微波等离子体条件下甲烷偶联制乙炔的特性探究

Methane Conversion to Acetylene via Microwave Plasmas

采用绞状缠绕式的热电偶计工作在打火功率以下时,测量了不同反应压强下的微波等离子体空间温度.采用HFSS软件计算了不同压强下反应管中的场强分布,研究了压强、功率、等离子体空间温度和场强分布对乙炔收率的影响.在此实验中得到一个最佳状态:反应压强为4.655×103Pa,反应管内中心区域场强为1887.9 V/m,等离子体吸收功率为40 W,等离子体中心区域的空间温度为1194 K,此条件下甲烷转化率为91.7%,生成乙炔的选择性为100%.与传统的化学热力学理论分析结果进行对比,发现在微波等离子体条件下,甲烷偶联制乙炔的反应温度大大降低且乙炔收率大大提高,这是由于非膨胀功引起的结果.

Under striking power, the temperature of microwave plasmas interspace with different reaction pressure was measured by the intertwined thermocouple. A high frequency structure simulator （HFSS） was used to calculate the distribution of electromagnetic field in reaction tube. The paper presents the effect of the pressure, microwave power, plasmas interspace temperature and the distribution of electromagnetic field on the acetylene yield. Under the reaction pressure 4.655 × 10^3 Pa, electric field intensity was 1 887.9 Vim in the core of reaction tube, the absorbed power of plasmas was 40 W and the interspace temperature was 1 194 K. Under the above condition, the experiment provided the best results that methane conversion was 91.7 %, and acetylene selectivity was 100% . It is concluded that, to compare with the conventional thermodynamic method, microwave plasmas can convert much more methane into acetylene with a much lower temperature. This phenomena occurs in the non-volume work.