Title Određivanje utjecaja reakcijskih parametara na sintezu izopentilnih estera masnih kiselina Title (english) Determination of the influence of reaction parameters on the synthesis of isopentyl fatty acid esters Author Iva Žuvić Mentor Fabio Faraguna (mentor)Committee member Fabio Faraguna (predsjednik povjerenstva)Committee member Marko Racar (član povjerenstva)Committee member Petar Kassal (član povjerenstva)Granter University of Zagreb Defense date and country 2021-09-24, Croatia Scientific / art field, TECHNICAL SCIENCES Abstract Ograničene količine fosilnih goriva i njihov nepovoljan utjecaj na klimatske promjene potaknuli su znanstvenike na traženje alternativnih izvora energije. Kao jedno od boljih rješenja tog problema pokazao se biodizel. Reakcija transesterifikacije temeljna je reakcija kojom se proizvodi biodizel. Reakcijom alkohola i triglicerida, koji su glavni sastojak masti i ulja, uz prisutnost katalizatora nastaju esteri masnih kiselina. Osim jestivih, nejestivih i otpadnih ulja koja mogu biti korištena prilikom sinteze biodizela, izbor alkohola također je prilično širok. Najviše je istražena sinteza biodizela iz metanola i etanola, ali u novije doba interes su privukli i određeni viši alkoholi. Odabrani alkohol u ovom radu je izopentanol koji reagira sa suncokretovim uljem uz prisutnost bazičnog katalizatora, kalijevog hidroksida. Pratio se utjecaj četiri reakcijska parametra na iskorištenje reakcije transesterifikacije, a to su: reakcijsko vrijeme, molarni omjer alkohola i ulja, maseni udio katalizatora i temperatura reakcije. Reakcijsko vrijeme bilo je u rasponu od 0,5 do 2,5 h, molarni omjer alkohola i ulja od 4:1 do 10:1, maseni udio katalizatora od 1 do 3 % i temperatura reakcije od 40 do 80 ˚C . Uz pomoć programskog paketa Design Expert 11 napravljen je Box-Behnkenov plan koji sadrži 29 pokusa. Iako se najčešće primjenjuje kao kvalitativna metoda, 1H NMR spektroskopija korištena je za kvantitativnu analizu tj. određivanje iskorištenja reakcije. Analizirani su brojni grafički prikazi kojima se potvrđuje ili negira poklapanje eksperimentalnih podataka s modelom dobivenim uz pomoć programskog paketa Design Expert 11. Cilj rada bio je osim određivanja utjecaja reakcijskih parametara na iskorištenje reakcije, pronaći optimalne uvjete za sintezu izopentilnih estera masnih kiselina. Programski paket nudi opciju optimiranja i ovisno o željama postavlja se maksimalna i minimalna važnost određenog reakcijskog parametra, a kao rezultat dobivaju se uvjeti sinteze i predviđeno iskorištenje koje prema HRN ISO 14214 treba minimalno iznositi 95 %. Optimiranjem procesa pokazalo se da je maksimalno moguće iskorištenje uz minimalan iznos ostalih reakcijskih parametara 98,56 %. Ukoliko se želi postići navedeno iskorištenje, potrebno je reakciju transesterifikacije provoditi 2,43 h pri temperaturi od 78,64 ˚C uz omjer alkohola i ulja 8,86:1 te maseni udio katalizatora od 2,57 %.
Abstract (english) Limited amounts of fossil fuels and their adverse effects on climate change have prompted scientists to look for alternative energy sources. Biodiesel is proven to be one of the solutions for this problem. Fundamental reaction that produces biodiesel is the transesterification reaction. Esters of fatty acids are formed in the reaction between alcohol and triglycerides, which are the main constituents of fats and oils, in the presence of catalysts. In addition to edible, inedible and waste oils that can be used in biodiesel synthesis, the choice of alcohol is also quite wide. The synthesis of biodiesel from methanol and ethanol has been the most researched, but recently certain higher alcohols have also attracted interest. The alcohol of choice in this work is isopentanol which reacts with sunflower oil in the presence of a basic catalyst, potassium hydroxide. The influence of four reaction parameters on the yield of the transesterification reaction was monitored, namely: reaction time, molar ratio of alcohol and oil, mass fraction of catalyst and reaction temperature. The reaction time ranged from 0.5 to 2.5 h, the molar ratio of alcohol and oil from 4: 1 to 10: 1, the mass fraction of catalyst from 1 to 3 % and the reaction temperature from 40 to 80 ˚C. With the help of the Design Expert 11 software package, a Box-Behnken plan, containing 29 experiments, was created. Although it is most often used as a qualitative method, 1H NMR spectroscopy was used for quantitative analysis, i.e. to determine the yield of the reaction. Numerous graphical representations were analyzed which confirm or deny the coincidence of the experimental data with the model obtained with the help of the Design Expert 11 software package. In addition to determining the influence of reaction parameters on the reaction yield, the aim of this work was to find optimal conditions for the synthesis of isopentyl fatty acid esters. The software package offers the option of optimization and, depending on the wishes, the maximum and minimum importance of a certain reaction parameter is set, and as a result the synthesis conditions and predicted yield are obtained, which according to HRN ISO 14214 should be at least 95 %. By optimizing the process, it was shown that the maximum possible yield with a minimum amount of other reaction parameters is 98.56 %. If the desired yield is to be achieved, the transesterification reaction must be carried out for 2.43 h at a temperature of 78.64 ˚C with an alcohol to oil ratio of 8.86: 1 and a catalyst mass fraction of 2.57 %.
Keywords
transesterifikacija
biodizel
izopentanol
optimiranje
Keywords (english)
transesterification
biodiesel
isopentanol
optimization
Language croatian URN:NBN urn:nbn:hr:149:097118 Project Number: UIP-2019-04-5242 Study programme Title: Applied Chemistry - Undergraduate study; specializations in: Environmental chemistry and green technologies, Advanced materials and technologies, Applied organic chemistry Type of resource Text File origin Born digital Access conditions Access restricted to students and staff of home institution Terms of use Created on 2023-04-27 11:19:52
