Investigating the Impact of Biomass Additives in Paraffin-based Hypergolic Solid Fuel with Rocket Grade Hydrogen Peroxide

The research presented the hypergolicity of a paraffin-based hybrid solid fuel with biomass based additive and demonstrated the feasibility of using it in combination with rocket-grade hydrogen peroxide as an oxidizer. Corn cob biomass was pre-treated with potassium hydroxide and subjected to activation at 500-750°C to obtain a carbonaceous char (CC750). Combined with potassium permanganate in a paraffin matrix, eight types of samples were prepared and investigated. The most promising sample (HSPF4) contained 40 % paraffin wax, 58 % carbonaceous char, and 2 % KMnO 4 and it demonstrated the shortest ignition delay (1.9 ms) when exposed to 90 % H 2 O 2 in an open-cup drop test visualized through high-speed video recording. This effect was attributed to CC750’s large surface area and oxygen containing groups and high potassium content in it which contribute to enhanced water absorption capacity and catalytic decomposition of hydrogen peroxide as also observed from DSC peaks at lower temperatures for prepared hybrid fuel sample HSPF4. The EDX analysis revealed the presence of Al and Mn catalytic particles in HSPF4 and a fractured surface as observed from FESEM photographs. It can be seen that the increased content of carbonaceous content in paraffin-based fuel promotes both catalytic oxidation and mechanical stability of the grain. Overall, the obtained results suggest that it may be possible to replace the traditional inorganic hypergolic additives in paraffin-based fuel with a biomass derivative to improve the performance and reduce the cost of hybrid rocket propellants.