Title Optimiranje geometrije i konfiguracije 3D-ispisanog modularnog sustava za sintezu biodizela Title (english) Optimizing the geometry and configuration of 3D-printed modular system for biodiesel synthesis Author Ivan Karlo Cingesar Mentor Domagoj Vrsaljko (mentor)Committee member Anita Šalić (predsjednik povjerenstva)Committee member Igor Dejanović (član povjerenstva)Committee member Ivana Grčić (član povjerenstva)Granter University of Zagreb Defense date and country 2024-05-17, Croatia Scientific / art field, TECHNICAL SCIENCES Universal decimal classificationUDC ) 662 - Explosives. Fuels 678 - Industries based on macromolecular materials. Rubber industry. Plastics industry 62 - Engineering. Technology in general Abstract U ovom radu eksperimentalno je ispitana mogućnost 3D-ispisa mikroreaktora i mikroseparatora korištenih za kemijsku transesterifikaciju ulja u biodizel. Tehnologija
3D-ispisa pruža izvrsnu fleksibilnost u dizajnu i izradi reakcijskog sustava i uređaja za protočnu kemiju. Brza izrada i mogućnost lake izmjene dizajna prototipa otvara mogućnost brzom napretku. Istražena je uloga računalno potpomognutog dizajna (CAD), 3D-ispisa, mikrostrukturiranih uređaja i računalne dinamike fluida (CFD) u svrhu optimiranja procesa proizvodnje mikroreaktora i procesa sinteze biodizela. Specifični cilj rada bio je 3D-ispisom izraditi optimirani modularni sustav za kontinuiranu sintezu i separaciju biodizela, a ujedno i optimiranje uvjeta 3D-ispisa. Moduli koji su korišteni u sustavu su mikroreaktor i mikroseparator koji su međusobno spojeni teflonskim cijevima. 3D-ispisano je sedam različitih modela mikroreaktora sa statičkim miješalicama i šest modela mikroseparatora u kojima je ispitana učinkovitost sinteze i separacije biodizela. Provedeno je optimiranje 3D-ispisa i naknadne obrade materijala u svrhu analize i odabira optimalnog materijala za izradu svih modela. Provedena je mehanička, toplinska i fizikalno-kemijska karakterizacija materijala kojima je pronađena korelacija između mehaničkih, toplinskih i određenih fizikalno-kemijskih svojstava materijala. Dizajnirani su različiti modeli mikroreaktora u kojima je provedena simulacija gibanja fluida u mikrokanalu, zatim su 3D-ispisani te je na kraju u njima provedena reakcija sinteze biodizela. Nakon 3D-ispisa mikroreaktora tehnologijom proizvodnje rastaljenim filamentom i stereolitografijom analizirani su kvaliteta izrađenih modela, prozirnost i vidljivost slojeva te je na temelju toga odabrana odgovarajuća tehnologija za 3D-ispis mikroreaktora i mikroseparatora. Prilikom sinteze biodizela, uzorci su sakupljani na izlazu pri stacionarnom stanju i analizirani za četiri vremena zadržavanja. Kriterij odabira optimalnog mikroreaktora bio je da u što kraćem vremenu zadržavanja ostvari iskorištenje od minimalno 96 %. Potom je u svakom od šest dizajniranih mikroseparatora proveden proces separacije u spoju sa odabranim mikroreaktorom. Provedenom karakterizacijom materijala korištenih u stereolitografiji i analizom kvalitete predmeta 3D-ispisanih prema zadanim kriterijima, za izradu mikroreaktora i mikroseparatora je odabran materijal High Temp. Materijal High Temp i stereolitografija kao tehnologija izrade, zadovoljili su uvjete dimenzijske točnosti izrade i prozirnosti, te su mehanička, toplinska i fizikalno-kemijska svojstva odgovarajuća za provedbu reakcije sinteze biodizela. Rezultati simulacija strujanja u mikroreaktorima predviđaju najveću brzinu strujanja u središtu kružnog poprečnog presjeka te promjenu raspodjele brzina prilikom prolaska fluida kroz statičke miješalice u obliku koljena. Rezultati analize dobiveni plinskom kromatografijom i nuklearnom magnetskom rezonancijom utvrdili su utjecaj različitih vrsta i broja statičkih miješalica na iskorištenje reakcije. U 3D-ispisanom cijevnom mikroreaktoru sa sedam koljena (C7K) za vrijeme zadržavanja 19,9 min te u cijevnom mikroreaktoru sa deset koljena (C10K) za vrijeme zadržavanja 19,2 min iskorištenje je doseglo 100 %. Za daljnju provedbu reakcije sinteze i separacije odabran je 3D-ispisani mikroreaktor C10K koji je pri vremenu zadržavanja 9,6 min postigao iskorištenje 96 %, a sastoji se od mikrokanala kružnog poprečnog presjeka i 10 statičkih miješalica u obliku koljena od 90°. Provedbom sinteze i separacije u integriranom modularnom sustavu primjenom pet mikroseparatora nije došlo do separacije toka, dok je primjenom mikroseparatora MSv5, čiji volumen je najmanji u usporedbi s ostalih pet, došlo do separacije toka uz učinak separacije 55 %. Prema dobivenim rezultatima zaključuje se da je tehnologija aditivne proizvodnje pogodna za proizvodnju mikrofluidnih sustava. Rezultati CFD simulacije su dobra polazna točka za izmjenu i modificiranje različitih dizajna mikroreaktora. Promjenom reakcijskih uvjeta moguće je postići veliko iskorištenje reakcije sinteze biodizela. Koljena u kanalu mikroreaktora ponašaju se kao statičke miješalice. Povećanjem broja statičkih miješalica u mikroreaktoru povećava se iskorištenje reakcije sinteze biodizela. Dokazana je mogućnost 3D-ispisa modularnog sustava za sintezu i separaciju biodizela.
