Trade-offs between manure management with and without biogas production

Abstract

Introduction: In rural developing countries with a traditional manure management, animal manure is a value-added agricultural commodity being utilized as a source of fuel and plant nutrients. The sustainable environmental management of this resource has to consider the whole upstream and downstream activities of current management systems. Methods & Materials: In line with this requirement, this study has integrated the Intergovernmental Panel on Climate Change (IPCC) method on manure managements into the life-cycle assessment of two different manure management systems: the traditional system without biogas production and the alternative system with biogas production. Special attention is given to compare the GHG emissions as well as Nitrogen (N), Phosphorous (P), and Potassium (K) Fertilizing Nutrients (NPK) from the two systems. Results: The great advantage of manure conversion to biogas is mainly due to the avoided wood (18 kg/animal.yr), crop-residues (12 kg/ animal.yr) and dung (8 kg/ animal.yr) used as cooking fuels in the region. If methane leakage is over 38% then this will offset the GHG emission reduction of manure-to-biogas system.