Urban biomass Third thematic seminar: Urban Waste Biomass, 6-8.3.2012, Växjö, Sweden The purpose of this seminar, held in the South East Sweden Region due to its long tradition in terms of knowhow and capacities for biomass in general and also waste to energy, was to get an essential understanding of how urban waste, biomass and sewage water is used for electricity and heat sources. The topic was chosen in order to show that there is great potential which is still largely unexploited in most EU regions. Study visits to a biogas plant in Växjö and a CHP plant for district heating in Ljungby provided rich informaton for the participants. 1. Biomass Experts involved. Project partners participated in the event, planning, coordinating and as speakers, providing experts in the field tackled. The external experts who participated are introduced below. Växjo municipality has a long tradition of using woody biomass from the forest sector for heat and electricity production in district heat plants. For the last 10 years waste has been transported to the plant in Ljungby. Since five years ago a plant for biogas is located at the sewage water treatment plant and now under development is a facility to also use organic waste for production of biomethane for the transport sector. Ljungby Energi AB is owned by the municipality and provides heat for the municipality of Ljungby from a district heating plant based on mainly urban waste but with a backup using traditional biomass. The mix is around 80 % coming from waste and 20 % from biomass; it is producing both heat (around 30 MW) and electricity (around 5 MW) in the CHP plant. Alvesta Energi AB is owned by the municipality and has four plants in the four main villages of the Alvesta municipality. They are quite similar with just heat production for the district heating systems in Alvesta, 20 MW, Moheda, 10 MW, Vislanda, 5 MW and Grimslöv, 1 MW. All are using residues from local sawmills and some from forest. Fondazione Edmund Mach promotes and carries out research, scientific experiments, education and training activities as well as providing technical assistance and services to companies. These activities are aimed at promoting cultural and socio-economic growth in the agricultural sector and at developing the forestry and agroalimentary systems, with particular regard for the environment and the safeguard of the territory of the Trentino region. Valoriza is an important Spanish firm working in the biomass sector, having two plants in operation and another one under construction and several projects under development in Spain and Portugal. Total installed power over 100 MW. 1
2. Presentations. During the seminar, aspects related to plans and strategies for sorting of residues, treatment and disposal of urban waste were outlined. Also the options for energy recovery of the organic fraction and the perspectives for these in the medium and long term were analysed. Apart from detailed information about the different technologies and power plants, Trentino, Castilla y Léon, Southeast Sweden, Western Macedonia, South-East Ireland and Tartu regions presented their current situations in regional and/or national urban waste biomass. Steve Karlsson, responsible for the waste treatment plant in the municipality of Växjö, talked about the production of biogas as a result of sewage water digestion and how in the future also organic household waste will be gathered and used for biogas production. The plant is owned and operated by the municipality. He explained that a new plant is under construction and it will incorporate new lines for urban organic residues and how a joint treatment will be performed to produce biogas. It was explained that the major utilization for biofuels is public bus transport. Nowadays, existing crude gas production at Sundet is 720, 000 Nm3 vehicle fuel. One of the problems highlighted was the lack of storage for biogas in the plant which results in the getting rid of surplus gas without a real use. Future crude gas production with food waste is planned to be 1,300,000 Nm 3 vehicle fuels which will be distributed to a biogas filling station in central Växjö by pipes. Silvia Silvestri from Edmund Mach Foundation pointed out the advanced waste sorting system which permits the recovery and recycling of different materials. Around 69 % of waste is sorted out and collected in Trentino region. She explained that anaerobic digestion, at the moment, is the best system for the treatment of the biodegradable fractions to obtain renewable energy (biogas) and organic matter for soil. Some of the problems outlined were the high costs of the treatment plants, difficulties in obtaining permits, and social opposition especially in rural areas. Bo Schönbäck is responsible for running the CHP plant of Ljungby Energi AB, owned by the municipality. He explained how the installations work. This is described in the good practices section. Alejandro Limburg Juan representing Valoriza, commented on the situation in Spain where urban solid waste has increased 60% in the last 15 years, reaching 528 Kg per person/year, meaning that 4.3% of the national total is produced in Castilla y León. Importance was given to the improvement of sorting systems, mechanical treatments and composting of the organic fraction of the solid waste where more than 45% has an organic origin or wood. The use of residues as an energy source is at an early stage in Spain and there are few examples where conversion technologies such as biomethanisation and the biogas energy use by cogeneration are applied. Marek Muiste from the Tartu regional energy agency pointed out the high unused potential in the country. He also mentioned that their priority is to use the great potential for biomass from forestry in his region. Nowadays, urban residues are not used for energy recovery but the increasing landfill costs could result in a benefit in this area. Lastly, he explained the biomethane production in landfill. Hans Gulliksson, from the energy agency for South East Sweden, explained the use of urban waste for power and heat generation which is extended throughout the country. Urban waste is considered biomass to a percentage around 75 % depending on the mix. 2
