon US Inc.
John Pagliaro, Gexcon US
Derek M. Engel, GexCon US


Industry analysis indicates that demand for compressed natural gas (CNG) vehicles has been rising substantially and their adoption as personal use and commercial use vehicles has been increasing. Growing awareness among individuals regarding protection of the environment has initiated the adoption of unconventional transportation fuels to reduce the emission of harmful gases. This has increased the use of CNG in vehicles, especially commercial vehicles. Given the increased presence of CNG, risk assessments need to be adequately performed to avoid severe consequences associated with CNG vehicles. This paper presents the investigation findings and lessons learned from an explosion that occurred within a CNG vehicle assembly facility. An explosion and ensuring fire occurred inside a finishing shop, where a CNG release occurred from a commercial while parked in one of the bake rooms. The incident injured five employees and the building sustained significant damage.

A detailed investigation was performed that included performing advanced computational fluid dynamic (CFD) simulations to determine the cause of the CNG release from the commercial vehicle. The study will discuss typical designs of CNG fuel pod systems and associated safeties that implemented on such fuel systems. The studied concluded that the incident was caused by a defectively assembled hose end, which catastrophically failed, causing the initial deflagration and sustained fire. This study will discuss the importance of properly performing a risk assessment, and if such an assessment had been properly performed, this incident and similar incidents would have been avoided.