The paper presents a case-based comparison of energy balances, green house gas emissions and costs of municipal wastewater sludge process chains based on anaerobic digestion or incineration. Several utilisation options were covered for biogas energy as well for energy from sludge incineration. The potential of enhancing anaerobic digestion by converting the process to thermophilic was studied. In addition, primary precipitation as an operation mode of a WWTP was evaluated as a possible means of enhancing the total energy efficiency. Based on the results, sludge incineration was the most expensive option of the studied scenarios, but justified if the heat generated can be utilised in district heating. Based on costs and energy balances as well as green house gas emissions it is most preferable in anaerobic digestion chains to feed the generated biogas to a gas engine to produce electricity and heat. Moreover, thermophilic anaerobic digestion can improve the overall economy of a WWTP provided that the biogas yield is sufficiently higher than in a mesophilic process.
|Number of pages||15|
|Publication status||Published - 2010|
|MoE publication type||Not Eligible|
|Event||IWA Water and Energy Conference 2010 - Amsterdam, Netherlands|
Duration: 10 Nov 2010 → 12 Nov 2010
|Conference||IWA Water and Energy Conference 2010|
|Period||10/11/10 → 12/11/10|
- anaerobic digestion
- sludge treatment
- sludge incineration
Merta, E., Arnold, M., Niemelä, A., & Kangas, A. (2010). Energy balances, GHG emissions and related costs of municipal wastewater sludge treatment chains. IWA Water and Energy Conference 2010, Amsterdam, Netherlands.