Influence of chemical composition on the biochemical methane potential of agro-industrial substrates from Estonia

M.A. Luna-delRisco¹,*, K. Orupõld², I. Diaz-Forero³ and M. González-Palacio¹

¹ Universidad de Medellin, Faculty of Engineering, Energy Engineering,
Carrera 87 # 30 – 65, P.O. 050026 Medellin, Colombia
² Estonian University of Life Sciences, Faculty of Agricultural and Environmental
Sciences, Kreutzwaldi 1, EE51014 Tartu, Estonia
³ Servicio Nacional de Aprendizaje – SENA, Center for Design and Manufacture of
Leather, BIOMATIC Research Group, Calle 63 # 58B – 03, P.O. 055413 Itagüí,
Colombia
*Correspondence: mluna@udem.edu.co

Abstract:

Batch trials were carried out to evaluate the Biochemical Methane Potential (BMP) of 61 different substrates collected from agricultural farms and industrial sites in Estonia. Tests were performed in 500 mL plasma bottles at 36°C. The highest methane yield from all tested substrates was obtained from unconsumed dairy products (557 ± 101 L kg-1 VS) while the lowest was obtained from animal slurries (238 L kg-1 VS ± 42). From tested energy crops, foxtail millet achieved the highest methane yield (320 L kg-1 VS). Silages from different crops presented methane yields from 296 ± 31 L CH4 kg-1 VS to 319 ± 19 L CH4 kg-1 VS. The influence of chemical composition and kinetic rate constants (k) on methane potential was analyzed. Anaerobic digestibility of selected agro-industrial substrates was markedly influenced by their organic content, i.e. total proteins and lignin concentrations. Rate constants were found to correlate negatively with hemicellulose, cellulose and lignin (p < 0.05). Results from this study suggest that an appropriate characterization of the chemical composition of the substrates is important not only for predicting BMP and the kinetics rates, but also for identifying possible inhibitors during the anaerobic digestion process. Results on the BMP and national availability of studied substrates indicate that herbal biomass and agro-industrial residues are promising substrates for biogas production in agricultural biogas facilities in Estonia.

Key words:

Agro-industrial, Biochemical Methane Potential, biogas, biomass, Kinetic rate, wastes

Physical properties of wastes from furniture industry for energy purposes

M. Dąbrowska-Salwin*, D. Raczkowska and A. Świętochowski

Warsaw University of Life Sciences, Faculty of Production Engineering, Department of Agricultural and Forest Machinery, Nowoursynowska 166, PL02-787 Warsaw, Poland *Correspondence: magdalena_dabrowska@sggw.pl

Abstract:

The aim of the study was to determine the physical properties such as moisture content, particle size distribution, density and calorific value of wastes from wood-based boards and to determine their suitability for energy purposes. The tested material included wastes from tooling fibreboards (MDF) and raw (PWP) and laminated (PWO) chipboards. Tests were conducted according to the standards. The materials from wastes after mechanical boards tooling were characterized by a similar low moisture content. The geometric mean of particle size values were 0.38 mm, 0.64 mm and 0.57 mm, respectively for MDF, PWO and PWP. The particle size distributions were right-hand skewed and non-aligned. It was found that the prevailing share had the smallest fraction and its largest share had wastes from MDF. Regarding to the high calorific value and low moisture content and high bulk density, it could be stated that the wastes from furniture industry are a good raw materials for energy purposes. These wastes can be combusted at proper conditions of this process.

Key words: