生物质铁盐催化加氢热解产生生物油与气态烃的研究

Iron salts-catalyzed biomass hydropyrolysis for production of bio-oil and gaseous hydrocarbons

  • 摘要: 利用加压固定床反应器进行了松木催化加氢热解实验(终温600-700 ℃、氢压5.0 MPa),考察了硝酸铁和硫酸亚铁两种铁盐对热解产物产率及分布的影响。研究发现,Fe(NO33能够显著促进生物炭加氢生成甲烷,碳转化率高达97.4%,CH4产率达21.2%,无水生物油产率为32.8%(产率基准均为干燥无灰生物质),生物油中含氧量降低,轻质芳烃产率增加,其中,苯、甲苯和二甲苯(BTX)产率为2.6%。而FeSO4迥异于Fe(NO33,具有抑制气态烃和生物油生成的作用。机理研究表明,Fe(NO33在加氢过程中主要形成α-Fe,并促使生物炭形成无定型和多孔结构,从而有利于其加氢生成甲烷,而FeSO4则部分转化为Fe2S3,由此可致使铁催化剂失活。

     

    Abstract: The catalytic hydropyrolysis of pine wood was conducted in a fixed bed reactor under a H2 pressure of 5 MPa at different temperatures (600-700 ℃) to investigate the effects of two iron salts, Fe(NO3)3 and FeSO4, on the upgrading of bio-oil and gaseous products. Fe(NO3)3 is found to promote the conversion of biomass to bio-oil and gaseous products, with a carbon conversion rate as high as 97.4%, a CH4 yield of 21.2%, and a bio-oil yield of 32.8% (daf. biomass basis). Moreover, the oxygen content in the bio-oil decreases, the yield of light aromatic hydrocarbon increases and the yield of BTX (benzene, toluene and xylene) reaches 2.6%. In contrast, FeSO4 has an inhibitory effect on the production of gaseous hydrocarbons and bio-oil. The XRD analysis shows that Fe(NO3)3 is transformed to α-Fe during hydropyrolysis, with the amorphous and porous structures of bio-char being formed. This is highly conducive to the catalytic hydrogenation and methanation of bio-char. But FeSO4 is converted to Fe2S3 during the hydropyrolysis, which might poison the catalytic activity.

     

/

返回文章
返回