Effectively using a waste mushroom bed (Mori & Company style mushroom bed processing) (Introduced to: Shiitake Production Plant) - Deodorization and Composting equipment - Miraie

CASE STUDY

Construction example

2021.10.03 EASYJET Jr.

Effectively using a waste mushroom bed (Mori & Company style mushroom bed processing) (Introduced to: Shiitake Production Plant)

By recycling all waste mushroom beds after cultivation, they were able to achieve zero emissions and reduce processing costs.

PlaceWakayama Prefecture
Processed Material and AmountWaste mushroom beds 3 tons/day
OverviewBy recycling all waste mushroom beds after cultivation, they were able to achieve zero emissions and reduce processing costs.

Measures and Effects

Increase processing amount 1They built a new facility and started a composting business.
Increase processing amount 2By adopting a high-pressure aeration system and efficiently composting in a limited space, they were able to increase the amount of processing compared to typical systems.
Reduce costsBy eliminating the turn over work, it became possible to operate the facility with a small number of staff, do low-cost processing.
Improve compost qualityDifficult to decompose woody materials are composted in a short period of time using high-pressure aeration. It achieves high quality composting without odors

The following is an aside about the recycling of mushroom beds, which we often receive inquiries about.

It is estimated that about 300,000 tons of mushroom beds are discarded per year in Japan, and although they show promise for use as biomass, recycling of mushroom beds has not progressed well in reality.

We posted about this several times before, and Miraie will continue to propose systems to successfully recycle waste mushroom beds.

Regarding mushroom beds in Japan, there are two companies that occupy a large market share as supply manufacturers; Mori & Company, Limited (Gunma Prefecture) and Hokken Co., Ltd. (Tochigi Prefecture).

There are differences between how these two companies cultivate mushrooms, and the mushroom beds discharged by each of them have their own characteristics, so here we explain the recycling methods used according to those characteristics.

First is the method for Mori & Company. Their waste mushroom beds are characterized by relatively low moisture content. Their moisture content is about 55%, and when fermentation starts, the moisture content drops further while generating high temperatures (see the figure on the left).

Therefore, to recycle Mori & Company’s mushroom beds, it is recommended to exploit these characteristics and do “bedding production” instead of compost.

This is because there is a chronic shortage of bedding in livestock farms, so bedding made from this process should be marketable.

The photo shows an example of aerobic fermentation of waste mushroom beds in a flexible container bag. This can be done easily by fermenting beds with a flexible container bag and EasyJet Jr. as shown in this photo.

One flexible container bag contains a mushroom bed of about 1 m3.

Put one EasyJet Jr. into a bag and ferment the bed.

Alternatively, if there is space such as a compost house, EasyJet Jr. can be installed on the floor.

For example, if there is a space of 5 m x 10 m, it is possible to ferment and dry about 50 m3 of mushroom beds. In either case, idle space in a factory or a farming house are adequate.

Drying with the heat of fermentation uses far less energy than drying with heavy oil (energy cost is 1/5 to 1/10 of the heavy oil method), and is more economical.

It is possible to gradually remove moisture just by blowing the beds with a blower at room temperature, but fermentation temperature does not rise, so the finished product will not be suitable for use as bedding. 

The reason why is that it is desirable to raise the temperature and sterilize the beds when supplying it as bedding for livestock.

The equipment needed includes a shredder for the mushroom beds, a conveyor device, EasyJet Jr., and a compressor. While it depends on the scale of production, the depreciation cost for equipment is ¥4.2 and the electricity bill is ¥0.8 per 1 kilogram of waste mushroom bed, for a total of about ¥5.

The selling price of bedding is about ¥7 to ¥12 per kilogram, making it possible to recover the cost quickly. For reference, the market price of typically available bedding is ¥15 to ¥25 per kilogram for sawdust and ¥5 to ¥10 per kilogram for rice husks.

Waste mushroom beds have excellent qualities as bedding, such as good moisture absorption qualities, and when mixed with livestock manure, the temperature rises well and cellulose decomposes quickly, so it is comparable to conventional bedding material.

In preparation for introduction, we did composting tests of mushroom beds using flexible container bags at our in-house test facility, and made a proposal for a plant based on the test data.