This is part of what I mean by "local and regional" solutions to energy. Take advantage of what you have. A large city like Detroit or Chicago has plenty of crap and trash floating around. Use it to make energy.

They might want to take a lesson from the movie "Soylent Green" and start feeding the bodies of their corrupt politicians into the thermochemical process while they are at it. Corrupt politicians to ethanol. I might not want to drink it, but my car probably would.

At 40 to 100 tons of waste processing per day, this solution appears to have advantages over other cellulosic technologies. The deep well pressure cooker design calls for a 9 inch vessel of 2000 ft plus containments. Municipal Solid Waste to fuel plus other salable products e.g. glycerol, exlose, urea, methane improves ROI potentials. If an algal bioreactor was added to the system the CO2 stream could be utilized. More positive news for a sustainable planet.

Multiply that by 1000 small cities and 100 large cities and USA could probably stop using corn to produce ethanol.

How does this process compare with plasma...?

Could anybody supply the pros and cons?

to gr and self: Just checked GeneSyst's FAQ: http://www.genesyst.com/faq.htm It seems they can indeed extract CO2 from the process, not sure about purity though.

SJC: From what I have read here and elsewhere the plasma processes are energy positive. In fact, applying it to coal and then burning the syngas yields more energy than just burning the coal straight (guess the resultant chemical reactions end at a lower potential energy than C -> CO2 would have.) Also, it seems the gravity vessel does not require the liquid to be pumped, it uses the process heat to move the liquid back up.

It seems to me the chief tradeoff between plasma and this process is that the plasma process basically destroys everything yielding only energy in syngas (which can of course be used to make any petrochemicals using FT) and some minerals in the slag, while other kinds of valuable chemicals can be made directly using the pressure vessel. I have no idea which works out better for a given use case though.

In other waste-to-something-useful news:

CO2 to cyclic carbonates.

BJ, SJC & Neilen,

Thank you for the info.

It seems that both process could find application in many places. What a noble way to get rid of garbage and various unwanted wastes.

Cities, States, counties and Fed governments should combine their efforts to have 1000 plants built to reduce travel distances for feedstock carriers.

Burn garbage-wastes and eat and/or export more corn. Good words for city politicians. It would also reduce trade deficits.

days of old and know we have coal miners.
but in the future maybe they will be minig garbage
cool stuff

Neilen: If a process, using C as feedstock, and CO2 as end product, would yield more energy than the direct buring of the carbon, you'd have a classical perpetuum mobile (you could use the excess energy to split the CO2 to O2 and Carbon again, and putting both thru your miracle process...

Combined cycle coal plants have a pretty high efficiency (quite close to the theoretical carnot limit).

Using energy (plasma) beforehand would definitely *decrease* that efficiency.

However, pre-processing waste material in order to use them later in more efficient conversion processes might lift the total process efficiency - but we are probably talking somewhere of 30 to 50% theoretical efficiency (which is, as common temperatures and pressures, around 50-60%)....

SJC: just because it mentions "acid", that doesn't need to be a bad thing. Even sparkling water is considered to be acid... Are you afraid of it?

Adding temperature and pressure actually "boosts" proton mobility (lowers the pH) - which is what you want.

Since the reactor chamber is obviously basically a vertical thermally isolated tube, reaching about 600m vertical down from ground level (typically, at those depths you already have geothermal heat all year round), you don't need to really pump anything around with lot of pressure. there are two hoses at the top; when you fill in some water in one, water will flow out the other hose - without the requirement of 70+ bar, high pressure pumps (it's gravity after all, providing the high pressure at the bottom of the tube).

Nice approach...

But digging / drilling 600+m meter shafts into the earth, though ground-water horizons, and making sure everything remains absolutely water-tight for the duration of the processing plant will be a challenge (increasing capital expense when buildign it).

There are cheaper ways of doing partial wet-air-oxidation. But no one paid me for any consulting. The gravity one, first tried years ago in colorado, allows for low pressure and temperature at the top of a pressure cooker. A small pump fitted to an equally long concentric pipe will supply the very limited amount of energy needed to bring water and some products back to to the surface. Gasses will come up on their own, and some ash may have to be brought up by jet pump or even bailing. The cost of presurising the air or oxygen is not high because of the incomplete combustion. Such a unit could produce vinegar from paper easily. The general method was used at first to produce artificial vanilla from mill wastes....HG....