Diels-Alder addition of dicyclopentadiene and cyclopentadiene in polar solvents has been studied to produce tricyclopentadiene（TCPD） that is a potential high-density fuel precursor. GC and MS analysis shows that the...Diels-Alder addition of dicyclopentadiene and cyclopentadiene in polar solvents has been studied to produce tricyclopentadiene（TCPD） that is a potential high-density fuel precursor. GC and MS analysis shows that the adducts contain two isomers, namely exo- and endo-TCPD. Theoretical simulation shows that although the transition state of endo-TCPD has a lower activation energy, exo-TCPD is thermodynamically preferred. Polar solvents can accelerate the reaction rate and improve the exo/endo ratio of TCPD because the transition state of exo-TCPD has a higher polarity than that of endo-TCPD. The solvent effect follows the order of polarity： benzyl methanol〉cyclohexanone〉toluene. The conversion rises when the temperature ranges from 120 to 150 ℃, but the selectivity of TCPD slightly decreases. Increasing the pressure can improve the conversion but the exo/endo ratio of TCPD is unchanged. The apparent kinetics in different solvents was determined via nonlinear regression. The activation energies are 99.47, 101.15, and 107.32 kJ/mol for benzyl methanol, cyclohexanone, and toluene, respectively. The optimal reaction conditions are as follows： benzyl methanol as solvent, temperature 150 ℃, and pressure 900 kPa. After an 11-hour reaction, a conversion of 58.0%, a TCPD selectivity of 95.7%, and an exo/endo ratio of 1/5.3 has been obtained.展开更多
High energy density fuels are critical for hypersonic aerospace propulsion but suffer from difficul- ties of ignition delay and incomplete combustion. This research reports aluminum nanoparticles （A1 NPs） assisted i...High energy density fuels are critical for hypersonic aerospace propulsion but suffer from difficul- ties of ignition delay and incomplete combustion. This research reports aluminum nanoparticles （A1 NPs） assisted ignition and combustion of high energy density JP-10 fuel. A1NPs with a size of 16 nm were fabricated through a mild and simple method by decomposing AIH3. Et20 with the addition of a surfactant ligand. The uniform size distribu- tion, nanoscaled size and surface ligand make A1 NPs stably suspend in JP-10, with 80% NPs being dispersed in the liquid fuel after six months. A shock tube test shows that the presence of 1 wt-% A1 NPs can significantly shorten ignition delay time at temperature of 1500 to 1750 K, promote the combustion, and enhance energy release of JP-10. This work demonstrates the potential of A1 NPs as ignition and combustion additive for high energy density fuel in hypersonic applications.展开更多
基金Supported by Fundamental Research Project of Commission of ScienceTechnology and Industry for National Defense of China(NoA1420060192)
文摘Diels-Alder addition of dicyclopentadiene and cyclopentadiene in polar solvents has been studied to produce tricyclopentadiene（TCPD） that is a potential high-density fuel precursor. GC and MS analysis shows that the adducts contain two isomers, namely exo- and endo-TCPD. Theoretical simulation shows that although the transition state of endo-TCPD has a lower activation energy, exo-TCPD is thermodynamically preferred. Polar solvents can accelerate the reaction rate and improve the exo/endo ratio of TCPD because the transition state of exo-TCPD has a higher polarity than that of endo-TCPD. The solvent effect follows the order of polarity： benzyl methanol〉cyclohexanone〉toluene. The conversion rises when the temperature ranges from 120 to 150 ℃, but the selectivity of TCPD slightly decreases. Increasing the pressure can improve the conversion but the exo/endo ratio of TCPD is unchanged. The apparent kinetics in different solvents was determined via nonlinear regression. The activation energies are 99.47, 101.15, and 107.32 kJ/mol for benzyl methanol, cyclohexanone, and toluene, respectively. The optimal reaction conditions are as follows： benzyl methanol as solvent, temperature 150 ℃, and pressure 900 kPa. After an 11-hour reaction, a conversion of 58.0%, a TCPD selectivity of 95.7%, and an exo/endo ratio of 1/5.3 has been obtained.
文摘High energy density fuels are critical for hypersonic aerospace propulsion but suffer from difficul- ties of ignition delay and incomplete combustion. This research reports aluminum nanoparticles （A1 NPs） assisted ignition and combustion of high energy density JP-10 fuel. A1NPs with a size of 16 nm were fabricated through a mild and simple method by decomposing AIH3. Et20 with the addition of a surfactant ligand. The uniform size distribu- tion, nanoscaled size and surface ligand make A1 NPs stably suspend in JP-10, with 80% NPs being dispersed in the liquid fuel after six months. A shock tube test shows that the presence of 1 wt-% A1 NPs can significantly shorten ignition delay time at temperature of 1500 to 1750 K, promote the combustion, and enhance energy release of JP-10. This work demonstrates the potential of A1 NPs as ignition and combustion additive for high energy density fuel in hypersonic applications.
