CAREER: High Equivalence Ratio Partial Oxidation of Liquid Fuels by Reactive Volatilization

University Of Minnesota-Twin Cities, Minneapolis MN

Investigators

Abstract

This proposal aims to use recirculated exhaust gas to reform a portion of the primary fuel can enable clean, high efficiency premixed combustion modes in diesel engines using a single stored fuel, with the benefits of extremely low tailpipe emissions of traditional pollutants. A novel thermo-chemical recuperation process is proposed where liquid fuels like diesel are vaporized and partially oxidized at high global equivalence ratio in a flameless environment. Such an operation is advantageous since less of the initial fuel?s heating value is consumed leading to more partially oxidized hydrocarbons that are useful for reactivity-controlled compression ignition combustion in diesel engines. The work experimentally and numerically examines counter-flow partial oxidation where fuel undergoes reactive volatilization forced by heat transfer from heterogeneous combustion sustained on a porous catalytic screen. The flameless environment ensures that thermal gradients and residence times do not favor soot production. It will further understanding of chemical kinetics, phase change, mass transport and heat transfer processes in in fuel-rich oxidative environments. It also explores underlying processes governing soot formation and kinetics of catalytic combustion over supported precious metal catalysts. The research will also explore the key mechanisms governing partial oxidation and reformation by reactive volatilization by using high-throughput fuel atomization, and determine the efficacy of using reformed gas products for modulating fuel reactivity. Knowledge in basic mechanisms involved in reactive volatilization of fuels where the onset temperature of pyrolysis is below the boiling point. It will also examine the sparsely investigated regime of high-equivalence-ratio partial oxidation for generation of non-equilibrium reforming products resulting from dehydrogenation and thermal decomposition reactions. The results of this research could lead to significant improvements in internal combustion engine efficiency through the implementation of thermo-chemical recuperation and high-equivalence-ratio partial oxidation. Products of high-equivalence-ratio reforming such as light olefins and oxygenates also have benefit for a number of industrial petrochemical processes. Broader outreach objectives of the project include merging the research activities with two STEM programs for K-8 students. These include an exhibit at a children?s museum and direct engagement with middle school students, introducing them to combustion science and engineering.