EMISSIONS OF GUN PROPELLANT COMPOSITIONS WITH ADDED UREA $1Chris van Driel$1Monique van Hulst

摘要

Addition of certain components to gun propellants may lead to a reduction of the NO_x content in combustion gases. This is described in the literature based on small scale laboratory research. One of these components is urea. In the investigation described here, propellants have been studied which contain different added urea concentrations. The urea containing propellants have been tested for the emission of volatile gases, among which NO_x, which are released when gun propellants are burned under conditions representative for gun firings. The applied experimental set-up included a 600 cc vented vessel, a l m~3 collecting vessel, and various analysis tools. The compositions of the gases were determined after they had reacted with air, similarly to what happens in the case of fire arms when the gases are released after the projectile has left the gun barrel. As expected, CO_2 is identified as the main combustion product for any of the tested propellant compositions. The concentrations of the other gases do not show clear trends, except for NO_x. The test results show that urea containing propellant indeed has the lowest emission of NO_x. The firing of each kg of the original propellant in a gun results in a release of 5 to 12 gram NO_x in the atmosphere, while the use of 10% to 20% urea reduces this amount to 3 to 5 gram NO_x per kg propellant.