金属类催化剂与复合分子筛协同催化特性研究

STUDY ON SYNERGISTIC CATALYTIC CHARACTERISTICS OF METAL CATALYSTS AND COMPOSITE MOLECULAR SIEVES

针对生物质热解制备所得生物油高氧含量、低热值等系列问题,提出金属类催化剂与复合分子筛HZSM-5/MCM-41(HM)协同催化的新方法。在Py-GC/MS热解仪以及催化热解重整系统上,采用单级和双级2种催化模式,考察不同金属类催化剂与HM对竹木屑热解产物分布的影响。实验结果表明:在单级催化模式下金属类催化剂有利于生物油含氧量的降低和品质的提高。在双级催化模式下引入HM,可进一步降低生物油的氧含量,同时显著提高烃类收率,最高达66.11%,单环芳烃选择性达66.87%。此外,在催化热解重整实验中发现Fe的添加可增强HM的芳构化能力,进一步降低酸醛酮等不利组分的相对含量,促进低聚物的二次裂解,提高单环芳烃的选择性,得到40.25%的最高烃类产率,协同效果更明显,具有很好的应用前景。

Due to the problems like high oxygen content and low calorific value of bio-oil produced by biomass pyrolysis,a new method of synergistic catalysis between metal catalysts and composite molecular sieve HZSM-5/MCM-41(HM)was proposed.The effects of metal catalysts and HM on the pyrolysis product distribution of bamboo chips were investigated in Py-GC/MS and catalytic pyrolysis reforming system respectively.The results showed that the metal catalysts are beneficial to the reduction of oxygen content and the improvement of bio-oil quality in the single-stage catalytic mode.In the two-stage catalytic mode,the introduction of HM further reduces the oxygen content of bio-oil and significantly increases the hydrocarbon yield up to 66.11%.meanwhile the selectivity of monocyclic aromatic hydrocarbons is 66.87%.In addition,the aromatization ability of HM is enhanced by the addition of Fe,and the relative contents of aldehydes and ketones are further reduced,which promotes the secondary cracking of oligomers.The selectivity of monocyclic aromatic hydrocarbons is improved and the highest hydrocarbon yield of 40.25%is obtained.The synergistic effect is more obvious and equips application potential.