Romanian Biotechnological Letters Vol. 18, No. 6, 2013 Copyright © 2013 University of Bucharest Printed in Romania. All rights reserved ORIGINAL PAPER 8812 Romanian Biotechnological Letters, Vol. 18, No. 6, 2013 Biogas generation from corn stalks and corn stalks bagasse resulted from ethanol production Received for publication, June 29, 2013 Accepted, August 27, 2013 TEODOR VINTILĂ 1 , VASILE GHERMAN 2 , MARIAN BURA 1 , MONICA DRAGOMIRESCU 1 , DANIELA ILIE 1,3 , CĂLIN JULEAN 1 , SIMINA-ILEANA NEO 1 1 University of Agricultural Science and Veterinary Medicine, Faculty of Animal Science and Biotechnologies, Timişoara, Romania 2 Politehnica University of Timişoara, Romania 3 Research and Development Station for Bovine - Arad, Arad, Romania Corresponding author: Simina-Ileana Neo, E-mail: neosimina@yahoo.com, Tel. 004(0)256277086, Calea Aradului nr. 119, Timisoara 300645, Romania Abstract: The main purpose of the experiment was to compare the biogas yield from corn stalks differently pretreated with the biogas yield from corn stalks bagasse resulted from the process of lignocellulosic ethanol production. Cattle manure and liquid sludge from an on-farm biogas plant was used as co-substrate and inoculums. The laboratory scale experiment was carried out in batch system. Volume and composition of the produced biogas was measured by using BlueSens measuring equipment. By addition in fermentation batches of 8% DM corn stalks (milled to 10 mm particles), the gas yield is improved with 32.2 ml / 100 ml fermentation medium, while by addition of 8% DM corn stalks bagasse (mechanicaly pretreated before alcoholic fermentation) exhausted in the process of bioethanol production, the gas yield increased with 158.7 ml / 100 ml fermentation medium compared with control batch (cattle manure and inoculum). In the case of physicochemical pretreated corn stalks bagasse exhausted in the process of bioethanol production, the gas yield decreased with 119.2 ml / 100 ml fermentation medium compared with control batch (this can be explained by accumulation in the physicochemical pretreatment of inhibitory compounds with negative effect on microbial activity). Mechanical pretreated corn stalks bagasse can be used as raw material for biogas production. Keywords: agricultural wastes, corn stalks, biogas, bioethanol, anaerobic fermentation, Introduction Biogas is a mixture composed mainly of CH 4 and CO 2 , during the degradation of organic substrate by anaerobic microorganisms. This biological process is called anaerobic digestion (AD). The degradation of organic substrate is carried out naturally in anaerobic environments such as the bottom of ponds, marshes (J. ROUSE & al. [1]), wetlands, the digestive tracts of ruminants and certain species of insects (J. RAPPORT & al. [2]). References related to biogas production from organic substrate dating back to about 3000 years ago (U.S ENVIRONMENTAL PROTECTION AGENCY: WASTE PROGRAMS [3]). For example biogas was used to heat water bath in Assyria in the 10 th century BC (P. D. LUSK [4]). In 1630 Van Helmont notices that the organic substrate is capable of producing an inflammable gas. For the first time, in 1808 Daviy recognized that methane was produced from decomposition of cattle manure (P. D. LUSK [4]). A biological process like AD known from the past turns out to be a useful solution for the present and for the future in a situation where sources of alternative renewable energy are absolutely necessary to be found (D. ELANGO [5]). The use of organic wastes as alternative energy sources is absolutely necessary because: