Alternative Utilization of Protein-Rich Waste by Its Conversion into Biogas in Co-Fermentation Conditions

Abstract

A large amount of litter is generated in industrial-scale animal breeding, and this is recognized as a big problem in animal-breeding technology. Troublesome waste may, however, be regarded as a useful, easily accessible cosubstrate for the production of biogas and semi-liquid residue suitable for fertilizing plants. Its utilization problem can thus be integrated with the production of an environmentally friendly energy carrier: biomethane. The results of litter decomposition are visible just after excretion as odor compounds are emitted. Animal litter of high protein concentration and moisture >40% undergoes complex biochemical decomposition that is closely related to the intensive emission of ammonia. It directly affects living conditions of animals in rooms [1]. The amount and composition of the gaseous mixture produced from litter depends, among other things, on: temperature, moisture level, mixing frequency, bedding type, composition and Pol. J. Environ. Stud. Vol. 26, No. 3 (2017) AbstractThe recommended process conditions and problems reported during anaerobic (co-)fermentation of waste biomass rich in proteins are discussed. Theoretical potentials of the individual biogas components (CH 4 , CO 2 , NH 3 , H 2 S) formed during chemical decomposition of aminoacids -feed additives commonly used in feeding animals -are shown, and we discuss side production of odors, e.g., ammonia and organic sulphur compounds. We also suggest the potential alternative production of biohydrogen (a future energy carrier) from specific waste biomass with high protein content.