[scareduck]

$this->bbcode_second_pass_quote('0mar', 'I') know they can't be scaled up in time or ever really, nor can they recycle everything.

However, at a forum I visit, people seem to cling onto this as the last savior (along with fusion). I have been formulating some sort of rebuttal but it doesn't look as solid as it can be.

So far I have:

1. TD needs electricity, which requires gas/coal. Gas is plateau, and coal could be useless by 2040 if the current decline in EPR continues.

[Guest]

this doesn't make sence to me at all.

When it gets even remotely close to having to tap the turkey-biodiesel to make more turkeys, it's all over. [I]


Why?


if i have turkey biodiesel...and have to use some of it to make more turkeys, why would it "all be over" that is plain stupid.


turkeys eat, shit , and breed. we aren't talking about extracting oil from the ground with more oil here, we are talking about harvesting a natural food source's byproduct (waste) and converting it into fuels.

[Cash]

I think the important thing to remember about TDP is that it's basically just a recycling operation. We put our newspapers and tin cans out to be recycled. The TDP folks are doing the same with other parts of the waste stream. More power to them, but it's not a cure-all. It's just a way of getting out some of the energy we have already put into a product, whether it's a plastic jug or a turkey.

Cash

[Aaron]

Also important to remember that when considering any energy source including recycling, just how high a peak do we want to drop from?

It's not as if recycling or conservation energy savings go into some "energy bank" for future generations, but simply allows humanity to further increase our global energy profile.

[pup55]

http://peakoil.com/fortopic505.html

We have been following this for awhile.

The CWT website has recently been updated: a lot of the technical papers have been removed (no doubt to keep people like us from analyzing them), and also, there is a link to the JV with Con Agra. No word on how they are dealing with the odor problems coming from the plant, or even how well the plant is running.

The character R James Woolsey has emerged again recently. This fellow was the former CIA director under Clinton, and frequent talking head on CNN. For awile, he was a paid "military affairs consultant" for CWT. It appears his main function was a lobbying-type role to open doors for government grants, etc.

Woolsey made a presentation the other day at the conference at the US Capitol on the importance of biofuels as they relate to national security.

He is no longer listed as part of the management of CWT, interestingly, but maybe they have already opened all the doors they need. He is quoted in one of their press blurbs.

Gotta keep an eye on him, too.

[Optimist]

$this->bbcode_second_pass_quote('', '3'). TD can only produce oil from wastes, which will turn into products and back into waste. Because of the 2nd law, we will be getting diminishing returns.

[Cash]

TDP, as thermodepolymerization is often called, is basically just a recycling program, not unlike recycling newspaper and tin cans. Assuming it works as advertised, it sounds like a great way to squeeze another cycle of productive use out of waste materials, from municipal garbage to old computers. I've read that it can even process municipal sewage into oil and fertilizer, as well as producing natgas and pure water.

But it is just recycling. It needs an initial supply stream, and I haven't seen the numbers that support the idea that it can be anything more than a nice supplement to oil requirements, not a huge savior.

I believe that post-Peak we will see major decentralization in energy sources to a much more locally produced model -- wind, solar, PV, biodiesel, ethanol, wood-fired generating station, horses, mini-hydro, and things like TDP. Nothing is going to provide the silver bullet, but there's no reason TDP can't be part of the larger mix.

Cash

[Optimist]

$this->bbcode_second_pass_quote('', 'I') haven't seen the numbers that support the idea that it can be anything more than a nice supplement to oil requirements, not a huge savior.

[0mar]

$this->bbcode_second_pass_quote('Optimist', '')$this->bbcode_second_pass_quote('', 'I') haven't seen the numbers that support the idea that it can be anything more than a nice supplement to oil requirements, not a huge savior.

[Optimist]

$this->bbcode_second_pass_quote('', 'A')t 1,000 bpd per plant, we would need 1,000 plants. So 13 million barrels will need 13,000 plants. Bringing this online in 15 years would require 2.5 plants being built daily (365 x 15 = 5475, 13,000 / 5475 = 2.38....). TD is viable at a technical level only, not on an economic level.

[eric_b]

$this->bbcode_second_pass_quote('Optimist', '')$this->bbcode_second_pass_quote('', 'A')t 1,000 bpd per plant, we would need 1,000 plants. So 13 million barrels will need 13,000 plants. Bringing this online in 15 years would require 2.5 plants being built daily (365 x 15 = 5475, 13,000 / 5475 = 2.38....). TD is viable at a technical level only, not on an economic level.

