Does combustion/gas fuel not pack enough of a punch? Rocket Fuel is another type of fuel, with it’s own set of generators (generator, singular, realistically) to turn it into power. In addition it is also used for Galacticraft/Extra Planets rockets. Rocket fuel used to fuel rockets, who could have foreseen that?
Fuelling rockets aside, rocket fuel as a power source is competitive with (nitro)benzene gas power in terms of efficiency, output, cost, etc. The two basically bounce back and forth on all fronts from IV to ZPM, gaining one edge while losing another throughout the tiers. The biggest failing of rocket fuel is the fact that to get it off the ground in the first place you’re going to need some sort of power production already in place, and it’s entirely possible that scaling said power production further is a better choice than switching to rocket fuel. Nevertheless, I’ll list what I’ve learned experimenting with rocket fuel power in creative here
Rp-1 Rocket Fuel, AKA “Why checking your work is important”
Rp-1 Rocket Fuel is the first and weakest of the rocket fuels, being craftable in mid-HV. It has a few problems, however: The first rocket fuel generator is EV tier, Rp-1 RF is expensive to make to the point it might not actually be power positive when you do craft that first (very inefficient) single block EV tier rocket fuel generator, and as far as actual rocket fuel for Galacticraft rockets is concerned you can also use Cetane-Boosted Diesel for the same tiers of rockets that Rp-1 RF is sufficient for. “But I don’t have any diesel production”, you say? Well, even if you had to craft CBD from scratch it would still be significantly cheaper and easier, and that’s if you did. There’s a number of quests that reward some amount of CBD cells as a quest reward, most notably the quest for an MV World Accelerator giving you a (choice) reward of a full stack of CBD cells. Unless you’re taking your rocket out on joyrides that should be sufficient
For the record, using the least EU efficient methods of producing RP-1 RF and burning it in an EV single block, it is still power positive…even if you’re spending ~75% of the EU gained on producing the fuel. Any overclocks to produce more fuel faster, and you’re quickly in net negative territory
So that’s not a strong start for rocket fuel. But there’s three more rocket fuels to go
Dense Hydrazine Fuel Mixture, AKA “Why tiering is important”
Dense Hydrazine Fuel Mixture is the second rocket fuel, and while not as objectively useless as Rp-1 RF it unfortunately doesn’t fare much better. The thing is that DHFM, as the name suggests, requires Hydrazine as an input. What happens when you mix hydrazine, hydrogen, carbon dust and nitric acid? You get CN3H7O3 Rocket Fuel AKA Purple Rocket Fuel, the third tier of rocket fuel. Now yes, Purple Rocket Fuel does require a Tungstensteel chemical plant instead of merely a Titanium one, which is a non-zero investment of tungstensteel, but when you look at the cost of rocket fuel-related items tungstensteel is the least of your worries. If you really want to hard rush a T3 rocket ASAP I could see going for DHFM as a temporary solution to the problem of how to fuel the rocket, given that CBD/Rp-1 RF will no longer be sufficient, but in all other situations I’d recommend skipping DHFM in favor of Purple Rocket Fuel
CN3H7O3 Rocket Fuel AKA Purple Rocket Fuel, AKA “Slow and steady wins the race”
After two false starts you might have gotten the impression that rocket fuel in general is a joke, but Purple is where rocket power starts to become serious. Now I won’t sugar coat that the up front cost of getting power out of rocket fuel is going to be severe, much more so than a comparable amount of power from a Benzene based setup (some exceptions aside). The biggest contributer to this is going to be what will actually extract the power - on paper this can be single block rocket fuel generators, a Rocketdyne multiblock, or a Universal Chemical Fuel Engine AKA UCGE (the G stands for Garbage, as this multi used to have a very nasty habit of unavoidably detonating upon worldload in earlier versions, necessitating strict redstone controlled fuel input in order to use the multi at all). In practice only the UCGE is worth considering, as the single blocks are far too expensive to spam at scale (and have garbage fuel efficiency besides) and the Rocketdyne is both expensive to craft, difficult to make run continuously, and very limited in terms of potential output. The UCGE has it’s own quirks, of course, but if you want serious power out of rocket fuel production a UCGE is the only practical option. This will run you a minor amount of Naquadah, Osmium, Rhodium and Palladium for the controller block, in addition to Special Ceramics Dust for one of the blocks required to craft the multi. Naquadah ore you can get from IV lootbags, otherwise you’ll need a T3 rocket to grab some. The platline stuff can be batch crafted worst case, you don’t need much of it
To get power out of a UCGE you need one more key ingredient: Combustion Promoter. How much promoter you supply the multi determines fuel efficiency - the theoretical maximum is 150%, but this would require infinity promoter, so assume ~148% is the practical limit - and what ratio of promoter to fuel you need depends on the type of fuel you use. UCGEs can burn gas/combustion fuel, but the Diesel tab will cover that. Promoter has four recipes total - you’re given a choice between using LOX or Hydrogen Peroxide, and using Saltpeter or Sodium Nitrate - but the only recipe worth using is the Peroxide/Saltpeter one. Peroxide produces more promoter than LOX, and is much cheaper to produce besides, and Saltpeter over Sodium Nitrate means not spending an extra 200mb Nitric Acid per bucket of combustion promoter. Rocket Fuel is already quite demanding in tems of Ammonia, so use Salty Roots/Bees to supply Saltpeter
As for purple rocket fuel itself, aside from a steady supply of oxygen, nitrogen, hydrogen, and carbon dust you only need two special inputs: Orange Metal Catalysts, and Coal Tar. The former requires Vanadium Dust and Palladium Dust, but don’t worry about it being consumed in large quantities. Giving your Chem Plants Tungstensteel Pipe Casings, in addition to giving you up to 8 parallel recipes, also deceases the chance a catalyst will consume durability by 60%(?). Coal Tar can be sourced from four different sources: Lignite Coal, Charcoal, Coal, and Coal Coke. Of those the easiest/best is Charcoal, given you use an Industrial Coke Oven to convert logs + nitrogen into Wood Tar + Charcoal - why, yes, that may indeed sound strangely familiar. Really though, it’s the best way to get a good supply of charcoal while also getting byproducts that can pay for the cost of producing the stuff. An alternative is to use an EEC to farm Redcap Sappers from the Twilight Forest, but beware that in terms of power cost per coal produced this method is very expensive. If you were planning on running Redcaps anyway for diamonds and/or TC shards feel free to make use of the excess coal, though. Might as well get good power out of it after all
So, what machines will you need to turn all of those things into usable power? Broadly speaking, as I frankly don’t feel like going as in-depth as I did with diesel/benzene, purple rocket fuel will require 5 chemical plants, a good amount of DTs for processing Wood Tar, a good amount of LCRs for various recipes, and either an ICO or EEC to source (Char)coal. And, of course, whatever machines you need for whatever methods of producing nitrogen/oxygen/hydrogen you use. Carbon dust, if you need it, can be gotten from excess (char)coal dust, if you really need to do that. And Saltpeter for Combustion Promoter
According to ingame testing and calculating (which I admittedly cannot vouch for, having never stress tested a full setup in creative let stand survival): 4x LuV/HSS-S coils chem plants (CN3H7O3 Rocket Fuel, Monomethylhydrazine, Hydrazine and 2-Ethylanthrahydroquinone) and 1 EV/HSS-S coils chem plant (Hydrogen Peroxide) should be able to produce 8000mb purple rocket fuel every 80 ticks (the bottleneck being Monomethylhydrazine). Sound expensive, especially compared to benzene? Perhaps, but do note this setup requires less than 8 HV DTs, let stand a DT++, and doesn’t require a Large Fluid Extractor or turbine rotors. As I mentioned (nitro)benzene and rocket power will go back and forth constanly in terms of which is (sometimes marginally) better than the other in every possible aspect, so on the whole the two can best be described as “comparable”
That said now is the time to explain two quirks that are important to keep an eye on when calculating rocket fuel power production: Hydrogen Peroxide Overhead and Dynamo Hatch Restictions. Hydrogen Peroxide is required for both rocket fuel and for combustion promoter, so keep an eye on how much downtime your 2-Ethylanthrahydroquinone Chemical Plant has. Hydrogen Peroxide by itself is a fast recipe, but the recipe to recycle 2-Ethylanthraquinone is not. That recipe, not the hydrogen peroxide recipe itself, will determine how much you can produce on the side to feed into promoter production. The Dynamo Hatch restriction is much more noticeable - a UCGE can only have a single multi-amp dynamo or laser source hatch for power output, so until you are able to utilize lasers you’ll be limited to 64A output of whatever tier you’re in. In IV that is 1A UV, or 524288 EU/t output. Why is this a problem? 100mb/t purple rocket fuel, at a very modest 120% fuel efficiency, is 737280 EU/t. Until you get better hatches you will either be limited in your power output or need multiple UCGEs to burn the full amount of rocket fuel you can produce. This will continue in LuV, and again in ZPM, for the record
Wondering what Coal Tar Oil, Naphtha, Ethylbenzene and Kerosene are good for in the context of serious rocket fuel power, which seemingly only uses the Antrace for rocket fuel itself and combustion promoter? Well, here’s a quick list:
Coal Tar Oil is a semi-fluid generator fuel with 32 EU/mb density (for the record Creosote Oil is 48 EU/mb), can be distilled 20:6 into Cyclopentadiene (70 EU/mb gas fuel, Ferrocene ingredient) or chemically reacted with Sulfuric Acid to yield Sulfuric Coal Tar Oil. That, in addition to being another semi-fluid fuel (64 EU/mb), can be distilled 1:1 into Naphthalene. That, in turn, can be chemically reacted with Lithium to produce 1.25x the amount of Napthalene worth of Phthalic Acid, a critical component of higher end bees, or used to chemically bathe Reinforced Stone to produce…one sec, takes a deep breath… Superplasticizer-Treated High Strength Concrete, which is a required block to form the Water Purification Plant multiblock. No, I don’t know why plain old dirt just isn’t good enough for the water plant, or why chemically reacting hydrogen and oxygen in a chemical reactor can’t produce pure H2O for that matter, but it’s what it is. Superplasticizer-Treated High Strength Concrete does look nice, I’ll admit, but it’s probably too expensive to use as a building block for a few tiers. Phthalic Acid will come in very useful if you’re doing bees, though, and bees are one way of automating Saltpeter (though that itself doesn’t require acid)
Naphtha you’re probably already familiar with - gas fuel with 220 EU/mb density, can be combined with Saltpeter you should also be producing to produce Polycaprolactam AKA String Ingots, mixed into Raw Gasoline/reacted into Jet Fuels, or cracked to produce a huge amount of potential byproducts. If you don’t have a petrochem setup already you could try to source things like Propene from this Naphtha byproduct, but “byproduct” is very much the key phrase there. Unless you expand your coal tar production/processing beyond what rocket fuel needs, say if you wanted to produce a ton of Phthalic Acid to feed bees
Ethylbenzene is used to produce 2-Ethylanthraquinone, which while fully recycled in a closed loop during actual rocket fuel production does need to have it’s initial supply produced in the first place. After that the only real use for Ethylbenzene is dehydrating Leather into Tanned Leather - you really ought to have gotten used to using the chemical bath recipe with Phosphoric Acid if you’re still needing Tanned Leather at this stage - or being chemically reacted with…nothing…to turn into Styrene and Hydrogen. Styrene, in turn, can be turned into Polystyrene (only used to craft Bio Lab machines and Electromagnet Housings, which are a required part for the Magnetic Flux Exhibitor multi, an Electromagnetic Separator/Polarizer multi introduced in 2.7) or Styrene-Butadiene Rubber. SBR isn’t used for anything that Silicone Rubber can’t do as well or better, though, bar the YOTTank’s Fluid Cell Block T4 which requires SBR specifically. Finally, what you’ll most likely be doing, Styrene can be electrolysed into carbon dust and hydrogen in a 1:8:8 ratio. Adding the extra hydrogen from producing Styrene from Ethylbenzene that’s 8 carbon dust and 10 hydrogen per bucket of Ethylbenzene, both of which are used in the production of rocket fuel
