Alcohols, and particularly isoalcohols, are potentially advantageous blendstocks towards achieving efficient, low-carbon intensity internal combustion engines. Their use in advanced configurations, such as boosted spark-ignition or spark-assisted compression ignition, requires a comprehensive understanding of their blending effects on the low- and intermediate-temperature autoignition behavior of petroleum-derived gasoline. This work reports an experimental and modeling study of such autoignition characteristics quantified in a twin-piston rapid compression machine. Isopropanol and isobutanol are blended into a research-grade gasoline (FACE-F) at oxygenate blend levels of 0 to 30% vol/vol, with tests conducted at pressures of 20 and 40 bar, temperatures from 700 to 1000 K, and dilute stoichiometric fuel loadings. Changes to overall reactivity, including first-stage and main ignition times, and preliminary exothermicity are established, with comparisons made to previous measurements with ethanol-blended FACE-F gasoline.

It is found that at low-temperature/NTC conditions (700–860 K) the isoalcohols suppress first-stage reactivity and associated heat release while main ignition times are extended. At NTC/intermediate-temperature (860–1000 K) conditions changes to fuel reactivity are less significant with isopropanol slightly suppressing reactivity and isobutanol promoting ignition. Detailed chemical kinetic modeling is used to interpret the experimental measurements. Overall trends of suppression or promotion in the blending behavior are reasonably captured by the model. Sensitivity and rate of production analyses indicate that at lower temperatures H-atom abstraction reactions from the surrogate fuel molecules (e.g., cyclopentane, isooctane) and the isoalcohols via ȮH are important leading to TC3H6OH and IC4H8OH–C radicals, for isopropanol and isobutanol respectively, which act as scavengers in the system. At higher temperatures, similar chemistries are dominant, but there is an increasing importance of abstraction by HO₂. The kinetic modeling also indicates that the promoting effect of isobutanol at higher temperatures is due to the increased abstractions at the γ-sites, while at lower temperatures abstraction at the α-site leads to greater reactivity suppression.

醇，尤其是异醇，是实现高效，低碳强度内燃机的潜在有利的混合原料。它们在高级配置中的使用，例如增压火花点火或火花辅助压缩点火，需要全面了解其对石油衍生汽油的低温和中温自燃行为的混合作用。这项工作报告了在双活塞快速压缩机中量化的这种自燃特性的实验和模型研究。将异丙醇和异丁醇以0至30％vol / vol的含氧混合水平混合到研究级汽油（FACE-F）中，在20和40 bar的压力，700至1000 K的温度和稀化学计量下进行测试燃料装载量。整体反应性的变化，

结果发现，在低温/ NTC条件下（700–860 K），异醇抑制了一级反应性并伴有热量释放，同时延长了主要着火时间。在NTC /中温（860–1000 K）条件下，燃料反应性的变化不那么明显，异丙醇会略微抑制反应性，而异丁醇会促进点火。详细的化学动力学建模用于解释实验测量。该模型合理地捕获了混合行为中抑制或促进的总体趋势。敏感性和生产率分析表明，在较低温度下，替代燃料分子（例如环戊烷，异辛烷）和异醇通过ȮH引起的H原子抽象反应很重要，可导致TC3H6OH和IC4H8OH-C自由基，分别用于异丙醇和异丁醇，它们在系统中充当清除剂。在更高的温度下，相似的化学物质占主导地位，但是HO提取的重要性越来越高₂。动力学模型还表明，异丁醇在较高温度下的促进作用是由于γ位上的提取增加，而在较低温度下，α位上的提取导致更大的反应性抑制。