[0mar]

The most optimistic of sites say that TD plants can have a capacity of 1,000 bpd.

[Optimist]

That's very convincing guys!
$this->bbcode_second_pass_quote('', 'D')on't make me throw more numbers at you.

[0mar]

Because that is the inherent limitation of the technology.

Things just can't scale up to something convienant.

[RdSnt]

Let's look at this in a much more basic way.

Assume for a moment that fossil oil took 1billion years to create. I just using a nice round number. There was a certain amount of energy expended to create that fossil oil. From year to year though the amount was very small.

In our present circumstances, we want to convert waste material into oil. However we don't want to wait a billion years, we need to accelerate the conversion process. Acceleration requires additional energy. In the end we don't have enough energy to convert the waste to oil in any type of positive EROEI calculation.

Also keep in mind some products, such as plastic, require much more energy to break down than it took to create the origin component from fossil fuel resources. Also it is good to keep in mind that we don't calculate the cost of the making of fossil fuel in our estimates for making a product. We should.

[nero]

One factor to consider with TD is that the quality of the trash is important. Not just the energy content but the contamination. If the waste is homogenous and reliably contamination free then you're golden but what happens if you start throwing in real trash, then you will get oil contaminated with heavy metals that would be dangerously polluting.

Another consideration is that agricultural waste often isn't. It's fertilizer.

A third consideration is that waste is dispersed. If it must be trucked to a central TD processing unit to achieve the efficiencies of scale, that aslo is a significant cost.

[0mar]

$this->bbcode_second_pass_quote('RdSnt', 'L')et's look at this in a much more basic way.

Assume for a moment that fossil oil took 1billion years to create. I just using a nice round number. There was a certain amount of energy expended to create that fossil oil. From year to year though the amount was very small.

In our present circumstances, we want to convert waste material into oil. However we don't want to wait a billion years, we need to accelerate the conversion process. Acceleration requires additional energy. In the end we don't have enough energy to convert the waste to oil in any type of positive EROEI calculation.

Also keep in mind some products, such as plastic, require much more energy to break down than it took to create the origin component from fossil fuel resources. Also it is good to keep in mind that we don't calculate the cost of the making of fossil fuel in our estimates for making a product. We should.

[FrankRichards]

Omar,

Would you please post a reference that explains why a TDP plant can't be scaled?

And I can't avoid the feeling that when you're talking about waste, EROEI calculations on just the waste are all bogus. You need to get rid of the stuff and that cost is part of the EREOI of what you really wanted to do, which I expect is never to just make a pile of waste. So for the extant case of turkey guts, the issue is "does using TDP to rid of the offal improve the EREOI of raising turkeys by 'conventional' means?" I haven't seen any claim by anyone that implies that it doesn't.

The PITA is that you have to look at each waste stream individually. I'm sure that TDP is better than say landfilling feedlot manure, but it's less clear that you can't get a better return using a conventional methane digester, and then either TDPing or just using the (much smaller now) residue for fertilizer.

[Licho]

There is probably no real obstacle in sizing the plants or even building enough of them in few decades.. There is also no problem with powering these plants, as they casn use their own produced methane to power self.
What I see as an obstacle is stealing the energy from ecosystem. If you treat all biological waste this way, you are certainly not going to return it back to ecosystem (as fertilizer and base for next generation of plants/animals) but instead throw it into atmosphere as CO2. But ecosystem is where it belongs. If you remove tonnes of biological material from it, then you need to use tonnes of synthetic fertilizers and other stuff to "refill" organic base for plants. You can't increase efficiency of primary energy source (which is photosynthesis) this way for longer period, if you do, you are stealing from organic base and reducing fertility of land. You can only come as close as possible to photosynthetic efficiency limit with tdp. If we are now using 1/5 or 1/10 of energy provided by plant photosynthesis, using this process we could come closer to 100%, but we cannot go beyond it.. we cannot surpass limits of plants which actually capture this energy from sun with this technology.

If we put it this way, then the question is not how many TDP do we need to construct, but rather:
How large area of farmland do we need to capture enough energy from sun to power society.

[nocar]

To give a hint on the scaling potential, let's look at Stockholm, Sweden

We have a very great sewage treatment system, and it actually produces biogas for running buses (aside from treating the sewage).

Shit and toilet paper from a million people now power about ten buses.
That's it. All the thousands other buses and about 300.000 cars and xx thousand trucks just have to sit still if we would have to rely on this sources of waste for powering motor vehicles. (We have electric trains and subways that can keep running on nuclear and hydro like they do today)

Nocar