Chemical Characterization of Soot Particles for Model Development
EMSL Project ID
47859
Abstract
An experimental and numerical study is proposed to better understand the evolution of soot morphology and the chemical characterization of particles produced in laminar, co-flow diffusion flames of the surrogates for jet fuels. Two different soot evolutionary processes were observed experimentally in the flames: 1. Gas phase nucleation and soot aggregate formation from the collision of solid individual primary particles and 2. Formation of large transparent liquid-like particles and nucleation followed by aggregation within the transparent phase. Current models are unable to accurately predict the liquid-like content, morphology and chemistry of particles produced in low temperature regions of the diffusion flames. Laser extinction, rapid thermocouple insertion and thermophoretic sampling followed by transmission electron microscopy and atomic force microscopy will be used to measure soot volume fraction, flow field temperature and the 2D and 3D morphologies of soot particles respectively. In addition, micro-FTIR spectroscopy (reflection mode) and high-resolution mass spectrometry (nano-DESI/HR-MS) will be utilized to determine the functionalities and molecular constituents that they belong to, respectively, in the sampled particles. The measured physical and chemical properties of the particulates will be analyzed to reveal the differences between particle nucleation and growth mechanisms across the flames. Chemical measurements will provide researchers direction for which molecules to target in formulating the reaction mechanism for soot formation. Finally the computational model will be fine-tuned to obtain physical and chemical results close to experimental results. The ultimate goal is to model the morphology and chemical content of soot particles emitted from real combustion devices such as aircraft and automotive engines. Project Details
Project type
Large-Scale EMSL Research
Start Date
2013-10-01
End Date
2015-09-30
Status
Closed
Released Data Link
Team
Principal Investigator
Co-Investigator(s)
Team Members
Related Publications
Cain JP, A Laskin, MR Kholghy, M Thomson, and H Wang. 2014. "Molecular Characterization of Organic Content of Soot along the Centerline of a Coflow Diffusion Flame." PNNL-SA-104338, Pacific Northwest National Laboratory, Richland, WA. [Unpublished]