FreeThinker

[1.8.1, 1.7.3/1.6.1/1.5.1/1.4.5] KSP Interstellar Extended 1.25 Continued Development Thread

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Version 0.7.24 for Kerbal Space Program 0.90

Released on 2015-03-14

  • Dusty Plasma Particle generation is affected by reactor activity
  • Fixed thrust magnetic nozzles with multiple nozzles
  • increased surface area upgraded radiator by 70%
  • increased max temperature non upgraded radiators to 1600K
  • Match mass and surface area of Small Flat radiators with Foldable radiators, making them competitive.
  • match stats stack radiator equal to radial radiator in performance
  • Mo Li Heat Pipes upgrade to Graphene Radiator with MetaMaterials
  • NaK Loop Radiator upgrade to Mo Li Heat Pipe with Specialized Construction

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Hello.

which file do I tweak to adjust the WasteHeat capacity of specific reactors and radiators? I need to modify that of the unupgraded Huge Heat Radiator and 2.5m Dusty reactor, but I cannot find their names in the Tweak_Warp_Radiators and Tweak_Warp_Reactors.cfg files.

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Hello.

which file do I tweak to adjust the WasteHeat capacity of specific reactors and radiators? I need to modify that of the unupgraded Huge Heat Radiator and 2.5m Dusty reactor, but I cannot find their names in the Tweak_Warp_Radiators and Tweak_Warp_Reactors.cfg files.

That's a KSPI NF question, which is replaced by KSPI Extended with KSP-E . But to answer you question, the Huge Foldable Radiator can be found a Tweak_Warp_Reactor.cfg @PART[radiator2]. The 2.5m Dusty Reactor is the upgraded mode of the FNPFissionReactor250 can be found in Tweak_Warp_Reactors.cfg

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According to the Interstellar Wiki they never did.

I tried your magnetic noozles but they show no particle effect what so ever :(

I'll take a look at them tonight - Can I confirm that you have Smokescreen and MP_Nazari's FX pack installed?

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Gosh dang I'd love this to be CKAN installable, but the file overwriting is a hurdle there.

I've noticed the github repo has a lot more files than the release, are there any plans to make a stand-alone release of KSPIE, rather than one that depends upon KSPIBoris? I'm happy to offer my own humble gitomancy skills if they can be of assistance.

Many thanks for all your great work!

~ pjf

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Gosh dang I'd love this to be CKAN installable, but the file overwriting is a hurdle there.

I've noticed the github repo has a lot more files than the release, are there any plans to make a stand-alone release of KSPIE, rather than one that depends upon KSPIBoris? I'm happy to offer my own humble gitomancy skills if they can be of assistance.

Many thanks for all your great work!

~ pjf

I plan is to create a full release when KSP 1.0 is released. This is because KSPIE is currently still a WIP which will break save games once the new CRP 2.0 standard is adopted. Note the same will be true for all other mods which rely on CRP. Until them I will continue to update kSPIE with small incremental improvements.

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[h=2]Version 0.7.25 for Kerbal Space Program 0.90[/h] Released on 2015-03-15

  • Added support for NFT Propulsion, without NFT-Electrics all NFT-Propulsion require Megajoule instead of ElectricCharge, and Magnetic Noozle and Vista Engine require LiquidHydrogen instead of LiquidFuel
  • Hydrogen mode for Interstellar plasma thruster uses NTF-E particle FX
  • Without RealFuels installed all NFT-P hydrogen tanks have cryostat added to to prevent boil-off based with power requirement based on surface area
  • Fixed WasteHeat storage of Small Flat radiator conform its mass.

Edited by FreeThinker

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Regarding Ammonia, I want to add an electrolyser to KSPI that convert Ammonia to Nitrogen and Hydrogen. The Hydrogen would be usefull for high ISP propulsion and the Nitrogen would also be usefull for higher trust applications. This would allow a SSTO with Ammonia get into orbit, convert parts of the Ammonia into Hydrogen/Nitrogen to use as electric propulsion. My question is, would Ammonia Electrolysation be comparable with Water Electrolisation, or would it require significantly more or less power?

