Study On Catalytic Cracking And Coke Deposit Of Iso-octane And RP-3 Under Supercritical Condition

The cooling problem caused by hypersonic flight is one challenge of hypersonic propellant technology. Endothermic hydrocarbon fuels, which can chemically decompose into energetic gases via cracking reactions and provide significantly chemical heat sink, has attracted increasing attention with potential in resolving this problem. Using physical and chemical heat sink of endothermic hydrocarbon fuels, the hypersonic aircrafts can be effectively cooled.Numerous studies have been conducted on the endothermic fuels, including the choice of fuels, the types of cracking reaction, the improvement of fuels performance and test of fuels on practical aircraft. The present work focuses on the catalytic cracking of iso-octane (2,2,4-trimethylpentane) and RP-3.Under supercritical condition, used HZSM-5 and Hβas catalysts, catalytic cracking of iso-octane and RP-3 were performed to investigate the effects of reaction conditions. The results indicate that the conversion and gas yield of iso-octane and RP-3 increase with the rising of reaction temperature respectively. The reasonable reaction condition is 450℃and 4MPaGas yield of iso-octane and RP-3 cracking catalyzed by Hβis less than that by HZSM-5. However hydrogen molar ratio in gas products catalyzed by Hβis greatly more than that by HZSM-5.In the cracking reactions catalyzed by HZSM-5, hydrogen molar ratio in gas products of iso-octane cracking increases with the increase of temperature, and the maximum is 13.8%. However, hydrogen molar ratio in gas products of iso-octane cracking decreases with the increase of temperature, and the maximum is 8.9%. In the cracking reactions catalyzed by Hβ, hydrogen molar ratio in gas products of iso-octane cracking decreases with the increase of temperature, and the maximum is 43.6%. Meanwhile hydrogen molar ratio in gas products of iso-octane cracking decreases with the increase of temperature, and the maximum is 41.8%.The major gas products are C3 and C4 components. With the increase of temperature, the molar ratio of C3 and C4 components decreases and the molar ratio of smaller components increases. It indicates that C3 and C4 components crack...