Methane Production from Plant Wastes and Chicken Manure at Different Working Conditions of a One-stage Anaerobic Digester

Abstract

This article presents laboratory scale studies on the anaerobic digestion of plant wastes using a continuously flow type vertical cylindrical biogas plant. In the first experiment, plant wastes and chicken manure mixture at a dry matter content of 12%, retention time of 30 days, and fermentation temperature of 35°C were examined (Exp. 1). In the second experiment, fermentation material was grass and grass silage, covered marketplace wastes, rumen waste, chicken manure, and cattle manure. The experiments were conducted at a dry matter content of 9%, retention time of 47 days, and fermentation temperature of 35°C (Exp. 2). According to the results, biogas production was 1,055.7 l per day in Exp. 1 and 721.4 l per day in Exp. 2. The raw material specific biogas production was 0.310 l per g of organic dry matter per day in Exp. 1 and 0.443 l per g of organic dry matter per day in Exp. 2. The reactor specific biogas production was 1.05 l per l per day in Exp. 1 and 0.72 l per l per day in Exp. 2. Reactor specific methane production was 0.425 l per l per day in Exp. 1 and 0.381 l per l per day in Exp. 2. Raw material specific methane production was 0.125 l per g of organic dry matter per day in Exp. 1 and 0.234 l per g of organic dry matter per day in Exp. 2. The material pH value was 5.59 and 6.15 for inlet and 7.97 and 8.19 for outlet for Exp. 1 and Exp. 2, respectively. The methane content ranged between 40.3 and 52.9%.

Keywords:

• anaerobic fermentation
• biogas
• plant wastes