Recycling Rocket Exhaust Gases?

[VitorF]

So I took a shot at cooling and recycling rocket exhaust gases, and it turns out that it is quite viable!

The rockets have a fixed mass exhaust, so if you build small rockets with small quantity of fuel, it is even possible to generate more water with rockets. EDIT: i.e. You can generate more water than what you're consuming.

It is possible to recycle water with the steam/hydrogen engines, and recycle the carbon dioxyde from petrol engines.

 

I made this setup using a super-coolant loop and petrol pockets for heat dispersal and higher thermal heat capacity.

 

The "squares" with petrol in them, altough expensive, help out in the heat dispersal along with the super-coolant loop.

[cblack]

Out of curiosity, is it better to use PW over petroleum?  It doesn't have the heat range, or the conductivity, but it does have a higher specific heat.

Anyway, it's an interesting idea but I always have excess water in my games, so I never feel the need to conserve the exhaust gasses.

[VitorF]

1 hour ago, cblack said:

Out of curiosity, is it better to use PW over petroleum?  It doesn't have the heat range, or the conductivity, but it does have a higher specific heat.

Anyway, it's an interesting idea but I always have excess water in my games, so I never feel the need to conserve the exhaust gasses.

PW would work too! I only chose petroleum because of its thermal conductivity and thermal range in the liquid state.

1 hour ago, cblack said:

Out of curiosity, is it better to use PW over petroleum?  It doesn't have the heat range, or the conductivity, but it does have a higher specific heat.

Anyway, it's an interesting idea but I always have excess water in my games, so I never feel the need to conserve the exhaust gasses.

BTW, I'm still testing this idea out. And it's not even completed yet, since this demands a huge ammount of super-coolant (for the pipes that go along all the rocket silo)

[ChickenMadness]

Very cool. I like this.

[biopon]

5 hours ago, VitorF said:

You can generate more water than what you're consuming.

Any specifics maybe?

[VitorF]

19 minutes ago, biopon said:

Any specifics maybe?

I haven't measured exactly, since my silo's floor is too large, and it takes a while for all the steam to condensate. But with the Hydrogen engine, I can estimate I get about 800 kg of water per launch and 800 kg per landing.

I can't confirm this though, and this depends on many things, such as how tall your rocket silo is, how fast you manage to close the doors to prevent loss to vacuum, and so on.

 

It's way easier to cool down the petrol engins exhaust gas though, since the gas' temperature isn't as high, and carbon dioxyde's specific heat is much lower than steam's. (Steam = 4.179, Carbon Dioxyde = 0.846).

I have no idea how much carbon dioxyde the petrol engine generates though. But it was a considerable ammount. When I was using petrol engines, I had 2 pumps with 100% uptime, and the pressure would still be around 3 kg in the silo. Slicksters were getting fat.

[ishakaru]

I can't tell, do you have a tempshift plate behind the petrol in those boxes? I wonder how well a vacuum in those boxes with a low TC material tempshift would work. 

[VitorF]

1 hour ago, ishakaru said:

I can't tell, do you have a tempshift plate behind the petrol in those boxes? I wonder how well a vacuum in those boxes with a low TC material tempshift would work. 

Yes, I placed tempshifts in every box, though they're made of igneous rock for their specific heat.

I don't know how it would fare in a vacuum though, but the higher TC, the better also.

I think that the best liquid would be super-coolant, but getting to fill all the "boxes" with it would be a nightmare. It would be nice though, if you had that much super-coolant to spend.

[Sasza22]

Ideally you should put the rocket on the bottom of the map, right above magma. The longer the rocket`s travel path the more exhaust gas it produces. If you seal the entire silo off and condense the water near the top the steam will eventually have to get up there as it has nowhere to go.

Can`t tell how deep is your silo design based on the screenshot.

[VitorF]

6 minutes ago, Sasza22 said:

Ideally you should put the rocket on the bottom of the map, right above magma. The longer the rocket`s travel path the more exhaust gas it produces. If you seal the entire silo off and condense the water near the top the steam will eventually have to get up there as it has nowhere to go.

Can`t tell how deep is your silo design based on the screenshot.

It's only 70 tiles deep. But you do get diminishing returns from having a deeper rocket silo, since the rocket accelerates quickly. This one I built is just tall enough to fit all rocket designs.

Also, watch out when condensing the steam using super-coolant. If you cool the air in the silo too much, the carbon dioxyde will also condense, and the water at the bottom will turn into polluted water on contact with the liquid carbon dioxyde. I usually limit the outlet of my aquatuners to -47 C.

[Lilalaunekuh]

2 hours ago, VitorF said:

the water at the bottom will turn into polluted water on contact with the liquid carbon dioxyde.

Wait, is it really that easy to create more polluted water ?

(Never thought about cooling my silo below 40°C^^)

[VitorF]

Just now, Lilalaunekuh said:

Wait, is it really that easy to create more polluted water ?

(Never thought about cooling my silo below 40°C^^)

Yes! I didn't know that either.

I thought that my pipes were breaking, because polluted water kept appearing at the bottom of the silo. Turns out it was the liquid carbon. It merges with clean water and turns into polluted water. I don't know what the water/carbon ratio is though...

[Lilalaunekuh]

Now the big question: How does it compare to a carbon skimmer.

 

[Xenologist]

7 minutes ago, Lilalaunekuh said:

Now the big question: How does it compare to a carbon skimmer.

 

Has to be more as the carbon skimmer removes carbon dioxide, but the water merges with the carbon dioxide

[Nitroturtle]

3 hours ago, VitorF said:

Also, watch out when condensing the steam using super-coolant. If you cool the air in the silo too much, the carbon dioxyde will also condense, and the water at the bottom will turn into polluted water on contact with the liquid carbon dioxyde. I usually limit the outlet of my aquatuners to -47 C.

I'm a little skeptical.  I don't know where your polluted water is coming from, but I just did some brief testing in debug and saw nothing like what you're describing here.

[VitorF]

14 minutes ago, Nitroturtle said:

I'm a little skeptical.  I don't know where your polluted water is coming from, but I just did some brief testing in debug and saw nothing like what you're describing here.

You're right, I tried re-creating it on sandbox,  but I couldn't do it. But I still need to figure where that polluted water came from, I was sure it was the condensing carbon, since it started appearing at around -45 C. I might remove the output pipe minimum temperature and check it again. Super-cooling the silo is still not a great deal though, the carbon condenses and it's still a bad sight.

Edit: also, the visco-gel door freezes shut

[biopon]

16 hours ago, VitorF said:

I haven't measured exactly, since my silo's floor is too large, and it takes a while for all the steam to condensate. But with the Hydrogen engine, I can estimate I get about 800 kg of water per launch and 800 kg per landing.

I can't confirm this though, and this depends on many things, such as how tall your rocket silo is, how fast you manage to close the doors to prevent loss to vacuum, and so on.

Thanks for this! But you know this isn't nearly close to the water you're using for a launch? 1600 kilos will only get you about 180kg H2 after electrolysis. You'd need over 200 kilos just to get to 10k with nothing but tanks and a command module.

I will give this a shot with a bottom-of-the-map silo when I get around to it in my game. The rocket might accelerate quickly but it seems that the steam output is unceasing until it leaves the map.

[VitorF]

3 hours ago, biopon said:

Thanks for this! But you know this isn't nearly close to the water you're using for a launch? 1600 kilos will only get you about 180kg H2 after electrolysis. You'd need over 200 kilos just to get to 10k with nothing but tanks and a command module.

I will give this a shot with a bottom-of-the-map silo when I get around to it in my game. The rocket might accelerate quickly but it seems that the steam output is unceasing until it leaves the map.

Yes, I tested it again, and there really isnt diminishing returns when it comes to making the rocket silo deeper. I wish I could do it from the bottom of the map, but in the current map seed, there are a few indestructible structures (geysers and ruins) that prevent me from trying this out.

Edit: btw, I know it isn't much water recycled, but in this map seed, clean water and polluted water is very scarce. There's only 2 steam geysers with small mass output.

4 hours ago, biopon said:

Thanks for this! But you know this isn't nearly close to the water you're using for a launch? 1600 kilos will only get you about 180kg H2 after electrolysis. You'd need over 200 kilos just to get to 10k with nothing but tanks and a command module.

I will give this a shot with a bottom-of-the-map silo when I get around to it in my game. The rocket might accelerate quickly but it seems that the steam output is unceasing until it leaves the map.

And other thing, if you're planning on making a rocket silo that deep, you should try out farming CO2 gas from meteors. I've had this idea for some time now, but haven't tried it out myself... 

My idea was opening the silo's bunker doors when meteor showers happen, and make the structures in the silo meteor-proof. Each meteor outputs tons of CO2, great for slickster farms.

[hackcasual]

I'm meaning to play around with exhaust capture on my next playthrough. The easiest way to measure I've found is to use debug mode, delete every gas and liquid in your tube, launch the rocket, then once your launch tube is sealed, pause and use the heat tool to cool all your gases to liquid/solid, un-pause, wait for them to fall, pause, wall them off (should just be 1 tile high at the bottom), then apply heat if needed, leaving yourself with a nice neat row to count.

[Lilalaunekuh]

10 hours ago, hackcasual said:

The easiest way to measure I've found is to use debug mode, delete every gas and liquid in your tube, launch the rocket, then once your launch tube is sealed, pause and

select the rocket silo with the debug tool (not sandbox^^) and the total amount of steam/water/CO2 will be displayed on the right.

(Everything added up, no need to change the temperature or wait for anything)

[VitorF]

On 17/01/2019 at 12:11 AM, hackcasual said:

I'm meaning to play around with exhaust capture on my next playthrough. The easiest way to measure I've found is to use debug mode, delete every gas and liquid in your tube, launch the rocket, then once your launch tube is sealed, pause and use the heat tool to cool all your gases to liquid/solid, un-pause, wait for them to fall, pause, wall them off (should just be 1 tile high at the bottom), then apply heat if needed, leaving yourself with a nice neat row to count.

I just tested it out. I launched a steam rocket from a very deep silo. The silo's base was just above the slickster/oil biome. I managed to condense all the steam from launch and landing, and the grand total was 3300 kg of water. It's quite a lot imo, since I just spent 695 kg of steam to launch it. I launched it with 5 research modules.

The steam exhausted by the steam engine is considerably cooler than the one from the hydrogen engine, so condensing it was almost instant.

It wasn't in debug mode tho, it took a lot of time to setup. The "deep silo" is just to the right, in the screenshot.