The thermal decomposition of furfural is investigated experimentally and through theoretical calculations at the CBS-QB3 level of theory. Furfural is a major product observed during biomass pyrolysis, but despite its importance there are many speculations about the thermal decomposition channels of this compound. To address these open questions new experiments are performed in a jet-stirred reactor at atmospheric pressure and temperatures ranging from 900 to 1100 K with a furfural inlet mole fraction of 0.005 and He as diluent. The residence time is set to 2 s. The main products observed by GC analysis are CO, CO₂, α-pyrone, furan, 3-furaldehyde, propyne, propadiene, acetylene, methane and benzene. Small amounts of other aromatics, e.g. toluene, styrene, benzaldehyde and phenol are observed as well.

Theoretical calculations at the CBS-QB3 level are used to extend the furfural potential energy surface and to identify possible reaction pathways to the observed products. The unimolecular non-radical decomposition channel through α-pyrone as proposed in literature is confirmed as the main channel, but carbene pathways are found to make small contributions as well. Furthermore, pericyclic reactions are suggested to contribute to the molecular elimination of CO in open-chain molecules and Diels Alder reactions are found to be important for the formation of CO₂ and aromatics. Finally, even radical chemistry initiated by homolytic scission of the approximately 380 kJ/mol strong CH bond in the furfural carbonyl group has a non-negligible influence.

在CBS-QB3的理论水平上，通过理论计算和实验研究了糠醛的热分解。糠醛是生物质热解过程中观察到的主要产物，但尽管其重要性，但仍对该化合物的热分解通道有许多猜测。为了解决这些悬而未决的问题，在大气压和900至1100 K的温度范围内，糠醛入口摩尔分数为0.005和He作为稀释剂的喷射搅拌反应器中进行了新的实验。停留时间设置为2 s。通过GC分析观察到的主要产物是CO，CO ₂，α-吡喃酮，呋喃，3-呋喃醛，丙炔，丙二烯，乙炔，甲烷和苯。还观察到少量其他芳香族化合物，例如甲苯，苯乙烯，苯甲醛和苯酚。

CBS-QB3级的理论计算用于扩展糠醛势能表面并确定通往观察产物的可能反应途径。如文献中所述，通过α-吡喃酮的单分子非自由基分解通道被确认为主要通道，但发现卡宾途径也贡献不大。此外，据认为周环反应有助于开链分子中CO的分子消除，并且发现Diels Alder反应对于CO ₂和芳族化合物的形成很重要。最后，即使通过糠醛羰基中约380 kJ / mol的强C H键的均相断裂而引发的自由基化学也具有不可忽略的影响。