20.500.12556/DKUM-86060 Proizvodnja biogoriv s procesom torefikacije in njihov vpliv na okolje doktorska disertacija Production of solid biofuels by torrefication process and their impact on the environment Skozi zgodovino se je ves svet ukvarjal s pridobivanjem energije in njeno oskrbo ter posledično razvojem goriv. Zaradi postopnega izčrpavanja zalog fosilnih goriv, tehnološkega napredka in vse večjih okoljskih vprašanj so začela prihajati v ospredje alternativna goriva, ki jih je mogoče črpati na bolj učinkovit in trajnosten način. Energija iz biomase danes predstavlja enega bolj obetavnih obnovljivih virov energije (OVE) v Sloveniji, eni najmanjših držav v Evropi. Med obstoječimi tehnologijami za izboljšanje kakovosti biomase predstavlja proces torefikacije odpadne biomase ambiciozno tehniko predhodne obdelave biomateriala, ki lahko bistveno izboljša lastnosti surove biomase tako, da dobimo ekološko in energetsko sprejemljivejši energent. Toreficirana oz. termično obdelana biomasa je hidrofobna, odporna na biorazgradnjo in primerna za skladiščenje. Pomembna prednost toreficirane biomase je tudi v tem, da ima manjšo žilavost od lesa, kar omogoča lažje mletje in aplikacijo tega biomateriala v industrijske namene. Čeprav so prednosti uporabe toreficirane biomase na svetovni ravni že raziskane in priznane, torefikacija v Sloveniji še ni poznana. V nadaljevanju doktorska disertacija obravnava proces torefikacije odpadne biomase tipične v Sloveniji z namenom proizvesti trdno biogorivo, ki ima višjo kurilno vrednost kot surova biomasa in je tudi hidrofobno: energetska rastlina miskantus (M), ostanek hmelja po žetvi (H), odpadni mešani (MWW) in hrastov les (OWW), odpadno blato iz komunalnih čistilnih naprav (SS), mešane komunalne odpadke (MSW) in njihove mešanice. Torefikacija odpadne lignocelulozne in ne-lignocelulozne biomase je potekala v temperaturnem območju med 200 °C in 300 °C, v inertni ali pol-inertni atmosferi, od nekaj minut do nekaj ur. Na surovih in termično obdelanih biomaterialih so bile izvedene standardne fizikalno-kemijske analize, s katerimi je bila raziskovana odpadna biomasa kvantitativno in kvalitativno ovrednotena (proksimativna in elementna analiza, masni in energijski izplen, faktor izboljšav kurilne vrednosti, indeks stopnje torefikacije itd.). Z infrardečo spektroskopijo s Fourierjevo transformacijo (FTIR) je bila določena struktura vzorcev, s termogravimetrično analizo (TGA in DTG) pa je bila določena termična razgradnja surovih in obdelanih biomaterialov. Pridobljeni podatki so bili analizirani z dvema kinetičnima modeloma: Friedman (FR) in Kissinger-Akahira-Sunose (KAS). Na koncu je bila še izračunana energetska donosnost procesa torefikacije, določene so bile emisije toplogrednih plinov (TGP) in določeni so bili plini, ki se sprostijo med procesom. Ugotovljeno je bilo naslednje: z naraščajočo temperaturo in/ali daljšanjem procesa torefikacije se masni in energetski izpleni vseh raziskovanih vzorcev nižajo, kurilne vrednosti (HHV) se višajo. Delež kisika v vzorcih se zmanjša, prav tako se zniža delež hlapljivih komponent, medtem ko se deleži ogljika in fiksnega ogljika zvišajo. Prav tako se delež lignina v lignoceluloznih vzorcih viša z višanjem temperature, deleža celuloze in hemiceluloze pa se nižata. Temperatura torefikacije ima večji vpliv na proces kot čas torefikacije, pri čemer je optimalna temperatura procesa pri približno 260 °C. To je bilo potrjeno tudi z indeksom stopnje (TSI) torefikacije in EMCI indeksom. Nadalje je FTIR analiza pokazala, da imajo tako surovi kot termično obdelani vzorci funkcionalne skupine tipične za lignocelulozne in ne-lignocelulozne vzorce. Termogravimetrična analiza je pokazala, da se večina obravnavanih vzorcev razgradi v temperaturnem območju do 550 °C. Med samo torefikacijo pa se je sprostilo največ CO2 plina. Obravnavi vzorci odpadne biomase se na podlagi dobljenih rezultatov lahko uporabijo kot možno alternativno biogorivo. Več raziskav in analiz na tem področju je še potrebnih. Throughout history, the world has been concerned with the extraction and supply of energy, leading to the development of fossil fuels. However, with the gradual depletion of fossil fuel reserves, technological progress, and pressing environmental issues, alternative fuels extracted in a more efficient and sustainable manner have come to the forefront. Today, energy from