Japan's Largest Methane Fermentation Plant to Recycle Food Waste

[Bdog]

http://www.japanfs.org/db/database.cgi?cmd=dp&num=662&UserNum=&Pass=&AdminPass=&
The Bioenergy Co. of Japan has decided to construct a power plant in Tokyo Bay to recycle food waste as part of its methane fermentation power generation project, which is part of the "Super Eco-Town Project" promulgated by the Tokyo Metropolitan Government. The plant will come on stream in fiscal 2005.

Under the Food Recycling Law enacted in 2001, all business entities in the food industry are obliged to reduce or recycle food waste by more than 20 percent by 2006. Methane fermentation power generation is recommended in the law as one way to recycle food waste.

Tokyo Metropolitan Government launched the Super Eco-Town Project to promote the transformation of current society into a recycling-based society. Under the project, the Metropolitan government offers private businesses the use of City property in the Tokyo waterfront area for the development of waste treatment and recycling facilities. Against this backdrop, Ichikawa Kankyo Engineering Co., Kaname Kogyo Co. and San-R (3R) have jointly established a new company, called Bioenergy Co.

[papau]

1. Great news!

:-)

[amandabeech]

2. There is some recycling of kitchen vegetable matter

in San Francisco and the Bay Area. Their main goal is to produce compost for farms and gardens. You can google "San Francisco vegetable compost" for some information.

They are not using a methane digester to make the compost, but are using black plastic to cover the composting material. However, I think that what's left after methane digestions is compost or can be composted for fertilizer. I certainly hope that the San Francisco folk see this article about Japan or figure it out for themselves.

The problem in setting up a system to produce both methane and compost is that animal products, except clean eggshells, cannot be used to make compost, so you'd have to separate animal from vegetable in recycling. I suspect that might be a chore for business and industry.

If it would be possible to manage separating animal from vegetable, then a thermal depolymerization system would reduce the animal waste, before or after composting, to oil, carbon and other elements.

This Japanese set-up is a really great idea!

[NNadir]

3. This is very impressive. According to the link provided, the plant,

Japan's largest, will process 110 metric tons of vegetable matter per day. Assuming (and of course we should always assume the best in matters like these), 100% yield, and ignoring for the moment molecular weights, we might expect to get 110 metric tons of methane per day or 40,000 metric tons per year. (Before you accuse me of pulling numbers out of a hat, I'll apprise you of the fact that I am using the common conversion factor of 365 days per year. I have ignored the 0.24 days that result in the "leap year.")

40,000 metric tons of methane is 1.6% of the amount of methane recovered or flared at US landfills in 2000.

http://www.eia.doe.gov/oiaf/1605/gg01rpt/methane.html

The world consumes about 75 trillion cubic feet of natural gas equivalent to 4.5 billion tons. Help with the conversion factor

This wonderful plant, worthy of a whole new thread, will thus produce 0.003% of world demand. Oh well, every little bit helps.

[amandabeech]

4. Yes, every little bit helps!

You actually get a little bit more savings if you use what's left after digestion as compost fertilizer.

The compost fertilizer contains nitrogen, phosphorous and potassium, the major fertilizers, as well as trace minerals needed by plants.

If spread on gardens or farms, it will cut down on the amount of nitrogen fertilizer needed, and since nitrogen fertilizer is now made with loads of natural gas, you will get some savings there.

Additionally, the compost will most likely be used locally, thus saving on transportation costs for phosphorous, potassium and trace minerals which are transported long distances (phosphorous from Florida and the Southeast)and frequently require energy for processing.

The decayed organic matter in the compost also improves soil quality, inducing natural helpful microbes and worms in the soil. The compost also reduces compaction and lets more air and water penetrate the soil. I have read that soil amended by organic matter holds more
water, as much as 20% over soil fertilized only with chemical fertilizers. This reduces the need for energy for irrigation pumps, and, of course, may reduce the amount of water pumped from depleting aquifers.

On edit: using methane digester residue for fertilizer and putting animal products through TDP frees up space in landfills. Of course, some of the methane produced by landfills comes from the decomposition of food waste, both vegetable and animal.

[NNadir]

5. Well the environmental benefits of this scheme will depend on the

collection costs. If one drives trucks endless miles to pick up the food to compost, there isn't much advantage. If on the other hand the food wastes are collected near a food processing plant, that's quite another.

