Waste disposal is a global problem contributing to the ongoing climate change by large emissions of greenhouse gases. By using waste material as a resource instead of landfilling, the greenhouse gas emissions from landfills are reduced.
Waste material can be used for waste incineration with energy recovery, thus decreasing the greenhouse gas emission from energy utilization by changing from fossil fuels to a partly renewable fuel.
Arges County in Romania has severe problems with its waste material, mainly sewage sludge and waste from households and industries. As a consequence of the Romanian EU accession in 2007, Arges County is obliged to close its landfills for waste in a near future.
A reconstruction of the wastewater treatment plant and an improved management of the sewage sludge residue are necessary in order to comply with EU standards. The requirements from the EU regarding waste disposal together with the existence of a district heating network in the residence city Pitesti, makes it interesting to investigate energy recovery from waste material in Arges County.
Therefore, the goal of the study is to evaluate the possibility to extract energy from co-incineration of the waste material, sewage sludge and waste generated in Arges County. In order to reach this goal, the composition and quantities of the waste material is investigated. A suitable technology for the waste-to-energy (WTE) plant is proposed, based on the data of the waste material as well as on established WTE technologies and their costs.
It is assumed that the WTE plant will be implemented in 2020 and that all the generated waste will be incinerated. Furthermore, an environmental analysis is carried out, which presents the reductions of greenhouse gas emissions with the proposed WTE plant in comparison with the present system; including the management of waste and sludge and the district heating production, which is based on fossil fuels.
The result shows that the waste material in Arges County has a calorific value of 7.5 MJ per kg, which is suitable for co-incineration of waste and sludge. The suggested WTE plant has the total power of 130 MW, annually recovering 620 and 330 GWh of heat and electric power respectively. The investment cost of the WTE plant is estimated to 226 million euro with a payback time of 8 years. The environmental analysis shows that the proposed system in comparison with the present system will decrease greenhouse gas emissions by 88 percent.
A WTE plant appears to be a sound investment in Arges County and would sharply reduce the emissions of greenhouse gases in the county. However, some obstacles exist. Waste management is a new field in Romania and currently there are no WTE plants. Furthermore, the data used in this study concerning the quantity and composition of the waste, is uncertain and further studies are necessary before a WTE plant can be established.
Source: Linköping University
Author: Nordström, Emma | Enochsson, Evelina