Investigation of Integrated Resource Management Examples in Sweden
(31-DP-2)
Discussion Paper Summary
As the CRD plans for wastewater treatment, there has been an increasing interest in the beneficial use of treatment by-products, recovery of energy and integration of solid waste and liquid waste resource management options, where possible. Integrated Resource Management (IRM) may provide opportunities for the CRD to recover costs from the treatment process, provide environmentally sustainable facilities and reduce greenhouse gas emissions.
Sweden is recognized as an IRM leader, and thus a delegation from the CRD visited waste management facilities in three cities in Sweden on a fact-finding mission. The Spring 2008 visit included facility tours and meetings in Göteborg, Stockholm and Västerås.
What did investigations involve?
Participants from the Capital Region visited Municipal Solid Waste (MSW) Waste to Energy (WTE) facilities, wastewater treatment plants and a purpose-built source-separated organics digestion facility. Discussions were held on:
- Use of heat pumps for energy extraction from wastewater
- District heating systems
- Biogas utilization as vehicle fuel
- Land application of biowaste from source-separated organics digestion and biosolids from wastewater treatment plants
Research Findings
The fact finding mission furnished many ideas about IRM technologies, many of which are in wide use in Sweden. Facilities in Sweden are operated in an environmentally responsible manner with respect to odour control, air pollution control and wastewater treatment. The energy from these facilities is a significant contributor to the overall heat and electricity requirements of the populations that are served.
Sweden uses a wide variety of technologies to extract energy and reuse the products of wastewater treatment. Heat pumps and district heating were both used to extract heat from wastewater effluent. District heating, common in larger Swedish cities, is extensive and evolved, unlike cities in the CRD; supplementary heating sources, such as wood waste and fossil fuels, are still used in winter.
Source separated organics (food and agricultural wastes) are being used extensively to create biogas, fertilizer and soil supplements in Sweden. Incineration is not used as a method of processing either organics or biosolids from the wastewater treatment process. Biosolids from wastewater are being land-applied in large scale landscaping and mine reclamation operations.
It was found that the use of biogas as a vehicle fuel was a better use of this resource, from economic and environmental (greenhouse gas credit) viewpoints, when compared to burning biogas in a cogen engine system to create electricity and heat. Finally, decentralized wastewater treatment was not observed as a trend; in fact, increased centralization (including plant dismantling), both in Göteborg and Stockholm, was noted.
What technologies can the CRD use?
Not all Swedish technologies and programs will be directly applicable to the CRD’s situation. Siting conditions, economics and social acceptance are all likely to differ from those in Sweden and the CRD must find the best solution for the Core Area’s needs. Some technologies, however, could be extremely applicable. Recommended technologies for the CRD include:
- A source separated organics collection and utilization program.
- Separated biosolids and organics collection; use of biosolids for fuel, non-food related land application or combustion.
- Biogas in a cogen system should be considered to allow biogas to biomethane conversion, allowing for vehicle fuel use.
- Integration of biogas with the natural gas pipe network, to provide a secondary source of green energy for transit buses.
© Image courtesy of Evan Leeson