# Comparative Investigation of the High Pressure Autoignition of the Butanol Isomers

## TL;DR

This study compares the autoignition delays of butanol isomers at high pressures and varying temperatures, revealing differences in reactivity and unique pre-ignition behavior of tert-butanol under specific conditions.

## Contribution

It provides new insights into the autoignition characteristics of butanol isomers at elevated pressures, including reactivity rankings and heat release phenomena.

## Key findings

- Reactivity ranking varies with pressure: n-butanol > sec-butanol ~ iso-butanol > tert-butanol at 15 bar.
- At 30 bar, the ranking shifts to n-butanol > tert-butanol > sec-butanol > iso-butanol.
- Tert-butanol exhibits unique pre-ignition heat release behavior under studied conditions.

## Abstract

Investigation of the autoignition delay of the butanol isomers has been performed at elevated pressures of 15 bar and 30 bar and low to intermediate temperatures of 680-860 K. The reactivity of the stoichiometric isomers of butanol, in terms of inverse ignition delay, was ranked as n-butanol > sec-butanol ~ iso-butanol > tert-butanol at a compressed pressure of 15 bar but changed to n-butanol > tert-butanol > sec-butanol > iso-butanol at 30 bar. For the temperature and pressure conditions in this study, no NTC or two-stage ignition behavior were observed. However, for both of the compressed pressures studied in this work, tert-butanol exhibited unique pre-ignition heat release characteristics. As such, tert-butanol was further studied at two additional equivalence ratios ($\phi$ = 0.5 and 2.0) to help determine the cause of the heat release.

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Source: https://tomesphere.com/paper/1706.01842