Case of composting with dairy cow manure (Introduced to: S Ranch) - Deodorization and Composting equipment - Miraie

CASE STUDY

Construction example

2021.10.19 EASYJET

Case of composting with dairy cow manure (Introduced to: S Ranch)

PlaceShimane Prefecture
Processed Material and AmountCow manure, moisture content 85%
OverviewIn this case, dairy cow manure composting suffered from incomplete fermentation and a long period until fermentation is complete, but they succeeded in shortening the fermentation period and saving labor with high pressure aeration.

Measures and Effects

Increase processing amountBy sustaining aerobic fermentation with high pressure aeration and shortening the formation period, they increased the amount of material processed in each compost building.
Raise fermentation temperatureBy introducing high pressure aeration, the fermentation temperature was raised by 10 to 20˚ C.
Reduce costBy eliminating the need for turn over, they reduced operation costs (labor costs + fuel costs).
Improve compost qualityBy improving aeration, they eliminated foul odors, and enabled high quality compost production.

Recently, we have received more inquiries from livestock farmers, so we have uploaded a past case for reference.

This dairy farmer has 50 dairy cows, and they mix cow manure with rice husks to compost it.

However, due to the rapidly rising cost of auxiliary materials, they were not able to secure an adequate amount. This posed a challenge, as the temperature would not rise very much even during composting.

Preliminary measurements showed that the cow manure piled up in the compost building has a moisture content of 77% (after mixing in rice husks), and a large amount of wastewater was flowing onto the floor. (Photos 1, 2)

We installed EasyJet for the purpose of improving fermentation reducing turn over work, and verified the effects.

This photo shows the facility during installation. EasyJet pipes are installed on the floor, and the material cow manure is deposited on top. The compost is not turned over after it is deposited.

This graph shows temperature data after the start of fermentation. The compost ingredients did not heat up easily before, but as shown in the data, fermentation temperature rose and was kept high for a long time. 

These photos show the compost immediately after it was deposited and eight weeks after it was deposited. As fermentation progresses, organic matter decomposes and the volume is reduced, so the height of deposited compost gets lower. Photo 6 shows compost at the time of removal (shipment).

At time of removal

As shown above, we confirmed that fermentation started and the temperature rose even under somewhat poor conditions. This reconfirmed that the foundation of composting is carefully adjusting moisture content.

In that case, we recommend that instead of using fine-grained (highly moisture-absorbent) materials as was done in the past, but rather use coarse materials (primary shredded materials, etc.) in order to create gaps and promote aerobic fermentation.

Coarse materials can be procured in abundance, making costs much lower. (Sometimes the unit price of secondary shredded materials can be nearly twice as much as primary shredded materials.)

If it is too difficult to raise the temperature in initial fermentation using coarse materials, then EasyJet can be used only in the yard initially in order to reduce initial costs.