Sinteza biodizela u betain:urea prirodnom eutektičnom otapalu katalizirana enzimom lipaza

master's thesis

• Title (english): Biodiesel synthesis in betaine: urea natural deep eutectic solvent catalyzed by lipase
• Author: Tomislav Marčinko
• Mentor: Anita Šalić (mentor)
• Mentor: Ana Vrsalović Presečki (komentor)
• Committee member: Anita Šalić (predsjednik povjerenstva)
• Committee member: Ana Vrsalović Presečki (član povjerenstva)
• Committee member: Domagoj Vrsaljko (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2022-09-27, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering

Abstract

Prekomjerna eksploatacija i rast cijena fosilnih goriva potaknuli su intenzivnija istraživanja u području proizvodnje alternativnih goriva poput biodizela. Kao jedno od mogućih rješenja u procesu proizvodnje biodizela, primjenjuje se enzimski katalizirana transesterifikacija ulja ili masti u prisutnosti jednostavnih alkohola. Dodatni korak u razvoju procesa proizvodnje biodizela, a s obzirom na intenzifikaciju prijenosa tvari i energije te posljedično povećanje ukupne prividne brzine reakcije i smanjenje reakcijskog vremena, je primjena mikroreaktorskih sustava. Kako bi proces proizvodnje biodizela bio u potpunosti održiv i primjenjiv u industriji, potrebno je stabilizirati enzim i upotrijebiti ga u više ciklusa proizvodnje. Jedan od načina očuvanja enzimatske aktivnosti je i zamjena tradicionalnih puferskih otopina s prirodnim eutektičkim otapalima (engl. Natural Deep Eutectic Solvents (NADES)). U ovom radu biodizel je proizveden procesom transesterifikacije katalizirane enzimom lipaza podrijetlom iz Aspergillus oryzae. Kao prvi korak u zamjeni konvencionalnih otapala zelenim otapalima, bio je ispitati aktivnost enzima u NADES betain:urea 1:3 s 40 % (w/w) vode. Volumna aktivnost enzima lipaza pokazala se najvišom nakon što je enzim lipaza direktno ekstrahiran u NADES betain:urea 1:3 s 40 % (w/w) vode. Nakon ekstrakcije, sinteza biodizela je provedena u šaržnom reaktoru, membranskom reaktoru i mikroreaktoru. Provedbom eksperimenata s molarnim omjerom ulje:metanol 1:90 u šaržnom reaktoru postignuto je iskorištenje od 99 % nakon 30 sati sinteze. Nakon završetka sinteze, biodizel je izdvojen iz reakcijske smjese, a enzim ponovno upotrijebljen za sintezu biodizela. Uspješno su provedena tri ciklusa sinteze biodizela, bez dodatka novog enzima, u ukupnom trajanju od 216 sati.

Abstract (english)

Excessive exploitation and rise in price of fossil fuels have stimulated more intensive research into the production of alternative fuels such as biodiesel. One of the possible solutions for biodiesel production process, is the enzyme-catalyzed transesterification of oils or fats in the presence of simple alcohols. A step forward in the development of the biodiesel production process, in terms of intensification of mass and energy transfer and the consequent increase in the overall apparent reaction rateand reduction in reaction time is the use of microreactor systems. In order for the biodiesel production process to be fully sustainable and industrially applicable, the enzyme must be stabilized and used in multiple production cycles. One way to preserve enzymatic activity is to replace conventional buffer solutions with Natural Deep Eutectic Solvents (NADES). In this research, biodiesel was produced by the process of transesterification catalyzed by the lipase enzyme derived from Aspergillus oryzae. The first step in replacing conventional solvents with green solvents was to test the enzyme activity in NADES betaine:urea 1:3 with 40% (w/w) water. The volume activity of the lipase enzyme proved to be the highest after the lipase was extracted directly in NADES betaine:urea 1:3 with 40% (w/w) water. After extraction, biodiesel synthesis was carried out in a batch reactor, a membrane reactor and a microreactor. In experiments with a molar ratio of oil:methanol of 1:90 in a batch reactor, a yield of 99% was obtained after 30 hours of synthesis. After completion of the synthesis, the biodiesel was separated from the reaction mixture and the enzyme was used again for biodiesel synthesis. Three cycles of biodiesel synthesis were successfully carried out without the addition of a new enzyme, with a total duration of 216 hours.

• Keywords: biodizel; lipaza; ekstrakcija; separacija; imobilizacija; prirodna eutektička otapala
• Keywords (english): biodiesel; lipase; extraction; separation; immobilization; natural eutectic solvents
• Language: croatian
• URN:NBN: urn:nbn:hr:149:413307
• Study programme: Title: Environmental Engineering - Graduate study; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka ekoinženjerstva (magistar/magistra inženjer/inženjerka ekoinženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2023-03-23 14:24:54