Weltec Biopower builds biomethane plant for Spanish dairy farm
Since the first 250 kW biogas plant went live in 2011, the Catalan family business has covered its entire energy demand from its residues. The farm was the first milk producer in Spain to use any residual materials to produce energy.
The investment in the new renewable natural gas/biomethane plants amounts to more than €4 million; a quarter of this sum will be spent on modernising the existing infrastructure and biogas plant. According to Weltec, one of the reasons why the dairy producer can allocate such a large budget is because biomethane sales had already been contractually secured at an early stage.
“We view this anaerobic digestion (AD) plant as an environmental investment, as it allows us to cut our greenhouse gas emissions to almost zero and generate additional income from biomethane,” said Juan Bautista Pons Torrades, managing director and owner of Torre Santamaria.
Every year, some 60,000 tonnes of input substrates accumulate for use in biogas production. Cow manure accounts for approximately 90% of the substrates. Bedding consisting of ground straw, as well as silage leftovers, are also fed into the digesters.
Currently, Weltec is setting up two additional stainless-steel digesters for the digestion of all farm residues. Each of the digesters has a height of 6.30 m, a diameter of 26.87 m and a capacity of 3,573 m3. After processing the biogas generated in the digesters, Torre Santamaria feeds 300 standard m3/h of biomethane into the natural gas grid.
The existing 250 kW cogeneration power plant will continue to operate despite the transition to RNG production. The farm is, therefore, able to cover its own demand for power, heat, and hot water. Once the new plant is completed in the summer, Torre Santamaria will continue to meet its energy demand from its raw material.