Uncovering Complex Reaction Mechanisms in Combustion


Responsible use of natural resources for sustainable transportation energy motivates ongoing research efforts towards increasing fuel efficiency and decreasing emissions of combustion systems. At current rates, over 70% of annual petroleum consumption in the United States is diverted to the transportation sector, which derives more than 95% of its energy requirements from liquid hydrocarbons and biofuels. Because of the high energy density of liquid fuels, among other reasons, the transportation sector is projected to remain reliant on petroleum-based hydrocarbons for decades to come.

However, the combined approach of advanced combustion strategies and new, advanced biofuels intends to augment this scenario by enabling more-efficient, cleaner-burning combustion systems and by providing sustainable sources of liquid fuels produced from a growing number of biomass conversion technologies. One critical aspect to the success of these concurrently developing areas of research is the availability of high-fidelity predictive modeling and simulation tools that can enable co-optimization of combustion strategies with complex biofuels. Chemical kinetics models are one piece of the larger scientific puzzle and require basic research into questions such as how molecular structure impacts reaction mechanisms, ignition chemistry, pollutant formation, and other combustion phenomena.

Research Themes

Combustion Chemistry

Combustion Chemistry

Combustion chemistry, along with fluid dynamics and multi-phase physics, plays an integral role in the production of energy for transportation, and is governed by a complex network of interconnected reaction mechanisms.

Understanding the intricacies of such mechanisms, which span thousands of distinct chemical species and elementary reactions, enables the development of computational models that are employed in the design and simulation of next-generation combustion strategies focused on higher efficiency and reduced pollutant formation.



Biofuels are an alternative energy source purposed for mitigating consumption of petroleum-based fuels, namely gasoline, diesel, and aviation fuel, as well as augmenting internal combustion engine efficiency and contributing to a lower carbon-intensive transportation sector.

Most biofuels are functionalized hydrocarbons such as ethanol (H3CCH2OH) and butanone (H3CC(=O)CH2CH3), although alkanes, aromatics, and other hydrocarbons produced from biomass are not, e.g. farnesane (2,6,10-trimethyldodecane).

Under certain combustion conditions, functional groups can impact reaction pathways that govern autoignition, which is sustained by chain-branching reactions, and reaction pathways involved in pollutant formation.

Atmospheric Chemistry

Atmospheric Chemistry

In addition to CO, NOx, CO2, and H2O, byproducts of combustion include volatile organic compounds (VOC), which are implicated in health- and climate-related issues.

Globally, the transportation sector, which is driven principally by combustion, is responsible for 128 Tg per year of VOC emissions – approximately 10% compared to biogenic sources that largely produce isoprene, monoterpenes, and sesquiterpenes.

Because of the differences in molecular structure between functionalized biofuels and conventional, petroleum-derived hydrocarbons, the combustion of biofuels can alter the types of VOC emitted from the transportation sector, and understanding the ensuing impact on atmospheric chemistry is an important area in the atmospheric sciences.

Professor Brandon Rotavera


  • Ph.D. 2012

    Ph.D., Interdisciplinary Engineering

    Texas A&M University

  • BSME 2006

    B.S., Mechanical Engineering

    University of Central Florida

Positions and Appointments


  • 2023
    CURO Research Mentoring Award
  • 2022
    Irvin Glassman Young Investigator Award
  • 2021
    Fred C. Davison Early Career Scholar
  • 2020
    National Science Foundation CAREER Award
  • 2017
    Distinguished Fellow - Student Veterans Resource Center (SVRC)

University of Georgia

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