Anaerobna digestija sirutke prije i nakon proizvodnje skute

master's thesis

• Title (english): Anaerobic digestion of cheese whey before and after curd production
• Author: Antonia Primorac
• Mentor: Vanja Jurišić (mentor)
• Committee member: Vanja Jurišić (predsjednik povjerenstva)
• Committee member: Milna Tudor Kalit (član povjerenstva)
• Committee member: Ana Matin (član povjerenstva)
• Granter: University of Zagreb; Faculty of Agriculture; (Sustainable Technologies and Renewable Energy Sources); Zagreb
• Defense date and country: 2023-07-27, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Agronomy

Abstract

Sirutka je nusproizvod koji nastaje nakon proizvodnje sira. Zbog količine u kojoj nastaje, sirutka mljekarskoj industriji predstavlja veliko opterećenje. Pretpostavlja se da se gotovo 50 % svjetske količine ispušta u otpadne vode čime predstavlja opasnost za onečišćenje okoliša, a ujedno se gubi i vrijedan resurs. Kao jedan od načina njezine upotrebe je proces anaerobne digestije kojim bi se od nusproizvoda mogao proizvesti bioplin. Bioplin je zapaljivi plin u čijem sastavu se u najvećoj mjeri nalaze metan i ugljikov dioksid, a njegova važnost kao jeftinog i CO2 neutralnog izvora energije proizlazi iz mogućnosti njegove upotrebe u transportu i proizvodnji toplinske i električne energije. U ovom radu uspoređuje se prinos bioplina i metana iz dvanaest uzoraka sirutke dobivene prije i poslije proizvodnje skute pri čemu su dodane različite količine limunske kiseline. Također, prikazana je međuzavisnost pojedinog uzorka o parametrima kao što su udio suhe tvari, udio vlage, te udio makro i mikro elemenata koji utječu na kvalitetu sirovine, te ovisnost prinosa bioplina i kemijske potrošnje kisika. Dobiveni rezultati su pokazali kako veće količine limunske kiseline u uzorku daju manji prinos bioplina, te kako na prinos metana u bioplinu utječe kvaliteta sirutke. Također, prema podacima kemijske potrošnje kisika dobivenim u istraživanju, vrijednosti koje se nalaze u uzorcima sirutke bile su optimalne te su uzorci sa najvišom vrijednosti dali najveći prinos bioplina.

Abstract (english)

Whey is a by-product of cheese production. Due to the amount in which it is produced, the whey of the dairy industry represents a large burden. It is assumed that almost 50 % of the world's volume is discharged into wastewater, which represents a danger for environmental pollution, and at the same time a valuable resource is lost. One of the ways of its use is the process of anaerobic digestion, which could produce biogas from the by-products. Biogas is a flammable gas whose composition contains methane and carbon dioxide to the greatest extent, and its importance as a cheap and CO2-neutral source of energy stems from the possibility of its use in transport and production of heat and electricity. This research compares the yield of biogas and methane from twelve samples of whey obtained before and after the production of cottage cheese, to which different amounts of citric acid were added. Also, the interdependence of individual samples on parameters such as dry matter content, moisture content, and macro and microelements that affect the quality of the raw material, as well as dependence of biogas yield and chemical oxygen demand. The obtained results showed that larger amounts of citric acid in the sample give a lower yield of biogas, and that the yield of methane in biogas is affected by the quality of the whey. Also, according to the chemical oxygen consumption data obtained in the research, the values found in the whey samples were optimal and the samples with the highest values gave the highest biogas yield.

• Keywords: sirutka; mliječna industrija; bioplin; metan; anaerobna digestija
• Keywords (english): whey; diary industry; biogas; methane; anaerobic digestion
• Language: croatian
• URN:NBN: urn:nbn:hr:204:952381
• Study programme: Title: Renewable energy sources in agriculture; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra obnovljivih izvora energije u poljoprivredi (magistar/magistra obnovljivih izvora energije u poljoprivredi)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to authenticated users
• Created on: 2023-08-23 06:54:14