Utilization of Post-Ferment from Co-Fermentation Methane for Energy Purposes

Abstract

The main civilization issue of the 21 century is a rapid increase of the waste and pollution amount which influences the natural environment degradation. As early as in the 20 century, the increase in the amount of municipal waste and waste from agri-food industry was reported. Waste chemical composition gives optimal conditions for the development of microorganisms. Under aerobic and non-aerobic conditions bacteria decompose organic compounds which results in gases emission (CH4, H2S, CO2, NOx), while nitrogen, phosphorus and potassium compounds remain in the post-ferment. These compounds may be diffused into the environment and create a risk of homeostasis corruption. Biogenic elements are transferred to surface water and corrupt the ecosystem balance causing its eutrophication. Various types of fermentation may be distinguished, but the methane fermentation may play a special role with regard to the sustainable energy sources and waste management. This process converts energy included in the biomass into the utility fuel – a source of clean sustainable energy which does not negatively influence the environment. Biogas may be combusted in the boiler in order to obtain thermal energy used for heating rooms or in a gas engine which drives the current generator. It is worth noticing that the above method is a desired one of transforming waste ie organic recycling. The research results of biogas production from the organic fraction of municipal waste in co-fermentation with the agricultural mass as well as the suitability of the post-ferment for energy purposes were presented in the paper. In order to image the calorific value of the post-ferment, the tests were carried out on 6 batch mixes where in each one the organic fraction of municipal waste occurred.