Suspensoid of HZSM-5 or HY zeolites mixed with a self-made ceramic-like binder was coated on the inner wall of a tubular reactor by gas-aided fluid displacement technology.The coated zeolites were characterized by mea...Suspensoid of HZSM-5 or HY zeolites mixed with a self-made ceramic-like binder was coated on the inner wall of a tubular reactor by gas-aided fluid displacement technology.The coated zeolites were characterized by means of X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FT-IR)and scanning electron microscopy(SEM).The coating thickness is 10–20 mm and the particle size of the zeolites is in the range of 1–5 mm.In the coated reactor,cracking of endothermic fuels including n-dodecane and aviation fuel RP-3 was carried out separately under supercritical conditions at 600uC and 625uC to investigate their heat sinks and conversion of catalytic reactions.For the reaction catalyzed by HY(25%mass fraction)coating,the heat sink capacity of ndodecane are 815.7 and 901.9 kJ/kg higher than that of the bare tube at 600uC and at 625uC,respectively.Conversion of n-dodecane also increases from 42%to 60%at 600uC and from 66%to 80%at 625uC.The coated zeolite can significantly inhibit the carbon deposition during supercritical cracking reactions.展开更多
Continuous-flow reactor experiments were carried out to study coke formation from thermal crack-ing of home-made jet fuel RP-3 under supercritical con-ditions.The mechanism and precursor of coke forming were analyzed....Continuous-flow reactor experiments were carried out to study coke formation from thermal crack-ing of home-made jet fuel RP-3 under supercritical con-ditions.The mechanism and precursor of coke forming were analyzed.The starting cracking temperature of RP-3 fuel was determined to be 471.8uC by differential scan-ning calorimetry(DSC).Temperature-programmed oxidation and scanning electron microscopy(SEM)characterizations of the stressed tubes showed that there are three different coke species including chemisorbed carbon,amorphous carbon and filamentous coke in the solid deposits.More than 90%of coke deposits are carried away by the supercritical fluid,which has strong capabilities of extraction for coke deposits and their pre-cursors.There were 17.1 wt-%of iron and 11.1 wt-%of chromium found on the coke surface detected by energy dispersive spectroscopy(EDS)which suggests carbure-tion on alloy.RP-3 fuel and its cracking liquids were analyzed by GC-MS,which showed that the content of alkyl benzene and alkyl naphthalene increased evidently in cracking liquids.展开更多
文摘Suspensoid of HZSM-5 or HY zeolites mixed with a self-made ceramic-like binder was coated on the inner wall of a tubular reactor by gas-aided fluid displacement technology.The coated zeolites were characterized by means of X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FT-IR)and scanning electron microscopy(SEM).The coating thickness is 10–20 mm and the particle size of the zeolites is in the range of 1–5 mm.In the coated reactor,cracking of endothermic fuels including n-dodecane and aviation fuel RP-3 was carried out separately under supercritical conditions at 600uC and 625uC to investigate their heat sinks and conversion of catalytic reactions.For the reaction catalyzed by HY(25%mass fraction)coating,the heat sink capacity of ndodecane are 815.7 and 901.9 kJ/kg higher than that of the bare tube at 600uC and at 625uC,respectively.Conversion of n-dodecane also increases from 42%to 60%at 600uC and from 66%to 80%at 625uC.The coated zeolite can significantly inhibit the carbon deposition during supercritical cracking reactions.
文摘Continuous-flow reactor experiments were carried out to study coke formation from thermal crack-ing of home-made jet fuel RP-3 under supercritical con-ditions.The mechanism and precursor of coke forming were analyzed.The starting cracking temperature of RP-3 fuel was determined to be 471.8uC by differential scan-ning calorimetry(DSC).Temperature-programmed oxidation and scanning electron microscopy(SEM)characterizations of the stressed tubes showed that there are three different coke species including chemisorbed carbon,amorphous carbon and filamentous coke in the solid deposits.More than 90%of coke deposits are carried away by the supercritical fluid,which has strong capabilities of extraction for coke deposits and their pre-cursors.There were 17.1 wt-%of iron and 11.1 wt-%of chromium found on the coke surface detected by energy dispersive spectroscopy(EDS)which suggests carbure-tion on alloy.RP-3 fuel and its cracking liquids were analyzed by GC-MS,which showed that the content of alkyl benzene and alkyl naphthalene increased evidently in cracking liquids.
