The German plant manufacturer Weltec Biopower recently signed the contract for a biogas plant extension of the milk powder producer Estancias del Lago (EDL) in Uruguay. From late 2018, the plant with its eight digesters will generate a rated thermal input of more than six megawatt from cattle manure and fodder leftovers. The company will use the biogas for drying and steam generation purposes in the production process.
Founded in 2007, the agricultural company EDL now farms an area of about 37,000 hectare. On this area, the South Americans grow maize, sorghum and soya as feed for their approximately 14,000 dairy cows. The company foundation was accompanied by the establishment of a huge site in Durazno, north of the capital Montevideo. Apart from the cowsheds with milking centers and feed silos as well as the biogas plant, the premises now host a dairy and a grain mill. In Durazno, Estancias del Lago produces about 20,000 tons of milk powder per year for export. Most of the milk solids are sold to China, Brazil and the Middle East.
In 2013, Weltec had set up the first 800 kW biogas plant for EDL. Back then, expansion plans were already being considered. First, however, more cattle were needed. In the meantime, the number has therefore been stocked up from 8,000 to 14,000 cows. Now, 1,365 tons of cattle manure plus 8.4 tons of feed leftovers are available for the energy generation.
The AD plant structural preparations started in September 2017. In early 2018, Weltec Biopower will begin installing the 6 new 5,000-m³ stainless-steel digesters and the two 1,050-m³ pre-storage tanks for the slurry. With Weltec’s custom-developed process control system CeMOS, the entire biogas plant will be fully automated from the end of 2018.
Two gas boilers use part of the 30,000 standard m³ of biogas that is produced every day to generate heat for the biogas process. Most of the biogas is transferred to the close-by milk powder production facility via a pipeline. The biogas covers up to 35 percent of the heat required for the drying process. 100 percent of the steam needed is generated with biogas.
All operational units of the entire site are run in a very sustainable way. EDL contributes to this by growing its own fodder. The digestate from the biogas plant is used as fertilizer. Moreover, the cycle is closed by raising its own dairy cows and processing the milk on-site.
At the facilities located just 150 m from the cowsheds, the milk is processed to powder within four to eight hours. Another synergy has been established between EDL’s fuel production and other parts of the business: Apart from soya oil for the biodiesel plant, the oil mill yields press cake that is fed to the animals.
Published in the January 2018 Edition