Development of shock-tube technique for hydrogen production using the low level energy of water vapor

利用激波管产生含碳颗粒的高温水蒸气。碳+水蒸气混合物通过水-气反应生成氢气和一氧化碳，用氩气稀释的高温正辛烷也通过同样的方法生成。通过热分解和热氧化反应生成氢气、乙烯和碳烟，并考察了气体温度对碳烟生成的影响，同时对初始混合比进行了实验研究。结果表明：（1）在激波管试验段中，氩气吹到碳颗粒上，碳颗粒与氩气的混合物在反射激波中被加热，碳颗粒与氩气的混合物发生了爆炸。在波长为0.63，0.80，1.12，1.52，2.30，3.44，3.92，4.26 μm的单色辐射功率的时间历程被跟踪，并使用Hottel-Broughton方程计算颗粒温度。经证实，5 μm的颗粒 ...更多信息 在1500- 2000 K温度范围内，直径为1.5 μ m的纳米晶在200 μs内加热到平衡温度。(2)在我们的激波管系统的反射激波中获得了几千ppm的氢气。(3)在冲击加热的气体中观察到氢气、乙烯和烟灰。预测了甲烷和乙炔的产量。以氦气和氮气为驱动气体，在1500 K时，氮气驱动的产氢速率x={H_2}/[C_8H_<18>]约为1，氦气驱动的产氢速率x = 1/10。以反射冲击温度T_5为代表温度时，产氢的表观活化能为70-80 kJ/mol，符合Arrhenius公式。在2000 K以下，产氢速率与正辛烷浓度成正比。此外，如果在正辛烷混合物中加入少量的氧气，则氢气的产率增大。从这些结果中，我们证实了可以利用冲击波系统加热低能级气体，并且存在利用该能量从高级烃工业化生产氢气的可能性。少

The high temperature water-vapor containing carbon-particles was generated by using shock tube. The generation of hydrogen and carbon-monoxide from the carbon + water-vapor mixture were generated from water-gas reaction, And also the high temperature n-octane diluted with argon was generated by the same method. The hydrogen, ethylene, and soot were generated by the thermal decomposition and the thermal oxidation and the influence of the gas temperature, and the initial mixture ratio was observed experimentally. The following results were obtained: (1) the carbon particles blew up with argon in the test section of shock tube, when the argon gas blew on the carbon particles and the mixture was heated in the reflected shock wave. The time histories of the monochromatic emissive powers at the wavelengths 0.63, 0.80, 1.12, 1.52, 2.30, 3.44, 3.92, 4.26 μm were followed and the particle temperature was calculated using the Hottel-Broughton equation. It was confirmed that the particle of 5 μm … More diameter could be heated till the equilibrium temperature within 200 μs at temperature 1500-2000K. (2) The hydrogen gas of several thousands ppm was obtained in the reflected shock wave of our shock tube system. (3) The hydrogen, ethylene and the soot were observed in the shock-heated gas. Production of methane and acetylene was predicted. Helium and nitrogen were used as the driver gas and the rate of hydrogen production x={H_2}/[C_8H_<18>] was about 1 for nitrogen driver and the 1/10 for helium driver at T_5=1500 K. The apparent activation energy for the hydrogen production was 70-80 kJ/mol with the Arrhenius expression, when one used the reflected shock temperature T_5 as the representative temperature in this experiment. The rate of hydrogen production was proportional to the concentration of n-octane under 2000K. Furthermore the hydrogen production rate became larger, if the small amount of oxygen was added in the n-octane mixture.From these results we confirmed that one can heat up the gas of the low-level-energy by using the shock wave system and that there is a possibility that using the energy the hydrogen gas from higher hydrocarbons was produced industrially. Less