Skirtingų regionų nuotekų dumblo perdirbimo į biodujas energinis įvertinimas

Abstract

Biogas plants are implemented in newly build wastewater treatment facilities. A large part of investments in wastewater treatment consists of investments in biogas plant. The purpose of this study was to perform energy assessment of sewage sludge digestion to biogas from four different regions of Lithuania. Results show that the biggest biomass energy value is from sewage sludge from the city of Siauiiai - 1,08 to 1,18 MJ/kg. However, this sewage sludge digestion was problematic due to the low carbon and nitrogen ratio (C:N) 5,3:1 and high concentration of dry matter. High energy value was from cities of Kaunas and Alytus. Energy value of dry organic matter of Kaunas city sewage sludge ranged from 16,4 to 16,9 MJ/kg, and the city of Alytus was - 17,1 to 17,3 MJ/kg. Due to low dry matter concentration of sewage sludge it should be mixed with a waste containing higher concentration of dry matter.