Abstract (english) In this dissertation, the possibility of additive manufacturing technologies for the purpose of 3D printing of microreactors and microseparators used for oil transesterification into biodiesel was experimentally investigated. 3D printing technology offers superb versatility in the design and fabrication of custom reactionware for flow chemistry. There is potential for creating complex geometries in microfluidic devices to influence the yield of chemical reactions. Rapid fabrication of models, and the ability to easily modify designs open up the possibility of fast progress in flow chemistry. The role of computer-aided design (CAD),
3D printing, microfluidics, and computational fluid dynamics (CFD) was explored to optimise the production process of microreactors and biodiesel synthesis. The specific aim of the work is to 3D print an optimised modular system for biodiesel synthesis and separation, while also optimising the conditions of 3D printing. The modules in the system are a microreactor and microseparator connected by PTFE tubes. Seven different models of microreactors with static mixers and six models of microseparators were 3D printed to assess the efficiency of biodiesel synthesis and separation. The optimization of 3D printing and material post-processing was conducted in order to analyze and select the optimal material for 3D printing of all models. Mechanical, thermal, and physicochemical characterisation of the materials was performed, revealing correlations between the mechanical, thermal, and certain physicochemical properties of the materials. Various models of microreactors were designed in which the fluid movement in a microchannel was simulated and then 3D printed and in which the biodiesel synthesis reaction was finally carried out. After 3D printing of the microreactors using fused filament fabrication and stereolithography, the quality of the model production, the transparency and the layer visibility were analysed. Based on these analyses, the appropriate technology for 3D printing microreactors and microseparators was selected. Sampling from the 3D-printed microreactors was conducted at four different residence times. The criterion for selecting the optimum microreactor was to achieve a conversion of at least 96% in the shortest possible residence time. The separation process was then carried out in each of the six designed microseparators in conjunction with the selected microreactor. The characterisation of the materials used in stereolithography and the analysis of the quality of the 3D-printed objects according to specified criteria led to the selection of High Temp material for the fabrication of microreactors and microseparators. High Temp material and stereolithography as a manufacturing technology met the requirements for dimensional accuracy and transparency, and their mechanical, thermal and physicochemical properties were suitable for carrying out the biodiesel synthesis reaction. The results of the flow simulation in the microreactors predict the highest flow velocity in the centre of the circular cross-section and a change in the velocity distribution as the fluid passes through the bends. Gas chromatography and nuclear magnetic resonance analysis showed the influence of different types and numbers of static mixers on the reaction efficiency. In the 3D-printed tubular microreactor with seven bends (C7K), with a residence time of 19.9 minutes, and in the tubular microreactor with ten bends (C10K), with a residence time of 19.2 minutes, the conversion reached 100%. The 3D-printed microreactor C10K, which achieved a conversion of 96% with a residence time of 9.6 minutes and consists of microchannels with a circular cross-section and 10 static mixers in the form of 90° bends, was selected for the further performance of the synthesis and separation reaction. When performing synthesis and separation in an integrated modular system with five microseparators, there was no flow separation, while when using the MSv5 microseparator, which has the smallest volume compared to the other five, flow separation was achieved with a separation efficiency of 55%. The results obtained lead to the conclusion that additive manufacturing technology is suitable for the production of microfluidic systems. The results of the numerical flow simulations provide a good starting point for modifying and adapting various microreactor designs. By changing the reaction conditions, high efficiency can be achieved in the biodiesel synthesis reaction. The bends in the microreactor channel act as static mixers. Increasing the number of static mixers in the microreactor increases the efficiency of the biodiesel synthesis reaction. The feasibility of 3D printed modular system for biodiesel synthesis and separation was confirmed.
Keywords
aditivna proizvodnja
biodizel
mikroreaktor
mikroseparator
računalna dinamika fluida
statička miješalica
stereolitografija
Keywords (english)
additive manufacturing
biodiesel
microreactor
microseparator
computational fluid dynamics
static mixer
stereolithography
Language croatian URN:NBN urn:nbn:hr:149:172020 Promotion 2024 Project Number: IP-2022-10-8004 Project Number: KK.01.1.1.04.0006 Study programme Title: Chemical Engineering and Applied Chemistry - Doctoral course Type of resource Text Extent 157 str. ; 30 cm File origin Born digital Access conditions Open access Terms of use Public note Izradu ovog doktorskog rada financirala je Hrvatska zaklada za znanost u okviru projekata Projekt razvoja karijera mladih istraživača - izobrazba novih doktora znanosti (DOK-2020-01). Created on 2024-05-28 11:58:08
