Determination of the influence of reaction parameters on the synthesis of propyl esters of fatty acids

U suvremenom svijetu zbog rastućih problema s okolišem dolazi do potrebe za korištenjem obnovljivih izvora energije u svakodnevnom životu i industriji. Zbog toga se nad klasičnim izvorima energije dobivenim iz fosilnih izvora nadmeće biodizel, koji se sintetizira reakcijom transesterifikacije alkohola i masti/ulja biljnog ili životinjskog porijekla, uz prisutnost katalizatora. U ovom diplomskom radu ispitan je utjecaj reakcijskih parametara na iskorištenje reakcije između propanola i suncokretovog ulja, uz KOH kao katalizator. Ispitano je četiri parametra: temperatura reakcije, vrijeme provedbe reakcije, maseni udio katalizatora i molarni omjer propanol:suncokretovo ulje. Najveće postignuto iskorištenje iznosilo je 99,79 % pri temperaturi od 60 °C, razdoblju od 2 h, masenom udjelu katalizatora od 1 mas. %, te omjeru propanol:ulje u iznosu od 10:1. Dizajniranju eksperimenta prethodila su 3 preliminarna pokusa, gdje su vrijednosti temperature bile od 40 do 80 °C, vremena od 1 do 3 h, omjera propanol:ulje od 6:1 do 10:1 i masenog udjela katalizatora od 1 do 3 mas. %. Planiranje eksperimenta i statistička obrada provedeni su u programskom paketu Design Expert. Nakon provedenih eksperimenata, provedena je optimizacija procesa transesterifikacije, s ciljem postizanja iskorištenja većeg od 95 %. Zbog toga se težilo što kraćem vremenu reakcije, nižoj temperaturi, manjem omjeru propanola i suncokretovog ulja, te manjem masenom udjelu katalizatora. Ovisno o tome kolika je zadana važnost pojedinog cilja (1-5), dobiveno je tri slučaja s različitim optimalnim uvjetima. Odabrani optimalni uvjeti iznosili su: temperatura 40,00 °C, vrijeme 2,42 h, omjer propanol:ulje 9,53:1, maseni udio katalizatora 1 mas. % pri čemu predviđeno iskorištenje iznosi 96,81 %.SUMMARY In the modern world, due to growing environmental problems, there is a need to use renewable energy sources in everyday life and industry. Therefore, biodiesel, which is obtained by the transesterification reaction of alcohol and fats/oils of vegetable or animal origin, with the presence of a catalyst, competes over classical energy sources obtained from fossil sources. In this thesis, the influence of reaction parameters on the yield of the reaction between propanol and sunflower oil, with KOH as a catalyst, was investigated. Four parameters were examined: reaction temperature, time of reaction, mass fraction of catalyst and molar ratio of propanol:sunflower oil. The highest conversion of 99.79 % is achieved at the temperature of 60 °C, reaction time of 2 hours, propanol:oil ratio in the amount of 10:1 and the mass fraction of catalyst 1 wt. %. The design of the experiment was preceded by 3 preliminary experiments, where the temperature values were from 40 to 80 °C, time from 1 to 3 hours, propanol:oil ratio from 6:1 to 10:1 and a mass fraction of catalyst from 1 to 3 wt. %. Experiment planning and processing statistics were performed in the Design Expert software package. After the experiments, the optimization of the transesterification process was made, with the aim of achieving the highest possible conversion. Therefore, we strived for the shortest possible reaction time, lower temperatures, lower ratio of propanol and sunflower oil, and lower mass fraction of catalyst. Depending on the given importance of each goal (1-5), three cases with different optimal conditions were obtained. The selected optimal conditions were: temperature 40,00 °C, time 2,42 h, propanol:oil ratio 9,53:1, mass fraction of catalyst 1 wt. %, where the predicted yield is 96,81 %