CO2 capture system for engine exhaust - field movable

[dev_ops]

Is there a viable, field movable CO2 capture solution that exists in the market for engine exhaust?
Field movable = something transported on the back of a flat bed truck and not requiring permanent installation on the ground
Capacity = ability to capture atleast a proportion of ~700tons of CO2/year from engine exhaust post treatment

 

[LittleInch]

Capture and put where exactly?

None I'm aware of.

The back pressure is a bit of a killer usually as is the power to run the said CO2 capture plant

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[dev_ops]

Capture, store in barrels (liquid?) and dispose, probably at a CCS facility. Came across this recently and got me thinking of options, especially if miniaturization is not a requirement -

https://www.sciencedaily.com/releases/2019/12/191223122804.htm

Seeing as you are a petroleum engineer, I'm actually exploring this for generators and engines on wellsites.

 

[georgeverghese]

The devil is often in the details - how do these metal organic frameworks fare with contaminants in the exhaust stream - CO, NO, NO2, unburnt paraffins, olefins and aromatics? Irreversibly poisoned? In diesel engines, there is also particulate carbon which could bung up the pores in this MOF.
If you ask me, I'd say the fossil fuel based IC engine's days are numbered, given thermal eff is less than 15%: major contributor to global warming with this hot exhaust; getting investment agencies to put their money on this wont be easy.
Heat recovery from this hot exhaust from larger engines to generate supplementary power would be more stable, process wise, and may generate better returns on investment in the short term while IC engines live out their remaining days. At the current slow rise from 400ppmv CO2 in the atmosphere, incremental radiative absorptivity due to CO2 is most likely only a small contributor to global warming compared to hot exhausts from all types of power plants, ships, aircraft and civilian transport.

 

[LittleInch]

I read the attached and find it very difficult to believe you can get all of that work inside a box 2m3 with no energy losses.

I'm also not sure what this mysterious process is to turn CO2 back into some sort of fuel.

If it was that easy then I think all the CO2 carbon capture plants would have done that and not looked at just pumping it into underground storage systems.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[SuperSalad]

It mentions the weight being 7% of the vehicle weight. Keep in mind that means the truck's carrying capacity is then reduced by 7% since many trucks operate at or near the overland weight limit. Trucking companies won't be too keen on that.

Another thing is that you are reducing fuel efficiency by about 2.8% with the extra weight, if my math is right, for a truck at the 80,000 lb overland limit. That is another hard sell to the trucking industry.

One last point that makes this seem extremely dicey to me is the storage of the CO[sub]2[/sub] onboard. A 55 gal drum of liquid CO[sub]2[/sub] weighs around 505 lbs. With ≈22 lbs of CO[sub]2[/sub] produced for every gallon of diesel burned, you are looking at an extra 505 lbs of freight every ≈23 gallons of fuel used. Even the smallest semis fuel tanks are around 125 gallons, so that means an additional 1,705 lbs (weight of CO[sub]2[/sub] produced minus the weight of fuel burned to produce it) needs to be factored into every load.

I'm sorry, but even if the technology is there, this would be a tremendously difficult sell to the trucking industry.

Andrew H.

http://www.MotoTribology.com

 

[MortenA]

You cant have liquid CO2 at atm pressure. You would have to stay above 74 barg. When you burn a kg of HC you get 2 kg of co2. It seems like an impossible task.

 

[SuperSalad]

The article does mention the use of:

High speed turbocompressors developed by Jürg Schiffmann's laboratory at EPFL's Neuchâtel campus use heat from the vehicle's engine to compress the extracted CO2 and turn it into a liquid.

Andrew H.

http://www.MotoTribology.com

 

[TiCl4]

This isn't going to be feasible. The ultimate idea of CO2 recapture would be to do something like a reverse water gas shift into Fischer Tropsch process to turn the CO2 into fuel.

I worked with the development of some Fischer Tropsch catalysts and reactors. Given you need to run a RWGS reaction (CO2 + H2 -> CO + H20), you'll need a large supply of H2. There isn't really an economical means of generating large amounts of H2 - electrolysis can handle the volume, but is expensive.

The LTFT proces (low temp Fischer Tropsch) that Sasol uses (supposedly) has higher efficiency once the syngas is available, but the economics of this idea mean that it will only be economically feasible when oil prices are something like $130+/bbl (give or take a fairly large margin of error - I worked on this almost a decade ago). Adding modular CO2 recapture will only increase breakeven prices further.

 

[MortenA]

@TiCl4 - and if you had a large supply of H2 in your vehicle - wouldnt you just use that as a fuel?