Determination of the biomethanic potential of corn grain

Although it is primarily grown as food, corn also represents a very good raw material for the production of biogas due to the favourable starch and fibre ratio that is the basis of its structure. In addition, an important fact is that there are large arable or potentially arable areas in our country that are triturated with different pollutants, so that the production of plant crops for dietary purposes on these surfaces is not possible. The aim of this paper was to determine the biometric potential of various varieties of corn grain in laboratory conditions through a series of experimental measurements. The obtained results are based on the assessment of the possibility of applying energy plantations of corn grown on contaminated arable or recultivated surfaces in the production of biogas

O spektru nelinearnih operatora

U ovom radu pokazujemo da preslikavajući spektar nelinearnih operatora ne zadržava neke bitne osobine koje ima spektar linearnih operatora. To ilustriramo nizom primjera

OPTIMIZING PROCESS CONTROL OF THE ANAEROBIC DIGESTION OF ORGANIC MATTER

The proper process control is the key to achieving both environmental and commercial goals of conducting the process of anaerobic digestion. Taking into account that the parameters that can be monitored are quite numerous, and that the monitoring equipment, its installation and maintenance require significant financial resources, it is, from commercial aspect, necessary to minimize the number of parameters to the set of parameters which are necessary but sufficient for the proper conduct of the process to the point after which the further continuation of the process is not economically justified. The paper presents the model developed for determination of the minimum number of parameters to be monitored in order to ensure sufficient quality control of this process and describes its validation through the laboratory test

Thermal pretreatment of cattle manure for enhancing biogas production

The low degradability of waste materials containing lignocellulosic material is one of the factors that hinder the production of biogas. The increased need for advanced techniques in the anaerobic digestion process has led to the use of different pretreatment raw materials prior to the anaerobic digestion process in order to increase the yield of biogas. In order to maximize the yield of biogas from cattle manure in a mixture with waste sludge, the anaerobic digestion process was performed at mesophilic conditions for 54 days. As pretreatment, the thermal treatment of cattle manure at temperatures of 55 and 70°C was applied. The highest biogas production was obtained in the sample of cattle manure, previously treated at 70°C (M70), while the lowest was recorded in the control sample M. The specific biogas production in relation to the input quantity of volatile organic matter had the highest value in sample M70 and the lowest in the control sample. Overall results have shown that the thermal treatment of cattle manure before the anaerobic digestion process can increase both yield and biogas quality