20.500.12556/RUL-101194 Optimizacija produkcije biovodika z imobiliziranimi obogatenimi mikrobnimi združbami v reaktorju s čepastim tokom doktorska disertacija Optimizing the production of biohydrogen with immobilized enriched microbial communities in the plug-flow reactor V zadnjem času se kot procesu z nizko ogljično bilanco posebno pozornost posveča fermentativni produkciji vodika, s tem, da nizka učinkovitost pretvorbe substrata v vodik in nezadovoljiva stabilnost procesa v kontinuirnem režimu obratovanja omejujeta prenos procesa na komercialno raven. Doktorsko delo je bilo zato usmerjeno predvsem v preučevanje postopkov za povečanje učinkovitosti procesa anaerobne razgradnje pri razgradnji hitro razgradljivih organskih substratov. Ugotovili smo, da imajo na produkcijo vodika velik vpliv številni procesni dejavniki, kot tudi različni načini priprave inokuluma. Najvišji donos vodika (2,04±0,11 mol H2/mol glukoze) smo dosegli z izpostavitvijo inokuluma 80 °C za 2 h, pri starosti inokuluma 1 dan, procesni temperaturi 37 °C, organski obremenitvi 5 g OSglukoze/L in intenziteti mešanja z Reynoldsovim številom 500. Dosedanje raziskave so usmerjene predvsem na obratovanje pri pH vrednosti 5,0-7,0, medtem ko so študije izvedene pri nizkih pH vrednostih zelo redke, čeprav bi bilo obratovanje pri le-teh tehnološko in ekonomsko ugodnejše. Tako smo pri pH vrednosti 4,0±0,2 z uporabo glukoze kot substrata v reaktorju s čepastim tokom z različnimi nosilnimi materiali (Mutag BioChipTM, ekspandirana glina in aktivno oglje) dosegli dolgoročno stabilnost procesa. V reaktorjih z Mutag BioChipTM, ekspandirano glino in aktivnim ogljem smo dosegli 1,80±0,07, 1,74±0,10 in 1,46±0,09 mol H2/mol glukoze. Visok donos ter stabilno produkcijo vodika smo pri nizki pH vrednosti ter aktivnem oglju za imobilizacijo mikroorganizmov dosegli tudi z uporabo odpadne hrane (168,5 NmL H2/g OS). Dolgoročna stabilnost procesa fermentativne produkcije vodika pri nizki pH vrednosti tako predstavlja pomembno novost v optimizaciji procesa, saj je obratovanje pri nizki pH vrednosti povezano z nižjimi stroški obratovanja in manjšimi negativnimi vplivi procesa na okolje. Biohydrogen produced through dark fermentation is currently gaining importance as biofuel of the future and a potential replacement of fossil fuels. However, low conversion efficiency of substrate into hydrogen and unstable hydrogen production during continuous operation mode are limiting largescale industrial production. Doctoral dissertation was therefore assessing different techniques in order to enhance the efficiency of fermentative hydrogen production with degradation of readily biodegradable organic substrates. We have found out, that numerous environmental factors are influencing hydrogen production, as well as different inoculum pretreatment methods. Highest hydrogen yield (2.04±0.11 mol H2/mol glucose) was achieved in case of thermal pretreatment on 80 °C for 2 h, at inoculum age of 1 day, incubation temperature of 37 °C, organic loading of 5 g OMglucose/L and mixing intensity with Reynolds number of 500. Previous studies have focused primarily on the operation in the pH range of 5.0-7.0, while there are less studies for low pH conditions, which would be however technical and economic advantage. Our results successfully demonstrated stable dark fermentation process in plug flow reactor filled with different support materials (Mutag BioChipTM, expanded clay and activated carbon) at acidic pH value (4.0±0.2) and glucose as substrate. Obtained hydrogen yields in reactors filled with Mutag BioChipTM, expanded clay and activated carbon were 1.80±0.07, 1.74±0.10 and 1.46±0.09 mol H2/mol glucose, respectively. High yield and stable hydrogen production at low pH value and activated carbon as support material for immobilization was achieved also with the use of food waste (168.5 NmL H2/g OM). With achieved stable hydrogen production process throughout the operation period at low pH values, we proposed a novel strategy that could contribute to the reduction of financial as well as environmental costs. fermentativna produkcija vodika okoljski dejavniki priprava inokuluma imobilizacija mikrobne združbe nosilni materiali odpadna hrana metabolne poti razgradnje fermentative hydrogen production environmental conditions inoculum pretreatment immobilization of microbiota carrier materials food waste metabolic pathways true false false [P. Muri] Slovenski jezik Angleški jezik Doktorska disertacija 2018-05-10 11:12:05 2018-05-10 11:12:06 2022-08-14 03:43:31 0000-00-00 00:00:00 2017 0 Ljubljana 2017 Ljubljana XIII f., 132 str., [8] str. pril. 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 546.11:502/504(043.3)=163.6 4984742 DR_Muri_Petra_i2017.pdf DR_Muri_Petra_i2017.pdf 1 9C2FA3DFEDA352EEDAD465771B388E0F ab330df971c993917b26c07f06a8c64e92ac49a27f69c1a02b0fbce1e0d956b3 30b39bc0-a1b5-11eb-a523-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=111107 Biotehniška fakulteta 0 0 0