Sporadic sour gas from oil volcano cooling - bug or not?

[riwenna]

So while I know it's a bit old, I decided to try out Neotuck's simple metal volcano build on my gold volcano. I was also at a late enough stage to be able to fill the liquid pit with Crude Oil instead of Water (but not Petroleum, as I don't have much). I was a bit afraid of the new Sour Gas thing - but never expected this to happen.

Granted, I still have to bring down the cooling chamber to a temperature sustainable by weezeworts (I've already brought the temperature down for about 30*C by "resetting" them by planting them in the base for a second when they overheat, and bringing them back), but the hydrogen chamber is currently fluctuating between 85-100*C, and the Crude Oil is usually 2-3 degrees warmer, which is well below Crude Oil boiling point.

The setup worked with no problems for some 20-30 cycles or more (except that I am still stabilizing the cooling chamber), and then I look at the volcano and puf - sour gas and droplets of Petroleum sitting on the Crude Oil. I reloaded the cycle, but the chamber kept sitting in vacuum for several cycles after. And then some 10 cycles later, maybe more, as I'm changing the worts, I see Petroleum+Sour Gas releasing when Gold fell into the oil. (No dupes in the volcano chamber so no chance they interfered with anything) I made a save, reloaded the cycle again, and this time payed attention to the volcano eurpting. This time - no Petroleum + Sour Gas. And so it continued for the next few cycles.

My question is - can this be the intended behaviour or should I report it as a bug? It seems a bit too... random to be intended, but I'd like to check with you guys if you think I missed something before I make a bug report - been leaving lots lately

Here are the screenshots, as you can see from the cycle counter, it's the same cycle, same time, so it is exactly the same volcano eruption on both screenshots, except one caused Oil->Petrol+SourGas, and upon reload it did not. I realize there's an extra wort on the vacuum picture, but it was literally planted seconds before as I realized I need more cooling, so it could not have made a difference on this particular eruption.

Sour gas:

No sour gas:

[KittenIsAGeek]

The only thing I Can think of is.. how dense is the top layer of your oil? Is it possible that the eruption is flash-boiling some of the oil?

[riwenna]

I think it's about 400kg/tile.

I think flash-boiling is the only possible thing that happened, but, again... why only once in thirty cycles, and then not again on a reload?

So... bug report?

[axxionx12]

When i built my volcano based refinery, i noticed that when liquid metal or magma came into contact with oil, it would instantly convert a small amount to petroleum, then that petroleum would rise to the top and be heated more. This caused that low mass layer to heat up rapidly and turn to gas. The solution is to slow your heat exchange with a metal rule tile/or spread the heat more evenly with temp plates.

 

As for the reload... I have no clue 

[PhailRaptor]

So...  Judging by what you're describing, it seems like the...freezing?... of the liquid Gold into a solid in the Crude is very quickly heating small amounts of Crude into first Petro, then Sour Gas.  This would suggest that the Gold is giving off it's heat much faster than the Crude can spread it around, which is why small quantities are doing this.

But...  There's no reason this should be happening only after 10+ cycles of a reload, and not doing it before that.  It should be doing it every eruption.

Definitely take this to the Bug Tracker.

[riwenna]

I took it to the bug tracker because no, it's not doing it consistently. It happened, I believe, 1 more time in the 25 cycles following the screenshots I posted. I reloaded, kept on being vacuum during the eruption.

I should check the oil temperature at those two saves... it is possible, tho very unlikely, that hot gold will turn oil into petroleum on contact above exactly the temperature I was hovering around when those screenhots were taken, and the literally 3-5 seconds of +1 wort did make a difference. But, since I started cooling all of this down from much higher temperatures (I think the oil got to 130+ before I set up the hydrogen chamber), I somehow doubt that this is it...

I'll add a couple more temp plates on those two tiles of oil, see if that makes any difference, but again... not like it's consistent in the first place.

[SakuraKoi]

It's worth noting whether the gold pattern is always the same, i.e no sour gas=solid gold in one spot and sour glass=solid gold in two spots.

I find it likely that it makes a difference if the liquid gold floats shortly or does not since if small amounts of oil being displaced through that interaction (repeatedly each frame to fill slowly up) such would be indeed the culprit.

[Neotuck]

This is why I now submerge my gold volcanoes, this makes sure the gold is in contact with full tiles of cooling liquid

 

[The Flying Fox]

I'd assume the behavior you're all seeing is related to this feature which I played around a tiny bit some many updates ago.  

 

@Neotuck  Showed off an oil-to-petro device that uses this very same feature.  This is also what causes cold biomes to 'sweat' from time to time.  Even though a polluted ice/ice block itself might not be at melting temperature, if the air around them gets warmer then their melting temp, then small amounts of of the ice melts and creates polluted water/water dripping.

 

So, I'd imagine what's happening is a very brief tile of liquid gold forms in the pool which causes a bubble of sour gas to form.  I'd guess the amount of gold that pours off has something to do with if a tile of liquid gold can briefly form or not.  Which could explain why it happens sometimes, but not other times.

[riwenna]

I also taught that the solid gold pattern might be significant, but all the times except the one I posted, the gold was only in one pile.

@The Flying Fox What you propose is very interesting - but again, I would expect it to happen consistently and not once in 30 cycles. I also seem to remember (can't be 100%) that the one gassy eruption that I did actually see (the one on the picture), there was no tiles forming.

However, I also notice just now that on my sour-gas picture the liquid gold is occupying the tile with the ladder, while normally it is not. Now, I am not sure if this happened after some of the oil got transformed and a thin layer of petroleum was left on top, or if this was what turned oil into petroleum in the first place.

[Djoums]

Maybe this has something to do with how close the molten gold is to your liquid ?

This setup has an additional empty row and I've never had petro/sour gas with it, even though the oil is constantly around 230°C.

Spoiler

 

[riwenna]

I kinda suspect that could be it, if the liquid gold touches the liquid oil when it overflows, it might cause problems.

I'll eventually try out both an extra row of tempshift plates and removing the top layer of oil, but it's going to be a while before I manage to run both of this for some number of cycles to check how consistent it is. Vacation over, not much time to play