The modelling of anaerobic digestion of organic substrate

Anaerobna razgradnja način je oporabe energije iz organskog biorazgradivog otpada pri čemu nastaju bioplin i digestat kao vrjedniji produkti. Prema sastavu bioplina najzastupljeniji spojevi su metan i ugljikov (IV) oksid, dok ostalih spojeva kao sumporovodika, kisika, amonijaka i dušika ima u tragovima. Upotreba bioplina je višestruka, od goriva za proizvodnju električne i toplinske energije do proizvodnje biogoriva i kemikalija više dodane vrijednosti. U ovom radu istražuje se primjena matematičkog modela Anaerobic Digestion Model No. 1 implementiranog u procesni simulator AQUASIM s ciljem opisivanja procesa anaerobne kodigestije. Provedeno je modeliranje kontinuiranog procesa i rezultati modela uspoređeni su s mjerenim podatcima s bioplinskog postrojenja. Kao supstrati na bioplinskom postrojenju primarno se koriste kukuruzna silaža i životinjska gnojovka. Prosječna temperatura provođenja kontinuiranog procesa je 39 °C što odgovara mezofilnom načinu rada. U nastalom bioplinu mjeri se udio metana kao glavne komponente bioplina, udio kisika i zastupljenost sumporovodika. Postrojenje nastali bioplin koristi kao gorivo za proizvodnju toplinske i električne energije, a preostali digestat kao gnojivo za poljoprivredne površine. Na osnovi koreliranosti podataka istražuje se adekvatnost primijenjenog modela na kontinuirani proces.Anaerobic digestion is acceptable technology of energy recovery from organic biodegradable waste that results in production of biogas and digestate. Biogas is composed mainly from methane and carbon dioxide, while other components like hydrogen sulphide, oxygen, ammonia and nitrogen can be find in traces. Use of biogas is various, as a fuel for production of electricity and heat or in production of other biofuels and value-added chemicals. The application of mathematical model Anaerobic Digestion Model No.1 implemented in process simulator AQUASIM on anaerobic co-digestion process has been investigated. The continuous process of anaerobic co-digestion has been modelled in a programme and result compared with the measured ones. Feedstock in the biogas power plant is primarily composed from maize silage and animal manure and slurry. Average temperature of the process is about 39 °C that defines mesophilic conditions in reactors. In generated biogas the presence of following components has been determined: methane, oxygen and hydrogen sulphide. Biogas power plant uses generated biogas as a fuel in production of electricity and heat, and digestate is used as a fertilizer on fields. By the correlation of experimental data and model results, the acceptability of model on continuous process has been considered