VILNIUS TECH Library invites you to follow the published new dissertations. The dissertation „Research on energetic and ecological indicators of a compression ignition engine fuelled by animal non-edible fats and biofuel blends“ prepared by VILNIUS TECH Oleksandra Shepel. The dissertation was prepared in 2018–2025. Scientific consultant – Assoc. Prof. Dr Jonas Matijošius.
The dissertation will be defended at the public meeting of the Dissertation Defence Council of the Scientific Field of Transport Engineering in the Aula Doctoralis Meeting Hall of Vilnius Gediminas Technical University at 10 a.m. on 8 July 2025.
The dissertation investigates the energy and environmental performance of a compression ignition engine operating on biodiesel blends derived from animal-based non-food fats and first- and second-generation biodiesel fuels. The research encompasses experimental and numerical analyses, evaluating how diverse biodiesel compositions influence engine operation. Nine fuel blends, including hydrotreated vegetable oils (HVO) and fatty acid methyl esters (FAME), were prepared and tested under controlled conditions. The research examined key parameters such as ignition delay, combustion pressure, temperature variations, CO₂, CO, NOₓ, HC emissions, and particulate matter (PM). A numerical model using AVL BOOST was developed to simulate in-cylinder combustion processes, providing insights into pressure rise rates, heat release dynamics, and fuel efficiency under various load conditions. The results highlighted the impact of biodiesel composition on combustion phases, revealing that HVO-based blends exhibit shorter ignition delays, improved combustion efficiency, and lower emissions compared to FAME-rich blends. The findings of this dissertation indicate that HVO-based biodiesel blends offer the most promising alternative to diesel, maintaining high energy efficiency while significantly reducing CO, HC, and particulate emissions. However, FAME-rich blends require further optimisation due to their higher viscosity, increased NOₓ emissions, and greater fuel consumption. The dissertation consists of an introduction, four chapters, a summary of findings, references, and a list of scientific publications by the author. The First Chapter provides an overview of biodiesel properties and their relevance in the transport sector. The Second Chapter details the experimental methodology, including biodiesel preparation, engine testing, and data acquisition techniques. The Third Chapter presents numerical and experimental results, evaluating combustion characteristics, energy indicators, and emission trends. The Fourth Chapter applies machine learning models to predict fuel performance and optimise biodiesel blends. The dissertation concludes with a discussion of the feasibility of biodiesel use in diesel engines and recommendations for future research. This research represents a significant step towards integrating alternative biofuels into the transportation sector, supporting global efforts to reduce greenhouse gas emissions and enhance energy sustainability. Five scientific articles have been published on the dissertation topic: two in the Web of Science database with a citation index, two in the Web of Science database, conference proceedings, one in other international databases and two in other peer-reviewed scientific journals. Two papers were presented at conferences in Lithuania and one in Poland.
Doctoral dissertation readers can search via VILNIUS TECH Virtual Library.
