Hidrogenētas augu eļļas izmantošana dīzeļmotoros = Hydrotreated vegetable oil application in diesel engines
Authors:   , Sondors Kristaps 
Published: December 2023

Sondors K. Hydrotreated vegetable oil application in diesel engines: doctoral thesis for the Doctoral degree of Science (Ph.D.). Jelgava: Latvia University of Life Sciences and Technologies, 2023. 154 p., 77 fig., 24 tab., 159 bibl. sources, 25 appendices. Key words: biofuel, hydrotreated vegetable oil, diesel engine, power, torque, fuel consumption, emissions. Working hypothesis of the thesis: using hydrotreated vegetable oil or its blends with fossil diesel fuel it is possible to obtain better or equivalent technical, economic and ecological results compared to fossil fuel or first generation biofuels. The aim of the work is to evaluate theoretically and experimentally the possibilities of using hydrotreated vegetable oil in diesel engines, thus creating an opportunity to promote the wider use of renewable energy resources in Latvia and the world. The following tasks have been set to achieve the goal of the work:  to analyse the studies carried out in the production, use and influence of hydrotreated vegetable oil on the operating parameters of engines and vehicles;  to develop a testing methodology for vehicles powered by hydrotreated vegetable oil;  to investigate experimentally and to evaluate the possibilities of using hydrotreated vegetable oil and engine operating parameters in different types of diesel vehicles;  to perform mathematical modeling for determining the operating parameters of diesel engine-powered vehicles using different fuels and their blends, and to evaluate the effectiveness of the model;  to evaluate the economic and ecological feasibility of using hydrotreated vegetable oil. The first chapter presents the classification of biofuels and identifies the place of HVO in this topology, compares the properties of HVO fuel with other fuels used in diesel engines, analyzes the technologies and raw materials used in the production of HVO, as well as the use of HVO fuel in diesel engines and its impact on vehicle operating parameters. The second chapter describes the equipment and materials used in the experimental research, as well as the methodology of each research program. Since the experimental studies, based on the specifics of the researched objects (car, tractor and engine), are carried out using different equipment – chassis dynamometer, PTO dynamometer and motor AC dynamometer, three separate experimental research methodologies have been developed. A description of the theoretical model is given. The third chapter presents the results and conclusions of each research program, comparing them with the findings of researchers from other countries. In general, all research programs cover both the results of power, torque, fuel consumption and composition of exhaust gases obtained with clean fuels (HVO and fossil diesel fuel) in various vehicles and engines, as well as their comparison with the use of various blended fuels. The fourth chapter emphasizes the analysis of the amount of direct greenhouse gases, comparing the use of HVO and fossil diesel fuel, while also generalizing the emission results obtained in various experimental research programs. An economic assessment of the use of HVO fuel is also given. As a result of research, it has been proven that hydrotreated vegetable oil is a promising new generation fuel for use in pure form or in blends to replace fossil diesel fuel and its blends with the first generation biofuels, providing better or equivalent technical characteristics. The wider use of HVO fuel will contribute to the reduction of GHG emissions and the achievement of the targets for the use of renewable resources.