Understanding the relationship between the chemical composition and pyrolysis performance of endothermic hydrocarbon fuel(EHF) is of great significance for the design and optimization of advanced EHFs. In this work, t...Understanding the relationship between the chemical composition and pyrolysis performance of endothermic hydrocarbon fuel(EHF) is of great significance for the design and optimization of advanced EHFs. In this work, the effect of deep hydrogenation on the pyrolysis of commercial RP-3 is investigated.Fuels with different hydrogenation degrees were obtained by the partially and completely catalytic hydrogenation and their pyrolysis performances were investigated using an apparatus equipped with an electrically heated tubular reactor. The results show that with the increase of hydrogenation degree, fuel conversion almost remains constant during the pyrolysis process(500-650°C, 4 MPa);however, the heat sink increases slightly, and the anti-coking performance significantly improves, which are highly related to their H/C ratios. Detailed characterisations reveal that the difference of the pyrolysis performance can be ascribed to the content of aromatics and cycloalkanes: the former are prone to initiate secondary reactions to form coking precursors, while the latter could act as the hydrogen donor and release hydrogen, which will terminate the radical propagation reactions and suppress the coke deposition. This work should provide the guidance for upgrading EHFs by modulating the composition of EHFs.展开更多
Jet fuel is widely used in air transportation,and sometimes for special vehicles in ground transportation.In the latter case,fuel spray auto-ignition behavior is an important index for engine operation reliability.Sur...Jet fuel is widely used in air transportation,and sometimes for special vehicles in ground transportation.In the latter case,fuel spray auto-ignition behavior is an important index for engine operation reliability.Surrogate fuel is usually used for fundamental combustion study due to the complex composition of practical fuels.As for jet fuels,two-component or three-component surrogate is usually selected to emulate practical fuels.The spray auto-ignition characteristics of RP-3 jet fuel and its three surrogates,the 70%mol n-decane/30%mol 1,2,4-trimethylbenzene blend(Surrogate 1),the 51%mol n-decane/49%mol 1,2,4-trimethylbenzene blend(Surrogate 2),and the 49.8%mol n-dodecane/21.6%mol iso-cetane/28.6%mol toluene blend(Surrogate 3)were studied in a heated constant volume combustion chamber.Surrogate 1 and Surrogate 2 possess the same components,but their blending percentages are different,as the two surrogates were designed to capture the H/C ratio(Surrogate 1)and DCN(Surrogate 2)of RP-3 jet fuel,respectively.Surrogate 3 could emulate more physiochemical properties of RP-3 jet fuel,including molecular weight,H/C ratio and DCN.Experimental results indicate that Surrogate 1 overestimates the auto-ignition propensity of RP-3 jet fuel,whereas Surrogates 2 and 3 show quite similar auto-ignition propensity with RP-3 jet fuel.Therefore,to capture the spray auto-ignition behaviors,DCN is the most important parameter to match when designing the surrogate formulation.However,as the ambient temperature changes,the surrogates matching DCN may still show some differences from the RP-3 jet fuel,e.g.,the first-stage heat release influenced by low-temperature chemistry.展开更多
基金support from National Key Research and Development Program of China(2021YFC2103701)the National Postdoctoral Program of China(GZB20230630)the National Natural Science Foundation of China(22208295).
文摘Understanding the relationship between the chemical composition and pyrolysis performance of endothermic hydrocarbon fuel(EHF) is of great significance for the design and optimization of advanced EHFs. In this work, the effect of deep hydrogenation on the pyrolysis of commercial RP-3 is investigated.Fuels with different hydrogenation degrees were obtained by the partially and completely catalytic hydrogenation and their pyrolysis performances were investigated using an apparatus equipped with an electrically heated tubular reactor. The results show that with the increase of hydrogenation degree, fuel conversion almost remains constant during the pyrolysis process(500-650°C, 4 MPa);however, the heat sink increases slightly, and the anti-coking performance significantly improves, which are highly related to their H/C ratios. Detailed characterisations reveal that the difference of the pyrolysis performance can be ascribed to the content of aromatics and cycloalkanes: the former are prone to initiate secondary reactions to form coking precursors, while the latter could act as the hydrogen donor and release hydrogen, which will terminate the radical propagation reactions and suppress the coke deposition. This work should provide the guidance for upgrading EHFs by modulating the composition of EHFs.
基金This research work was supported by the National Natural Science Foundation of China(Grant Nos.51776124 and 51861135303)the Belt and Road International Collaboration Program by Shanghai Science and Technology Committee(Grant No.19160745400).
文摘Jet fuel is widely used in air transportation,and sometimes for special vehicles in ground transportation.In the latter case,fuel spray auto-ignition behavior is an important index for engine operation reliability.Surrogate fuel is usually used for fundamental combustion study due to the complex composition of practical fuels.As for jet fuels,two-component or three-component surrogate is usually selected to emulate practical fuels.The spray auto-ignition characteristics of RP-3 jet fuel and its three surrogates,the 70%mol n-decane/30%mol 1,2,4-trimethylbenzene blend(Surrogate 1),the 51%mol n-decane/49%mol 1,2,4-trimethylbenzene blend(Surrogate 2),and the 49.8%mol n-dodecane/21.6%mol iso-cetane/28.6%mol toluene blend(Surrogate 3)were studied in a heated constant volume combustion chamber.Surrogate 1 and Surrogate 2 possess the same components,but their blending percentages are different,as the two surrogates were designed to capture the H/C ratio(Surrogate 1)and DCN(Surrogate 2)of RP-3 jet fuel,respectively.Surrogate 3 could emulate more physiochemical properties of RP-3 jet fuel,including molecular weight,H/C ratio and DCN.Experimental results indicate that Surrogate 1 overestimates the auto-ignition propensity of RP-3 jet fuel,whereas Surrogates 2 and 3 show quite similar auto-ignition propensity with RP-3 jet fuel.Therefore,to capture the spray auto-ignition behaviors,DCN is the most important parameter to match when designing the surrogate formulation.However,as the ambient temperature changes,the surrogates matching DCN may still show some differences from the RP-3 jet fuel,e.g.,the first-stage heat release influenced by low-temperature chemistry.
