大同煤在等离子体热解中生成HCN和NH3的研究

对大同煤中氮在等离子体反应器内的转化进行了研究，考察了输煤速率、输入功率和反应气氛等实验条件对HCN和NH₃生成的影响，同时基于Gibbs自由能最小原理，计算了C-H-O-N的热力学平衡组成. 实验和计算结果表明：煤中氮在等离子体中主要以HCN形式存在，也有少量氮转化为NH₃.随着温度的升高，理论计算得到HCN的产率逐渐增大而NH₃的产率逐渐降低，而实验结果却显示HCN和NH₃的产率逐渐升高.在纯Ar等离子气氛中随供煤速率的增加，HCN的产率呈先增大后减小的趋势，NH₃的变化趋势相反；随反应器输入功率的提高，HCN和NH3的产率逐渐增大. H₂的引入有利于HCN和NH₃的生成，CO₂降低了HCN和NH₃的产率，而O₂有利于NH₃的生成，但也促进了HCN 的进一步转化.

Formation of HCN and NH3 during Datong coal pyrolysis in arc plasma jet

The formation of HCN and NH_3 from coal-N was investigated in a plasma coal pyrolysis reactor.Based on Gibbs free energy minimization principle,Thermodynamic equilibrium fraction of C-H-O-N was calculated.The results from experiments and calculation suggest that HCN is the main product of coal-N at high temperature.Only a little coal-N convertes to NH_3.As the temperature increases,the yields of HCN and NH_3 increases from the experimental results,but the theoretic calculated results show that HCN gradually increases and NH_3 decreases.The possible reason is the influence of practical operating condition.The yield of HCN increases firstly and then decreases with increasing coal feeding rate,but NH_3 is reverse.Enhancement of input power leads to the increase of HCN and NH_3 yields.H_2 acting as the reactive atmosphere benefits to the formation of HCN and NH_3,and CO_2 may reduce the yields of HCN and NH_3,O_2 enhances the formation of NH_3,but promotes the furthermore conversion of HCN.