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Hi,

Liquide ammonia electrolysis requires 7.4 MJ per kg of H2 (gaz) using a standard voltage of 7,7 mV assuming the eletrolysing cell is 100% efficient (a standard steel/pt/ceramic cell is 71% efficient IIRC)

To compare Water electrolysis is 130 MJ/H2 kg (gaz) assuming a 100% efficiency and need higher voltage (> 1.23 V)

So ammonia electrolysis is approx 94% more efficient than water electrolysis, but the energy needed to get liquid hydrogen should not be forgotten (I'll come back and edit this post with the correct value)

As far as I know, ammonia electrolysis is good to make direct H2 feeding for fuel cells, however I'm not sure it'll be enough of a fuel flow to use it in direct engine feeding (calculations must be done to be sure of that)

Cheers.

Source: http://www.rsc.org/suppdata/cc/c0/c0cc01982h/c0cc01982h.pdf

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Hi,

Liquide ammonia electrolysis requires 7.4 MJ per kg of H2 (gaz) using a standard voltage of 7,7 mV assuming the eletrolysing cell is 100% efficient (a standard steel/pt/ceramic cell is 71% efficient IIRC)

To compare Water electrolysis is 130 MJ/H2 kg (gaz) assuming a 100% efficiency and need higher voltage (> 1.23 V)

So ammonia electrolysis is approx 94% more efficient than water electrolysis, but the energy needed to get liquid hydrogen should not be forgotten (I'll come back and edit this post with the correct value)

As far as I know, ammonia electrolysis is good to make direct H2 feeding for fuel cells, however I'm not sure it'll be enough of a fuel flow to use it in direct engine feeding (calculations must be done to be sure of that)

Cheers.

Source: http://www.rsc.org/suppdata/cc/c0/c0cc01982h/c0cc01982h.pdf

Would a few Megawatts be enough to do the Job? No, rally, if you can power the Gigawatts electric plasma thrusters, even if the electrolysis is highly inefficent, Power is not realy an issue on a nuclear/fusion powered rocket. I guess it's just a matter of scaling up the processing, which in game term means mass. When electric thrusters/magnetic nozzles use hydrogen for propulsion, they are not going to use a lot of it, which is kind of the whole point

Note the reason I want to do this is because in 1 m3 you can store 702.1 kg of Liquid Ammonia, from which 17.647% mass is Hydrogen meaning 123.9 kg of Hydrogen / m3. Compare this with raw Liquid Hydrogen storage of only 70.85 kg of Hydrogen / m3, and it becomes obvious that storing Hydrogen, is 75% more compact when stored as Ammonia. Also Ammonia Boiloff temperature is much higher, meaning less heavy tanks. The Nitrogen itself is universal propellant which can be used directly by both thermal and electric propusion, making it ideal for high thrust application, like landing on a mun, where you want maximum trust just before landing, or at takeoff when getting back into orbit. Nitrogen is almost litteraly the Nitro of interstellar rocketry! :cool:

A potential bonus of Ammonia is that the stuff can be used in a fuel cell. This would be ideal as an alternative power source when cooling down the Nuclear Reactor and you need to keep your crew alive. Instead of using clumsy solar panels which don't work after mars/duna or in the shadow, you would have reliable power source from a Ammonia fuel cell. You only need some poisoness Oxygen, which coincidently is also used to keep the Kerbals breathing ;)

Edited by FreeThinker

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I'm thinking about implementing it with a univeral storage module, that way it will be scalable and work together with exisitng machinery, like fuel cell, electrolyser, waterstorage, oxygen storage, etc.

While at it, we also might add other usefull reactions. Northstar1989 could you create a batch of suplemental modules which will be usefull? Just create a few part files (and ad you name to the author ;) )

Edited by FreeThinker

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You are indeed correct on the ammonia being way more efficient for hydrogen storage (urea is a good candidate too).

