[Devil]

Link to 9% of your electricity!

[WatchfulEye]

Is it really you? We've missed you.

Anyway, we've got a similar system where I live. All the local landfill sites are full, and a local energy recovery facility has been built.

The domestic waste is incinerated in a state-of-the-art incinerator, with electricity produced from the resulting heat. Waste heat is then piped to various buildings, including the commerical district, hospitals and university. Although, rather the ship waste in, this is a municipal system - installed at the heart of the city, and is the drop off point for all the garbage trucks.

[Ferretlover]

A waste-to-energy plant in Minnesota:

Instead of a landfill

[Devil]

Is it really you? We've missed you.

Yes, it's really me, but I'm not here for long.

Anyway, we've got a similar system where I live. All the local landfill sites are full, and a local energy recovery facility has been built.

I'd be interested to know where this is. I know the technology is hot in Japan and a few other places, including some cities in the USA.

[DomusAlbion]

Spokane, Washington has one of these plants. Very effective.

[DomusAlbion]

Spokane, Washington has one of these plants. Very effective.

[dohboi]

Burning trash for energy (or for any other reason) is generally a very bad idea. There are generally lots of toxic heavy metals that end up in the air and in the extremely toxic ash, which then needs to be somehow safely disposed of. Particulates released into the air are generally quite high, especially the very small micro particles that get deepest into people's lungs and cause asthma and other nasty problems.

Why the great urge to burn everything? Burning stuff is what got us into this mess. We need to massively REDUCE the amount of trash we generate, and burning it, among other things, lulls us into the false notion that we can keep on generating trash because it will "go away" when we burn it, and give us a nice treat of extra electricity for our ipods.

There is a huge literature on how bad an idea this is, but that hasn't stopped lots of projects like this from going through.

[Devil]

Burning trash for energy (or for any other reason) is generally a very bad idea. There are generally lots of toxic heavy metals that end up in the air and in the extremely toxic ash, which then needs to be somehow safely disposed of. Particulates released into the air are generally quite high, especially the very small micro particles that get deepest into people's lungs and cause asthma and other nasty problems.

Why the great urge to burn everything? Burning stuff is what got us into this mess. We need to massively REDUCE the amount of trash we generate, and burning it, among other things, lulls us into the false notion that we can keep on generating trash because it will "go away" when we burn it, and give us a nice treat of extra electricity for our ipods.

There is a huge literature on how bad an idea this is, but that hasn't stopped lots of projects like this from going through.

Did you even read the link? Switzerland has extremely severe limits on all pollutants and, as stated, all of these, except NOx, are kept to about 1/10th of these severe limits in the plant. NOx is maintained at about half the limit value. You can see the actual figures, measured by an independent authority, on the Tridel site, if you read French. The days of dirty trash burning were 20th century; we are now in the 21st century. Please go back and read it up.

Furthermore, the solid waste stream is 1/10th the volume of compacted garbage: would you prefer that waste goes into huge, smelly, rat-infested, noisome landfills, where it emits greenhouse-gas methane to further climate change? Don't be ridiculous!

[TheDude]

Hey Devil, always enjoyed your posts in the past and please do keep contributing!

For the US perspective, here is the EPA's page on LMOP (Landfill Methane Outreach Program), encouraging the use of waste gases as energy sources. Also this paper on methane powered microturbines: pdf.

Here is a page on the EPA's Landfill Gas Regulations.

Landfills subject to the rule are expected to collect at least 75 percent of the gas produced by the landfill. The collected landfill gas must be combusted at a high enough temperature to destroy 98 percent of the toxics.

Very sensible if the energy balance is positive - doesn't look like we'll be cutting back on the amount of trash we produce soon, after all.

[Tyler_JC]

Did you even read the link? Switzerland has extremely severe limits on all pollutants and, as stated, all of these, except NOx, are kept to about 1/10th of these severe limits in the plant. NOx is maintained at about half the limit value. You can see the actual figures, measured by an independent authority, on the Tridel site, if you read French. The days of dirty trash burning were 20th century; we are now in the 21st century. Please go back and read it up.

Furthermore, the solid waste stream is 1/10th the volume of compacted garbage: would you prefer that waste goes into huge, smelly, rat-infested, noisome landfills, where it emits greenhouse-gas methane to further climate change? Don't be ridiculous!

Devil, of course he didn't read the link.

Doomers aren't interested in information that might prove them wrong.

In the United States in 2005, municipal solid waste and landfill gas amounted to 447 trillion Btu of energy production.[1]

Or the energy equivalent of 51,724,137 barrels of oil. That's not bad , especially considering how little of our garbage is converted into energy.

[1]http://www.eia.doe.gov/cneaf/solar.renewables/page/mswaste/msw.html

[dohboi]

I read the link. I'm a skeptic. You obviously aren't. And you don't seem to have read my post. We need to massively reduce the amount of trash we generate, and recylce and compost what is left.

We have to get past linear thinking, that we can endlessly extract resources and that they will just go away when we are done with them .

This is not what you want to hear, so you will doubtlessly hurl more insults my direction, but I am not interested in getting into that level of discussion today. Sorry.

[Devil]

I read the link. I'm a skeptic. You obviously aren't. And you don't seem to have read my post. We need to massively reduce the amount of trash we generate, and recylce and compost what is left.

No, you are not a sceptic, you are a pie-in-the-sky dreamer!

I agree with you that we should reduce trash and recycle to a maximum. But there will always be some residual trash that has to be landfilled or incinerated.

Have a look at this:



This set of photos was taken in Romanel-sur-Lausanne, a village of about 3000 inhabitants, about 5 km from the Tridel plant. There are three such recycling 'stockades' in the village and, believe me, nearly all the recyclable material is deposited there. There is also a large composting site in the village. Only the garbage that is left is collected in the twice-weekly collection is used to generate power in the Tridel plant: in fact, Mr Allenbach, the technical director of Tridel, told me jokingly that he wished there was less recycling! This is not exceptional; all the Swiss communes have means of recyclable collections. The Swiss people are very serious and disciplined, as far as waste is concerned.

I honestly cannot believe that more could be done, on a practical basis, to come close to your theoretical ideal, short of going back to the stone age. Yet there remains sufficient garbage to justify the clean extraction of the calorific value of the residues to generate 9% of the electricity consumed within the catchment area and provide heat and hot water to a large teaching hospital and the apartments housing 18,000 persons, rather than depositing them in a noisome, space-consuming, gas-emitting, landfill. This is recycling par excellence, extracting value from what no one wants! (Incidentally, the hospital also supplies Tridel with its medical waste which is thus safely disposed of!)

[Devil]

As an afterthought, maybe this is the future of cremation. I'd be quite happy to leave my body to a power plant! That way, I'd be more useful dead than alive!

[dohboi]

Wow, I went from being a "doomer" to a "pie-in-the-sky dreamer" in the space of two posts!

You're right. I give. We can just burn our way out of any problem we make.

Burn, Baby, Burn

[Devil]

'Twasn't I who called you a doomer!

I don't think you're a pragmatist, though, with all due respect !

[bodigami]

Burning trash for energy (or for any other reason) is generally a very bad idea. There are generally lots of toxic heavy metals that end up in the air and in the extremely toxic ash, which then needs to be somehow safely disposed of. Particulates released into the air are generally quite high, especially the very small micro particles that get deepest into people's lungs and cause asthma and other nasty problems.

Why the great urge to burn everything? Burning stuff is what got us into this mess. We need to massively REDUCE the amount of trash we generate, and burning it, among other things, lulls us into the false notion that we can keep on generating trash because it will "go away" when we burn it, and give us a nice treat of extra electricity for our ipods.

There is a huge literature on how bad an idea this is, but that hasn't stopped lots of projects like this from going through.

Did you even read the link? Switzerland has extremely severe limits on all pollutants and, as stated, all of these, except NOx, are kept to about 1/10th of these severe limits in the plant. NOx is maintained at about half the limit value. You can see the actual figures, measured by an independent authority, on the Tridel site, if you read French. The days of dirty trash burning were 20th century; we are now in the 21st century. Please go back and read it up.

Furthermore, the solid waste stream is 1/10th the volume of compacted garbage: would you prefer that waste goes into huge, smelly, rat-infested, noisome landfills, where it emits greenhouse-gas methane to further climate change? Don't be ridiculous!

why not use the methane for energy? trash does not need to be burned...

[BigTex]

Why the great urge to burn everything?

You're asking the Devil that?

[Devil]

why not use the methane for energy? trash does not need to be burned...

Some very good reasons:
1. Anerobic decomposition produces methane and carbon dioxide in roughly equal proportions. As each molecule of both gases contains one carbon atom, the carbon in the CO2 is wasted. With incineration, it is used, along with its concomitant hydrogen atoms, to generate heat before it is emitted as CO2. Incineration is therefore roughly twice as efficient in generating energy from waste.

2. You still need ~10 times the landfill volume, compared with the clinker from incineration

3. Capping landfills, yet allowing new waste to be added, is not easy and some methane is bound to be emitted.

4. Efficient separation of the CO2 from the CH4 is tricky and not cheap.

5. Anaerobic decomposition is never complete: large quantities of organic matter remain. Incineration is always complete in an efficient firebed (in practice, there is usually <0.25% carbon in the combined fly ash and clinker). Greater conversion efficiency.

6. Toxic compounds in a landfill remain as a potential source of ground-water pollution. They are either incinerated (if organic, such as PCBs and other persistent substances) or recovered and recycled (if heavy metals, such as mercury, arsenic, lead etc.) in an incineration plant.

7. The foregoing assumes capped landfill technology using anaerobic decomposition, which is the most common and most economical. However, there are also thermal gasification plants. These are also very inefficient as half the energy generated is required to maintain the gasification process. It is more efficient in terms of waste volume. However, the gasification process is efficient only with a single type of waste (e.g., waste from poultry processing). Mixed waste, such as household garbage, is too variable in composition to keep a constant process running and efficiency drops. Also, the residues may still contain toxic materials and are more voluminous than with incineration.

The conclusion is, therefore, that efficient incineration is preferable. The downside of it is that flue gas and solid waste treatment to avoid pollution requires heavy capital expenditure and the running costs are not negligible, either. However, the increased thermal efficiency more than pays for itself (the energy consumption to keep an incineration plant running is <5% of the total energy produced).

Does this answer your question?