Validating "NET Power's" use of the Allam-Fetvedt cycle

[Joseph M. Zias]

TL;DR Summary

www.netpower.com claims they have commercial use of the Allam-Fetvedt cycle.

The Allam-Fedvedt cycle is a method to burn natural gas without releasing Carbon to the atmosphere. www.netpower.com claims they have a 50 Mw commercial grade power plant using this innovation and I hope that is the case. Netpower states they are building a 300 Mw plant. This NEEDS TO BE VALIDATED! Does anyone reading this thread have any "pull" to have it done and if so make it a news item? Imagine the benefit of using fossil fuels without putting greenhouse gasses into the atmosphere. I have via tweets tried to get Ernest Moniz's attention, an email to Fox and NBC news, and an email to one of my state senators. Goodness, if this proposed system is in operation and is indeed viable it would be quite important.

 

[anorlunda]

You can read more about it on Wikipedia.
https://en.wikipedia.org/wiki/Allam_power_cycle

Be sure to read the talk page of that article where several of the claims are disputed.
https://en.wikipedia.org/wiki/Talk:Allam_power_cycle

The article said, that the final product is a pure stream of CO2 "ready for sequestration". That is not the same as sequestered. That is like saying that I have a dollar bill, "ready for investment." There are several other obstacles to overcome. See the Wikipedia article on Carbon Sequestration.

A commercial plant using this cycle is not yet ready. If it proves practical, and if affordable, and if effective, and if reliable, and if long-lived, and if maintainable, and if the CO2 is actually and permanently sequestered, it will indeed be a significant breakthrough. But don't count your chickens before they hatch.

 

[russ_watters]

The Allam-Fedvedt cycle is a method to burn natural gas without releasing Carbon to the atmosphere.

My first reaction to this is: So what.

The primary combustion products of *any* hydrocarbon thermo plant are carbon dioxide and water vapor. Condense out the water vapor and you're left with carbon dioxide. Heck, my propane furnace does that!

[Edit] Slight correction: my furnace takes in air, which has nitrogen in it. This "cycle" uses pure oxygen in the combustion. You could easily convert my furnace to do that.

The main potential benefit I see would be from *if* this cycle is any more efficient than a standard Brayton cycle/combined cycle system. But the idea has nothing specifically to do with carbon sequestration that I can see. Just adding "ready for carbon sequestration" to the label of the waste stream doesn't mean anything.

[Also edit] Due to the requirement of using pure oxygen as the oxidizer, there can't possibly be an efficiency improvement over a standard system. But it may be more efficient to remove the nitrogen before combustion rather than after.

 

[anorlunda]

The primary combustion products of *any* hydrocarbon thermo plant are carbon dioxide and water vapor.

Their claim is that the output is a liquified and pressurized stream of pure CO2. So that differs, from gaseous emissions.

If they could then inject that liquid in the ocean at depths deeper than 2700 meters, it could be sequestered in the form of stable hydrate crystals.

All that is easier said than done, but it not the same as your home furnace.

p.s. There's at least one place where this has been done, so it is an issue of practicality rather than impossibility.

https://en.wikipedia.org/wiki/Carbon_sequestration
The first large-scale CO2 sequestration project which began in 1996 is called Sleipner, and is located in the North Sea where Norway's StatoilHydro strips carbon dioxide from natural gas with amine solvents and disposed of this carbon dioxide in a deep saline aquifer.

 

[russ_watters]

Their claim is that the output is a liquified and pressurized stream of pure CO2. So that differs, from gaseous emissions.

Sure: because they paired the power plant with a gas liquefication/distillation plant. There's no secret sauce in that, and they aren't inherently connected systems.

The only secret sauce I see here is using carbon dioxide as a working fluid in the gte.

 

[Bill Sitting]

Yes, if it's successfully validated. However, no lab or pilot scale demonstration of the technology exists. The 50 MW facility at La Porte, TX never actually produced power, suggesting issues with the turbine. Now, a similar attempt is being made with a 300 MW plant in the Permian Basin. There is no guarantee that this will work either.

 

[The Fez]

My company CEO was very interested in this technology to support our zero carbon goal, so he sent two of our engineers out to La Porte to get a tour of the "fully functional" 50 MW plant, per the manufacturer. When they got out there, all the "Well, actually.." started coming out. Well, actually the plant only ever produced 2 MW. Well, actually that was with a 6 MW parasitic load (It never was able to produce even as much energy as it took to run.) Well, actually the turbine manufacturer we were working with is backing out of the partnership and taking all their designs with them, so we are going to be starting from scratch with a new vendor TBD. Finally, even if the technology is functional, the only way it can be economically viable is to find someone to actually buy all the CO2, N2, He, etc that is produced during the process. Might as well wait for commercially viable fusion.