I think the refinery should have defined cell volumes (for mass flow) and densities (for part mass) for all the processes (some processes can use the same cells) so you can balance all of them properly (I didn't dive into the code yet so maybe you already have this convention). This way the mass flow from the different reactions can be precisly calculated. And as inline refinery can already do alumina electrolysis wich has high energy requierement I see no problem to do the ammonia one. (For information: industrial alumina electrolysis need a cell temperature above 900°C and strong currents, this is a lot of energy - source: http://www.balcoindia.com/operation/pdf/aluminium-production-process.pdf)

Another thing is most of the numbers are from current electrode geometries (plain rod-like or parallelepiped-like), but you can find in the litterature meso/nano-porous electrodes that have way more specific surface areas thus cells with higher yields for a given volume. It could be an upgrade feature for the refineries (like the radiators) and a good excuse to have high yield cells to fuel engines (but the calculation must be done first ^^).

Maybe Northstar can solve the issue with a simpler formalism.

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Regarding Ammonia, I want to add an electrolyser to KSPI that convert Ammonia to Nitrogen and Hydrogen. The Hydrogen would be usefull for high ISP propulsion and the Nitrogen would also be usefull for higher trust applications. This would allow a SSTO with Ammonia get into orbit, convert parts of the Ammonia into Hydrogen/Nitrogen to use as electric propulsion. My question is, would Ammonia Electrolysation be comparable with Water Electrolisation, or would it require significantly more or less power?

Re-posted from a PM for future easy reference:

Regarding the energy-requirements, all you need to do is look at the magnitude of the Gibbs Free Energy of formation of Water vs. Ammonia...

Water: -237 kJ/mol

Ammonia: -16.4 kJ/mol

Note that this is the Gibbs Free Energy for pure ammonia- it requires more energy to electrolyze (26.57 kJ/mol) if it's dissolved in water... (dissolving ammonia in water releases energy- separating the two again consumes it...)

1 MW = 1000 kJ/s, so this means that it requires a minimum of 0.0164 MW per mole of Ammonia you need to electrolyze. As a mole of Ammonia weighs 17.031 grams, this means it requires a minimum of 9629.5 MW to electrolyze one metric-ton of Ammonia (1424298.5 units of Ammonia in KSP using a density of 702.1 kg/m3, or approximately 147.91 units/MW, or approximately 0.006761 MW/unit). These are also numbers assuming a 100%-efficient process, so you can round them up to reflect inefficiency and get nice even numbers to your heart's content... :)

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Re-posted from a PM for future easy reference:

Regarding the energy-requirements, all you need to do is look at the magnitude of the Gibbs Free Energy of formation of Water vs. Ammonia...

Water: -237 kJ/mol

Ammonia: -16.4 kJ/mol

Note that this is the Gibbs Free Energy for pure ammonia- it requires more energy to electrolyze (26.57 kJ/mol) if it's dissolved in water... (dissolving ammonia in water releases energy- separating the two again consumes it...)

1 MW = 1000 kJ/s, so this means that it requires a minimum of 0.0164 MW per mole of Ammonia you need to electrolyze. As a mole of Ammonia weighs 17.031 grams, this means it requires a minimum of 9629.5 MW to electrolyze one metric-ton of Ammonia (1424298.5 units of Ammonia in KSP using a density of 702.1 kg/m3, or approximately 147.91 units/MW, or approximately 0.006761 MW/unit). These are also numbers assuming a 100%-efficient process, so you can round them up to reflect inefficiency and get nice even numbers to your heart's content... :)

Intresting, but how much Ammonia would a single generic storage converter unit be realsiticly be able to convert at maximum power?

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Liquide ammonia electrolysis requires 7.4 MJ per kg of H2 (gaz) using a standard voltage of 7,7 mV assuming the eletrolysing cell is 100% efficient (a standard steel/pt/ceramic cell is 71% efficient IIRC)

That number seems... Over-optimistic to say the least.

No electrolytic process can consume less than the Gibbs Free Energy of formation of the compound, and the Gibbs Free Energy of Ammonia formation is -16.4 kJ/mol. Which means it should cost approximately 16.4 kJ/mol * 1 kW-s/kJ * .001 MW/kW * 1000 g/kg * (1/17.031 g/mol for ammonia's molar-mass) * (1 / 0.1776 for the 17.76% hydrogen-fraction of ammonia) = 42.95 MW/kg of hydrogen-formation, not 7.4 MW/kg...

