The main goal of the LIFE-OPTIMAL 2012 Project is the demonstration of an innovative approach for the handling of the manure produced by livestock farming, which aims to:
- The decrease of regional nutrient surplus in the air, caused by intensive rearing of diary cattle and agricultural land shortages
- Production of natural high quality both solid and liquid fertilizers, that can be used in adjacent regions of the same province, especially for the growing of wine and orchard
- Conservation of the life standards of the farmers involved in the project. They do not have to reduce the amount of animals in order to meet the environmental specifications.
The specific objectives of the project, in descending order, are the following:
- Reduction of the nitrogen/nitrates load per hectare of agricultural land ( predominantly grassland) considering half part of manure will be turned into natural fertilizer, which will be used for the fertilization of vineyards and orchards, the amount of nitrogen and nitrates that currently is spread on grassland of the project area, will be halved. This will help farmers in complying with the ceilings of Nitrates Directive 91/676/CEE, without need of reducing the number of animals;
- The reduction of greenhouse gas emissions through replacement of mineral fertilizers by fertilizers of own production;
- Decrease of emissions of ammonia in the atmosphere. The transformation of part of the ammonia contained in manure in high quality liquid fertilizer and the development of a high precision and low emission system for the spreading of the digestate, will allow to comply with the Directive 2001/81/CE on national emissions ceilings for atmospheric pollutants (including ammonia).
Furthermore the projects aims to demonstrate that innovative systems is transferable to other regions of Europe with similar features.
Thanks to the implementation of this project the following concrete results can be achieved:
- Reduction of the nutrient load by 50% in the area in which the system is implemented. With the digestate treatment plant, the amount of digestate used to be spread on grassland and arable land of the farms participating will be halved;
- Increase of the quality and the diversity of ecological fertilizers, which can be used by the southtirolian farmers. Out of estimated 30500t of digestate it will be possible to produce 2500t of solid and 130t liquid fertilizers;
- Conservation of income for the farmers in mountainous regions.
Specific aims of the project:
- Faultless functioning of the plant due to the demonstrative activities of the project.
- Decrease of nitrate load. Due to production of solid fertilizers and their use for fertilization processes of vineyards and orchards in other areas of South Tyrolean Province, a reduction of nitrate load equal to 50 kg per LU per year will be achieved;
- Reduction of the ammonia emissions. Different production modalities, such as covered storage tanks, the spreading system of high precision and low emissions and the innovative treatment of the digestate, will allow to reduce the quantity of NH3 emitted in the atmosphere, which is equivalent to 12 kg of nitrogen per LU;
- Increase of information and knowledge exchange between the general popoulation, the farmers, the local authorities and other stakeholders involved directly or indirectly in the project,about environmental issues, reduction of pollutant emission and environmentally sound systems for manure management. This result will be achieved through the communication and dissemination actions.
To achieve the objectives reported above, a ecological friendly systems in order to manage the digest (coming from traditional biogas plants) will be implemented. The powerplant feeded by manure of the dairy cattle farmers of the Wipptal will be put in operation on end of the year. The digestate, produced by the system will in part be used for the fertilization of the fields (especially grassland) of the farmers taking part of the project. The existing biogas plant permits to solve the problem of the odour (spreading digestate instead of slurry or manure) and also to produce electricity and heat, which are sold, but does not solve the environmental problem of the excessive load of nutrients and ammoniac produced in the area.
The solution proposed is to annex to the biogas plant a digestate treatment plant, formed by the following sections: screw press separator, centrifuge separator (decanter), ultrafiltration unit, reserve osmosis, zeolite filter unit, ammonia stripping unit and drying and pelletting unit.
Trough this system, two types of high quality fertilizer will be produced:
- A solid one, obtained by separating the solid fraction of the digestate, that can be enriched with the concentrates from the ultrafiltration and reverse osmosis process in order to produce a “new fertilizer” with nutrient concentrations and proportions according to the requirements of the fertilized crops;
- A liquid one, consisting in an ammonium sulphate solution, obtained from the ammonia coming from the ammonia stripping unit.
The fertilizers will be used in other areas of the region, for vineyards and orchards.
General framework of the project
At the partners’ farmsteads, some 25,000 tons of manure and 45,000 tons of slurry are collected with specific machinery for their transportation. This manure is then treated using anaerobic digestion in the Wipptal biogas system, and the biogas produced there is transformed into electrical energy and heat.
Around half of the digestate produced is returned to the farmers and distributed over the land using a specifically made high-precision, low-emission prototype. The other half of the digestate undergoes mechanical separation using a spiral compression separator and a vibrating screen to separate the solid and liquid components of the digestate. The liquid part undergoes a three-stage reverse osmosis process that makes it possible to obtain purified water that can be discharged into a surface water body, together with a concentrate that is rich in nutrients for crops.
