不同催化剂对麦草组分乙醇溶剂热分离效果的影响

Effects of Catalytic Ethanol-based Organosolv on Components Separation of Wheat Straw

关键词:  麦草  乙醇处理  催化剂  组分分离

Key Words:wheat straw  ethanol-based organosolv  catalyst  components separation

摘要:高效清洁的纤维生物质组分分离技术是生物质深度精炼和高值化利用的前提。乙醇溶剂高温热分解是一项极具前景的生物质组分高效分离技术，催化剂的加入可以明显加快脱木质素效率。本研究在麦草乙醇溶剂热分离过程中加入催化剂，探讨了催化剂乙酸、MgCl₂、H₃PO₄以及3种催化剂与H₂O₂组成的二元催化体系对麦草组分分离效果的影响。结果表明，H₂O₂的加入对乙酸、MgCl₂催化半纤维素的脱除有明显的提高，而对木质素的脱除影响不显著；H₂O₂的添加对于H₃PO₄催化来说，木质素脱除率有明显的上升，而半纤维素脱除率则保持较高水平。当反应温度190℃、催化剂浓度0.02 mol/L、H₃PO₄/H₂O₂质量比为5∶5时，木质素脱除率由单独H₃PO₄催化的80.99%增加到88.64%；半纤维素脱除率为68.99%。

Abstract:Efficient and clean separation technology is the precondition of deeper biorefining and high value utilization of biomass. Ethanol organosolv process is a promising high-efficiency separation technology for biomass. The addition of catalyst can significantly accelerate the efficiency of delignification. This study explored the effect of different catalysts on the separation of three main components of wheat straw.The effect of addition of CH₃COOH， MgCl₂， H₃PO₄ and binary catalytic system CH₃COOH/H₂O₂， MgCl₂/H₂O₂， H₃PO₄/H₂O₂ was discussed. The results showed that the addition of H₂O₂ significantly improved the removal of hemicellulose in the presence of CH3COOH or MgCl₂， but no significant effect on delignification. For using H₃PO₄ as catalyst， the delignification increased significantly with the addition of H₂O₂， the removal of hemicellulose remained at higher level. When H₃PO₄/H₂O₂ was 5∶5 （w/w）， the delignification increased from 80.99% without adding H2O2to 88.64%. The removal of hemicellulose was 68.99%．