ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Anaerobic treatment of rapeseed meal

Nina Kolesárová, Miroslav Hutňan, Viera Špalková, and Michal Lazor

Department of Environmental Engineering, Institute of Chemical and Environmental Engineering, Faculty of Chemical and Food Technology, Slovak Technical University, Radlinskeho 9, 812 37, Bratislava, Slovakia

E-mail: nina.kolesarova@stuba.sk

Abstract: Rapeseed meal is a solid by-product obtained from rapeseed after oil extraction. This contribution summarises experiences from batch experiments as well as the long-term processing of this substrate in a laboratory stirred anaerobic reactor (continuous stirred-tank reactor). On the basis of the batch tests of hydrolysis, acidogenesis, and methanogenic activity, it was concluded that the anaerobic degradation of rapeseed meal can be performed using a one-step system and it is not necessary to include a hydrolytic-acidogenic step prior to the methanogenic step. Although the methanogenic potential of rapeseed meal appears to be very promising, the long-term processing as a single substrate led to serious problems arising from the inhibitory effects. It was, therefore, co-fermented with crude glycerol from biodiesel production. From the long-term operation of the laboratory model, it may be stated that, due to the co-fermentation of by-products from biodiesel production, the individual inhibition effects can be suppressed to a large extent and biogas production can be stabilised. The maximum organic loading rate in the continuous stirred reactor achieved 2.42 kg m⁻³ d⁻¹ of volatile solids (15 g of rapeseed meal and 20 mL of gas-phase), which was 3.13 kg m⁻³ d⁻¹ of chemical oxygen demand.

Keywords: biodiesel – biogas – rapeseed meal – crude glycerol – anaerobic digestion

Full paper is available at www.springerlink.com.

DOI: 10.2478/s11696-013-0318-8

Chemical Papers 67 (12) 1569–1576 (2013)