Department of Chemical and Biological Engineering, Iowa State University, Ames, IA 50011, USA.
Bioresour Technol. 2010 Jun;101(12):4646-55. doi: 10.1016/j.biortech.2010.01.112. Epub 2010 Feb 19.
Processing bio-oil with the help of currently existing petroleum refinery infrastructure has been considered as a promising alternative to produce sustainable fuels in the future. The feasibility of bio-oil production and upgrading processes depend upon its chemical composition which in turn depends on the biomass composition and the process conditions of the fast pyrolysis reactions. The primary goal of this paper was to investigate the effect of mineral salts including mixtures of salts in the form of switchgrass ash on the chemical speciation resulting from primary pyrolysis reactions of cellulose and to gain an insight of the underlying mechanisms. Various concentrations of inorganic salts (NaCl, KCl, MgCl(2), CaCl(2), Ca(OH)(2), Ca(NO(3))(2), CaCO(3) and CaHPO(4)) and switchgrass ash were impregnated on pure cellulose. These samples were pyrolyzed in a micro-pyrolyzer connected to a GC-MS/FID system. Effects of minerals on the formation of (a) low molecular weight species - formic acid, glycolaldehyde and acetol, (b) furan ring derivatives - 2-furaldehyde and 5-hydroxy methyl furfural and (c) anhydro sugar - levoglucosan are reported exclusively. Further, the effect of reaction temperature ranging from 350 to 600 degrees C on the pyrolysis speciation of pure and ash-doped cellulose is also reported. The pyrolysis speciation revealed the competitive nature of the primary reactions. Mineral salts and higher temperatures accelerated the reactions that led to the formation of low molecular weight species from cellulose as compared to those leading to anhydro sugars.
利用现有的石油精炼厂基础设施来处理生物油被认为是未来生产可持续燃料的一种很有前途的替代方法。生物油的生产和升级工艺的可行性取决于其化学成分，而化学成分又取决于生物质的组成和快速热解反应的工艺条件。本文的主要目的是研究矿物质盐（包括草灰中的盐混合物）对纤维素的初级热解反应所导致的化学形态的影响，并深入了解其潜在的机制。各种浓度的无机盐（NaCl、KCl、MgCl₂、CaCl₂、Ca(OH)₂、Ca(NO₃)₂、CaCO₃和 CaHPO₄）和草灰被浸渍在纯纤维素上。这些样品在与 GC-MS/FID 系统相连的微型热解仪中进行热解。矿物质对（a）低分子量物质——甲酸、乙二醇醛和乙缩醛、（b）呋喃环衍生物——2-糠醛和 5-羟甲基糠醛以及（c）脱水糖——左旋葡聚糖的形成的影响被单独报道。此外，还报告了反应温度从 350 到 600 摄氏度对纯纤维素和灰掺杂纤维素的热解形态的影响。热解形态揭示了初级反应的竞争性。与导致脱水糖形成的反应相比，矿物质盐和更高的温度加速了导致纤维素形成低分子量物质的反应。
