Title On-line mjerenje koncentracije biodizela u mikrosustavima Title (english) On - line measurement of biodiesel concentration in microsystems Author Emanuel-Nino Fiala Mentor Anita Šalić (mentor)Committee member Anita Šalić (predsjednik povjerenstva)Committee member Bruno Zelić (član povjerenstva)Committee member Davor Valinger (član povjerenstva)Granter University of Zagreb Defense date and country 2020-09-21, Croatia Scientific / art field, TECHNICAL SCIENCES Abstract Kako su količine fosilnih goriva ograničene,a sama goriva štetna za okoliš, preporuča se prelazak na obnovljive izvore energije, između kojih je i biodizel. Biodizel je danas sve popularnije gorivo zbog svoje biorazgradivosti, niske emisije štetnih plinova, manjeg zagađenja okoliša i netoksičnosti. Najčešće se proizvodnja biodizela odvija procesom transesterifikacije raznih ulja i masti uz metanol u kotlastim reaktorima te uz prisustvo kiselina, lužina ili enzima kao katalizatora. Cilj proizvodnje je dobiti što čišći primarni produkt,koji se može odmah koristiti kao gorivo sa što manje nusprodukta kako bi se izbjegli često vrlo skupi procesi pročišćavanja. Kako bi proces proizvodnje bio što uspješniji, potrebno je kontinuirano pratiti i analizirati produkte reakcije. Iako već postoje razne metode analize biodizela i glicerola, svakodnevno se istražuju nove metode čiji je glavni cilj da budu što jednostavnije, preciznije i brže. U ovom radu, biodizel je sintetiziran enzimatski kataliziranom transesterifikacijom korištenjem suncokretovog ulja i metanola kao supstrata. Tijekom procesa praćena je koncentracija nastalog glicerola kao jednog od pokazatelja uspješnosti procesa. Prvo je određena koncentracije estera masnih kiselina – biodizela plinskom kromatografijom na temelju čega je iz stehiometrije reakcije transesterifikacije izračunata teoretska koncentracija nastalog glicerola. Izračunata koncentracija glicerola je uspoređena s koncentracijom glicerola dobivenom analizom standardnim postupcima na UV-VIS spektrofotometru i plinskom kromatografu. Kako niti jedna od metoda nije dala zadovoljavajuće rezultate tj. obje analize pokazale su značajna odstupanja od teorijske vrijednosti koncentracije glicerola, kao zamjenska analitička metoda provedena je analiza na NIR spektrometru. Analiza na NIR spektrometru je provedena na dva načina, off-line iz uzorka prikupljenih tijekom provedbe procesa transesterifikacije te on-line na način da se koncentracija glicerola određivala kontinuirano prolaskom reakcijske smjese kroz protočnu kivetu NIR spektrometra. Od svih analiziranih metoda mjerenja koncentracije glicerola, NIR spektroskopija je pokazala najveće podudaranje s teoretskom, izračunatom koncentracijom glicerola.
Abstract (english) As the amount of fossil fuels is limited and the fuel itself is harmful to the environment, it is recommended to switch to renewable energy sources, including biodiesel. Biodiesel is an increasingly popular fuel today due to its biodegradability, low emissions, less environmental pollution and non-toxicity. Most often, the production of biodiesel takes place by the process of transesterification of various oils and fats with methanol in batch reactors, with the addition of acids, bases or enzymes as catalysts. The goal of production is to get the primary product as pure as possible, which can be used immediately as a fuel with small amount ofby-products as possible in order to avoid often very expensive purification processes. To make production process as successful as possible, it is necessary to continuously monitor and analyse the reaction products during the process. Although there are already various methods of analysis of biodiesel and glycerol, new methods are being researched every day, the main goal of which is to be as simple, precise and fast as possible. In this work biodiesel was synthesized by enzymatically catalysed transesterification using sunflower oil and methanol as substrates. During the process, the concentration of glycerol, as one of the indicators of the success of the process, was monitored. At the very beginning, an analysis of the fatty acid esters concentration using gas chromatography was performed from which the theoretical value of the glycerol concentration was calculated. The calculated glycerol concentration was compared with the glycerol concentration obtained by analysis using standard methods on a UV-VIS spectrophotometer and by the gas chromatography. Because neither of the methods gave satisfactory results, meaning both analyses showed significant deviations from the theoretical value of glycerol, the analysis on NIR spectrometer was proposed. During the synthesis reaction, the analysis of biodiesel concentration was performed in such a way that samples were taken at certain time intervals for the off-line analysis and on-line in such a way that the concentration was determined continuously by screening the reaction mixture which was passing through a flow cell of the NIR spectrometer. The NIR spectroscopy method proved to be the best, with the greatest agreement of the measured glycerol concentration with the theoretically calculated concentration.
Keywords
biodizel
transesterifikacija
glicerol
UV-VIS spektrofotometar
plinski kromatograf
NIR spektrometar
Keywords (english)
biodiesel
transesterification
glycerol
UV-VIS spectrophotometer
gas chromatograph
NIR spectrometer
Language croatian URN:NBN urn:nbn:hr:149:569678 Project Number: IP-2016-06-7993 Study programme Title: Chemical Engineering - Undergraduate study Type of resource Text File origin Born digital Access conditions Open access Terms of use Created on 2023-05-03 12:58:27
