Degan’s System – Draco I – The primary manure providers at the The site for the installation – just down from the top of the flat hill in the center. Note the cleared land running down, across, and up the other side. Within this is a 24” high-pressure natural gas line transporting gas collected from the many wells in the area. (Ah, the irony)Degen Homestead
Degan’s System – Draco I – The primary suppliers of this digester’s feed.
Degan’s System – Draco I – Completed concrete and block work
Degan’s System – Draco I – The entire digester and retaining walls plastered with b-bond, a fiberglass reinforced plaster said to be used on dry-stacked block in coal mines to keep methane out. I believe this plastering was done with care, but there was even a bit of water leakage – which stopped as sludge filled the small cracks on the inside.
Degan’s System – Draco I -The back and ends of the digester were insulated before backfilling.
Degan’s System – Draco I – The double-glazed greenhouse, attached and ready for installation of insulated door.
Degan’s System – Draco I – The system after backfilling and during an open house. Note thermosiphon for drawing hot air from the top of the greenhouse and through pipes set in the concrete base of the digester.
Degan’s System – Draco I -The greenhouse in the first summer. Note chimney of small wood heater in greenhouse. It did get to 20 degrees below 0 F the first winter – but with no auxiliary heating, the greenhouse dropped to only 27 degrees above.
Degan’s System – Draco I – Spring loading of the digester with year’s collection of manure and urine-soaked bedding.
Degan’s System – Draco I – The open primary loading port. Note the gas line attached to the cover.
Degan’s System – Draco I – The local fire company providing a tanker full of needed water.
Degan’s System – Draco I – Gas line pieces attached to the front of the digester; condensation trap at bottom of orange line; 4” plastic pipe for in-line up-flow and down-flow hydrogen sulfide scrubber.
Degan’s System – Draco I – Commercial iron sponge for scrubbing hydrogen sulfide from the gas. Methane and carbon dioxide are odorless. The trace of H2S provides most of the odor of raw biogas. Removing this trace of highly odorous (rotten eggs) and poisonous gas can leave the biogas odorless, which means leaks are far more difficult to detect. Fortunately, H2S easily oxidizes/burns to odorless sulfur dioxide.
Degan’s System – Draco I -A regulation gas meter – for precise extensive testing – at the house.
Degan’s System – Draco I -A basic biogas burner on the old cookstove.
Degan’s System – Draco I – An efficient biogas flame. Quite similar to the flames from natural gas or propane.
Degan’s System – Draco I -Pond growth – water hyacinth – This gradually died off, but I suspect that a more plentiful starter might well have survived.
Degan’s System – Draco I – Pond growth – duck weed and water lilies – This also gradually died off, but I suspect that a more plentiful starter might well have survived.
Degan’s System – Draco I -Pond growth – algae – This thick layer of algae grew during the heat of summer. Skimmed into digester inlet.
Degan’s System – Draco I – Drawing off digestion liquid for fertilizing greenhouse. This strong nutrient solution never burned any growing plants.
Degan’s System – Draco I -Greenhouse espaliered tomatoes
Degan’s System – Draco I – Greenhouse growth in early fall. Note small wood burner.
Degan’s System – Draco I – Watering the garden with digester liquid. Again, never any burning of plants.
Degan’s System – Draco I – Emptying the digester liquid. Not a perfect fit, but flows easily downhill.
Degan’s System – Draco I – Entry port opened and ready for removal of only partially digested bedding. Removed by pitchfork.
Degan’s System – Draco I – Draco I going into its first winter.