The systems, both biogas production and district heating, are built up in such a way that there is a plant in a 100 km sector radius from each municipality. Some problems were associated with these treatments in the 80s, mostly associated to dioxin emissions. These have been solved and there are no big problems nowadays except how to deposit the fly ash. 3. Study visits. Visits during the seminar helped to show real examples of urban waste treatment in South East Sweden. Details about types of energy use from organic residues such as biomass were given. Also, district heating systems and installations to produce heat energy for its distribution to a number of users were explained. - Biomethane production plant in Växjö municipality Since 1994, Växjö has a waste treatment plant which incorporates several anaerobic digesters to obtain biogas. The techniques applied have been improved to jointly treat organic material from various origins (sewage sludge, urban waste, livestock residues, etc). Policies to improve organic waste sorting from urban and household origin have increased the plant treatment capacity and to organise a new system to collect and transport residues to the plant. There, the conversion to biogas and high quality biomethane takes place and there are energy recovery installations to generate power and heat. The plant has piping to conduct biomethane towards the pump filling station where it will be used as biofuel for vehicles. - Ljunby Energi AB CHP Plant Ljungby Energi AB is owned by the municipality of Ljungby and has been distributing heat for the district heating system to private and public customers all over Ljungby for over 15 years, through a district heating network. The total power is around 30 MW t for heat and 4 MW e for electricity using a mix approximately in a proportion of 75 % waste and 25 % biomass, usually from forest. - CHP Plant Sandvik II in Växjö CHP plant in Växjö, VEAB, presented by Mr. Lars Ehrlen The central district heating in Växjö is provided via the CHP plant with a power on around 100 MW, 900 GWh/year heat and 40 MW, 200 Gwh/year electricity. VEAB is owned 100 % by the municipality and is covering around 80 % of all heat in Växjö and 25 % of electricity. Fuel is biomass with moisture of around 55% with a mix of wood chips, sawdust, bark and a small part of peat (< 5 %). 3
4. Key aspects from each region. The following section of the report has been developed from information provided by the project partners in individual regional-specific reports. In the following tables urban biomass resources in the different regions participating in the BIO-EN-AREA project are shown. Region Total biomass (GWh/year) Heat production from Urban waste biomass (GWh/year) Electricity production from Urban waste biomass (GWh/year) Urban waste Biofuels for transport (GWh/year) Castilla y León, Spain South-East Ireland Western Macedonia, Greece 290 11,7 68 43 34 0,5 0,43 0 400 0 0 0 Tartu, Estonia 900 170 - - Southeast Sweden 620 400 20 200 Trentino, Italy 103 8,3 7,1 0 Fig. 4.1. Urban biomass current situation in BIO-EN-AREA regions The second table is about the main characteristics and the future developments for each region of the BIO-EN- AREA project in the urban biomass field. REGION Main characteristics Future developments Castilla y León, Spain - Urban biomass includes organic residues generated at industries and those from household, retail businesses or services. Sewage from WWTP, wood from construction and demolition sites, and wood packaging waste is also included. Its energy recovery compiles with the Regional Administration and local public entities regulations and waste policies. - Regional Bioenergy Plan intends to increase the energy recovery capacity of the urban waste more than 145,000 t/year by 2020. - Ongoing improvement of the selective collection systems for urban waste. 4
- In 14 Waste treatment centres the organic fraction is treated by anaerobic digestion and biogas production or composting. 5 include electrical use of biogas with a total 5.4 MW e power installed. - 2 electricity installations in landfills use the gas generated with high methane content. - Urban WWTP, sludge production is estimated at 110,000tons/year. The preferential use as fertilizer is implemented following the regulations; nevertheless there are plants which include biogas production for thermal and/or electricity use. (4.3 MW e and aprox. 3 MW t ). - Used vegetable oil wastes are selectively collected in 90% from services and public and less than 10% from household. A biodiesel plant of 6,900 tons/year recovers part of that total. - To promote biomethanisation of the organic fraction specially that of high quality coming from large producers selective collection. - To apply preventive management models, orientated to prevent waste generation. South-East Ireland - There is no incinerator in the South-East Region only waste biowaste can be considered for the purpose of energy generation. - 14.4% of national brown bin waste is collected in the South- East Region. - Only 5.8% of household waste is collected in brown bins. - Over 2.8m tonnes (t) of municipal waste were generated in Ireland during one year. The municipal waste recovery rate was 42% and the municipal waste recycling rate (excluding energy recovery) was 38%, close to the EU27 norm of 40%. - A 3-bin waste collection service is being introduced across the Region to ensure the segregation of waste at source. - Waterford City Council, are planning to build an anaerobic digestion facility that is capable of processing 22,000 tonnes of organic waste per annum. 5
