Lessons Learned

What is Lessons Learned?

A sulfur deprivation test was conducted in a sealed 250 ml vessel. More hydrogen was generated in this process than was anticipated, and the vessel cracked.
An individual inadvertently connected a pure hydrogen gas bottle to a chamber/glove box as opposed to a 10% hydrogen (in nitrogen) bottle that should have been used. [The wrong bottle had mistakenly been delivered, and the inexperienced individual did not know the difference.] The hydrogen concentration increased within the chamber to about 9%. Since there was insufficient oxygen in the chamber to support combustion, the hydrogen did not burn, and was quickly diluted with nitrogen.
An incident occurred when Ti-doped sodium alanate was exposed to air, apparently resulting in an unstable compound that experienced a rapid exothermic reaction. The sample consisted of mechanically milled NaAlH4 with 4% TiCl3 dopant which was prepared in an argon atmosphere. The sample was sealed and placed in the probe head of an NMR magic angle-spinning (MAS) rotor and spun at approximately 9,000-13,000 rpm. During the process, the sealing cap dislodged and exposed the sample to ambient air for a little less than 24 hours. When discovered, the sample was visually inspected and showed no evidence of oxidation. The sample was re-capped and returned to an argon environment for removal. Most of the sample material was removed using a small stainless steel needle, but a residual amount,...
A laboratory had an incident with an ammonia tank. When the valve was opened, the packing in the valve apparently "moved," and a faint ammonia smell was noticed. The tank was returned to the supplier.
An employee of an incubator company that was working in a university-owned laboratory facility was checking the hydrogen pressure through the main valve on a hydrogen cylinder. The regulator on this cylinder had not been properly closed. Hydrogen escaped through the regulator and was ignited. The fire was contained in the laboratory and extinguished by the building's fire sprinkler system before fire crews arrived. There were no injuries, and damage estimates were not available.
A facility uses small crucibles to heat precious metals within a fume hood, with natural gas as the fuel source for the Bunsen burner. Hydrogen is fed into the crucible at low pressure (<20 psi) to control the atmosphere within the vessel in order to prevent oxidation. The hydrogen is routed through a manifold with flexible tubing, which is connected to a ceramic tip and fitted into the crucible through a small opening in the crucible's lid. The hydrogen is consumed in the process. The facility believes that the hydrogen tubing developed a leak which eventually ignited. The plastic interior of the fume hood ignited and started to spread. The person working in the area shut off the natural gas and hydrogen (they had valves at the hood) and used a halon extinguisher in the hood.
A researcher was working with hydrogen storage materials in a laboratory. Several other researchers were working in adjacent laboratories. The researcher had prepared a sample of aluminum deuteride, AlD3, by reacting lithium aluminum deuteride and aluminum chloride in diethyl ether. The actual composition/phase of the material synthesized was unknown, but the researcher had attempted to produce the gamma phase of aluminum deuteride. The synthesis steps used to produce the material were complete and the researcher attempted to seal the material in a glass ampoule for offsite shipment and analysis. The sample size was approximately 1 gram. The ampoule with the sample had previously been placed under vacuum and had been isolated from the atmosphere. The process for sealing the ampoule was to...
A liquid hydrogen tank’s rupture disc failed prematurely, which caused the tank to vent its entire gas contents through the tank’s vent stack. Venting was very loud and formed a condensed moisture cloud visible from the top of the stack. Liquid air was also visible coming off the stack. Venting ceased after approximately 5 minutes. On-site staff called the fire department, which arrived promptly and evacuated the area. Normal operations resumed after the Fire Department was able to determine there were no unsafe conditions.
A hydrogen cylinder was initially located in an adjacent laboratory, with tubing going through the wall into the laboratory in use. When the cylinder was moved to the laboratory in use, a required leak check was not performed. Unfortunately, a leak had developed that was sufficient to cause an accumulation of hydrogen to a level above the Lower Flammability Limit. The hydrogen ignited when a computer power plug was pulled from an outlet. The exact configuration of the leak location and the outlet plug is unknown.
During preparation of a new hydrogen storage material, ammonia borane (AB) loaded onto mesoporous carbon, an unexpected incident was observed. As with all procedures with new materials the work is conducted on a small scale and in a laboratory fume hood. They followed the procedures that they had used for absorption of ammonia borane onto mesoporous silica without incident. To absorb the solid AB into a scaffold material they dissolve AB in a dry aprotic polar solvent, THF. The saturated solution of AB in THF is added to the mesoporous carbon material in a round bottom flask, stirred for 10 minutes to saturate the mesoporous scaffold with AB and then the solvent is slowly removed under vacuum. At this point the sample is assumed to be prepared and ready for transfer to a sample vial for...

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