Proizvodnja bioplina iz mikroalg

diplomsko delo

Petra Zupančič (Author), Andreja Žgajnar Gotvajn (Mentor)

Abstract

Zaradi velike potrebe po energiji se področje obnovljivih virov energije hitro razvija. V zadnjem desetletju se mikroalge intenzivno preučujejo kot alternativni vir biomase za nadomeščanje fosilnih goriv. Glavne prednosti uporabe mikroalg za proizvodnjo bioplina so visoka fotosintetska učinkovitost, manjhna poraba vode, njihova hitra rast, vzporedna poraba CO2 in razmeroma majhna potreba po površini za gojenje. Lahko jih gojimo v odprtih bazenih ali zaprtih reaktorjih, t. i. fotobioreaktorjih (PBR). Anaerobna razgradnja mikroalg je uveljavljen biološki proces za proizvodnjo bioplina, ki ga lahko očiščenega primesi uporabimo za proizvodnjo toplotne in električne energije. Končni produkt je sestavljen iz metana (40–75 %), ogljikovega dioksida (15–60 %) in sledov ostalih plinov. Proizvodnja bioplina poteka v več korakih, vključno z gojenjem, odstranjevanjem mikroalg iz suspenzije, predobdelavo in končno anaerobno razgradnjo. Anaerobno razgradnjo, ki poteka pod nadzorovanimi pogoji v okolju brez kisika, se izvaja v digestorju v štirih korakih: (1) hidroliza, (2) acidogeneza, (3) acetogeneza in (4) metanogeneza. Ker se zaradi raznolike sestave mikroalg biometanski potencial bistveno razlikuje, je pri optimizaciji procesa zelo pomembna izbira vrste mikroalg. Na učinkovitost procesa vplivajo mešanje, temperatura, pH vrednost, razmerje med ogljikom in dušikom (C/N), inhibitorji, organska obremenitev in hidravlični zadrževalni čas (HRT). Glavni oviri, ki ju je treba izboljšati na industrijski ravni, sta nizko razmerje C/N in težka razgradljivost celičnih sten mikroalg, ki pa jo je mogoče premagati z učinkovito termično, mehansko, kemično ali biološko predobdelavo. Namen diplomske naloge je opisati proces proizvodnje bioplina, določiti dejavnike, ki vplivajo na anaerobno razgradnjo, in primerjati različne preobdelave mikroalgne biomase.

Keywords

mikroalge;biomasa;predobdelava;anaerobna razgradnja;bioplin;fotobioreaktorji;diplomska dela;

Data

Language:	Slovenian
Year of publishing:	2021
Typology:	2.11 - Undergraduate Thesis
Organization:	UL FKKT - Faculty of Chemistry and Chemical Technology
Publisher:	[P. Zupančič]
UDC:	620.925:579(043.2)
COBISS:	82756355
Views:	367
Downloads:	40
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	English
Secondary title:	Biogas production from microalgae
Secondary abstract:	Due to high energy demand, renewable energy sources are developing rapidly. In the last decade, microalgae have been studied extensively as an alternative source of biomass to replace fossil fuels. The main advantages of using microalgae for biogas production are high photosynthetic efficiency, low water consumption, their rapid growth, CO2 consumption and relatively low surface area for cultivation. They can be cultivated in open ponds or closed photobioreactors (PBR). Anaerobic digestion of microalgae is an established biological process for biogas production. Refined biogas can be used to produce thermal and electric energy. The final product consists of methane (40-75%), carbon dioxide (15-60%) and other gas traces. Biogas production follow several steps, including cultivation, harvesting, pretreatment and final anaerobic digestion. Anaerobic digestion, which takes place under controlled conditions without oxygen, is carried out in the digestate in four steps: (1) hydrolysis, (2) acidogenesis, (3) acetogenesis and (4) methanogenesis. Because of significant differences in biomethane yield due to the diverse structure of microalgae, selection of microalgae species is very important for process optimisation. The efficiency of the process is affected by mixing, temperature, pH level, carbon to nitrogen ratio (C/N), inhibitors, organic biomass loading and hydraulic retention time (HRT). The main challenges at the industrial level that need to be improved are low C/N ratio and tough microalgae cell wall biodegradability, which can be overcome by effective thermal, mechanical, chemical or biological pretreatment. The aim of the thesis is to describe the process of biogas production, to determine the factors affecting anaerobic digestion and to compare different pretreatments of microalgae biomass.
Secondary keywords:	anaerobic digestion;biogas;microalgae;photobioreactors;pretreatment;
Type (COBISS):	Bachelor thesis/paper
Study programme:	1000372
Embargo end date (OpenAIRE):	1970-01-01
Thesis comment:	Univ. v Ljubljani, Fak. za kemijo in kemijsko tehnologijo, UNI Kemijsko inženirstvo
Pages:	28 str.
ID:	13359926