Abstract For high-quality utilization of biomass resources, co-production of bio-oil and MgO-impregnated biochar from catalytic pyrolysis of Mg-loaded biomass samples is a prospective approach. In this study, the effects of MgCl2 and Mg(NO3)2 loading on catalytic pyrolysis of sawdust for production of high value-added bio-oil and biochar, as well as the catalytic pyrolysis process mechanism were explored. The thermal degradation process behavior and the pyrolysis products of non-condensable gas, bio-oil and biochar were obtained by thermogravimetric analyzer (TGA) and lab-scale fixed-bed reactor system. The product properties were analyzed and characterized by gas chromatography (GC), gas chromatography-mass spectrometry (GC-MS), N2 adsorption-desorption, X-rays diffraction (XRD) and transmission electron microscopy (TEM). The obtained results indicated that the loading of Mg salts favored the thermal degradation process of catalytic pyrolysis due to the weakened hydrogen-bonding networks and disrupted the crystalline structures. The enhanced cross-linking and repolymerization reactions of pyrolysis intermediates by the catalytic effect of Mg resulted in the increased non-condensable gas and biochar yields and the decrease of bio-oil yield. The loading of Mg salts also resulted in the decreased CO yield and increased CO2 yield. The relative contents of ketones and furans increased, and the relative contents of phenols and sugars decreased for Mg-loaded SD samples in bio-oil. In addition, the Mg salts loading also favored the formation of developed pore structure and uniformly dispersed MgO nanoparticles in obtained biochar. In general, catalytic pyrolysis of MgCl2-loaded or Mg(NO3)2-loaded sawdust is a feasible method to obtain high value-added bio-oil and MgO-impregnated biochar products.

中文翻译：

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MgCl2和Mg(NO3)2负载量对木屑催化热解生物油和MgO浸渍生物炭生产的影响

摘要 为了生物质资源的高质量利用，通过催化热解负载镁的生物质样品共同生产生物油和氧化镁浸渍的生物炭是一种有前景的方法。本研究探讨了MgCl2和Mg(NO3)2负载量对木屑催化热解生产高附加值生物油和生物炭的影响，以及催化热解过程机理。通过热重分析仪（TGA）和实验室规模的固定床反应器系统获得了不凝气、生物油和生物炭的热降解过程行为和热解产物。采用气相色谱(GC)、气相色谱-质谱(GC-MS)、N2吸附-解吸、X射线衍射(XRD)和透射电子显微镜(TEM)对产物的性质进行了分析和表征。所得结果表明，由于氢键网络减弱并破坏了晶体结构，镁盐的负载有利于催化热解的热降解过程。Mg的催化作用增强了热解中间体的交联和再聚合反应，导致不凝气和生物炭产率增加，生物油产率下降。镁盐的加载也导致 CO 产率降低和 CO2 产率增加。生物油中Mg负载的SD样品酮和呋喃的相对含量增加，酚和糖的相对含量降低。此外，镁盐的负载也有利于在获得的生物炭中形成发达的孔隙结构和均匀分散的 MgO 纳米颗粒。一般来说，