Low-Cost, Minimal Staffing, Odor-Free Food Waste Composting Recycling Facility (Client: Nagawa Town, Nagano Prefecture)

Overview of Composting in Nagawa Town, Nagano Prefecture

This is a case study of a food waste recycling facility delivered to Nagawa Town, Nagano Prefecture. Despite being in a cold region, the facility operates stably even during winter.
It is built on the site of a local tourist ranch with a processing capacity of 250 tons/year. The facility collects and recycles food waste from town residents twice a week, producing high-quality compost. It has successfully reduced waste incineration costs.

 

Implemented Measures and Effects

Increased Processing Volume Through Reduced Processing Time	Pre-treatment and fermentation equipment were optimized to shorten processing time.
Reduced Odor Through Improved Fermentation	Maintains aerobic fermentation year-round with minimal odor.
Expanded Sales Channels Through Bagged Compost	Some of the produced fertilizer is sold in bags, expanding its usage.
Cost Reduction Through Review of Auxiliary Materials	Utilizing beef manure as auxiliary material achieved zero auxiliary material costs and reduced the cost of purchasing sawdust, etc. (300,000 yen/year).
Improved Compost Quality Through Raw Material Crushing and Foreign Matter Removal Equipment	Crushing raw materials in the pre-treatment equipment shortened fermentation time and improved compost quality.

 

 

Features of Nagawa Town’s Recycling Facility

The facility has three main features

1. Utilizes beef manure as auxiliary material

2. Maintains high-temperature fermentation even in sub-zero conditions

3. Produces virtually no odor

 

Typically, composting facilities use auxiliary materials such as sawdust or rice husks, but this facility uses beef manure, eliminating the cost of purchasing auxiliary materials.
Despite having a higher moisture content compared to rice husks, beef manure starts high-temperature fermentation with the help of the EasyJet, which forces in oxygen during the process.

Although the moisture content of the finished compost is slightly higher, it produces high-quality compost with no odor. The compost is distributed to local residents for use.

The facility has been inspected by many people, allowing them to experience the differences from typical food waste composting facilities.

 

Composting Process

1. Refurbishment and Delivery of Food Waste

First, twice a week, food waste (household and business waste) generated in the town are collected and brought in.
The trash bags are crushed by a crusher and mixed with cow manure, with the rule that the garbage bags must be biodegradable bags prepared for this facility.

2. Fermentation in Easy Jet

The raw materials are then placed on top of the EasyJet tank and fermentation is completed in 45 days.
During the winter, the outside temperature can be as low as -5℃, but the fermentation temperature exceeds 80℃, and the system runs smoothly.

 

 

Operation by One Staff Member

One local silver worker manages the entire process, including weighing, shredding, mixing, and cleaning, finishing the work by noon.

 

Odor-Free with “Easy Jet”

The use of the high-pressure ventilation system “Easy Jet” enables high-temperature fermentation even at sub-zero temperatures without using heaters.
The raw materials maintain an aerobic state, and minimal turning results in an odor-free composting plant.

The facility can operate safely even in areas with residential neighborhoods nearby.

The Easy Jet system also allows for easy operation, making it possible to run the facility without extensive composting expertise.

 

 

Proposal for New Plant Design and Construction

This is a low running cost plant suitable for companies that want to start new food waste treatment and municipalities that want to reduce waste treatment costs.
We have extensive experience in designing such plant-type composting facilities. We can select the optimum model from a wealth of back data, and conduct precise simulations of management costs after operation.

In this case, maintaining aerobic conditions and eliminating turning has resulted in a facility with almost no odor. It can also comply with regulatory zones.

 

Summary

This facility, installed at a ranch, is expected to contribute to the promotion of municipal food waste recycling by gaining approval from residents and reducing high waste processing costs.
It also provides a new revenue source for the ranch through the use of beef manure.

For residents, reduced waste processing financial burdens can lead to improved administrative services, and the availability of high-quality compost at no cost benefits all three parties involved.

 

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