A garbage composting and recycling facility with low cost and no odor - Deodorization and Composting equipment - Miraie

CASE STUDY

Construction example

2021.11.05 PLANT GARBAGE

A garbage composting and recycling facility with low cost and no odor

Place:Nagano Prefecture
Processed Material and Amount:Garbage 1 ton/day
Overview:Garbage generated in the town is composted at recycling plants. Reducing garbage incineration costs.

Measures and Effects

Increased processing volume by shortening processing time:Processing time is shortened by selecting models with appropriate capacity in the facility where compost goes from pre-processing to fermentation processing.
Reduced foul odors by eliminating incomplete fermentation:By keeping aerobic fermentation going throughout the year, this facility produces almost no foul odor.
Raising fermentation temperature with improved aeration:Even when the outside temperature is -20˚ C, inside the facility it maintained high fermentation temperature of 70˚ C to 80˚ C.
Reduced costs by revising auxiliary materialsUsing cow manure as an auxiliary material, it realized zero auxiliary material costs. Reduces sawdust purchasing costs (¥3,000,000/year).
Improving compost quality by crushing materials and introducing equipment to remove contaminants:By crushing materials with a pre-processing device, it shortened the fermentation period and improved the compost quality.

This example is for a garbage recycling facility delivered to Nagano Prefecture. This facility is located in a cold region, but it operates reliably even in winter.

This facility was delivered to Nagawa Town, Nagano Prefecture, and was built on the grounds of a tourism ranch inside the town limits. It has a processing capacity of 250 tons/year and operates twice per week. It collects and recycles garbage produced by residents of the town, in order to produce high quality compost.

This facility has two important features, one of which is that it produces almost no odor. (Everyone who has toured this facility has been surprised by this fact) The other feature is that this facility uses cow manure as an auxiliary material.

By immediately mixing the garbage carried in with cow manure and depositing it to EasyJet, aerobic fermentation started in a short period, reducing foul odors from garbage. This facility does not need a deodorization device, so costs can be kept low.

Ordinary composting facilities use auxiliary materials including sawdust and rice husks. However, this facility uses cow manure, so there is no cost for purchasing auxiliary materials.

Cow manure has a moisture content higher than rice husks, so it is not normally used as an auxiliary material. By forcibly sending oxygen in during the fermentation process with EasyJet, fermentation starts at high temperature.

Finished compost has a somewhat high moisture content, so it is possible to make high quality compost with no odor. Compost is distributed to residents of the region so they can use it.

Processing is done twice a week, with garbage (household garbage and industrial garbage) generated in the town collected and carried to this facility.

The rules require residents to use biodegradable bags prepared for this facility. Bags and garbage are crushed together in a crusher and mixed with cow manure.

Next, the materials are put in the EasyJet tank and fermentation is completed in 45 days. In this season, the outside temperature on site is already -5˚ C, but the fermentation temperature is higher than 80˚ C, so the facility operates smoothly.

A senior citizen from the area is in charge of work, but even after doing garbage measurement, crushing, mixing, and cleaning, their work is done by the afternoon.

Many municipalities are worried about the cost burden of garbage disposal.

Disposing of garbage with incinerators is expensive, costing about ¥150,000,000 per year per 10,000 residents.  Recycling garbage by composting it can reduce the cost to 1/2 to 1/3 that of incineration disposal.

By installing this facility on a ranch, it was easier to get consent from local residents, and reduce the high costs of garbage disposal. We expect that this will contribute to promoting garbage recycling by local governments in the future.

The ranch benefits as well, because its cow manure can be used as an auxiliary material, creating a new source of income. In addition, residents can expect improved public services by reducing the financial burden of garbage disposal, and obtain high quality compost free of charge. We believe this arrangement is highly beneficial to all three parties.

In the case of this facility, the amount of burnable waste brought to garbage incinerators was reduced by 200 tons per year.

We have successfully designed many such plant-type composting facilities. We can select the optimal model from our wealth of back data, and conduct precise simulations of management costs after operation.

Odor Measurement Report

This odor data was measured at the entrance (downwind side) of the facility.