An ammonia cylinder burst late Monday while being heated as part of preparations to restart the alkylation unit at a 86,000 barrel-per-day refinery, sources familiar with plant operations said on Tuesday. A company spokesman said the company responded to an incident at the refinery, in which there were neither injuries nor offsite impact. The refinery was continuing the restart of the 10,000 bpd alkylation unit. The unit had been shut to repair pinhole leaks in piping. The cylinder and the ammonia inside were being heated so the gas could be sent through the unit’s piping to increase its temperature as part of the restart, the sources said. Texas City residents took to social media after being shaken awake by the explosion shortly before midnight CDT on Monday (0500 GMT on Tuesday). Assistant emergency management director for Texas City said no alarms were sounded for residents because the incident posed no threat to them. In a notice filed Tuesday afternoon with the Texas Commission on Environmental Quality, the refinery said the event that released 300 pounds (136 kg) of ammonia began at 11:37 p.m. and ended at 11:52 p.m.
“Ammonia cylinder found empty. Cause is under investigation,” the filing read under the section to describe the cause