Population growth and increasing standards of living are leading to a rapidly growing demand for energy. Our primary energy production is still dominant on fossil fuels. This extensive usage of fossil fuels has led to global warming, environmental pollution, as well as depletion of hydrocarbon resources. The prevailing situation is highly challenging but it also offers an opportunity to search for alternatives sources of energy. There is an urgent need to explore environmentally friendly and cost-effective renewable fuels. Oxygenates (alcohols, ethers) and ammonia are among the potential renewable fuels of the future. This thesis investigates combustion characteristics of ethanol (EtOH), dimethyl ether (DME), diethyl ether (DEE), ethyl levulinate (EL), dimethoxy methane (DMM), γ-valerolactone (GVL), cyclopentanone (CPN), and ammonia (NH3) as well as their blends using a combination of experimental and modelling techniques.
- In this work, we showed that a high-reactivity fuel, diethyl ether, may be blended with a low-reactivity fuel, ethanol, in varying concentrations to achieve desired combustion characteristics. The ternary blend of ethanol/diethyl ether/ethyl levulinate may be formulated from a single production stream, and this blend is shown to behave similar to a conventional gasoline.
- Extremely low reactivity of ammonia makes it unsuitable for direct usage in many combustion systems. In this work, dimethyl ether, diethyl ether, and dimethoxy methane are explored as potential promoters of ammonia combustion. Our results showed that even a small addition (~ 5 – 10%) of combustion promoters can significantly alter ammonia combustion, and diethyl ether has been found to have the highest propensity of enhancing ammonia ignition and flame propagation. The blends of ammonia and combustion promoters can thus be utilized in modern downsized turbo charged engines.
- Octane boosting effects of oxygenated fuels, γ-valerolactone and cyclopentanone, are explored in this work. Our results showed that γ-valerolactone and cyclopentanone can be effective additives for octane boosting and emission reduction of conventional fuels.
Overall, the results and outcomes of this thesis will be highly useful in choosing and optimizing alternative fuels for future transportation systems.
Gani Issayev earned his bachelor's degree in 2005 from Kazakh-British Technical University and he obtained his M.S. degree in 2013 from the University of Nottingham. He joined KAUST Mechanical Engineering program in 2015 as a PhD student under the supervision of Prof. Aamir Farooq. Gani's research focused on studying promising alternative fuels using a rapid compression machine and chemical kinetic modelling.
Zoom link to join the defense: