First of its kind CO2-free natural gas burning power plant undergoes first fire

[rangerrebew]

First of its kind CO2-free natural gas burning power plant undergoes first fire
June 1, 2018 by Bob Yirka, Tech Xplore
NET Power's 50 MWth Demonstration Plant in La Porte, Texas

Officials with NET Power, LLC recently reported the first successful firing of the combustor for a new kind of natural gas-based power plant free of carbon emissions, without having to use carbon capture technology.

The new plant, based in La Porte Texas, is a demonstration and test facility to test a new way to make electricity—they call it Allam Cycle technology after Rodney Allam, the inventor of the design. Doing so, engineers report, involves employing a seven-stage process that results in the production of electricity and emission of liquid water. Also, a small amount of CO2 is collected in a form that can be used for other applications such as natural gas extraction.

https://techxplore.com/news/2018-06-kind-co2-free-natural-gas-power.html

[Elderberry]

"Officials with NET Power, LLC recently reported the first successful firing of the combustor for a new kind of natural gas-based power plant free of carbon emissions, without having to use carbon capture technology. "

They have only replaced "Carbon Capture" with "Carbon Dioxide Capture"

a small amount of CO2 is collected in a form that can be used for other applications such as natural gas extraction.

Since natural gas is mostly methane and 75% of the weight of methane is carbon, they must be collecting a whole lot more CO2 than a "small amount"

[IsailedawayfromFR]

I cannot make heads or tails of what is going on here.

Where is the CO2 going?  The paper is only saying 5% is being 'sold', apparently for 'natural gas extraction'.  What in the world is that?

Reminds me of the sidewalk trickster with the three cups suckering you in by asking which cup is the bean under.

[Oceander]

I cannot make heads or tails of what is going on here.

Where is the CO2 going?  The paper is only saying 5% is being 'sold', apparently for 'natural gas extraction'.  What in the world is that?

Reminds me of the sidewalk trickster with the three cups suckering you in by asking which cup is the bean under.

The bulk of the CO2 appears to be retained and used as the generating fluid (if that's the right term, or at least close enough that it conveys the idea). 

[Smokin Joe]

Since the products of burning CH₄ are CO₂ and H₂O, and most of the weight of the Methane molecule (as has been pointed out) is the Carbon Atom, somehow this stoichiometry isn't working out, quite. For every molecule of Methane, a molecule of Carbon dioxide should be produced. Unless they are only using a small amount of Methane, they will produce proportional amounts of Carbon Dioxide.

 

[Free Vulcan]

Apparently the CO2 is being used to spin the turbines instead of steam. Even so I'd think they'd still generate CO2 well beyond the need for the turbines, so saying they're only siphoning off 5% of that seems small.

Related article:

https://techxplore.com/news/2017-05-power-carbon-dioxide-steam.html

[Suppressed]

This article gets it wrong. 100% of the generated CO₂ is sent off for use, though a portion of the flow is reused.
https://en.wikipedia.org/wiki/Allam_power_cycle

Nothing earth-shattering on the carbon dioxide side. It still generates just as much.

[Elderberry]

I cannot make heads or tails of what is going on here.

Where is the CO2 going?  The paper is only saying 5% is being 'sold', apparently for 'natural gas extraction'.  What in the world is that?

Reminds me of the sidewalk trickster with the three cups suckering you in by asking which cup is the bean under.

They got that wrong too. CO2 is used for Enhanced Oil Recovery.

[Free Vulcan]

This article gets it wrong. 100% of the generated CO₂ is sent off for use, though a portion of the flow is reused.
https://en.wikipedia.org/wiki/Allam_power_cycle

Nothing earth-shattering on the carbon dioxide side. It still generates just as much.

That makes a helluva lot more sense.

[IsailedawayfromFR]

They got that wrong too. CO2 is used for Enhanced Oil Recovery.

But only in certain places.  It is impossible to get enhanced natural gas recovery from CO2.

[IsailedawayfromFR]

This article gets it wrong. 100% of the generated CO₂ is sent off for use, though a portion of the flow is reused.
https://en.wikipedia.org/wiki/Allam_power_cycle

Nothing earth-shattering on the carbon dioxide side. It still generates just as much.

what use is that?

[Elderberry]

what use is that?

It allows them to claim they are NOT an EVIL CO2 EMITTER

[IsailedawayfromFR]

It allows them to claim they are NOT an EVIL CO2 EMITTER

Actually, the best usage might be to send it into the atmosphere so our crops can grow better.

[Elderberry]

Actually, the best usage might be to send it into the atmosphere so our crops can grow better.

I totally agree.

[the_doc]

They got that wrong too. CO2 is used for Enhanced Oil Recovery.

Right.  You can get more oil out of a field by C02 injection--but not more natural gas unless you are willing to contaminate the natural gas with more C02. 

[thackney]

Right.  You can get more oil out of a field by C02 injection--but not more natural gasunless you are willing to contaminate the natural gas with more C02.

Not even then.  You don't decrease the natural gas viscosity with CO2 like you do with crude oil.

[the_doc]

Not even then.  You don't decrease the natural gas viscosity with CO2 like you do with crude oil.

Good point.

[Smokin Joe]

Actually, the best usage might be to send it into the atmosphere so our crops can grow better.

watch someone pipe it into one of those 'medical' grow operations to enhance yield....

[thackney]

watch someone pipe it into one of those 'medical' grow operations to enhance yield....

CANNABIS 101GROWING
How to Use CO2 to Increase Cannabis Yields
https://www.leafly.com/news/growing/co2-for-growing-marijuana-plants

[IsailedawayfromFR]

Not even then.  You don't decrease the natural gas viscosity with CO2 like you do with crude oil.

That is just one of the reasons why CO2 works to increase the amount of oil recovery.  It also serves as a displacement mechanism under conditions of immiscibility.

[thackney]

That is just one of the reasons why CO2 works to increase the amount of oil recovery.  It also serves as a displacement mechanism under conditions of immiscibility.

Thank you, I over simplified. CO2 does "push" as well, like a water injection system would.  The CO2 would mix into Natural Gas.

[IsailedawayfromFR]

Thank you, I over simplified. CO2 does "push" as well, like a water injection system would.  The CO2 would mix into Natural Gas.

It only 'pushes' if the CO2 is immiscible with the crude, or if the crude is completely saturated with CO2.

[thackney]

It only 'pushes' if the CO2 is immiscible with the crude, or if the crude is completely saturated with CO2.

Isn't that the same as what you said here?

It also serves as a displacement mechanism under conditions of immiscibility.

Perhaps I'm confusing something.  If you mean different things with these two, can you point me at something to read to understand it better?

[Elderberry]

CO2-EOR Primer: https://www.netl.doe.gov/file%20library/research/oil-gas/CO2_EOR_Primer.pdf

[IsailedawayfromFR]

Isn't that the same as what you said here?

It also serves as a displacement mechanism under conditions of immiscibility.

Perhaps I'm confusing something.  If you mean different things with these two, can you point me at something to read to understand it better?

Not exactly.

It is ONLY a displacement mechanism in immiscible conditions.

It is both a viscosity-lowering component under miscible conditions as it swells crude, but is also partially a displacement mechanism when the crude is CO2-saturated under miscible conditions, ie - there is extra CO2 available above full saturation.

The only time one does not get displacement is when CO2 is in insufficient volume to achieve full saturation under miscible conditions.  In that case, one does not achieve the full beneficial effects from miscibility.

[Smokin Joe]

CO2-EOR Primer: https://www.netl.doe.gov/file%20library/research/oil-gas/CO2_EOR_Primer.pdf

Thanks! I am always looking to learn more!

[thackney]

@Elderberry @IsailedawayfromFR

Thank you.  I really appreciated IsailedawayfromFR summary.  That made sense.

[IsailedawayfromFR]

CO2-EOR Primer: https://www.netl.doe.gov/file%20library/research/oil-gas/CO2_EOR_Primer.pdf

Pretty good summary.  I have been involved with EOR projects including CO2 floods for decades.

When one reads it, one has to be asking why more oil is not undergoing Enhanced Recovery using CO2?

It after all is proven to work but is not generally applied save in specific places in the industry.

1. It is expensive.  Adds a few bucks per bbl produced.
2. One needs CO2.  Seems obvious, but a source of CO2 is extremely important. The only large-scale floods such as out in West Texas have large quantities of sourced CO2 available, mostly in Colorado.  Gas plants invariably emit CO2 but that needs to be captured and pipelined to a nearby suitable field.
3. It is corrosive.  Yeah, CO2 in the presence of water greatly increases the corrosion of produced fluids.  More $/b to handle.
4. One needs miscibility to get best economics.  So most oil fields do not qualify as candidates. See
Criteria for Screening Reservoirs for CO2
 EOR Suitability
Depth, ft < 9,800 and >2,000
Temperature, °F <250, but not critical
Pressure, psia >1,200 to 1,500
Permeability, md >1 to 5
Oil gravity, °API >27 to 30
Viscosity, cp ≤10 to 12
Residual oil saturation after
waterflood, fraction of pore space >0.25 to 0.30

A couple of more bullets:
a.  It is my belief that most papers overestimate the amount of recovery of oil via CO2.  Why?  Because implementing a CO2 flood entails drilling a lot more infill wells, maybe 2X as much, to achieve the proper reservoir sweep.  An infill well will recover some oil without the help of CO2, but ALL of its production will be included anyway as incremental CO2 recovery.
b. Other fluids can produce the same effect as CO2 under miscibility.  NGLs is a good one, but is expensive to purchase and use and is normally rejected for that reason.  Nitrogen is abundant and cheap, but its miscibility pressures are high and need the right type of reservoir.
c.  The types of reservoirs currently being drilled (shales, unconventionals) do not lend themselves to the usage of CO2 as their permeability is too low.  There are test cases out there still as the IP volumes are so great it is tempting to try.