The Aichi Prefecture city of Toyohashi, with a population of 380,000, is set to embark on a unique and challenging project in fiscal 2017 of collecting biodegradable waste from households and companies for a combined biomass power generation facility.
To realize the scheme, the Toyohashi Municipal Government will make use of a private finance initiative in which companies provide funding for public infrastructure projects in what is hoped will save ¥12 billion over 20 years.
The key to success will be the cooperation of residents in separating garbage.
“This will be one of the largest biodegradable waste and sewage sludge treatment (facilities) in the country,” a Toyohashi Municipal Government official said.
Garbage collected from households will be treated along with sewage sludge and septic tank sludge at the Nakajima treatment plant, which is under construction.
The waste will then be broken down and converted into methane. The resulting biogas will be used to generate electricity, while the residue from methane fermentation will be converted to carbonized fuel and sold to power companies.
Toyohashi Biowill Co. was selected to carry out the operation based on the project plan and pricing proposal it submitted. In addition to designing and building the facility, the locally-based company will be in charge of operating the facility for 20 years until 2037.
The project is being funded by four companies, including Tokyo-based JFE Engineering Corp. and Kajima Corp.
The city of Toyohashi plans to collect 59 tons of raw garbage a day. This will enable the facility to generate electricity — enough to cover 1,900 households in a year — to sell to Chubu Electric Power Co.
If the project succeeds, it will not only help reduce waste and the cost of treating trash, but also generate income for the city. But it remains to be seen whether the city’s garbage collecting target can really be achieved.
The city’s projection is based on the actual amount of waste collected.
In Toyohashi, raw garbage is grouped under “combustible waste,” and currently household waste amounts to 37 percent of all combustible waste.
Starting in fiscal 2017, the city plans to collect raw garbage separately from other combustible waste. But taking into consideration that not all households can separate the two types of waste properly, the city predicts 70 percent of collected raw garbage — equivalent to 26 percent of all combustible waste — will be usable.
The daily target of 59 tons is calculated by combining usable raw garbage collected from households and 10 tons of raw garbage collected from companies.
Other cities, including Kitahiroshima in Hokkaido, Shiroishi in Miyagi Prefecture and Nagaoka in Niigata Prefecture, have already begun generating biogas from biodegradable waste.
The Nagaoka Municipal Government has been collecting raw garbage separately from other combustible waste since fiscal 2013, but is only able to collect 18 percent this way.
In addition, Nagaoka requires that its residents pay for waste treatment. Collection of raw garbage is priced at ¥0.3 per liter, lower than for combustible waste.
Despite the incentive, Nagaoka’s rate of collecting raw garbage remains far below its target of 26 percent.
Last spring, the Aichi Prefectural Government and Toyohashi University of Technology conducted a joint experiment at the prefecture’s Toyokawa Water Treatment Plant to test how much raw garbage they could collect.
Tomoko Okayama, an associate professor from Taisho University specializing in waste management and a member of the research team, reported that only 61 percent of households separated raw garbage from other waste.
“Even with the people who were willing to cooperate, we could only achieve this much,” she said. “I think the rate of raw garbage collection for the whole city will be even lower.”
What will happen if the total amount of biodegradable waste collected falls short of Toyohashi’s plan?
The city signed a contract last December with Biowill to “review the treatment cost for the following year” if the total amount collected is less than 80 percent of what was originally projected.
That means Biowill will be able to maintain the same profit by raising the price to offset the lower production. This means the city’s tax money will be used to make up for any shortfall.
“You don’t see a facility like ours often in this country,” said a Biowill spokesman. “We signed this contract to ensure that we can continue operation.”
“We believe our target of 59 tons can be met,” said Nobuaki Haga, deputy director of the municipal government’s environment policy division. “We will hold meetings with residents’ associations and do all we can to make sure that the message and importance of separating waste is conveyed to all households.”
This section, appearing Tuesdays, features topics and issues from the Chubu region covered by the Chunichi Shimbun. The original article was published on Nov. 3.
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