Catalytic Cracking Of N-Alkanes And Coke Deposite Under Supercritical Condition

As the available effective coolant used in hypersonic vehicles over 5 Mach, thephysical heat cannot meet the demand of hypoersonic flight over 5 Mach. To meet thischallege, endothermic fuels, which can chemically decompose into energetic gases viacracking reactions and provide extremely high chemical heat sink, have beendeveloped. These fuels provide the cooling for hypersonic flight and convert the fuelinto small hydrcarbons that can be burned in a hypersonic combustor.Numerous studies have been published on the endothermic fuels, which includedthe choice of fuels, the types of cracking reaction, the improvement of fuelspeformance and test of fuels on practical aircraft. The present work is focused oncatalytic cracking of fuels. The main contents were as follows: the catalytic crackingof n-decane and n-dodecane, the coke deposite on the catalyst.The supercritical properties of fuels were calculated by using SUPERSTRAPPsoftware (coded by NIST). The results showed that the peoperties of fuels aresignificantly different from that under atmosphere, which have great effect on reactionof fuels.The supercritical catalytic cracking of n-decaneand n-dodecane was studied. Theeffects of pressure,temperature and feedstock's flux rate on the conversition andyields of gas were studied. The results showed that the conversitions and yields of gasincreased as the cracking temperature rised. As increasing of the cracking pressure theconversition and yield of gas decreased.After analyzing the compents of the two fuels carcking products, the content ofarcomatic compents were higher under atmosphere than that under supercriticalcondition. The major gas products included C3 C4 compents and H2.The study on coke deposits showed that the coke deposites decreased as thecracking temperature increased. The higher cracking pressure led to more cokedeposites. As the cracking temperature rising, the outside coke deposites increasedand the inside coke deposite declined.Research was put on the supercritical catalytic cracking of TJ-02. The gasproducts included great amount of H2.