I have been looking at the image you have,posted, there seem to be missing buildings to the right side, and I wonder about the mods you are using... not that it is oil per se... but I am not familiar with the pipes, the number of modules per refinery/chem plant and those interesting wireless/logistics looking towers in the lower right.

Maybe you have an updated image you could post?

Also, if tar sands and natural gas are not used, can this be successfully added to an existing save? There is a mod that can regenerate the map... I think maybe it could be used, if tar sands and/or natural gas were desired.

there seem to be missing buildings to the right side

The fractionators there didn't have graphics at the time.

but I am not familiar with the pipes

The blue pipes are just plastic pipes from Bob's.

the number of modules per refinery/chem plant

Also Bob's.

those interesting wireless/logistics looking towers in the lower right.

If I understand what you're referring to correctly, those are Fuel Cells from Hydrogen Power Systems.

can this be successfully added to an existing save?

Yes, ish. If you have an existing oil setup, it'll likely stop working. Tar Sand and Natural Gas will be generated in new chunks you explore, and you could use a mod like Delete Empty Chunks to reroll ones you've explored already.

Thank you very much for the answers. Ah, that explains it, I have not played Bobs.
No, not the fuel cells, I should have been more clear. The thin towers that have the spinning top of roboports. There are two of them located just north of the sulfuric acid train station.

Edit: I found them, from Bob's Logistics... zone expanders.

| "Yes, ish. If you have an existing oil setup, it'll likely stop working."

The only thing I have noticed that stopped working, is plastics. Most everything seems to continue using vanilla recipes (with Oily fluids), allowing one to build a new processing plant, without breakage. Would it be possible to also preserve the vanilla recipe, as assigned to existing chemical plants for plastics? It seems to be the sole exception, at least for my save.

I already use the same name. If it's not working, it shouldn't be because of something I did.

I think the trick is to not use the same name, instead use olefines-plastic-bar, leaving the original recipe but make it hidden, so it can not be selected again. I think that will allow existing chem plants to use the vanilla plastic recipe but it can not be selected going forward.

To test this, I modified Oil Products.lua, by replacing all instances of 'plastic-bar' with 'olefines-plastic-bar' and then added a line to hide original recipe, and it all seems to work fine. My existing, petroleum build works... but then I do not make all possible recipes (ie. solid rocket fuel from heavy oil).

I make two other adjustments, I add sulfur to the lubricant recipe, to spice it up a tad and make it a little more like how lubricants are made. I also change the sulfur recipe... adding steam as an ingredient and replacing the hydrogen product with water, as one can not derive elemental sulfur and elemental hydrogen from a single process (at least to my understanding). But now I wonder if this will destroy the balance?

And thank you for the new images of the setup, very helpful.

(ie. solid rocket fuel from heavy oil).

Heavy oil doesn't make rocket fuel...? You mean Kerosene maybe?

I add sulfur to the lubricant recipe, to spice it up a tad and make it a little more like how lubricants are made.

https://www.machinerylubrication.com/Read/28548/sulfur-used-in-lubrication

I see.

as one can not derive elemental sulfur and elemental hydrogen from a single process (at least to my understanding)

According to this https://consequential-lca.org/clca/by-products-recycling-and-waste/not-fully-utilised-by-product/example-sulfur-from-refineries/, sulfur is typically processed by oxygen, not water.

Sulfur is a by-product of processing natural gas and refining high-sulfur crude oils. According to US EPA most of the 68,000,000 metric tons of sulfur produced worldwide in 2012 was a by-product from refineries and other hydrocarbon processing plants (US EPA 2014).

The most common conversion method used in refineries is the Claus process, named after the scientist that first patented the method (US EPA):

The process consists of multistage catalytic oxidation of hydrogen sulfide according to
the following overall reaction:
2H2S + O2 → 2S + 2H2O
The Claus process involves burning one-third of the H2S with air in a reactor furnace to form sulfur dioxide (SO2) according to the following reaction:
2H2S + 3O2 → 2SO2 + 2H2O + heat
The remaining un-combusted two-thirds of the hydrogen sulfide undergoes Claus reaction (reacts with SO2) to form elemental sulfur as follows:
2H2S + SO2 ←→3S + 2H2O + heat

Sulfur is an important component of fertilizer, but also has many other industrial uses.

And currently, you need the hydrogen back from that hydrogen sulfide to keep the refinery running. I should add a water electrolysis recipe, if I do that.

(ie. solid rocket fuel from heavy oil).

Heavy oil doesn't make rocket fuel...? You mean Kerosene maybe?

I was referring to the vanilla recipes that my setup has in place. Meaning the change that I made for preserving the vanilla plastic-bar recipe, seems to preserve my existing petroleum setup upon adding the mod to my save. However, I have not tested to ensure all other vanilla recipes are preserved.

I add sulfur to the lubricant recipe, to spice it up a tad and make it a little more like how lubricants are made.

https://www.machinerylubrication.com/Read/28548/sulfur-used-in-lubrication

I see.

as one can not derive elemental sulfur and elemental hydrogen from a single process (at least to my understanding)

According to this https://consequential-lca.org/clca/by-products-recycling-and-waste/not-fully-utilised-by-product/example-sulfur-from-refineries/, sulfur is typically processed by oxygen, not water.

Sulfur is a by-product of processing natural gas and refining high-sulfur crude oils. According to US EPA most of the 68,000,000 metric tons of sulfur produced worldwide in 2012 was a by-product from refineries and other hydrocarbon processing plants (US EPA 2014).

The most common conversion method used in refineries is the Claus process, named after the scientist that first patented the method (US EPA):

The process consists of multistage catalytic oxidation of hydrogen sulfide according to
the following overall reaction:
2H2S + O2 → 2S + 2H2O
The Claus process involves burning one-third of the H2S with air in a reactor furnace to form sulfur dioxide (SO2) according to the following reaction:
2H2S + 3O2 → 2SO2 + 2H2O + heat
The remaining un-combusted two-thirds of the hydrogen sulfide undergoes Claus reaction (reacts with SO2) to form elemental sulfur as follows:
2H2S + SO2 ←→3S + 2H2O + heat

Sulfur is an important component of fertilizer, but also has many other industrial uses.

And currently, you need the hydrogen back from that hydrogen sulfide to keep the refinery running. I should add a water electrolysis recipe, if I do that.

Yes, steam is less than ideal, but I have not decided to make an oxygen fluid yet... maybe if I find more things to do with it... like rocket fuel being made from both liquid hydrogen and liquid oxygen.

And good to know about the need to replace the hydrogen. If that is the case, I was thinking I could increase my use of natural gas -> methane -> steam reforming methane -> hydrogen, as a way to re-establish the balance. Just me trying to keep well over 100 mods working smoothly and integrated as possible.

Maybe you could add a few output fluid boxes to this, to bump it to 5 or 6 as needed?
https://mods.factorio.com/mod/advanced-chemical-plant

What does it do that it needs that many? It can't fractionate, which is the only thing that needs 5