Sulfurless sour gas boiler

[Onairda]

So, I was aiming to make my last colony 0 waste: no infinite storage of any kind, and no dumping gas/liquids into space. That meant that i could not make a sour gas boiler, since there is no sulfur sink in the game afaik. After i looked around on the forums and the subreddit, i came to the conclusion that I'm either terrible at basic research (very plausible) or that it is currently impossible, and resigned to just have a petroleum boiler.

That was until, while randomly checking the wiki, i notice this line in the tips section: "If Sour Gas at sufficiently low pressure is cooled, 100% of its mass condenses into methane. The exact pressure necessary for this is not currently known, but it seems to be around 5 grams of Sour Gas per tile (or less)."

That piqued my interest, and so i started testing and quickly found that any amount below 3 grams of sour gas condensing does not generate sulfur (the precise amount is 3.030303g, or exactly 1/330 kg down to the micrograms. I would guess that it's because the game just doesn't bother to spawn less than 1 gramm of sulfur). It needs a pool of methane to consense into, otherwise the game deletes such small amounts, but it's proper sulfurless methane production, and it gets you 50% more methane than the standard method for free.

A vent and valve pair is required to have a constant flow of gas (at least if you aim to keep it compact), and a pool of liquid is necesary to prevent deletion, so each unit producing 3g/s of methane requiries at least 3 tiles + 1 for the floor on which the liquid rests, so that refining a full pipe of crude oil would require 10000/3*4 ≈ 13000 tiles, or 130 * 100, which is not exactly viable, and seems to restrain this mostly to a theoretical curiosity and out of standard survival games.

 

Or so i thought. Lets fast forward a bit...

I present to you what is, to the best of my knowledge, the first ever sulfurless sour gas boiler:

It's just a prototype i used for testing this and has a lot of things that I'd like to work on and improve, but I have already delayed this post too much, and if I wait for it to be perfect it will never get finished.

Still, given that it takes in 10kg/s of crude oil and converts it completely to methane I fell like I still have the right to call it a ten out of ten.

It would output 10k/s of natural gas, but it currently outputs only 8.74kg/s since it has to supply a small generator room for powering the 11kw required on average to keep it running (10.08 kw of which are used by all 40 gas pumps and 2 liquid pumps running 24/7). This is in sandbox, but this design should work for survival too if you go a bit cheaper on some parts of it and have a lot of aluminium and super coolant to fill the pipes with.

 

Let's get a quick tour, these are the main components (ignore the completely radom color choices):

This is the sour gas boiler:

It's pretty simple: 95°C crude oil gets in, 140°C sour gas gets out, cooled further by the methane on top thanks to the thermal shift plates and metal tile ceiling to 110°C by the time it gets pumped out. It uses a bead pump for the counterflow heat exchange and 3 doors for thermal regulation: one (iron ore) is always engaged unless it overheats (should never happen unless the flow of crude oil gets cut off), and provides a little less than the heat needed. A second one (copper ore) engages briefly to keep the temperature above 541°C, and the third one (thermium) is used in case of emergencies where the boiler room gets too cold (should never happen during normal operations, it can help during startup if the flow is stopped, but you still have to start slow). The aquatuner keeps the steam room at 650°C and generates excess cooling, working at an average of 40% of the time. The excess cooling is managed by two liquid tepidizers working 3% and 5% of the time.

20 gas pumps send the sour gas counterflowing with 1kg packets of liquid methane (so that it can't boil in the pipes) kept thanks to a liquid tepidizer at above -165C° to avoid gas condensation in the pipes. Every stage of every line in the exchanger is vacuum isolated from everything else, and the first and last stage are all connected to make sure all the lines in the exchanger are kept at the same temperature, giving an output of sour gas at a constant -156.3°C and methane at 67°C, that gets further warmed up by sour gas trough the metal floor to 106°C. To the left is the cooling box cooled by the aquatuner (and warmed if below -180°C by a liquid tepidizer). It cools the liquid pipes used to condense the methane, and uses a checkerboard pattern of aluminum metal tiles and thempshift plates to maximize thermal condutivity both with the pipes and with itself.