Kerosene has a grand total of two uses - being distilled 20:15 into Rp-1, one of the ingredients to make Rp-1 Rocket Fuel AKA the weakest rocket fuel I mentioned being of very dubious value given the LOX cost, or being chemically reacted with Ferrocene Dust, Sodium Hydroxide, Naphtha, and Diethylamine into Jet Fuel No.3. “Hey, Ferrocene and naphtha? Aren’t we producing that as well?” you ask, and yes, you are. Coal Tar isn’t just for rocket fuel, it’s both for rocket fuel and for the Jet Fuels, but don’t make the mistake of thinking jet fuels are good. They are ruinously expensive to craft in terms of EU cost per mb fuel produced (still power positive, mind, but you’re paying a premium tax and a half on that profit), Ferrocene is a rabbithole you don’t want to jump down when you could be producing better HOG with less difficulty instead, and in any case the long term prospects of these higher end combustion fuels aren’t all that great anyhow. Remember, UCGE does not do non-rocket fuels without stupid amounts of combustion promoter, and you’re here to produce rocket fuel that’s going to hit the dynamo hatch cap of 1A UV output by itself. Not to build 16 ECEs that’ll devour your profit margins just to keep themselves fed and running
Optimizing Output in LuV (Chem Plant upgrades, Combustion Promoter)
Once you have access to LuV you’ll be able to upgrade your chemical plants to ZPM (except the Hydrogen Peroxide one, which can stay at EV but will need Naq Alloy coils if kept at that tier) and Naq Alloy coils. With that setup you will be able to produce 8000mb purple rocket fuel every 30 ticks, and have enough overhead to produce 54mb/t hydrogen peroxide on the side, which you will be able to turn into 108mb/t combustion promoter if you choose to produce and convert the maximum amount of extra hydrogen peroxide you can produce. Of course keep in mind the extra Antrace, Nitric Acid and Saltpeter cost
So…how much combustion promoter should you actually produce? And for that matter, use? LuV also gives access to 64A LuV Dynamo Hatches, so your power output cap has been raised to 2097152 EU/t - 1A UHV. My advice: Don’t be afraid to invest in a lot of combustion promoter. Is it optimal? No, I’m quite confident that despite how contradictive it must sound - investing heavily into a side thing doesn’t yield appreciable benefits? - shafting combustion promoter is the optimal choice. That said a lot of combustion promoter can be good, especially later on. So don’t be afaid to invest. Numbers? Can provide:
| Mb/t Purple | mb/t Promoter | Fuel Efficiency | Output (EU/t) | So, here’s the tricky thing with Combustion Promoter - it is very cheap to produce, if only relative to purple rocket fuel. Using suboptimal, but entirely reasonable methods of producing the base resources combustion promoter | |
|---|---|---|---|---|---|
| 231 | 77 | 147.76 | 2097104 | should cost roughly 200 EU/mb to produce. Purple rocket fuel, for the record, consumes over 800 EU/mb just with the last three chem plant recipes, to say nothing of the base ingredients (I’m dismissing the cost of Coal Tar | |
| 232 | 60 | 147.12 | 2097060 | and Hydrogen here, since in theory a charcoal + wood tar production line for coal tar should be able to provide both at little to no meaningful power cost, but these are only estimates at best all the same). Even at very high | |
| 233 | 49 | 146.47 | 2096794 | combustion promoter numbers you’re getting more than 200 EU/t output from the marginal fuel efficiency increase than it costs to produce the promoter itself. Enough of this, and you could even consume slightly less fuel too | |
| 234 | 41 | 145.78 | 2095873 | ||
| 235 | 37 | 145.31 | 2096166 | In practice, though, again, it’s probably best to not bother. Getting an extra, what, 1000 EU/t when you’re producing ~1A UHV is very thoroughly in “rounding error” territory, so don’t take combustion promoter too seriously. So | |
| 236 | 32 | 144.56 | 2096096 | long as you supply at least 1mb/t promoter per 81mb/t rocket fuel you’re burning you’ll be at basically 100% fuel efficiency, which even if not optimal should be respectable. If you want ~120% efficiency supply 1mb/t promoter | |
| 237 | 29 | 143.99 | 2096678 | per 36mb/t rocket fuel, and 1mb/t promoter per 13mb/t fuel to maintain ~140% fuel efficiency | |
| 238 | 26 | 143.28 | 2095143 | ||
