Transesterifikacija jestivog suncokretovog ulja u mikroreaktoru katalizirana komercijalnim enzimom lipaza

undergraduate thesis

• Title (english): Transesterification of sunflower oil in a microeactor catalysed by commercial lipase
• Author: Anabela Ljubić
• Mentor: Bruno Zelić (mentor)
• Committee member: Bruno Zelić (predsjednik povjerenstva)
• Committee member: Anita Šalić (član povjerenstva)
• Committee member: Gordana Matijašić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2019-09-13, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering

Abstract

Zbog sve manjih zaliha fosilnih goriva, ali i štetnog utjecaja na okoliš, proizvodnja biogoriva danas privlači sve više pažnje. Kao alternativno gorivo i zamjena za fosilni dizel sve se više nameće biodizel. Biodizel ekološki prihvatljivim čine njegova biorazgradivost, netoksičnost i niske emisije stakleničkih plinova, kao i ostalih tvari koje štete okolišu. Najzastupljeniji postupak proizvodnje biodizela je transesterifikacija raznih ulja uz metanol u kotlastim reaktorima uz kiseline ili lužine kao katalizatore. Zbog visokih troškova i malih brzina reakcije u ovim procesima, danas se sve više istražuju mogućnosti primjene drugih tehnologija i katalizatora. Velika poboljšanja procesa predviđaju se provedbom procesa transesterifikacije uz korištenje enzima lipaze kao katalizatora. Primjena enzima lipaze u procesu transesterifikacije, u usporedbi s kiselinama i lužinama kao katalizatorima, rezultira blažim reakcijskim uvjetima i manjom količinom nastalih nusprodukata. Također, sve se više uočavaju i prednosti kontinuirane proizvodnje biodizela pri čemu primjena mikroreaktora rezultira brojnim prednostima u odnosu na konvencionalne, šaržne procese. Intenzivniji prijenos tvari i energije u mikroreaktorima, koji je posljedica velikog omjera površine i volumena reaktora, rezultira povećanjem ukupne brzine reakcije te posljedično znatnom uštedom energije i sirovina. Veliki omjer površine i volumena posljedica je izvedbe reaktorskog sustava, odnosno činjenice da je mikroreaktor mreža mikrokanala, čije su dimenzije 10 μm – 500 μm, pri čemu su mikrokanali izvedeni urezivanjem u čvrstu pločicu. Strujanje u mikrokanalima većinom je laminarno zbog njihovog malog promjera što posljedično omoguće precizniju regulaciju procesa. U ovom radu biodizel je proizveden enzimatskom transesterifikacijom jestivog suncokretovog ulja metanolom pri čemu je kao katalizator korišten komercijalni i pročišćeni (proizveden fermentacijom na pogači buče) enzim lipaza porijeklom iz Thermomyces lanuginosus. Sinteza je provedena u mikroreaktoru s dva ulaza pri čemu je jedna procesna struja bila čisti metanol, a drugi emulzija koju su činili ulje, enzim i emulgator suspendirani u vodenom puferu ili eutektičkom otapalu. Najveća konverzija postignuta je u sustavu s emulzijom ulja i komercijalnog enzima suspendiranog u vodenom puferu te ona iznosi 28,85 % za vrijeme zadržavanja (τ = 16,4 min) te se taj sustav može smatrati najboljim izborom za daljnju optimizaciju procesa proizvodnje biodizela.

Abstract (english)

Due to a significant decrease of fossil fuel resources, but also due to their significant negative impact of the environment, production of biofuels attracts more and more attention every day. Nowadays, biodiesel imposes as an alternative fuel instead of fossil diesel. Biodiesel is environmentally acceptable because of its biodegradability, non-toxicity and low emission of greenhouse gasses as well as due to the emission of other substances that harm the environment. The most common process of biodiesel production is transesterification of different oils with methanol in a batch reactor using acids or bases as catalysts. Due to high costs and low reaction rates in these processes, possibilities of applying some other technologies and catalysts are being explored. Significant process improvements are predicted by implementation of transesterification using lipase as a catalyst. Application of lipase in the transesterification process, comparing to acids and bases as catalysts, results with mild reaction conditions and less by-product. Likewise, advantages of continuous production of biodiesel are being more and more noticed whereby application of microreactors results with many advantages compared to conventional, batch processes. More intensive mass and heat transfer in microreactors, which is a result of high surface-to-volume ratio of the reactor, leads to higher reaction rate and consequently to considerable savings in energy and raw material consumption. High surface-tovolume ratio is a result of the reactor's structure, regarding the fact that a microreactor is build-up of microchannels, whose dimensions are 10 μm – 500 μm, whereby microchannels are made by cutting on a solid plate. Flow in microchannels is mostly laminar due to their small diameter which consequently allows more precise regulation of the process. In this paper biodiesel was produced by enzymatic transesterification of edible sunflower oil with methanol whereby a commercial and purified (produced by fermentation on squash cake) enzyme lipase from Thermomyces lanuginosus was used as a catalyst. Synthesis was carried out in a microreactor with two inlets where one process flow was methanol and the second one was an emulsion made of oil, enzyme and emulsifier suspended in a water buffer or deep eutectic solvent. The highest conversion of 28,85 % for residence time τ = 16,4 min was obtained in the system with an emulsion of oil and commercial enzyme suspended in a water buffer. This system could be considered the best choice for future biodiesel production process optimization.

• Keywords: transesterifikacija; jestivo suncokretovo ulje; enzim lipaza; mikroreaktori
• Keywords (english): transesterification; edible sunflower oil; lipase; microreactor
• Language: croatian
• URN:NBN: urn:nbn:hr:149:276708
• Project: Number: IP-2016-06-7993; Title: Razvoj integriranog mikrosustava za biokatalitičku proizvodnju biodizela; Acronym: DeMSy(BioPro)2; Leader: Bruno Zelić; Jurisdiction: Croatia; Funder: HRZZ; Funding stream: IP
• Study programme: Title: Chemical Engineering - Undergraduate study; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka kemijskog inženjerstva (sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka kemijskog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2023-05-25 08:39:14