Company ProfileCase Study: Dairy Cattle Farm—Chamusca, Portugal
The Problem
The waste from this 3000-head dairy farm, in the form of manure slurry, is collected in a sump and then transferred by pump through two brush screens to remove the fiber. The fiber is then stored adjacent to the screens for spreading after partial composting. The liquor, after screening, flows by gravity to the first of a series of three lagoons, where the solids in suspension are settled out to digest slowly over several months.
The owners of the farm hoped to find a way to maximize the recovery of valuable resources from the waste—such as energy, biomass products and water—which could be utilized directly or further processed for secondary farming. Such products, with blending and packaging, could also be marketed to other commercial areas of even higher value.The EversTech Solution
The EversTech team put together a technical and economic study and process design as the initial steps in developing a Total Waste Management strategy for this farm.
The three major aspects of resource recovery, Energy, Biomass and Water, are all included in this process. EverTech found the following benefits would result:
1. The energy generation potential is a minimum of 36 Megawatts per day.
2. The annual net benefit from all resources recovered would be 1,455,000 Euros (approx.). This is based on capital costs for the first phase of 3.8 million Euros (approx.).
3. The biomass production would be about 6,500 kgs/day of 30–35% moisture, 6–8% Total Nitrogen, organic, odor-free fertilizer. This product could be utilized directly on arable land and would add physical stability as well as humus and long term nutrient release. It could also b e bagged as it is, after shredding. There is approximately a further 3,400 kgs/day of feed grade biomass <70% protein, which could be palletized and bagged for a high value market.
4. There is the potential for taking advantage of solar energy, with a very economical system, which would utilize the roof area, producing over 72 Megawatts per day of hot water during sunshine hours.
5. The treated effluent after the aerobic phase would be of sufficient quality to recycle as wash water in the flushing systems, and could save over 80% of current water usage.
The farm has now come under new ownership and they are reviewing the proposals.