Finally, last but definitely not least, the condenser:

With a size of 53x31 for a total of 1643 tiles it's way more compact that I though I could have ever got it in the beginning, and is the result of a few iterations that kept shrinking it. It takes in 10kg/s of sour gas at -156°C and -180°C super coolant (that get warmed up 0.5°C before going back in the cooling box) and generates around 10kg/s of methane at -171°C, with small losses due to sulfur production. It almost never generates sulfur as long as the temperatures are kept low enough, and i suspect that the few piles that i keep finding are made during reloading. The methane get collected by a pump at the bottom and sent to the heat exchanger. This is the new design:

First of all i realized that i don't need the pool at the base since a coloumn of vents can drop in the same tile and if tall enough the ammount of methane produced is enough to avoid deletion, so i could get rid of the floors. Then, instead of coming in contact with cold methane as soon as it gets out of the vent, the gas flows to the nearby tiles, where it freezes on contact before exchanging heat, so that the gas tile the vent is in is completely vacuum isolated. That allows us both to double the amount of methane produced by using both the top and the bottom of a tile, but also to have gas condense every tick instead of every second. Because of how the gas mechanics work it's not possible to get the theoretical maximum of 30g/s for vent, but this design manages 19g/s, which I think is close to as good as it's practically possible to get, unless there is some game mechanic that i'm unaware of or something that i'm overlooking. It's possible to set it higher and still have it working, but every now and then in my experiments it spat out some sulfur, so if you don't care about that and want a smaller condenser you can experiment with different flowrates.

It's possible to make this work without aluminum, but then the supercoolant must be at very low temperatures (in my tests it was around 40K iirc) and you have the risk of freezing the methane if you cool it too much, which is not a problem when you can keep the pipes at or above -180°C.

when the condenser is off it is possible to perform maintenance with a jet suit, since at the temperatures the pipes are kept at the co2 will freeze and not compromise the vaccum. If you use a jet suit while it's on it will displace the sour gas and cause it to drop lots of sulfur, eating all your frames in the process.

That said, as long as you don't open the gas overlay or cause it to spawn and drop hundreds of packets (i forgot how they are called) of sulfur i found that it doesn't lag the game to much, but it's probably becuse it's an empty sandbox game, so build it at your own risk. if you do build it i suggest to precool the heat excanger (to avoid a rain of sulfur and your computer melting) and the walls of the condenser even if they are insulated, because in testing i found it caused problems and produced some sulfur.

Anyway, this is what i found, I hope that i didn't forget anything important and that i didn't bore you too much with the small story at the beginning and the tour of my first sour gas boiler. I'll probably try to improve it in the future, but i think i'm bit burned out for now and want to set it aside for a while to go back to my survival game. Let me know what you think!

[thegroundbelow]

Holy CRAP that is a monster, and AFAIK the single most efficient sour gas boiler ever built in its conversion from crude oil to natural gas. Good job!

[Xenologist]

How would working around an oil well work for that? Or perhaps a leaky oil fissure? How would you adjust it to work with those?

[Onairda]

it's already designed to work with 3 oil wells, since it's tested with 95°C oil. if you have a leaky oil fissure mixed in it should not be a problem, since it has excess cooling to deal with that and it should not warm the oil too much since it's a small ammount of mass (max form 1 is 250g/s, so if you use 4 leaky fissures you have at most 10% of the oil being a 326°C, so you get 10kg/s of 118°C oil). If you somehow use it with only leaky fissures (it would take 40 of them all maxed out or around 80 with average output) it might be hotter that this design could handle, but i need some testing before i can say that for certain. If that's the case the first fixes that come to mind is a longer heat exchanger and to add between the sour gas boiler and the pumps a section where a supercoolant pipe syphons off the heat to a steam turbine to bring the gas to around the 150°C range.

[TheMule]

This is a fantastic job, but I can't keep my eyes off the jetsuit... I imagine CO2 freezes in there.

[Onairda]

yup, the dupes get a rain solid co2 following them as long as the pipes are at operating temparature, since it's 120 degrees lower than the freezing temperature. It also drops a lot of both sulfur and frames if the condenser is on since it displaces and heats the sour gas making it condense in larger packets.

[TheMule]

Flying dups who poop solid CO2 and sulfur? Fascinating. : )

[Onairda]

@Xenologist So, i tested it with 330°C crude oil to see if it could handle leaky oil fissures, and while the margins seem pretty thin, it's been able to manage it by lowering the target temperature of the aquatuner to 630°C (since otherwise the iron door transimetted too much heat) and lowering the temperature of the methane entering the exchanger to -167°C, but i'm not too sure this second one is necessary. The aquatuner uptime got down to 25%, the coolbox tepidizer is now permanently off and the methane one is at around 0.7% uptime. This build seems to be a lot more stable than i was expecting.

[TheMule]

Well, fissures have an avg output of 200g/s IIRC. You hardly need a 10kg/s boiler.