INTERACTION OF THE DRY MATTER ON CONTENTS OF BIOGAS PRODUCED FROM PIG MANURE

Korištenje svinjske gnojovke kao biomase za proizvodnju bioplina jedan je od načina za učinkovitu uporabu otpada uz minimalan utjecaj na okoliš. Prednost bioplina i biomase u odnosu na fosilna goriva je neusporedivo manje emisije štetnih plinova i otpadnih tvari. Opterećenje atmosfere ugljik dioksidom (CO2) pri korištenju biomase je zanemarivo, jer je količina emitiranog CO2 prilikom izgaranja jednaka količini apsorbiranog CO2 tijekom rasta biljaka. Materijal istraživanja je svinjska gnojovka sa farme u okolici Osijeka gdje su svinje držane na rešetkastom podu a u istraživanju koristila se standardna metoda i kvantitativni postupak. Na uzorku se ispitivao postotak suhe tvari (ST) i njegova ovisnost o količini nastalog bioplina različitog sastava. Količina (ST) je niska i teoretski se kreće se od 0,5 do 10 %. Ona je varijabilna i ovisi o pasmini, hranidbi, uvjetima držanja, tehnologiji, izgnojavanju itd. Uzorak sa niskom količinom (ST) sadržavao je veliku količinu pepela te je njegov postotak iznosio više od 50 %. Većina uzoraka s najvećim postotkom suhe tvari imala je visoki postotak (iznad 70 %) hlapljive organanske tvari (OT). Udio dušika (N) i CO2 viši je u bioplinu proizvedenom iz svinjske gnojovke s većim udjelom ST. Količina N obrnuto je proporcionalna količini metana (CH4) /r=-0,948; p<0,001/. Dokazana je visoko pozitivna korelacija između koncentracije ST i količine bioplina (r = 0,947, p<0,001). Količina bioplina ovisi o sadržaju ST s posebnim naglaskom na visoki postotak OT. Koncentracija CH4 najveća je kod skupine s najnižom proizvodnjom bioplina. Što je veći sadržaj suhe OT i udio masti u supstratu, veći je i postotak CH4.Taking advantage of pig manure as biomass for production of biogas, is one of the ways of efficient use of waste with minimum interaction with the environment. Biogas and biomass oposite on fossil fuels has less emission of harmfull gasses and wastage rate. Emissions of carbon dioxide (CO2) in biomass, as a fuels, become from burning out is almost equal with amoung of apsorpted CO2 during growth of plants. Material from investigation was pig manure from a farm near Osijek, where all the pigs were kept on latticed floor. Methods of investigation were quantitative procedure with standard methods. On pig manure was investigated percent of dry matter (DM) and her correlation on amount of biogas with different composition. Amount of (DM) is low and teoreticaly between 0,5- 10 %. Results are variable and depends on rase, nutrition, handeling conditions, technology... The sample with low (DM) had high amount of ash > 50 % mineral part and high amount of (DM) had > 70 % dry organic matter (DOM). Higher amount of (DM) represents nutritive base for microorganisms with growing faster and produce more methane (CH4). High amount of (DM) gave high percentage of nitrogen N and CO2. Amount of N was in inverse proportion to the amount of CH4 (r=-0,948; p<0,001). Highly positive correlation was determined between (DM) on special accent on (DOM) and biogas amount (r = 0,947, p<0,001). Methane concentration was the highest in the group with the lowest biogas production. Higher content the (DOM) and the share of has positive correlation with fat in pig manure and gave high percentage of CH4