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[My name is Dan Nemke, and I'm with Clear Horizons.]
[Clear Horizons owns and operates the facility out here at the Crave Brothers Farm.]
[The farm currently has about a thousand milking cows and about a thousand heifers.]
[From each one of the facilities we have a 30 thousand-gallon manure collection tank.]
[These tanks are pumped out into the digester facility on a daily basis, ]
[or on a regular, continuous basis.]
[They get pumped into each one these two 750 thousand-gallon]
[stainless steel digester tanks.]
[They're both in steel construction with about four inches of insulation on the outside]
[and then clad with aluminum siding.]
[The roof is a dual membrane construction, ]
[so the outer membrane is always supported with an air blower, ]
[and then the lower membrane is able to rise and fall with biogas production.]
[It gives us about 25 thousand good feet of biogas storage per digester.]
[The digesters are heated to about 100 degrees fahrenheit, ]
[utilizing the waste heat off our GE Jenbacher engine.]
[The tanks each have four mixers, ]
[so by heating them in order and mixing them in order we're able to generate the biogas.]
[Biogas is about 60% methane and about 35% carbon dioxide.]
[We remove the hydrogen sulfide, we just want to heat the cabinets in the biogas]
[in the head space above the digester.]
[It might introduce a little bit of outside air, we're able to precipitate out most of the sulfur]
[and get our hydrogen sulfide counts down to about 200 parts per million.]
[Coming out of the digester, the biogas goes to a chilling unit ]
[which cools the biogas from about 100 degrees fahrenheit down to about 30, 35 degrees.]
[When it cools it down to that temperature, most of the water vapor ]
[that's present in the gas will precipitate out, ]
[or will condensate, and then come out of the system.]
[From that point, the gas is depressed up to about 2½ feet a side ]
[and fed into our GE Jenbacher engine.]
[The engine we have out here is a GMC312, it's a V12 engine, ]
[spark-ignited engine, it's coupled to a 633 kilowatt generator.]
[This engine operates continuously as long as we have biogas.]
[For example, right now, with the biogas production that we've done ]
[since we started this unit, we're running at about 97.5% capacity factor on our production.]
[Those units basically run at 100% all the time other than the couple of times]
[we go down for repeat maintenance and the couple of times we go down ]
[due to utility trips from thunder storms in the area.]
[Following the digestive process of the tank, which takes about 25 days, ]
[the effluent flows up into a separation process ]
[where we separate out the fibers from the liquids.]
[The liquids from that process gravity flow off to the 10.8-million gallon lagoon]
[where they're stored until they're ready for land application.]
[The fiber is conveyed across to a composting facility where we'll compost ]
[the fiber down for another 20, 25 days, at which time about half of it gets used ]
[at the farm for bedding, and the other half gets sold ]
[as a peat moss replacement to horticultural industry.]
[Currently we sell probably about one semi-load a week--or a day ]
[is leaving this facility of the finished compost bottom.]
[With the fiber product we're also able to capture about 30% ]
[of the overall phosphorus of this farm.]
[From a nutrient management standpoint, ]
[we're able to reduce their land application requirements]
[because most of the time they're limited on their phosphorous spreading breaker.]
[The other part that's happening in the system is the nitrogen ]
[that's present in raw manure, the ammonia, and urea gets converted into nitrate.]
[So when the ammonia passes through and goes out to the lagoon, ]
[it's in a readily available state from the crop's perspective.]
[Typically, if you spread raw manure on growing crops]
[you either burn them or eventually you can kill them.]
[With this product, they're able to spread it on their growing crops,]
[so that the crops get the nutrients they require when they require them, ]
