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Indiana to Build Waste-to-Ethanol Facility Using Gravity Pressure Vessel Process

The GeneSyst process is based on the use of a gravity pressure vessel to convert municipal solid waste to ethanol. Click to enlarge.

Indiana Ethanol Power LLC (IEP) has begun contract negotiations with the Lake County Solid Waste Management District (LCSWMD) to build a facility to convert commercial municipal solid waste (MSW) to ethanol using the GeneSyst International gravity pressure vessel process. This will be the first facility in the United States using the GeneSyst process. The LCSWMD plans to review the final contract with IEP at its board meeting in May.

The 1,500 ton per day facility is expected to produce 20 million gallons of fuel-grade ethanol and other products each year.

The gravity pressure vessel is a continuous plug flow chemical reactor with an aspect ratio of cross-section to flow-path which is the antithesis of a batch reactor. The depth of a hydrolysis gravity pressure vessel, which hangs in a vacuum chamber within a steel and concrete casement, is designed to be typically 2,000 feet (610 meters). The design flow rate for a typical gravity pressure vessel is a little more than 1 foot (0.305 meter) per second, the governing parameter being thermal efficiency or heat recovery from processed fluids. Accumulated peak bottom water pressure (correcting for expansion and friction) will be about 750 pounds per square inch (51 atmospheres).

The gravity pressure vessel uses high transient pressure to work at higher transient temperatures in a fast reaction chamber. Higher transient temperatures enable the use of less acid to induce short interval very weak acid hydrolysis.

The first stage of the reaction chamber at the bottom of the gravity pressure vessel is wet oxidation providing only sufficient oxygen to react with organic debris dissolved in water which will use some of the lignin and other dissolved materials to provide exothermic heat to help sustain the process. It has been observed that slightly alkaline conditions also aid in dissolving portions of the lignin from the cell walls. Cellulose fibers are known to be refractory to short duration wet oxidation at these temperatures.

The second stage of the reaction zone reduces the pH condition to initiate de-polymerization of the cellulose using carbonic acid derived from later process fermentation steps, and supplemented using sulfuric acid or maleic acid in proportions at the operator’s discretion.

The reaction time is determined by the flow rate and distance between the point of acid injection and alkali quench, which is nominally engineered to be between one and ten seconds. The de-polymerized cellulosic materials are then cooled and depressurized by returning the fluids to the surface, and then cleaned and fermented to produce ethanol.

Construction could begin in 2008 and should be completed within two years.

Indiana Ethanol Power LLC was formed through the collaboration of RW Armstrong; GeneSyst International, Inc.; River’s Bend Engineering, Inc.; Ghafari Associates, LLC. Oppenheimer and the RBC Capital Markets Corporation have teamed to provide financial underwriting and consulting services for Indiana Ethanol Power.


Al Fin

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.

Hybrid fan

"Corrupt politicians to ethanol"

lol. As oily and greasy as most CP are, perhaps a biodiesel conversion would be even more efficient.


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.

Neilen Marais

gr: It seems they are already utilising the CO2 (to make carbonic acid), not sure how easy it would be to extract sterile CO2 again after that...

Harvey D

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?


I would say that plasma take a lot of energy. This process requires the liquid to be pumped back up, but is probably more efficient at higher volumes.

Neilen Marais

to gr and self: Just checked GeneSyst's FAQ: 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.


This sounds like a pretty efficient process, but it does use acids so the environmental impact may be there. The one company doing plasma was using a Westinghouse facility. It sounds like plasma torches are not something you buy on Ebay.


In other waste-to-something-useful news:

CO2 to cyclic carbonates.


There are plenty of differences between this process and plasma gasification; this process operates at low temps and pressure, has no emissions (it's totally sealed) and the capital cost is about $67,000 per ton per day of feedstock. A plasma system will run somewhere between $150,000 and $350,000 per ton per day and does have to be permitted for air emissions.

Harvey D

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.


What you will find with "officials" and what I have outlined in some other posts is a lack of willingness to get with the program. They collect paychecks and could not care less about much of anything else. Why take risks by rocking the boat, you get a pension and vacation and you get no rewards for doing more. I know this sounds cynical, but try talking to some of these people you will see.

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


I would like to add that this is a major advance not only for conversion of waste to biofuels but also to use the attendant methane (if sufficient volume) for power generation. The path of waste to electrical generation should be fully explored beyond the combustion of liquid biofuels.

In any case GeneSyst should be congratulated for its innovative solution and Indiana for seeing and acting upon it. Good 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).


I am not afraid of it and I have no idea where you got that idea, maybe you should examine that. If a lot of it is used in the process and can not be recycled, I think we can all see that it might be a problem.

Henry Gibson

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....

Roger A. de Leon

June 28, 2008

Your waste to ethanol process using GENE-SYST TECHNOLOGY is the most practical solution in addressing the worsening problem of garbage in our country ,Philippines and the whole world as well, once this technolgy is perfected, we are looking forward to the plan construction of this system at Indiana Ehanol Power LLC and hope to see it once operational. we salute and more power to you.
Very respectfully

Roger de Leon

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