Exploring the pyrolysis and oxidation kinetics of typical binary blends of renewable synthetic fuels from CO2 electroreduction

The electrochemical reduction of CO 2 produces synthetic fuel blends containing oxygenated C 2 species, yet their co-pyrolysis and co-oxidation kinetics remain poorly understood. This work presents an experimental and kinetic modeling investigation of acetic acid/ethanol binary blends, representative products of CO 2 electroreduction. The pyrolysis and oxidation experiments were conducted in an atmospheric jet-stirred reactor (JSR) over 750–1300 K, covering equivalence ratios from 0.4 to ∞, for two blend compositions (90/10 and 70/30 mol%). Species concentration profiles were measured and compared to predictions of three detailed kinetic models. Results showed that ethanol addition exerted negligible influence on acetic acid conversion under pyrolytic conditions, but significantly accelerated acetic acid consumption under oxidative atmospheres. This was because ethanol oxidation reactions enriched the radical pool. The present model, built upon validated ethanol and acetic acid sub-mechanisms with refined rate constants, reproduced the experimental data with satisfactory accuracy across all conditions, outperforming two literature models. Reaction path analyses revealed that acetic acid consumption was dominated by thermal decomposition and H/CH 3 abstraction reactions, while ethanol enhanced reactivity primarily through radical supply rather than altering acetic acid’s reaction network. In addition, sensitivity analyses identified chain-branching and terminating steps involving H and CH 3 as the key rate-controlling processes. This study provides the first comprehensive kinetic dataset and an updated model for acetic acid/ethanol blends, supporting the design and utilization of renewable electrofuels.