生物质裂解油模拟物乙酸的催化重整制氢

选取乙酸作为生物质裂解油的模拟物,在600～900℃下进行蒸汽催化重整反应,研究了乙酸在Ni/Al_2O_3、Al_2O_3和Ni催化剂上的蒸汽重整行为。实验结果表明,在Al_2O_3催化剂中加入Ni可显著提高H_2收率,使反应向重整制氢的方向进行;在Ni/Al_2O_3和Al_2O_3催化剂上的乙酸重整反应中,通入蒸汽可提高H_2收率,而在Ni催化剂上的乙酸重整反应中,通入蒸汽对H_2收率影响不大。反应前后催化剂的BET和SEM表征结果显示,反应后催化剂的比表面积和孔体积明显降低,平均孔径增大,说明催化效率降低的原因是积碳覆盖了催化剂表面的活性位,堵塞了催化剂的孔道,特别是堵塞了微孔,导致催化活性逐渐丧失。

Hydrogen Production by Catalytic Reforming of Acetic Acid-Simulacrum of Pyrolysis Bio-Oil

The catalytic reforming of acetic acid,which was selected as simulacrum of bio-oil from biomass pyrolysis,was studied on Ni/Al_2O_3,Al_2O_3 and Ni catalysts under 600-900℃.The results indicated that the presence of Ni could heighten H_2 yield evidently.The presence of steam could increase H_2 yield in the catalytic reforming of acetic acid on Ni/Al_2O_3 and Al_2O_3 catalysts,but not affect H_2 yield in the reaction on Ni catalyst.The used catalysts showed lower specific surface area, smaller total pore and micropore volumes,and larger pore diameter than the fresh catalysts by means of SEM and BET,which suggested that the reason for the catalyst deactivation was the carbon deposition in the pores,especially in the micropores.The carbon deposition could lead to blockage of the pores and coverage of the nickel active sites.