在自制的介质阻挡放电等离子体重整制氢装置上进行了甲烷部分氧化重整制氢的实验研究.本文研究了氧碳(O/C)摩尔比,进气流量,放电间隙,放电区间长度,填充物的直径、形状和材料,放电电压和放电频率对甲烷转化率、氢产率和产物的选择性(H2、CO和CO2)的影响.实验结果表明:放电区域的参数对甲烷转化率有较大的影响.甲烷转化率随着放电区域长度的增大而增大,当放电区域长度从5 cm增大到20 cm时,甲烷转化率从6.87%增大到22.26%,增大率为224%.同时,放电区域的填充物对产氢效果有较大的影响.当反应器填充颗粒时,甲烷转化率比无填充物时高.选择适当介电常数的填充物具有巨大的实际工程意义.另外,氢产率和氢气的选择性随着放电频率的增大而增大,当放电频率从1.5 k Hz增大到7.0 k Hz时,氢产率从1.10%增大到9.49%,氢气的选择性从21.18%增大到30.06%.实验结果将对碳氢燃料等离子体重整制氢的车载应用提供实验依据.
Hydrogen was produced from partial oxidation reforming of DME(dimethyl ether) by spark discharge plasma at atmospheric pressure. A plasma-catalyst reformer was designed. A series of experiments were carried out to investigate its performance of hydrogen-rich gas production. The effects of reaction temperature, catalyst and flow rate on gas concentrations(volume fraction), hydrogen yield, DME conversion ratio, specific energy consumption and thermal efficiency were investigated, respectively. The experimental results show that hydrogen concentration and the flow rate of produced H2 are improved when temperature increases from 300 °C to 700 °C. Hydrogen yield, hydrogen concentration and the flow rate of produced H2 are substantially improved in the use of Fe-based catalyst at high temperature. Moreover, hydrogen yield and thermal efficiency are improved and change slightly when flow rate increases. When catalyst is 12 g, and flow rate increases from 35 mL/min to 210 mL/min, hydrogen yield decreases from 66.4% to 57.7%,and thermal efficiency decreases from 35.6% to 30.9%. It is anticipated that the results would serve as a good guideline to the application of hydrogen generation from hydrocarbon fuels by plasma reforming onboard.
In this work,hydrogen is produced from partial oxidation reforming of dimethyl ether(DME)by a plasma-catalyst hybrid reformer under atmospheric pressure.The plasma-catalyst hybrid reformer which includes both plasma and catalyst reactors is designed.A spark discharge is used as a non-equilibrium plasma source,and it is used to ionize the mixture of DME and air.The performances of the reformer are characterized experimentally in terms of gas concentrations,hydrogen yield,DME conversion ratio,and specific energy consumption.The effects of discharge frequency,reaction temperature,air-to-DME ratio and space velocity are investigated.The experimental results show that the plasma-catalyst hybrid reformer enhances hydrogen yield when reaction temperature drops below 620 °C.At 450 °C,hydrogen yield of hybrid reforming is almost three times that of catalyst reforming.When space velocity is 510 h-1,hydrogen yield is 67.7%,and specific energy consumption is 12.2 kJ/L-H2.
