Ongoing progress in synthetic biology, metabolic engineering, and catalysis continues to produce a diverse array of advanced biofuels with complex molecular structure and functional groups. In order to integrate biofuels into existing combustion systems, and to optimize the design of next-generation combustion systems, understanding connections between molecular structure and ignition at low-temperature conditions (< 1000 K) remains a priority that is addressed in part using chemical kinetics modeling. The development of predictive models relies on detailed information, derived from experimental and theoretical studies, on molecular structure and chemical reactivity, both of which influence the balance of chain reactions that occur during combustion – propagation, termination, and branching. In broad context, three main categories of reactions affect ignition behavior: (i) initiation reactions that generate a distribution of organic radicals, $\dot{\mathrm{R}}$; (ii) competing unimolecular decomposition of $\dot{\mathrm{R}}$ and bimolecular reaction of $\dot{\mathrm{R}}$ with O₂; (iii) decomposition mechanisms of peroxy radical adducts (RO$\dot{\mathrm{O}}$), including isomerization via RO$\dot{\mathrm{O}}$ ⇌ $\dot{\mathrm{Q}}$OOH. All three categories are influenced by functional groups in different ways, which causes a shift in the balance of chain reactions that unfold over complex temperature- and pressure-dependent mechanisms.

The objective of the present review is three-fold: (1) to provide a historical account of research on low-temperature oxidation of biofuels, including initiation reactions, peroxy radical reactions, $\dot{\mathrm{Q}}$OOH-mediated reaction mechanisms, and chain-branching chemistry; (2) to summarize the influence of functional groups on chemical kinetics relevant to chain-branching reactions, which are responsible for the accelerated production of radicals that leads to ignition; (3) to identify areas of research that are needed – experimentally and computationally – to address fundamental questions that remain.

Results from experimental, quantum chemical, and chemical kinetics modeling studies are reviewed for several classes of biofuels – alcohols, esters, ketones, acyclic ethers and cyclic ethers – and are compared against analogous results in alkane oxidation. The review is organized into separate sections for each biofuel class, which include studies on thermochemistry and bond dissociation energies, rate coefficients for initiation reactions via H-abstraction and related branching fractions, reaction mechanisms and product formation from reactive intermediates, ignition delay times, and chemical kinetics modeling. Each section is then summarized in order to identify areas for which additional functional group-specific work is required. The review concludes with an outline for research directions for improving the fundamental understanding of biofuel ignition chemistry and related chemical kinetics modeling.

合成生物学、代谢工程和催化方面的持续进步继续产生具有复杂分子结构和官能团的各种先进生物燃料。为了将生物燃料集成到现有的燃烧系统中，并优化下一代燃烧系统的设计，了解分子结构与低温条件下（< 1000 K）点火之间的联系仍然是一个优先事项，部分使用化学动力学解决造型。预测模型的开发依赖于来自实验和理论研究的详细信息，涉及分子结构和化学反应性，这两者都会影响燃烧过程中发生的链式反应的平衡——传播、终止和支化。在广泛的背景下，$\dot{\mathrm{电阻}}$; (ii) 竞争性单分子分解$\dot{\mathrm{电阻}}$ 和双分子反应 $\dot{\mathrm{电阻}}$与O ₂ ; (iii) 过氧自由基加合物（RO）的分解机制$\dot{\mathrm{哦}}$)，包括通过 RO 的异构化$\dot{\mathrm{哦}}$ ⇌ $\dot{\mathrm{问}}$哦。所有这三个类别都以不同的方式受官能团的影响，这会导致在复杂的温度和压力依赖机制中展开的链式反应的平衡发生变化。

本综述的目的有三重：(1) 提供生物燃料低温氧化研究的历史记录，包括引发反应、过氧自由基反应、 $\dot{\mathrm{问}}$OOH 介导的反应机制和链支化化学；(2) 总结官能团对与链支化反应相关的化学动力学的影响，这些化学动力学负责加速产生导致着火的自由基；(3) 确定需要的研究领域——通过实验和计算——来解决仍然存在的基本问题。

对几类生物燃料（醇、酯、酮、无环醚和环醚）的实验、量子化学和化学动力学建模研究的结果进行了审查，并与烷烃氧化的类似结果进行了比较。该评论针对每个生物燃料类别分为单独的部分，其中包括对热化学和键解离能、通过 H-抽象和相关支化分数引发反应的速率系数、反应机制和反应中间体的产物形成、点火延迟时间和化学动力学建模。然后对每个部分进行总结，以确定需要针对特定​​职能组进行额外工作的领域。