The solid part of the digestate is dehydrated using waste heat produced by the cogeneration group and subsequently turned into pellets to become fertiliser. The concentrates obtained from reverse osmosis can be used as such for fertilising crops or they can be added to pellets.
The resulting pellet is a fertiliser containing a high concentration of organic substance and nutrients that can be used in areas dedicated to fruit and wine growing in South Tyrol.
Click here for the diagram.
The project aims to reduce the impact of slurry and manure from cows, using the following actions:
- full-scale construction using innovative technology, of the treatment plant for the digestate leaving the biogas plant, including the sections for drying, making pellets and air treatment;
- production and sale of solid and liquid fertilisers (including packaging with suitable packaging machinery), both for direct sale and as agricultural exchange with other farms and registration of same on the “National Register of Fertilisers” of the Ministry of Agricultural, Food and Forestry Policies and Tourism;
- construction and testing of a prototype to spread digestate, a high-precision and low-emission system to be used to distribute digestate on meadows and fields belonging to farmers participating in the project;
- creation of a system to monitor, check and control the whole system managing the effluent from a technical, economic, financial and environmental viewpoint, through the complete automation of the whole production process, the recording of production quality and quantity, and control of ammonia emissions in the air, both when taking the effluent to the plant and then while spreading with the prototype;
- fine-tuning and operational management of the system both during and after the time frame allocated to the LIFE-OPTIMAL2012 project;
- creation of a “Global assessment plant for the system” both in terms of the environmental aspects and the social and economic ones, with the contribution of research from the two universities associated with the project (Turin and Bolzano-Bozen), and studies of the effects of using the prototype spreader and the use of fertilisers, made using specific balances for mass (especially for the nitrogen parameter), gas and energy; the evaluation of fertilisers is audited via study campaigns with growth tests in pots and in the field during significant periods of the agricultural season;
- presentation of the system made, training of farming partners in the use of the fertilisers produced, and circulation of the results via guided visits, publication of articles and brochures, participation at trade fairs and conferences, creation of a website dedicated to the completed system, as well as collaboration and networking activities with other LIFE projects.
The main results achieved by the LIFE-OPTIMAL2012 project are summarised in the following points:
1) construction, start-up and running of the digestate treatment plant. This plant has been created in three main sections:
- section one: digestate separation and concentration. Innovative section – able to treat slurry or the derivatives of same from both cattle and pigs, as well as digestate from various anaerobic digesters – the process of which is based on a series of mechanical separation and concentration treatments via reverse osmosis membrane, using a combination of the innovative, patented anti-soiling, vibrating membrane with spiral-wound membranes. Within this section, there is an initial process to separate the solids and liquids of the digestate: the solid fraction is the raw material that, once dried and transformed to pellets, becomes the base for the production of BIWI, the solid fertiliser that is sold to reduce the nitrogen load from the agricultural area covered by the project. The remaining liquid fraction is further treated, allowing Biogas Wipptal to obtain purified water (permeate) that is suitable for discharging into surface water bodies, and also, a concentrate of nitrogen and phosphorus at a reduced volume of 40-45% compared to the initial liquid, which is then easy to transport, store or convert to fertiliser with a higher ammoniacal nitrogen and phosphorus content. This concentrate, which is also valid in the biological field, is used as liquid fertiliser. This section can treat up to a maximum of 160 tons of digestate per day, producing around 30 tons of purified water that can be discharged into the Eisack River, plus about some 55 tons of concentrate;
- second section: drying of the solid fraction by means of an 8-level belt system which makes use of the excess heat (via hot air heat exchangers) from biogas cogeneration to dry up to a maximum of around 15 tons of incoming solids per day;
- third section: formation of the dried material into pellets. The solids are dried in the form of pellets using a mill and pellet mill, on a line that is capable of processing up to six tons of incoming dried material per day.
2) Construction, testing and use of the prototype liquid manure spreader.
The prototype made by the associate beneficiary, Zunhammer, is equipped with a device to measure the nutritional elements of the digestate in real-time, a GPS position sensor, and an electronic system to control and regulate the dosage.
3) Gas, mass, and energy balances for the digestate treatment system. This activity, completed by the University of Turin, demonstrated the effectiveness of the digestate treatment system in terms of the efficiency of mass separation and the physical and chemical parameters. Overall consumption of thermal and electric energy (direct and indirect) identified and expressed as primary energy, are equivalent to 28.6*10-3 Tep/t of treated digestate and 55.7*10-4 Tep/kg of N contained in the pellet.
