张璐鑫 王 攀 于宏兵

摘要以Ni、Fe、Co等3种不同金属掺杂的TiO2介孔材料作催化剂对中药渣进行催化裂解,研究不同催化剂对生物油产率及油品的影响,采用热值分析和气质联用(GC-MS)分析裂解油的特性,利用N2吸附-脱附对催化剂进行表征。研究表明, Ni/TiO2的催化效果优于Fe/TiO2和Co/TiO2, Ni/TiO2作催化剂时,裂解油中脂肪烃和烷基苯的种数最多,且其中与汽油或柴油相近的组分占大多数,而芳香族化合物数量明显较少。在Ni/TiO2的催化作用下,大分子中的氧多以H2O分子的形式脱去,因而生物油中含水率较高,导致其热值降低。

关键词金属掺杂TiO2;中药渣;催化裂解;生物油

中图分类号 TK6 文献标识码A文章编号 1007-5739(2010)09-0013-03

EffectofMetalDopedTiO2ontheCharacteristicsofBio-oilfromPyrolysisofHerbResidue

ZHANG Lu-xinWANG PanYU Hong-bing *

(College of Environmental Science & Engineering,Nankai University,Tianjin 300071)

AbstractThree metal-doped mesoporous samples(Ni/TiO2、Fe/TiO2 and Co/TiO2) have been synthesized, characterized and tested as catalysts in the herb residue catalytic pyrolysis process. The effects of catalyst on the yield and quality of bio-oil were examined through the low heating value (LHV)and GC-MS analysis. The N2 adsorption-desorption was also employed to characterize the structure of the catalysts. Ni/TiO2 showed better catalytic activity than Fe/TiO2 and Co/TiO2. The results indicated that the Ni/TiO2 catalyst enhanced the formation of aliphatic hydrocarbon and alkyl, while the contents of aromatic apparently decreased significantly. Most of the chemical composition was similar to that of the petrol or the diesel. Meanwhile, oxygen in molecules was mainly removed in the form of H2O, leading to a lower heating value.

Key wordsmetal doped TiO2;herb residue;catalytic pyrolysis;bio-oil

我国对废弃药渣的处理一直采用填埋的方法,这不仅占用了大量的土地资源,污染了土壤及地下水,而且浪费资源。中药渣是绿色植物有机体被提取相关目标产物后的废弃物,其主要原材料基本上是草本植物的叶和以纤维素为主要成分的茎[1],一般情况下,纤维素含量高的物质在快速热裂解时更易得到液体产物[2],中药渣中高分子物质含量高,具备利用裂解技术实现高附加值的条件[3-4]。然而,作为燃料,生物油的品位较低,主要表现为氧含量高、具有酸性和腐蚀性、热稳定性和化学稳定性差、不能和化石燃油互溶等[5]。在多种生物油升级途径中,综合考虑操作条件、处理成本以及油品改善程度等因素可以得出,催化裂解是极有前途的精制方法[6-9]。目前热裂解所用的催化剂多为……