Work

Geometric and Positional Isomer Effects on Ignition Behavior of Cycloalkanes: Implications for Sustainable Aviation Fuels

Year: 2025

Type: article

Abstract: High Resolution Image Download MS PowerPoint Slide This study investigates the ignition behavior of six dimethylcyclohexane (DMCH) isomers and cis -/ trans -decalin, focusing on the effects of molecular geometry and substitution patterns. Ignition delay and derived cetane number (DCN) were measured using a CFR ignition quality tester under ASTM D6890 conditions. Among the DMCH isomers, cis -1,3-DMCH exhibited the highest reactivity (DCN = 37.4), while cis -1,2-DMCH showed the lowest (DCN = 21.8). The most significant stereochemical effect was observed between cis - and trans -1,3-DMCH, with a 12-unit DCN difference. Temperature- and pressure-dependent tests of decalin isomers revealed that cis -decalin consistently ignited faster and exhibited stronger pressure sensitivity, supporting a mechanistic interpretation based on 1,5- versus 1,6-H shift pathways. Additionally, the impact of trace polar degradation products on ignition delay (ID) was assessed, revealing significant ID reduction in trans isomers after storage. These findings highlight the need to consider geometric isomerism in kinetic modeling, sustainable aviation fuel formulation, and surrogate design, particularly for fuels rich in cycloalkanes.

Source: Energy & Fuels

DOI: 10.1021/acs.energyfuels.5c03856

Authors: Zhibin Yang, Conor Faulhaber, Randall Boehm, Joshua Heyne

Institutions: Washington State University, Pacific Northwest National Laboratory

Language: English

Topic: Advanced Combustion Engine Technologies

Subfield: Fluid Flow and Transfer Processes

Field: Chemical Engineering

Domain: Physical Sciences

SDG: Climate action

Open Access status: hybrid

Estimated APC paid: $4,500