- For the region the figure is 173,000 t waste produced and from this, 205 GWh/year goes to energy. Western Macedonia, Greece - No real use of waste for energy and there is no waste grading. - The design, development & operation of the regional Integrated Waste Management System of the area is covered by one firm since 1996. - The factors that participate in this initiative are the Municipalities of Kastoria, Grevena, Florina, Ptolemaida and Kozani and the Local Unions of the municipalities of the four prefectures of the region. - Each month, the network receives 2,500 truckloads of more than 10,000 tonnes of urban waste which are transferred to the Regional Landfill. - The unit has biogas monitoring systems. - Decrease of available quantities of urban waste in landfill when a new Mechanical Waste Treatment unit is constructed and put in operation. - To consider other technological options concerning the utilization of the biogenic and biodegradable part of Municipal Solid Waste, that can include electricity production and anaerobic fermentation. - A call for tender for this type of project is launched with an indicative budget of 97 million euros and duration of 27 years. The production is estimated at 1.1 MW e 3.3 MW e. Tartu, Estonia - The potential associated with waste for heat energy is around 650 GWh. - Biogas production potential from sewage wastes and biodegradable garbage is 37 GWh. - Potential energy wastes include wood-based residues as well. Most of the woodbased residues aren t currently re-used for producing heat. Using residues from water processing plants and biodegradable garbage for biogas production. Wood-based residues should all be re-used for heat production in the region. 6
Southeast Sweden - Energy from urban waste is used in district heating in two plants in our region. - Organic urban waste is used for biogas production in two plants. - Waste to energy has strong environmental rules but they are not so difficult to fulfil. - There is a very good tradition in sorting waste. - Biogas from organic urban waste will grow mainly to be used in combination with sewage and manure. - Use of waste for heat and electricity in CHP plants will grow. Trentino, Italy - Separate collection in the Province. Objective of 80% (currently close to 70%). - Historical tendency to move away from the area problematic biomass (odours, poor energy content) rather than exploit them before disposal. - Waste collection centres and purifiers are small, decentralized on the territory (the waste is not collected in a few large sites but in many, located in different valleys). - Hydropower covers almost all provincial requirements and accounts for almost all renewable energy. This condition did not "stimulate", until now, the policies for renewable energy from biomass. - Start another biogas plant fed with urban organic waste. - To install 2 or 3 landfill biogas CHP plants. 7
6. Conclusions. The third Inter-regional Thematic Seminar and Study Visits focused on the use of urban waste to produce energy from biomass. Possibilities of this resource were shown but, nowadays, the lack of utilization for this type of biomass in most of BIO-EN-AREA regions and European Union in general is clear. Added to the key theme of the seminar, given the occasion, the biomass value chain from the forest to its conversion to energy (heat or electricity) in cogeneration plants was also explained because South East Sweden region is an example to disseminate about these applications. As conclusions from the seminar: - There is considerable potential associated with the utilisation of urban waste as a source of energy to produce heat and electricity in cogeneration plants which its development is starting. - There is knowledge about the anaerobic treatments to the urban waste organic fraction to produce biogas and its use is increasing. It could also be added to the cogeneration systems. - There are possibilities to use biogas for transport, applying cleaning and grading techniques to obtain biomethane which is a quality fuel that could be used in vehicles. - High investments and associated maintenance costs, social opposition and lack of knowledge are some of the detected barriers but the examples showed and the technical visits prove that there are demonstrated and environmentally friendly solutions to use urban waste as an energy source. Presentations and information provided by experts during the seminar showed that there is availability of urban biomass in BIO-EN-AREA regions and an increasing interest in its development. The utilization of urban waste to produce energy is possible in these regions. Mainly, it will be based on household and industrial wastes. There are significant differences between the regions regarding selective collection and waste grading. In this way, in Sweden, Italy and Spain there are plants to separate the different fractions of waste. In the other regions, this system is in a development stage at the moment. Strategies such as bioenergy action plans are the starting point. The region of South East Sweden appears as a forerunner in urban waste collecting and management systems as well as most of their applications (heat and electricity generation, biogas conversion, even use of methane as biofuel for vehicles). In general terms, an important development necessity and sector improvement has been detected and BIO-EN- AREA constitutes a good platform to start these works. 8