A systemic thermodynamic analysis was conducted for the autothermal reforming of natural gas to produce hydrogen. A kinetic modeling was made for the autothermal reforming by employing the pre-mixed laminar model included in CHEMKIN package that incorporates the mechanisms of CH4 oxidation, steam reforming and dry reforming; kinetic parameters for methane reforming over Ni-based catalyst, widely used in the natural gas reforming industry, were adopted. The results show that the equilibrium composition of outflow gases is depended on the reaction temperature, the air-fuel ratio and water-fuel ratio. The pressure has a limited impact on the product distribution but has a remarkable impact on the time needed to reach the equilibrium. Under 715 ℃ ~ 730 ℃, 0. 7 Mpa ~ 1. 0 Mpa, O2/CH4 of 0. 60 ~ 0. 70, and H2O/CH4 of 3. 15 ~ 3. 25, the fraction of H2 in the product is higher than 68% , while CO does not exceed 10% (dry basis) and the carbon deposition is close to 0. The kinetic analysis suggests two distinct stages during the autothermal reforming process. The initial stage is a rapid oxidation zone, where H2O and CO2 are the main products. The second stage is a slow conversion zone, where methane steam reforming reaction as well as water gas shift reaction and slight dry reforming take place, with H2, CO and CO2 being the main products. Adding H2O in the feed gas is a visible measure for avoiding hot spot in the reactor and controlling the formation of CO.%对甲烷自热重整进行了系统的热力学分析,并采用预混合层流模型结合甲烷氧化、蒸汽重整、干重整机理对反应过程进行了动力学分析.结果表明,甲烷自热重整的平衡产物及其浓度主要受温度、O2/CH4、H2 O/CH4的影响；压力影响不是十分明显,主要影响达到平衡的速度.在715℃～ 730℃、压力0.7 Mpa～1.0 Mpa,控制O2/CH4在0.60 ～0.70、H2O/CH4在3.15～3.25,可以得到H2 ＞68％、CO＜ 10％的产物气,积炭率接近于0.动力学分析表明,自热重整过程分为两个主要阶段进行,在起始阶段主要发生甲烷氧化反应,产物主要为H2O和CO2；第二阶段以甲烷蒸汽重整反应为主,伴随水气变换反应(WGS)和微弱的干重整,H2、CO和CO2为主要产物.调节初始水浓度可以控制快速氧化阶段反应速率,避免“热点”出现,抑制CO的生成.
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