A representation of French companies visited the pilot plant of PercoMeta Project in the province of Valladolid during the month of June. This project led by Toro Equipment in collaboration with Cartif Technology Center and other enterprises from France tries to optimize the anaerobic digestion of cereal straw, reducing costs and increasing the quality of generated biogas. PercoMeta Project has developed a new simple, robust and trustworthy technical process of anaerobic digestion, in which the costs of functioning, energetic consumption, maintenance and personnel are reduced significantly with regard to other similar technologies.
PercoMeta Project is being carried out in W-Tank®, a bolted storage tank made of glassfiber modular plates that allows fast and economic installation and transport. Three W-Tank® that are installed in the pilot plant are focused on obtaining representative results to be reproduced on an industrial scale. Currently, the pilot plant has a W-Tank® of 251 m3 capacity to fermentation of straw and two more of 137 m3 and 152 m3 capacity to storage the produced biogas and the liquid digestate
This project led by Toro Equipment aims to solve problems produced by straw and other biomass treatment in methanisation sector. PercoMeta establishes a novel design at global level, reliable, low-risk and low-cost. With this new technology, cereal straw and other residues and biomass that are difficult to treat will be treated in an efficient way. These are some of the different waste to treat:
- Cereal straw, which is abundant in the surroundings of the Toro Equipment factory, located in Ribera del Duero. It is necessary to note the possibility that the straw contains other unwanted materials as stones, pieces of plastic or wood.
- Manure and livestock bedding, which also can contain these unwanted materials.
- Organic waste of the foodstuff industry, with carton, plastic, bones and other specific materials from this sector.
- Organic residues proceeding from large-scale distribution, they can include plastic, brass of canned food, glass from bottles.
- Municipal organic waste which can contain all kinds of unwanted materials.
PercoMeta supposes a technological improvement in anaerobic digestion process and tries to generate gas with large levels of methane to satisfy the needs of the agricultural world from a technical and financial point of view. Generated biogas, due to its high quality, also could be used in applications that require higher quality standards like the injection to natural gas network or the use in vehicles.
One of the keys of the financial saving lies in the pretreatment needed to apply to the straw to prepare it to digestion. The woody composition and the heterogeneous nature of the material increase the cost to carry out the separation of non desirable materials. With this new technology, the separation of straw and unwanted materials is no necessary. The system holds the residual solid matter and unwanted materials at the bottom of the reactor and it allows to extract them after completing the process. In this way it reduce considerably the investment cost, operatives costs, electrical consumption, personnel, exploitation costs…
Energy recovery from straw in Spain
In Spain, there is no tradition to digest the straw in terms of energy recovery. At regional level, this kind of waste, so abundant in the region, only is recovered in the province of Burgos at pilot level. The straw is a residue difficult to digest and it competes with very abundant others residues in our country as the food residues and livestock waste (purine pig) that are less problematic. However, in Spain it is common the energy recovery by anaerobic digestion from manure (cattle, pigs and poultry droppings) whose problems are very similar to cereal straw.