微型流化床中萘催化裂解生成H_(2) 和CH_(4) 反应动力学研究

Study on kinetics of catalytic cracking of naphthalene to H_(2) and CH_(4) in micro fluidized bed

生物质气化是生物质能代替化石能源中最具吸引力的方法之一,而生物质气化焦油中萘是最稳定、难以分解的环烃之一。选取萘作为气化焦油模型化合物,利用浸渍法制备了Cu/Ni负载橄榄石催化剂(15Ni/O、9Cu/6Ni/O、15Cu/O),在微型流化床反应器(MFBRA)中,采用模型拟合法计算了萘催化裂解生成H_(2) 和CH_(4) 的动力学参数,评价了双金属催化剂的性能。结果表明,所选的机理函数G(16)、G(20)和G(24)均满足不同催化剂催化裂解萘生成H_(2) 和CH_(4) 的反应。不同CuO和NiO质量分数的催化剂H_(2) 的生成活化能(Ea)值大小顺序为SiO_(2)> 15Ni/O>橄榄石> 15Cu/O> 9Cu/6Ni/O,CH_(4) 的Ea值大小顺序为橄榄石> 15Ni/O> SiO_(2)> 9Cu/6Ni/O> 15Cu/O。萘在9Cu/6Ni/O催化剂上裂解生成H_(2) 的Ea值均小于其他催化剂,说明双金属负载橄榄石催化剂对萘的催化裂解反应催化性能更好。

Biomass gasification is one of the most attractive methods to replace fossil energy with biomass energy, and naphthalene is one of the most stable and difficult to decompose cyclic hydrocarbons in biomass gasification tar. Naphthalene was selected as a model compound of gasification tar, and Cu/Ni-supported olivine catalysts(15Ni/O, 9Cu/6Ni/O, 15Cu/O) were prepared by impregnation method. In a micro-fluidized bed reactor(MFBRA), the kinetic parameters of catalytic cracking of naphthalene to H_(2) and CH_(4) were calculated by model fitting method, and the performance of bimetallic catalysts was evaluated. The results show that the selected mechanistic functions G(16), G(20) and G(24) all satisfy the catalytic cracking reactions of naphthalene to H_(2) and CH_(4) with different catalysts. The order of the activation energy(Ea) values for H_(2) production from catalysts with different mass fractions of CuO and NiO is SiO_(2)> 15Ni/O > olivine > 15Cu/O > 9Cu/6Ni/O and for CH_(4) formation is olivine > 15Ni/O > SiO_(2)> 9Cu/6Ni/O > 15Cu/O.Eaof naphthalene cracking to H_(2) on 9Cu/6Ni/O catalyst is lower than that of other catalysts, indicating that bimetallic supported olivine catalyst exhibits better catalytic property in catalytic cracking reaction of naphthalene.