Hacker News new | past | comments | ask | show | jobs | submit login
Japanese biomass venture using microorganisms to tackle waste disposal (mainichi.jp)
96 points by fagnerbrack on June 17, 2023 | hide | past | favorite | 38 comments



The term "biomass digestion"refers to an anaerobic process of reducing biomass to, among other things, "biogas". There are power generation plants based on that concept. [1] is a collection of paper abstracts on that topic. The linked piece does not give enough information to determine what, really,is going on with their process, but it's hard to rule out the notion that their process might be liberating biogas.

[1] https://www.sciencedirect.com/topics/immunology-and-microbio...


And if it is this is important as methane is a potent greenhouse gas.

If the bacteria used in the process are obligate aerobes this would encourage the carbon dioxide route. This would also be the case if the bacteria were selected or engineered to preferentially produce carbon dioxide.

But regardless, the waste put in to the bin will have its own bacteria too. So if any of those are methanogens then it would be especially important to keep the company's bacteria up to date ("Fresh bacteria are added every three months for quality control."), and/or to ensure good air flow through the waste bin.


“ The company supplies bacteria that can process 98 percent of organic waste into water and carbon dioxide in just 24 hours, eliminating the need to turn it into compost, which is often not put to use. Fresh bacteria are added every three months for quality control.”

Sounds good but I sense a lot of gotchas like where will water go, smell, clean up, does it work in subzero


>> does it work in subzero

The firm is headquartered in Sapporo. It doesn't directly answer the question, but certainly Hokkaido is not unfamiliar with such temperatures.

There seems to be a solar and a battery component. Also, it is required to sit on a concrete base. Presumably, temperature management is a key part of the system.


> eliminating the need to turn it into compost, which is often not put to use

I am skeptical about this part of the explanation.

We have strict limits on the amount of compost we can take from our city composting plant. Is this a real problem?


I know farmers that are using city compost to replace chemical fertilizers for their vegetables. There is probably an over supply of compost in some places, but it feels this will probably reverse over time as farmers adapt their techniques.


In my city, you can get as much as you'd like for free. We're not a very big/dense city.


From the article: Waste deposited in the boxes will decompose in a day meaning that, unlike regular compost, they will not produce any unpleasant odors, she said.

It doesn't seem to answer your other "gotchas".


Now just do it with plastic!

Isn't this just the same thing that happens with sewage plants. In the anaerobic digester before the bardenpho phase?


Why would you want to do this with plastic? Food decomposes into methane and CO2. Methane is bad from a climate change perspective. If you can convert food to purely CO2, then you can improve greenhouse gas emissions. It’s even better if you can capture the CO2. Plastic, on the other hand, does not readily decompose into CO2. If you were to put it through a process that decomposes it, you would make greenhouse gas emissions worse.


Because the ocean is filled with it and the way it degrades causes it to become very small and ingested by sea creatures and concentrate up the food chain with deleterious effects for all involved.


Plastic requires specific bacteria that can digest it. Still pretty early days for that.

It would be easier to reduce plastic to biochar at 1000C and bury it in farm fields or underground.


The japanese also have a coagulant made from mundane simple ingredients that creates a floating slime from contaminants in water, iirc called Polyglu, which can be used to purify large volumes of it quickly.


In fact, when I read the title of this submission, I thought it was related to Polyglu.


If it produces Carbon dioxide is it not doing the same thing as just burning it?


Yes and no.

When you exercise, are you burning calories? Yes.

Are you literally burning calories, as through combustion the way most people understand it? No.

I guess a way to look at this would be akin to community trash fires that are sub-combustion temperature. Yay, now we don't have to truck it 100km to the incinerator, we can just burn it in the village square.

Composting is really challenging because a number of waste products, from citrus to inorganic or hybrid-inorganic garbage, can ruin the compost process and compost product. If someone leaves a metal nail in the compost pile and someone else later plants potatoes in it, that nail could end up in your mouth after a potato grows around it.


Why is citrus to be avoided in composting? A quick Google says that’s a myth, but this is the first I’ve heard of it either way.

https://www.gardeningknowhow.com/composting/ingredients/citr...


You shouldn't put citrus in a vermicompost bin because the worms can't eat it (right away, at any rate). I haven't heard that you can't compost citrus in a regular compost pile however. May be people getting mixed up around different types of composting.


I assume that it's just like with meat, which lowers the pH of the compost, which in turn is problematic if the plants using it later on have specific requirements in this regard.


> potato grows around it

That's insane. And by the same process, does plastic/microplastic in compost/soil, end up in fruits/veggies?


My semi-educated guess is that micro plastics wind up within the plant via nutrient uptake. No idea how a nail ends up in a potato.


Yes but as it does not come from fossil fuel, its impact on the total amount of carbon dioxide currently in the surface is neutral. It’s not a panacea but it’s better than using extracted gas and is a way to bridge the gap between the current situation and one where we have enough clean energy.


To whoever downvoted the parent comment (yes, I see that the comment doesn't address the article):

When it comes to organic waste it's basically always going to convert to carbon gases, unless you're burying it in a peat bog or something of that nature. At least here the conversion is in a controlled manner that theoretically allows capture, as well as being conversion into carbon dioxide instead of carbon monoxide, methane, nitrous oxide, and various other gases that have sundry externalities, including greenhouse effects.

