Title Transesterifikacija otpadnog jestivog ulja u mikroreaktoru katalizirana komercijalnim enzimom lipaza Title (english) Transesterification of waste cooking oil in a microeactor catalysed by commercial lipase Author Matea Bačić Mentor Bruno Zelić (mentor)Committee member Bruno Zelić (predsjednik povjerenstva)Committee member Anita Šalić (član povjerenstva)Committee member Irena Škorić (član povjerenstva)Granter University of Zagreb Defense date and country 2019-09-13, Croatia Scientific / art field, TECHNICAL SCIENCES Abstract U novije vrijeme sve se više zaliha fosilnih goriva nekontrolirano iscrpljuje, a različiti ekonomski, gospodarski i politički interesi suverenih država, samo su dodatni faktori koji su utjecali na sve veća ulaganja u istraživanja alternativnih goriva u svrhu povećanja ekološke svijesti. Biogoriva, osobito biodizel, ističu se kao prikladno rješenje koje odgovara zahtjevima globalnog tržišta, održivog razvoja i postizanja zadanih ušteda. Biodizel se definira kao metilni ili etilni ester viših masnih kiselina proizveden raznim procesima među kojima se ističu mikroemulzifikacija, piroliza i transesterifikacija. Potonji proces je ujedno i najrašireniji zbog visoke učinkovitosti, manjih proizvodnih troškova i velike brzine reakcije. Kao sirovine za proizvodnju biodizela transesterifikacijom koristi se široki spektar proizvoda poput jestivih i/ili otpadnih ulja i masti te alge i jantrofa koji poboljšavaju svojstva biorazgradivosti i netoksičnosti, a biodizel proizveden iz ovih sirovina odlikuju niže emisije stakleničkih plinova. Stoga se biodizel proizveden transesterifikacijom iz ovih izvora smatra i ekološki prihvatljivim. Kako bi se odvila reakcija transesterifikacije između ulja/masti i alkohola, najčešće metanola, potreban je katalizator. Uporaba enzima tj biokatalizatora, posebice enzima lipaze porijeklom iz Thermomyces lanuginosus, pokazala se obećavajućom jer su enzimi specifični, kataliziraju reakcije u kojim sudjeluju brojni supstrati, selektivni su, posjeduju visoku aktivnost u blagim eksperimentalnim uvjetima čime njihova primjena rezultira manjom potrošnjom energije u odnosu na kiselo ili bazno katalizirane reakcije transesterifikacije. Učinkovitosti procesa transesterifikacije može pridonijeti i upotreba mikroreaktorskih sustava, odnosno reaktora u mikroskopskom mjerilu. U usporedbi s makroskopskim reaktorskim sustavima, primjena mikroreaktora omogućuje bolji prijenos tvari i topline, što je posljedica velikog omjera površine i volumena samog mikroreaktora, za provedbu reakcije potrebne su manje količine reaktanata i katalizatora što rezultira i manjom količinom otpadnih struja, a samim time i manjim utroškom energije. Povoljnija hidrodinamika sustava, laminaran tok i učinkovito miješanje procesnih struja vode k povećanju brzine kemijske reakcije. U ovom radu provedena je transesterifikacija otpadnog jestivog ulja uz enzim lipazu u mikroreaktoru širine kanala 500 μm s dva ulaza i dva izlaza, a praćene su veličine značajne za uspješnu provedbu procesa (konverzija, vrijeme zadržavanja i aktivnost enzima). Maksimalna konverzija X = 32,28 % postignuta je pri najdužem retencijskom vremenu (τ = 30,63 min) za sustav u kojemu je transesterifikacija otpadnog ulja provedena uz komercijalni enzim suspendiran u puferu.
Abstract (english) In recent years, more and more fossil fuel stocks have been uncontrollably depleted and the differing economic and political interests of sovereign countries are merely additional factors that have led to increasing investment in alternative fuel research with the purpose of increasing environmental awareness. Biofuels, especially biodiesel, stand out as a suitable solution that meets the demands of the global market, sustainable development as well as achieving the set savings. Biodiesel is defined as the methyl or ethyl ester of higher fatty acids produced through various processes such as microemulsification, pyrolysis and transesterification. Tranesterification is the most widespread due to its high efficiency, lower production costs and high reaction speed. As a raw material, it offers a wide range of products such as edible and / or waste oils and fats as well as algae and amber, which improve biodegradability, non-toxicity and lower greenhouse gas emissions. Therefore, biodiesel is produced by transesterification from these sources and is environmentally friendly. In order to carry out the transesterification reaction between oil / fat and alcohol, most commonly methanol, a catalyst is required. The use of enzymes, i.e. biocatalysts, especially lipases from Thermomyces lanuginosus, has proven to be very promising as they are very specific with the recognition of numerous substrates, selective and they show high activity in mild experimental conditions, which reduces energy consumption relative to acidic or base catalyzed reactions. The efficiency of the process is also contributed by the microreactor system, i.e. the microscopic scale reactors. Comparing micro- and macroscopic systems, microreactors enable better mass and heat transfer, which is due to the large surface-to-volume ratio of the microreactor itself, requires less reactants and catalysts to effect the reaction, resulting in less waste streams and, over time, lower energy consumption. It is also noticed that more favorable hydrodynamics of the system, laminar flow and effective mixing of currents are increasing the rate of chemical reaction. In this work the transesterification of waste edible oil with lipase enzyme in a 500 μm channel microreactor with two inputs and two outputs was carried. The sizes important for successful process implementation (conversion, retention time, enzyme activity) were monitored as well. A maximum conversion of X = 32.28% was achieved at the longest retention time (τ = 30.63 min) for a system in which transesterification of waste oils was carried out with a commercial enzyme suspended in buffer.
Keywords
biodizel
transesterifikacija
lipaza
mikroreaktor
Keywords (english)
biodiesel
transesterification
lipase
microreactor
Language croatian URN:NBN urn:nbn:hr:149:234193 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 2023-02-10 12:09:05