biomass represents one of the most promising renewable energy sources in Slovenia, one of the smallest countries in Europe. Among the existing technologies for improving the quality of biomass, the torrefaction process of waste biomass represents a promising material pretreatment technique. This process significantly improves the properties of raw biomass, resulting in an ecologically acceptable energy product similar to coal in its properties. Torrefied biomass is hydrophobic, resistant to biodegradation, and suitable for storage. Additionally, torrefied biomass has less toughness than wood, enabling easier grinding and application of the material for industrial purposes. Although the advantages of using torrefied biomass have already been researched and recognized globally, torrefaction is not yet widely known in Slovenia. The doctoral dissertation presented below focuses on the torrefaction process of waste biomass typical in Slovenia to produce biofuel with a higher calorific value than raw biomass and hydrophobic properties. The waste biomass studied includes miscanthus (M), hop residue (H), mixed waste (MWW), oak waste wood (OWW), waste sewage sludge from wastewater treatment plants (SS), municipal solid waste (MSW), and their mixtures. Torrefaction was conducted on both lignocellulosic and non-lignocellulosic biomass in the temperature range of 200 to 300 °C, under inert or semi-inert atmospheres, for durations ranging from minutes to hours. Standard physicochemical analyses were performed on both raw and torrefied materials to quantitatively and qualitatively evaluate the waste biomass. These analyses included proximate and elemental analysis, determination of mass and energy yields, calculation of calorific value improvement factors, and evaluation of torrefaction degrees. The structure of the samples was determined using Fourier transform infrared spectroscopy (FTIR), while thermogravimetric analysis (TGA and DTG) was employed to study the thermal decomposition of raw and processed materials. The data obtained were analyzed using two kinetic models: the Friedman (FR) model and the Kissinger-Akahira-Sunose (KAS) model. Furthermore, the dissertation calculated the energy return on investment of the torrefaction process and determined greenhouse gas emissions as well as the gases released during the process. With increasing temperature and/or longer torrefaction times, the mass and energy yields of all investigated samples decrease, while their calorific values (HHV) increase. The oxygen content in the samples decreases, along with the contents of volatile components, while the contents of carbon and fixed carbon increase. Additionally, the lignin content in lignocellulosic samples increases with higher temperatures, whereas the contents of cellulose and hemicellulose decrease. Torrefaction temperature exhibits a greater influence on the process compared to torrefaction time, with the optimum process temperature being around 260 °C. This finding was supported by the torrefaction severity index (TSI) and the EMCI index. Furthermore, FTIR analysis revealed that both raw and torrefied samples exhibit functional groups typical of lignocellulosic and non-lignocellulosic biomass. Thermogravimetric analysis indicated that most of the considered samples decompose in the temperature range up to 550 °C, with the highest concentration of CO2 gas released during torrefaction. Based on the obtained results, the investigated samples of waste biomass show promise as potential alternative biofuels. However, further research and analysis in this area are still required. obnovljivi viri energije torefikacija odpadna biomasa kurilna vrednost emisije TGP renewable energy sources torrefaction waste biomass heating value GHG emissions true true false [M. Ivanovski] Slovenski jezik Angleški jezik Doktorsko delo/naloga 2023-10-02 22:03:47 2024-05-06 08:54:33 2024-05-08 03:17:04 0000-00-00 00:00:00 2024 0 Maribor 0 Maribor XXVI, 288 str. 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 66.092-97:[604.4:662.6:579](043.3) 194550019 DOK_Ivanovski_Maja_2024.pdf DOK_Ivanovski_Maja_2024.pdf 1 9B3E7EE2223DBA7CE5D896CAD6C1C410 5ee14aca560f55a128413cc8e8a47a44d4b15939ef7634832af36d6c962eb15b a700da48-0ab2-11ef-8642-00155d000105 https://dk.um.si/Dokument.php?lang=slv&id=178998 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0