That source comes up with an overly-optimistic estimate of power-consumption partially by using a Gibbs Free Energy of formation of -10.984 kJ/mol instead of -14.2 kJ/mol, which conflicts directly with the value from Wikipedia (which it says ultimately come from Lange's Handbook of Chemistry (1999)). So, either the value used in that source is wrong, or the value on Wikipedia is wrong- both can't be true...

However even using a Gibbs Free Energy of -10.984 kJ/mol, the power-consumption should still be around 10.984 kJ/mol * 1 kW-s/kJ * .001 MW/kW * 1000 g/kg * (1/ 17.031 g/mol for ammonia's molar-mass) * (1 / 0.1776 for the 17.76% hydrogen-fraction of ammonia) = 33.23 MW/kg of hydrogen produced, not 7.4 MW/kg... So I'm really not sure where that number comes from...

OK, well there is an alternative explanation for the difference in Gibbs Free Energy, at least- http://www.rsc.org/suppdata/cc/c0/c0cc01982h/c0cc01982h.pdf'>the source you cited assumes the reaction occurs at 25 degrees Celsisus and very low vapor pressure. The source used by Wikipedia appears to assume the reaction occurs at 0 degrees Celsius and 1 atm of partial pressure for each electrolysis product. Of the two, the latter (reaction at 0 degrees Celsius) would be closer to the actual conditions likely to be found inside the ISRU refinery- after all this reaction is occurring in the depths of space, and even reaching 0 degrees Celsius (to increase the reaction-rate) would require active-heating of the reactor!

The decomposition of Ammonia becomes drastically less energy-costly the higher the temperature: in fact it even becomes energetically favorable at the temperatures of a Nuclear Thermal Rocket! (which leads to spontaneous decomposition of the Ammonia and generation of additional Thrust...)

To compare Water electrolysis is 130 MJ/H2 kg (gaz) assuming a 100% efficiency and need higher voltage (> 1.23 V)

So ammonia electrolysis is approx 94% more efficient than water electrolysis, but the energy needed to get liquid hydrogen should not be forgotten (I'll come back and edit this post with the correct value)

That value for energy-consumption of water electroylsis is also inaccurate. It's also too low (Wikipedia states that it requires 11.7 MW per cubic-meter of Hydrogen produced with an 100% efficient electrolysis- and the Hydrogen has a density of 0.085 kg/m3 at 1 barr and 15 C - meaning 137.65 MW of power should be required per kg of Hydrogen produced... And keep in mind that this assumes high-temperature electrolysis and low partial pressure of Hydrogen, neither of which are likely to be the case for a space-based ISRU refinery...) And you don't cite your source for it. Please provide a source so I can see why the value is so low...

As far as I know, ammonia electrolysis is good to make direct H2 feeding for fuel cells, however I'm not sure it'll be enough of a fuel flow to use it in direct engine feeding (calculations must be done to be sure of that)

The rate the electrolysis occurs at is directly-proportional to the power-consumption. So there is no such thing as the "rate being too low" to feed an engine- if you crank up the power high enough you can feed *any* engine with hydrogen from ammonia-electrolysis (and conveniently, KSP-Interstellar automatically uses all available surplus-power to run ISRU reactions as quickly as possible- up to the maximum power-consumption the ISRU refinery can handle...) Of course, that's not really a concern of any relevance here- because we're not assuming running an engine directly off the electrolysis products. Instead we're talking about converting LqdAmmonia into LqdHydrogen/LiquidFuel (depending on if the player has RealFuels installed) and LqdNitrogen. The electrolysis process can be carried out over weeks, months, or even years prior to the propellants actually being needed in an engine- so electrolysis rate is not really a concern...

Also, you're correct that the energy needed to cool the electrolysis-products back down to their cryogenic temperatures needs to be accounted for (which would increase power-requirements further). But the power-requirements to do that are really going to depend a lot on the energy-efficiency of the cooling systems, so I'm not even sure where to begin with that, or what would constitute a reasonable energy-efficiency for a space-grade heat exchanger...