| 239 | 24 | 142.71 | 2095576 | FYI, if you want to burn the full 266mb/t you’re producing, you can burn 133mb/t each in two UCGEs. With 50mb/t promoter per they’ll output ~1209466 EU/t each at ~148.01% fuel efficiency, or you can feed both a much more | |
| 240 | 22 | 142.03 | 2094317 | modest 10mb/t promoter for ~1146791 EU/t at ~140.34% fuel efficiency. “5x the promoter for 8.33% more fuel efficiency isn’t worth it”, you say? Realistically, yes, but even 49->50 promoter is technically power positive…barely |
“So what was that about a lot of combustion promoter being good later on, and is it actually good as opposed to ‘technically more profitable by like 0.01%’ ‘good’ on paper”? Well…
ZPM and H8N4C2O4 Rocket Fuel, AKA “The gloves come off”
ZPM tier gives access to Vigorous Laurenium Machine Casings, which are the gate for producing the fourth and final best tier of rocket fuel: Green rocket fuel. In addition ZPM gives access to laser hatches, functionally lifting the restriction the UCGE had on it’s maximum output. Both combined are a significant upgrade for your rocket fuel power, and the point where nitrobenzene’s clowning on rocket fuel’s power output comes to a very definitive end. Green rocket fuel does require 7 chem plants total to produce - H8N4C2O4 Rocket Fuel, Nitrogen Tetroxide and 2-Ethylanthrahydroquinone at UV, 1,1-Dimethylhydrazine and Hydrazine at ZPM, and Formaldehyde and Hydrogen Peroxide at EV - but given (notoriously dirt cheap once you’ve got an overclocked Large Scale Auto-Assembler v1.01) Electrum Flux coils is able to spit out 20000mb green rocket fuel every 15 ticks. At 100% fuel efficiency, that’s 16779804 EU/t. ~2A UEV
So, what does this supremely powerful fuel require to produce? I mean sure the chem plants weren’t exactly cheap, especially those hot pink casings, but of course anything producing 2A UEV worth of fuel in ZPM is going to require something special to produce…right?
There is a single item required to produce green rocket fuel that isn’t required to produce purple rocket fuel: Iron Dust for Formaldehyde Catalysts. That’s it. Obviously you’ll need more of the stuff you used before, but in terms of new ingredients that isn’t required for the multis themselves, Iron Dust. Just Iron Dust
Green rocket fuel is also where prior investment into (at that stage excessive amounts) combustion promoter starts to pay off. Burning 1333mb/t with the 22mb/t promoter you used before will only yield 110.79% fuel efficiency, whereas if you invested into 100mb/t combustion promoter you can now enjoy 140.32% fuel efficiency instead. A 29.53% increase, or about 4955076 EU/t worth? Not as much of a rounding error anymore, is it? And if you invested into that much combustion promoter in LuV already you certainly enjoyed better fuel efficiency during that entire stage as well, and the journey through ZPM to get here
Having issues with the Osmium cost of UV tier glass, which allows Lapotronic Super Capacitors to use laser hatches? You can fuel three UCGEs 444mb/t green rocket fuel. With 33mb/t promoter each will produce 7838114 EU/t at 140.24% fuel efficiency, below the 8388608 EU/t cap of a 64A ZPM dynamo hatch
Seeing Jet Fuel A/Jet Fuel No.3 in NEI, and wondering if jets are considered rockets as far as GTNH is concerned? The answer is no: Both jet fuels are considered combustion fuels, the second and third densest of that fuel type respectively behind HOG in fact, but for better or worse it is not a rocket fuel
Heard about the overpoweredness of single block EV/IV combustion/gas gens, and considering sneaking in a few single block rocket fuel gens to jumpstart the whole shebang? In (admittedly brief) testing of said single block engines I’ve encountered quirks such as <27% fuel efficiency energy conversion when drip fed fuel, greater than an order of magnitude more pollution output than the maximum amount listed, and refusal to fill the engine’s internal EU buffer beyond 4% of it’s maximum capacity. I’ve no idea if I’m doing something wrong of if these things are just borked (this testing did take place on a beta version of GTNH), but either way I can’t recommend using these single block engines at all. If you need to jumpstart rocket fuel production I’d recommend LGTs instead - you’ll (ideally) need one Wood Tar ICO for charcoal and DTs for Coal Tar down the line anyhow, might as well craft them early and get some use out of them