4) Production of solid pellet fertiliser called BIWI PLUS, registration of same under no. 0021548/18 of the “National Fertilisers Register” and development of marketing products for retail to private customers, farming consortia, and various distribution chains. Based on types of national fertiliser as per Lgs. Decree no.75/2010, BIWI is classified as an NP organic fertiliser (Annex 22.214.171.124) and is recommended for growing fruit, vegetables, and flowers;
5) Growing tests in pots (corn, cucumber, permanent pasture, strawberries) and in the field (vines) by the University of Bolzano-Bozen, show a positive effect (increase in surface biomass) above all for corn and cucumber;
6) printing and circulation of the “BIWI user’s manual”, containing instructions for dosage based on the type of crop, degree of organic substance in the soil, and the period of application;
7) control sampling for the quality of the purified water discharged into the surface water flowing near to the Biogas Wipptal plant, i.e., into the Eisack River, with continued monitoring of the unloaded capacity, the pH, conductivity, and ammoniacal nitrogen, as well as the implementation of the whole automatic system for management of livestock waste, from when it enters the plant by electronic weighing, to its return to the field with new weighing and control of spreading.
8) Overall assessment of the digestate treatment system
From examinations made by the School of Agricultural, Forest and Food Sciences (DISAFA) of the University of Turin, it has been found that implementation of the technological solutions proposed has made it possible to:
- make an annual saving of more than 2,300 TEP (ton equivalent petrol) as well as on the emission of approximately 7,000 tons of CO2eq thanks to the use of energy (electricity and heat) made available by the DA plant;
- reduce greenhouse gas emissions by about 95% and 70% emissions of odours and NH3, thanks to optimised management of livestock effluent;
reduce, emissions of PM10-equivalent from NH3 by about 11 tons per year.
After LIFE plan
The project partners continue to provide support to the company Biogas Wipptal, above all in terms of technical monitoring, as well as economic, environmental, and socio-economic support for the technical solutions completed.
Therefore, there will be data collection and processing operations, using the same data collection methods and assessment used during the project and with reference to all actions and expected results. The resulting reports will allow the consolidation of results obtained during the project and at the same time, implementation of the solutions proposed to achieve sustainability.
The project partners will also continue to provide support to the public authorities (European, national, and regional) for the transfer of the know-how acquired during monitoring and implementation.
The information and circulation activities will continue through the promotion of training courses and workshops, participation at national and international conferences, as well as participation at public events. The project website will remain active and constantly updated with information on subjects of interest and events. With the involvement of all partners, guided visits will be organised to promote increased knowledge of the management system proposed and the transferable nature of the technologies made as part of the LIFE-OPTIMAL2012 project.
Activities prior to the period of implementing the project will remain under the responsibility of Biogas Wipptal.
Currently, the BIOGAS Wipptal plant is undergoing extension and reconversion to upgrade the biogas and biomethane liquefaction for transport. The start of production for BioGNL for transport is envisaged for April 2021.
Click here for the diagram.
Cantina Tramin (Associated Beneficiary – AB): South Tyrolean winery.
Within the project LIFE12-ENV/IT/000671 – LIFE OPTIMAL2012 this AE is responsible for the second part of the evaluation plan of the solid fraction of the digestate, in collaboration with the Free University of Bolzano. Cooperates with the BC for the implementation of the global evaluation plan and in the implementation of measures of communication and dissemination of results.
University of Torino
University of Turin (Associated Beneficiary – AB): Department of Agriculture, Forest and Food Sciences –(DiSAFA).
Within the project LIFE12-ENV/IT/000671 – LIFE OPTIMAL2012 this AE is responsible for the system evaluation plan – technological aspects. Cooperates with the BC for the implementation of the global evaluation plan and in the implementation of measures of communication and dissemination of results.
Zunhammer Srl (Associated Beneficiary – AB): the company develops means and technologies for agriculture, and specifically, technologies to manage animal slurry.
Within the project LIFE12-ENV/IT/000671 – LIFE OPTIMAL2012 this AE is responsible for the development and the production of prototypes with high efficiency and low emissions for digestate spreading. Cooperates with the BC for the implementation of the global evaluation plan and in the implementation of measures of communication and dissemination of results.
University of Bolzano
Free University of Bozen – Bolzano (Associated Beneficiary – AB): Faculty of Science and Technology.
Within the project LIFE12-ENV/IT/000671 – LIFE OPTIMAL2012 this AE is responsible for the first part of the evaluation plan of the solid fraction of the digestate and supervises the execution of the second part of the evaluation plan by the Cantina Tramin. Cooperates with the BC for the implementation of the global evaluation plan and in the implementation of measures of communication and dissemination of results.