Regards,

Northstar

Edited by Northstar1989

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Intresting, but how much Ammonia would a single generic storage converter unit be realsiticly be able to convert at maximum power?

No idea. Probably not much. But you're planning on carrying out the reaction in a KSP-Interstellar ISRU Refinery, aren't you? And THAT thing can operate into the multi-MW range, I think up to at least 100 MW of power for the 3.75 meter refinery IIRC (or was that for the 2.5 meter refinery?) Anyways, much faster than anything a series of converters based off Apollo-era technology (which is what the Universal Storage converters represent) could handle...

We should probably try and avoid needlessly pulling in refinery/converter parts from other mods anyways, when we can just as easily add more ISRU reactions to the existing KSP-I Refinery...

Regards,

Northstar

- - - Updated - - -

I'm thinking about implementing it with a univeral storage module, that way it will be scalable and work together with exisitng machinery, like fuel cell, electrolyser, waterstorage, oxygen storage, etc.

While at it, we also might add other usefull reactions. Northstar1989 could you create a batch of suplemental modules which will be usefull? Just create a few part files (and ad you name to the author ;) )

There are loads and loads of ISRU reactions I've been wanting to add (including urea-electrolysis for when TAC Life Support is installed- allowing you to recycle WasteWater into drinkable Water and obtain usable Nitrogen and Hydrogen for propulsion from it simultaneously...) for some time now- so I'm glad you're finally looking at ISRU!

However, I don't know how to access or work with the ORS ISRU code. Or even for sure where to find it. As I understand it, it is buried within the WarpPlugin .dll file? I don't currently have any software that can open .dll files, and I only have about 800 MB of usable disk-space available on my laptop (I know, yikes!) Can you recommend any small, *efficient* (don't take up a lot of space), easy-to-use programs to open the .dll file up to get at the ISRU code?

EDIT: Also, I was also looking at adding some of the resource-to-resource conversions that don't involve an environmental component (i.e. like the Haber or Sabatier processes- which can draw their Nitrogen or CO2 from an atmosphere instead of from internal resources) using Regolith code, since it might be simpler and easier to work with when no atmospheric intake is involved (for those cases I do believe ORS still has the advantage). How do you feel about this? It would require re-distributing Regolith as a dependency, which worries me because if Regolith ever stops updating it could leave us high+dry... (say when 1.0 is released and a lot of the Regolith code becomes part of the stock resource-system) But on the other hand the ease-of-use for the converter code means we could probably whip up more useful ISRU reactions, faster... Also- would there be a way to make Regolith-based ISRU reactions show up in the existing ISRU menu that Fractal_UK put so much sweat, blood, and tears into creating right before he had to go AWOL? (and didn't get a chance to actually USE it to add more ISRU reactions as planned...) I really don't want to make players have to search through two separate menus- one for ORS based reactions and one for Regolith-based reactions, in order to find the ISRU reaction they are looking for...

Regards,

Northstar

Edited by Northstar1989

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You are indeed correct on the ammonia being way more efficient for hydrogen storage (urea is a good candidate too).

urea? CO(NH2)2 why, it seems to contain 2 molecules I'm not intrested in, C and O which cannot be used for propulsion like Nitrogen

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urea? CO(NH2)2 why, it seems to contain 2 molecules I'm not intrested in, C and O which cannot be used for propulsion like Nitrogen

That depends on the density and ease with which urea can be stored compared to the ammonia. also, CO2 is a usable electric propellant. You have extra Oxygen then - Is NO2 a viable electric propellant? I assume O2 is a poor/unusable electric propellant due to its high reactivity or something? The final evaluation boils down to:

1) are there reasonable ways to make use of all the components of urea?

2) for a given mass of urea, does the total Delta-v (fixing all other variables at convenient numbers) outdo that of the NH3 method?

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EDIT: Also, I was also looking at adding some of the resource-to-resource conversions that don't involve an environmental component (i.e. like the Haber or Sabatier processes- which can draw their Nitrogen or CO2 from an atmosphere instead of from internal resources) using Regolith code, since it might be simpler and easier to work with when no atmospheric intake is involved

Well I think the opposite is true, to get quick result, the easiers way to accomplish it to Regolith Converter modulle. The only problem with this module is that it is not scalable with Tweakscale. That's why I propose to first to use Universal Storage parts, which do not scale but are very modular. This will allows you to create some small working parts. These parts we can then turn in Mass production in the Inline refinery version.

