Nitrous oxides plant explosion

P12-5f Safety Problem The following is an excerpt from Tfie Morning News, Wilmington, Delaware (August 3. 1977) "Investigators sift through the debris from blast in quest for the cause [that destroyed the new nitrous oxide plant). A company spokesman. said it appears more likely that the fatal] blast was caused by another gas—ammrmium nitrate—used to produce nitrous oxide. An 83 X (wt) ammonium nitrate and water solution is fed at 200 F to the CSTR operated at a temperature of about SIO F. Molten ammonium nitrate decomposes directly to produce gaseous nitrous oxide and steain. It is believed that pressure fluctuations were observed in the system and. as a result, the molten ammonium nitrate feed to the reactor may have been shut otf approximately 4 min prior to the explosion. 

In an earlier disaster, a warehouse full of ammonium nitrate exploded in a chemical plant in Germany, killing thousands. A mixture of ammonium nitrate fertilizer and fuel oil was a tool in the Oklahoma City bombing in 1995. Such combinations are common industrial explosives. As mentioned earlier, the presence of flammable or combustible material can accelerate the fire and sustain it because of nitrous oxide and/or oxygen released during the exothermic decomposition of ammonium nitrate. 

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