Polluted Oxygen out gassing from Polluted Water

[The Flying Fox]

So, playing around in debug mode today as I wanted to find out exactly the out-gassing properties of Polluted water.  Started with full 799Kg tiles of Polluted water.  Apparently, they don't start out-gassing into a vacuum, so I started out the air pocket with 50 grams of polluted oxygen.

 

Seems that Polluted water out-gases into Polluted oxygen at a 1:1 ratio.  A gas bubble seems to appear randomly twice a day and every time a bubble happens, 1/1000th of the Polluted water out-gasses to Polluted oxygen.  Here, 27 cycles passed which is 16200 seconds and I now have 54Kgs of Polluted oxygen.  54000/16200=3.3333~  Or 3.3~ grams of Polluted oxygen generated per second on average as long as the polluted water tile is fully loaded.

 

This means that you could produce enough air for one Dupe, by having 30 tiles of exposed Polluted water.  I proceed to test this by trapping a Dupe in a room with shelves of out-gasing Polluted water, but then... I discovered that Dupes breathe, but apparently don't consume Polluted oxygen!   No wonder why the stuff is so hard to get rid of!

 

[RemyG]

Pretty on par with my own experiences. I am approaching cycle 4000 in a stress test run of a colony where I employed an average of 35 tiles of polluted water per duplicant to create polluted o2 for the base, going so far as to design tiers of mesh tiles braced by gas tiles to add more surface area throughout the colony. I have rarely been below 2000g/tile in my base since cycle 110 when I began flooding the area with polluted water, going so far as to create adequate pressure all the way to my top of the world expedition. I would say however that dupes do appear to breathe the polluted o2 in my colony otherwise my base pressure should be sky high due to the polluted water ignoring gas pressure limits.

[rezecib]

I've noticed that some aspects of creatures don't function properly after being debug-teleported (e.g. pufts will breath in but never produce slime). The solution I found was reloading after moving them. Perhaps that's what you encountered? @The Flying Fox

[Trego]

1 minute ago, RemyG said:

Pretty on par with my own experiences. I am approaching cycle 4000 in a stress test run of a colony where I employed an average of 35 tiles of polluted water per duplicant to create polluted o2 for the base, going so far as to design tiers of mesh tiles braced by gas tiles to add more surface area throughout the colony. I have rarely been below 2000g/tile in my base since cycle 110 when I began flooding the area with polluted water, going so far as to create adequate pressure all the way to my top of the world expedition. I would say however that dupes do appear to breathe the polluted o2 in my colony otherwise my base pressure should be sky high due to the polluted water ignoring gas pressure limits.

Yea, I always thought dupes consumed polluted oxygen, because my bases seem to gradually clean themselves out without active help from me.  Perhaps over time the polluted oxygen goes out through the airlocks in bits?  How do you avoid a layer of CO2 on top of your polluted water?

[RemyG]

Gas naturally gravitates to the bottom right by weight so I just let it flow down and through my base to this scrubber which then dumps what little co2 gets scrubbed into the reservoir. Eventually I'll send it to my peppers instead.

[The Flying Fox]

5 minutes ago, rezecib said:

I've noticed that some aspects of creatures don't function properly after being debug-teleported (e.g. pufts will breath in but never produce slime). The solution I found was reloading after moving them. Perhaps that's what you encountered? @The Flying Fox

I did not test for this originally, but just did.  Reloading the save with my Dupe in the room with Polluted Oxygen do not result in him consuming the polluted oxygen.  However, I can easily teleport him back and forth between the oxygen room and the polluted one and he always consumes oxygen with the resulting pressure going down.  Not for the polluted oxygen.

[rezecib]

A bit of a necro, but thanks to Risu's help here, I learned where the code was controlling this. However, it does pass the values into Sim so I had to do an experiment to really narrow it down.

The relevant code is:

        debugProperties.contaminatedOxygenEmitProbability = 0.001f;
        debugProperties.contaminatedOxygenConversionPercent = 0.001f;

So each time it bubbles, it converts 0.1% of the mass to polluted oxygen, as The Flying Fox found. The probability requires an experiment, because although it's also set to 0.1%, we don't know how often it rolls.

Changing the probability to 1, I did an experiment with a pool of polluted water. It decreased from 499 kg to 478.4 kg over 10.36 seconds. This is an average loss of 1.988 kg/s. Using the average of the start and end mass to calculate a theoretical loss rate (based on the code), we estimate 0.489 kg per emission. This is off by a factor of 4, so it seems that the probability is rolled 4 times a second.

I also tested briefly to see if it was just using the surface cell's mass or the whole column, and it just uses the surface cell. So the exact amount of polluted water matters a lot; near 800 kg on the surface it will be maximized, and with just a thin layer it will produce almost nothing.

So to turn this into practical knowledge, we can now find the expected conversion rate of polluted water: it's (4 rolls/second)*(0.001 emissions/roll)*(600 seconds/cycle)*(0.001 /emission)* = 0.0024 /cycle, or 0.24% converted per cycle.

So in the best case, if you keep a surface cell at 800 kg of polluted water, you can get 1.92 kg/cycle of polluted oxygen. Realistically it will be a bit lower than that, because at 800 kg you are exactly at the threshold for spilling over, which would create a very shallow layer in the next cell up, with extremely low production.

[The Flying Fox]

10 hours ago, rezecib said:

So to turn this into practical knowledge, we can now find the expected conversion rate of polluted water: it's (4 rolls/second)*(0.001 emissions/roll)*(600 seconds/cycle)*(0.001 /emission)* = 0.0024 /cycle, or 0.24% converted per cycle.

So in the best case, if you keep a surface cell at 800 kg of polluted water, you can get 1.92 kg/cycle of polluted oxygen. Realistically it will be a bit lower than that, because at 800 kg you are exactly at the threshold for spilling over, which would create a very shallow layer in the next cell up, with extremely low production.

Awesome man, that's great!  So, I was pretty darn close with my guess of a practical generator.  Dupes need 60 kg of air each cycle, so divide by 1.92 kg and you get 31.25.  So, around 31-32 tiles of exposed fully-loaded polluted water to generate enough air for one Dupe.

 

Also, from what I read of Risu's post and yours, that it's interesting to note that the sim ticks 4 times a second.  That could be handy to note for other things. 

[Risu]

34 minutes ago, The Flying Fox said:

Also, from what I read of Risu's post and yours, that it's interesting to note that the sim ticks 4 times a second.  That could be handy to note for other things.

It tries to. That's the problem. In an ideal situation it happens every 0.25 seconds but it realistically happens
at any point between 0.25 and 0.31 seconds but the simulator assumes 0.25 seconds passed.