Additionally, those microbes can often be used directly as chemical factories (or at least a bunch of scientists are working on this, with some production plants already in use). So the waste isn't being converted to carbon dioxide, it's being converted to inputs directly used for manufacturing. While this particular product isn't doing this, it might be adaptable for the purposes at some point.


same as my gut!

I think it's cool that small exoskeleton-based invertebrates (like ticks) also have this kind of relation with unicellular lifeforms.


ticks are arachnids, not insects :)


> "I want environmental protection to be a part of everyday life, not just something that big companies and entities with lots of money and time do," said Suno Nishiyama, 35, founder of Komham.

Ok so you're going for feel-good rather than effectiveness. One optimizes by starting from the biggest contributors, not "every little bit counts" distractions.


> The company supplies bacteria that can process 98 percent of organic waste into water and carbon dioxide in just 24 hours

Uh, there’s this new technology… “fire” which will do exactly the same thing considerably more quickly. Maybe I should create a startup and have chatgpt generate marketing material about how burning your garbage is environmentally sound.

Either this article is bad or the tech is not at all reasonable. You want compost because it fixes carbon. Put it in a landfill and you have carbon storage. Spread it on the ground and you’re building soil. It’s never “wasted”.


Fire creates a ton of other gases, and particles with health effects on respiratory animals and plants. Whatever you think about carbon dioxide, it's far better than an equivalent amount of nitrous oxide.

You want compost for growing things, not because it fixes carbon. It doesn't fix carbon, it provides nutrients for plant life (and some animals such as flies and worms). Some organic matter in a landfill will fossilize, but some of it will also turn into methane, which is typically seen as worse than carbon dioxide for the environment. And, of course, it has to be transported there through fossil fuel using trucks. It uses a lot less fuel to transport a packet of bacteria to waste than to transport waste.


What elements do you think make up the bulk of compost? The dry mass is indeed mostly carbon. What do you think happens to the nitrogen in plant matter digested by these bacteria? It’s either coming off as nitrogen gases or magically disappearing.

If you use the right tone apparently you can make anything seem environmentally friendly.

Composting creates solid carbon which can be used in agriculture, amended to soil, or just buried thereby keeping carbon out of the air which is the entire idea of reversing global warming trends. CO2 is CO2 however it got to be that way. “Equivalent amount of nitrous oxide” there’s no such issue, plant matter is made of mostly carbon, the nitrogen isn’t there to be anywhere near equivalent and comes out anyway regardless of if you burned or completely metabolized it with some bacteria.

The lack of critical thinking is very frustrating.


> What do you think happens to the nitrogen in plant matter digested by these bacteria?

My first guess is that it's being kept as, or converted into, amino acids for use in protein synthesis by the bacteria.

> thereby keeping carbon out of the air

For some of it, yes. However the production, and transportation of compost if it can't be used on site (possible in Japan), puts carbon into the air. I don't know how this balances out.

> The lack of critical thinking is very frustrating.

Critical thinking should go into study design and interpretation, but it doesn't hold a candle to actually doing a full lifecycle analysis. Is this technology better or worse for the environment than the status quo? We don't have enough information to determine that.


It has been well stablished that compost reduces the need of plaguicides and fertilizers.

But agriculture never having been a basic public service and running on such slim margins that it is tending towards oligopoly, let's not kid ourselves that compost will ever be given a chance

Not all industries have the luxury of joining the green revolution.


It is a problem. Some people are working on it, though a major solution to the issue appears to be tax or mandate. And some agricultural industries apparently are high-value enough that they can afford it on their own.

https://civileats.com/2022/03/02/california-compost-law-food...


My first guess was that it scaped as Elemental Nitrogen. ~78% of air is N2

But according to Natgeo

https://www.nationalgeographic.com/environment/article/how-t...

Compost is rich in Nitrogenated Nutrients. So far so good.


> You want compost for growing things, not because it fixes carbon. It doesn't fix carbon.

A composted plant fixes carbon more than a combusted one. It's the carbon capture.


Depending on how the compost is used, sure, but you have to do a lifecycle analysis to determine whether this ultimately results in more carbon fixed than carbon (or carbon-equivalent greenhouse gases) released.

https://pubs.acs.org/doi/suppl/10.1021/acs.est.2c05846/suppl...

> Offsetting nitrogen fertilizer use is particularly important with respect to net GHG emissions because fertilizer production (e.g., urea) is energy- and emissions-intensive to produce.


The intention is that consumers can do this at their home. Neighbors get a little unruly when I start fires to burn my leftovers.


Properly burning waste is environmentally sound, so yeah, go for it. Instead of spending fossil fuels to move waste long distances for disposal, you can harvest the energy in the waste and reduce fossil fuel use. Seems like a win-win, as long as you are careful about processing the exhaust and the slag.


Sounds like your understanding of biology is maybe not as good as your code skills. This is a pretty ignorant shitpost. Is somebody missing reddit?




Guidelines | FAQ | Lists | API | Security | Legal | Apply to YC | Contact

Search: