B1 Establishment of biomass plantations for CE demonstration model
The objective of this action is to establish 900 ha of biomass plantations within the 60 km radius around Vilnius city, which will contribute to the core of circular economy demonstration model to serve as natural phytoremediation and nutrient recycling filter.
Biomass plantation establishment in three years will allow to secure long term sustainability of Circular economy demonstration model operations, allowing continuous recycling of nutrients from dried municipal water treatment sludge digestate and biomass ashes.
In Lithuania and surrounding Baltic Sea countries three major woody biomass species are being planted to establish biomass plantations: hybrid aspen, poplars and willows. The major biomass crop selected for Circular economy demonstration model will be poplars due to the following reasons:
- poplar and hybrid aspen plantations, planted at lower density (3 or 4 m between the rows), are fully technically suitable for Circular economy demonstration model, because municipal water treatment sludge and biomass ashes can be recycled in poplar and hybrid aspen plantations during the most intensive growth periods, when they can utilize nutrients in the most efficient way;
- selecting suitable poplar breeds and fertilizing with municipal water treatment sludge high biomass yields can be achieved; within EUROSTARS project SNOWTIGER, we tested dried municipal water treatment sludge digestate application in 2016 and that showed significant increase in biomass yields (appr. 30% on the first year application basis);
- poplars and hybrid aspen are being grown for stem-wood (whole trees), rather than shrubs and that provide higher diversity in sales markets - poplar and hybrid aspen biomass may be used wider than willows (only bioenergy) but also by wood processing industry and by emerging bio-based industries.
Most of the biomass plantations in the will be established on land that is less suitable to agriculture or marginal, i.e. previously inactively used or even abandoned, thus land preparation for the establishment will be very important to ensure successful biomass plantation establishment (high survival rate) and achievement of targeted biomass yields. One of the objectives of CE demonstration model – to manage biomass plantations in a sustainable way, thus all biomass plantations will be established and further managed without using of any herbicides and chemical fertilizers.
B2 Recycling of nutrients from municipal water treatment sludge
In 2008 - 2013 “Vilniaus vandenys” implemented 50 million EUR investment project, partially co-funded by EU Cohesion fund, during which one of the most advanced in the EU municipal sewage treatment plants was installed. The scope of the project included sludge thickening, digestion, sludge dewatering and low-temperature drying as well as the utilization of the produced biogas in a combined heat and power plants. By the introduction of a thermal hydrolysis plant, the highly efficient sludge treatment facility ensures a pasteurized and stench free final bio- solids product, perfectly suitable for fertilization. Since installation of this modern facility, municipal water treatment sludge digestate drying and pallet production was operating at very low capacity, because there was no practical solution how to utilize 9000 dmt / year of municipal water treatment sludge pallets as bio-solid fertilizer.
“Vilniaus vandenys” operates the largest municipal water sludge treatment facility in Lithuania, which processes appr. 25% of country’s municipal water treatment sludge. “Vilniaus vandenys” produces 30000 t/year of municipal water treatment sludge digestate (30% dry matter content), which can be further processed into 9000 t/year dried municipal water treatment sludge digestate pellets (92% dmc). Municipal water treatment sludge digestate pellets are perfectly suited product for fertilization, because it has no stenches, which is the most important aspects, while dealing with local communities, it is easy to store during off-fertilization season (in big-bags), it is easy to transport (needs 3 times less transport comparing to municipal water treatment sludge digestate of 30% dmc), and it is easy to spread and insert into soil using conventional agricultural equipment. Dried municipal water treatment sludge digestate pellets are also the environmentally safest form of municipal water treatment sludge for fertilization, because it is pathogen free (passed sterilization treatment of Animal Bi Products category 2 (minimum 133 C, 3 bar pressure, 20 minutes, and treatment 165 C, 6 bar pressure, 30 minutes)) and has limited values of water soluble biogenic materials N and P, which substantially reduces risk of eutrophication, as leakage of N and P is limited.
