Green Propellant: A Study

The present study focuses simply on propellants which are environment friendly i.e. Green propellants. In Propulsion Systems, there are two ingredients burned together which are fuel & oxidizer and the resultant energy is used to propel the system. In composite solid rocket propellants, Ammonium perchlorate (AP) is being used extensively which has its own disadvantages i.e. HCl release during its decomposition, and Smoke Trail. HCl gas thus formed tends to react with water vapours resulting in the formation of HCl (l) which causes Acid Rain. The smoke trail left behind the rocket/missile can result in detection of the launching site which is not acceptable from the combat point of view. One more area that is of concern is in exhaust, due to high temperatures, HCl gas further dissociates into H and Cl ions. The Cl radicals react with the O3 molecules (Ozone layer), start decomposing it to O2 and start forming compounds like ClO, ClO2, ClO3, etc. which results in depletion of Ozone layer. In liquid Propellant, Hydrazine (N2H4) derivatives are commonly used such as Mono Methyl Hydrazine (MMH) or Unsymmetrical Dimethyl Hydrazine (UDMH). Hydrazine is extremely toxic in nature which can be hazardous during fuelling & handling. Hence there is a need to find the substitute of AP & Hydrazine based composition with the minimum compromise of performance and having environment friendly tendency.