People have argued that switching to natural gas is better for the environment than say, burning diesel. Often this is the case, but sometimes it is not. If the gas needs to be liquefied, shipped tremendous distances, if it leaks, it is often an environmental loser.

Methane's twenty year Global Warming Potential (a measure of its atmospheric lifetime and its IR absorbing power) is 20 times greater than that of carbon dioxide. The concentration of methane in the atmosphere from preindustrial times has risen from 720 ppvb to 1721 ppvb in recent times. Since methane is a much, much stronger absorber of IR radiation than is carbon dioxide, this concentration has ppb for ppb a much more profound effect on global climate change than does higher concentrations of carbon dioxide. This is the reason that where_ever methane is too far from a market to industrially ship, as in remote oil fields or remote landfills, it is generally flared (deliberately burned) to give carbon dioxide. Although too much carbon dioxide is a profound global warming threat, too much methane is worse.

It is, however, worth noting that food wastes generate methane whether contained in landfills or in cute Japanese plants. I very much suspect that the Japanese plant is a good thing. In general, the Japanese are infinitely smarter than the Americans where issues of a wise energy policy is involved. As I pointed out in my earlier post on this thread, methane is already recovered in the US from landfills and burned to generate power, so Americans are generally not completely stupid on the issue of energy. They're mostly stupid, but not completely stupid.

The reality is however that these small inputs should in no way be construed as addressing the more serious energy and environmental collapse issues that our planet faces. They, like many other biologically based approaches, can ameliorate the severity of the problem, but they cannot come close to eliminating the problem.

The danger is that one read threads like these and engage in magical thinking of the "problem solved!" nature. I have been dealing with exactly that kind of thinking for much of my adult life, and as comforting as it may seem, in another way, I think it a kind of naive cowardice. In this kind of thinking, one imagines that one can scale this by a factor of 50,000 and completely solve the world's natural gas needs. That will simply not happen. One need only think about how much food one wastes individually and how much gas the average person burns, and see that my statement is true.

[amandabeech]

6. The program in the Bay Area is all done in the vicinity.

The compost facility is not far from the institutions and individuals that participate. Obviously, one must do an EROEI (energy returned on energy invested) analysis as well as a cost/benefit analysis if one were doing this for profit not as a moral or political statement.

All food waste to compost programs that I've seen mentioned on the internet show the waste sources close to the user. My general impression is that the waste is not moving more than about 20 miles, which is similar to the economical range of moving animal manures for fertilizer. I would expect that waste for methane digestion would not be hauled any farther.

I have no idea of the potential for harnessing the methane generated by decomposing food waste, including waste at the farm, processing, retail and home level. Nor do I have a good idea of how much the addition of yard waste, wood product manufacturing waste or sewage system biosolids would increase the amount collected. In addition,
methane harvested at the plant or institution level, the methane may also be used for process heat or space heating, which may be more efficient than generating electricity.

As to using methane generated at remote locations, I have seen references to relatively small internal combustion electrical generation set-ups that can be installed at remote sites at which conventional plants or pipeline extensions would be uneconomical. I assume that these may be connected to the local grid now or in the future.

As you state, the more we harness the better because of the potency of methane as a global warming gas and the potential for obtaining a little more electricity. I am in complete agreement with you that harnessing methane in these ways will not solve energy or environmental crises on their own.

It seems as though my focus is a bit more toward agriculture than yours or in fact, most Americans, perhaps because of my background. I frequently contemplate the effect on U.S. food production and distribution of climate change, fossil fuel depletion and U.S. phosphate depletion (our phosphate is estimated to run out in 75-125 years). Admittedly the monetary and energetic cost of hauling compost long distances is substantial. However, in my opinion, in the future some of the problem will be solved by breaking up the large feeding operations into smaller operations so that the distance that the compost must travel will better match the amount generated, but not so small that the methane cannot be harnessed. Right now, there is experimentation with drying manures to increase economical transport distances, and I expect that may be further developed. I also believe that at some point many more backyards will sport vegetable gardens, thus soaking up some compost generated in urban areas, and that vegetable production become more dispersed so that your local chain supermarket will carry in-season local produce instead of that trucked across the continent from California. In other words, our agricultural system will look a bit more like it did 40-50 years ago.