Laboratory analysis of dried municipal water treatment sludge digestate of “Vilniaus vandenys” confirms that it meets II category according heavy metal content and the highest A microbiological safety category and according LAND 20-2005 can be used for recycling in biomass plantations. For many year municipal water treatment sludge of “Vilniaus vandenys” was used for food crop growing in Vilnius region, thus we will offer removal of municipal water treatment sludge from food crop growing activities thus reducing risk of contamination of food chain.
B3 Recycling of nutrients from biomass ashes
The objective of this action is to demonstrate closed loop of recycling of biomass ashes within Circular economy model – recycling of nutrients in biomass plantations from biomass ashes, amount of which correspond to the amount of biomass ashes received from biomass combustion supplied from the same biomass plantations. We will promote and contribute to legal usage of biomass ashes recycling in agriculture and forestry.
Over the last five years Lithuania strongly mowed towards renewable energy production in district heating sector – from 22% to 64% in total district heating production. Vilnius as the major city, still has big potential for biomass energy production expansion, which is being realized by new CHP project, which is being implemented by state controlled energy company "Lietuvos energija". Currently in Vilnius there are two private biomass based heat producers, which supply heat to district heating sector and operate total four biomass boilers with total installed capacity of 120 MW. Additionally, municipal district heating company operates two biomass boilers with installed capacity of 80 MW. The new biomass based CHP plant, which is expected to be commissioned in December 2020, will have biomass based 169 MW of heat and 73 MW of power production capacities.
In Vilnius – about 10 thousand t of biomass ashes are being produced annually and that may increase by additional 6 thousand t since 2021 when new CHP of "Lietuvos energija" will start operations.
By implementing the project we will recycle in biomass plantations 500 tons of biomass ashes annually, which corresponds to annual biomass ashes volume received calculated on targeted average annual biomass plantation increment in biomass plantations operated within Circular economy demonstration model (1800 ha).
Biomass ashes will be used to supplement soils with higher organic content and sandy structures mainly.
B4 Biomass to renewable energy
The goals of this action:
- To demonstrate close loop of Circular economy demonstration model – to produce renewable energy from biomass, which yielded from nutrient rich waste recycling;
- To develop business processes needed to harvest, transport and sell biomass from Circular economy demonstration model to renewable energy production of Vilnius city needs;
- To evaluate all costs related to biomass harvesting and transportation and revenues from biomass sales.
As biomass crop rotation in CE demonstration model will be 6 to 8 years, it is expected, that in the last year of the project implementation biomass could be harvested from biomass plantations, which will be mobilized from already established (prior the project implementation) plantations and included in the Circular economy model.
It is assumed that at the end of the project 300 ha of biomass plantations, already established before implementation of the project but benefiting from nutrient rich waste recycling within the scope of the project, will be harvested.
If 10 dmt/ha/a biomass targeted yield will be reached – 39,4 GWh of biomass will be supplied and processed into renewable energy for Vilnius city.
While fully operational, Circular economy demonstration model can meet of 5% total biomass demand from Vilnius city renewable energy market.
B5 Business plan development
The main objectives of this action is to prepare for transfer of circular economy demonstration model in other parts of Lithuania and other countries.
The business plan for Circular economy model for nutrient from municipal water treatment sludge and biomass ashes recycling in biomass plantations will be developed and will analyse two major activities: biomass plantation establishment and management business model and nutrient rich waste recycling activities business model.
Recently, biomass plantation establishment stopped in Lithuania due to lack of economic rationale. The possibility to increase biomass yields while joining circular economy model for nutrient rich waste streams recycling, will improve situation. Business plan will review biomass plantation development business in other target EU countries as well: Latvia, Poland, Sweden, Finland, Slovakia.
The business plan will provide estimations for business expansion while providing nutrient rich waste recycling services in other regions of Lithuania (Kaunas, Klaipėda and Panevėžys) and other countries (Poland, Latvia, Sweden and/or Finland).