Possibilities for Anaerobic Digestion of Slaughter Waste and Flotates for Biomethane Production

Abstract

Anaerobic digestion for biomethane production is an important tool regarding sustainable energy production. The objective of this study was to investigate the effects of the substrate composition and operating parameters on biomethane production during anaerobic digestion, focusing on the use of flotates and slaughterhouse waste as substrates with a high organic content. A novelty here was the use of a moving bed biofilm reactor (MBBR) with circulation pump for the anaerobic treatment of flotates, slaughter waste (SW), and their mixture. Flotates and waste from slaughterhouses offer a substrate with a high organic content. In this work, it was shown that both substrates provide a high biochemical methane potential (BMP). The highest methane yield was achieved by mixing both substrates. In continuous operation, special challenges arose, due to the high nitrogen and fat content of the substrates. These could be overcome by mixing the substrates and using a circulation pump in the reactor for improved back-mixing. As a result, the highest average methane yield of 0.65 NLCH4·gTS eli−1 was achieved in mesophilic operation at an organic loading rate (OLR) of 4.2 gTS·L−1·d−1.

Keywords

• anaerobic digestion
• slaughter wastewater
• slaughter waste
• bio gas
• methane potential