Solid-State NMR, Institute for Molecules and Materials, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands.
Energy Research Centre of the Netherlands (ECN), Biomass and Energy Efficiency, P.O. Box 1, 1755 ZG Petten, The Netherlands.
Bioresour Technol. 2013 Oct;146:585-590. doi: 10.1016/j.biortech.2013.07.104. Epub 2013 Jul 29.
The effects of thermochemical treatments (aquathermolysis, pyrolysis, and combinations thereof) on the lignocellulosic structure and composition of wheat straw were studied with (13)C and (1)H solid state NMR spectroscopy and proton T1ρ relaxation measurements. Results show that aquathermolysis removes hemicellulose, acetyl groups, and ash minerals. As a result, the susceptibility of lignocellulose to pyrolysis is reduced most likely due to the removal of catalytically active salts, although recondensation of lignin during aquathermolysis treatment can also play a role. In contrast to pyrolysis of wheat straw, pyrolysis of aquathermolysed wheat straw leaves traces of cellulose in the char as well as more intense lignin methoxy peaks. Finally, it was found that both pyrolysis chars contain aliphatic chains, which were attributed to the presence of cutin or cutin-like materials, a macromolecule that covers the aerial surface of plants, not soluble in water and seemingly stable under the pyrolysis conditions applied.
采用（13）C 和（1）H 固体核磁共振光谱和质子 T1ρ 弛豫测量研究了热化学处理（水热解、热解和它们的组合）对麦草木质纤维素结构和组成的影响。结果表明，水热解去除了半纤维素、乙酰基和灰分矿物质。因此，木质纤维素对热解的敏感性降低，这很可能是由于去除了催化活性盐，但水热解处理过程中木质素的再缩合也可能起作用。与麦草的热解相比，水热解的麦草在热解炭中留下了纤维素的痕迹，以及更强烈的木质素甲氧基峰。最后发现，两种热解炭都含有脂肪族链，这归因于存在角质或类角质材料，角质或类角质材料是一种覆盖在植物气生表面的高分子，不溶于水，在应用的热解条件下似乎稳定。
