High temperature shock tube experiments and kinetic modeling study of diisopropyl ketone ignition and pyrolysis

Abstract

Diisopropyl ketone (DIPK) is a promising biofuel candidate, which is produced using endophytic fungal conversion. In this work, a high temperature detailed combustion kinetic model for DIPK was developed using the reaction class approach. DIPK ignition and pyrolysis experiments were performed using UCF shock tube. The shock tube oxidation experiments were conducted between 1093 K and 1630 K for different reactant compositions, equivalence ratios (φ =0.5-2.0), and pressures (1-6 atm). In addition, methane concentration time-histories were measured during 2% DIPK pyrolysis in argon using cw laser absorption near 3400 nm at temperatures between 1300 and 1400 K near 1atm. To the best of our knowledge, current ignition delay times (above 1050 K) and methane time histories are the first such experiments performed in DIPK at high temperatures. Present data were used as validation targets for the new kinetic model and simulation results showed fair agreement compared to the experiments. The reaction rates corresponding to the main consumption pathways of DIPK were found to have high sensitivity in controlling the reactivity, so these were adjusted to attain better agreement between the simulation and experimental data. A correlation was developed based on the experimental data to predict the ignition delay times using the temperature, pressure, fuel concentration and oxygen concentration.

Shock Tube Demonstration of Acousto-Optically Modulated Quantum Cascade Laser as a Broadband, Time-Resolved Combustion Diagnostic

“…The temperature and pressure (T 5 and P 5 ) in the reflected shock region are calculated using the initial temperature and pressure of the driven section (T 1 and P 1 ) and extrapolated shock velocity using one-dimensional shock relations, assuming chemically frozen, vibrationally equilibrated gases. Incident shock attenuation was always less than 1%, and uncertainty in temperature and pressure in the reflected shock region are estimated to be less than 62% [12][13][14].…”

“…Shock tubes are ideal laboratory devices for producing controlled hightemperature and pressure conditions that exist inside gas turbines. Measurements were performed in a stainless-steel, heated, double-diaphragm shock tube with an inner diameter of 14 cm, located at the University of Central Florida, which has been described in our prior work [3,[12][13][14][20][21][22]. The driver and driven sections of the shock tube are separated by a polycarbonate diaphragm 0.381 mm thick which suddenly ruptures to create a normal shock wave which shock heats the test mixture.…”

“…Existing and widely used methods for measuring in situ species concentrations in combustion systems using midinfrared (MIR) laser absorption spectroscopy have been spectrally narrow. For instance, absorption spectroscopy at a single wavelength coincident with the absorption of a species of interest is well established [12][13][14]. This technique generally requires a dedicated laser and detector for each species to be measured.…”

Ellipsometric Measurements of the Thermal Stability of Alternative Fuels

“…In Eqs. (6), (9), and (10), the p superscript indicates that the equation pertains to the component of the light oscillating parallel to the plane of incidence, and the s superscript indicates that the equation pertains to the component oscillating perpendicular to the incidence plane…”

“…Alternative fuels are an important part of the plan to achieve these desires [6,7]. However, before an alternative fuel can be used, it must be comprehensively tested for its compatibility with existing infrastructure, engine architecture, combustion, and emission [8][9][10][11], and the infrastructure for its implementation must be built [12]. An important fuel property that must be characterized is the thermal stability [13], which is a measure of the degree to which a fuel breaks down when it is heated.…”