Step 1, implement all your Desired reactions with small Univeral Storage Parts

Step 2, Using the result of step 1 we can add them to the ISRU.

note that the ISRU has significant mass which can be a drag. If on the other hands your only intrested in a single conversion, and have enough storage for a few minutes of burn, a single Universal Storage unit might be all you realy need.

- - - Updated - - -

That depends on the density and ease with which urea can be stored compared to the ammonia. also, CO2 is a usable electric propellant. You have extra Oxygen then - Is NO2 a viable electric propellant?
True, but Hydrogen is my propellant which I try to get as much as possible of. CO2 is similar to Nitrogen in NTR performance with the nasty habit of cluttering the exhaust with Sut, so it would only be use when landing on a gravity well (like a planet or moon). Another issue with Urea is that it's solid, which it not very convenient when you want to transport it, except when you operate near the sun and it becomes liquid.

- - - Updated - - -

For Planet/Mun landings Ammonia seems very intresting as you can both use the Low Isp Nitrogen and High Isp Hydrogen, but if your already in orbit and only needs to make transfers, Pure Hydrogen is probably still king because of it's High Isp.

Edited by FreeThinker

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Water: -237 kJ/mol

Ammonia: -16.4 kJ/mol

Alright, for sake of convenience, I'm going to assume the Ammonia Electrolysis will be able to produce process 14.45 times more ammonia as water.

note the current waterElectrolysisEnergyPerTon= 18159 MW which would put ammoniaElectrolysisEnergyPerTon at 1256.68 MW. Now since ISRU Electrolysis is limited to 40 MW, Electrolysis will convert every minute 1.91 t into 0.33 t Hydrogen and 1.573 t Nitrogen, I hope this is enough to use the Nitrogen in the thermal thrusters at full thrust

Edited by FreeThinker

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Uploaded Version 0.7.26 for Kerbal Space Program 0.90 Released on 2015-03-16

  • Added Ammonia Electrolysis with overflow limiter
  • LiquidHydrogen is Hydrogen Resource when NFT Propulsion is installed

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urea? CO(NH2)2 why, it seems to contain 2 molecules I'm not intrested in, C and O which cannot be used for propulsion like Nitrogen

Actually, they can. Remember Carbon Dioxide is a resource (and there's plenty of extra Oxygen in the water the urea is dissolved in to add an extra Oxygen to the CO- some water will get electrolyzed with the water too...) Additionally, one more resource I would like to add is Carbon Monoxide, which has two major uses:

(1) It can be burned with Oxygen in a CO/O2 chemical rocket, allowing much simpler/easier ISRU than the Sabatier Process (which requires Hydrogen) or water-ice mining (water-ice is only found in certain locations on Mars/Duna...) It's most useful for small exploration-hoppers that make suborbital leaps, like has been proposed in real life.

(2) It can be combined with Hydrogen to manufacture Kerosene via the Fischer-Tropsch Process

So, there is already one useful resource (Carbon Dioxide) that can be produced, and another (Carbon Monoxide) that could alternatively be produced (in real life which is produced would vary based on the voltages, temperature, catalysts used, etc...) that I would like to add as well. So everything you get from electrolyzing urea is actually useful...

- - - Updated - - -

Well I think the opposite is true, to get quick result, the easiers way to accomplish it to Regolith Converter modulle. The only problem with this module is that it is not scalable with Tweakscale. That's why I propose to first to use Universal Storage parts, which do not scale but are very modular. This will allows you to create some small working parts. These parts we can then turn in Mass production in the Inline refinery version.

Step 1, implement all your Desired reactions with small Univeral Storage Parts

Step 2, Using the result of step 1 we can add them to the ISRU.

note that the ISRU has significant mass which can be a drag. If on the other hands your only intrested in a single conversion, and have enough storage for a few minutes of burn, a single Universal Storage unit might be all you realy need.

I'm not sure I fully understand this. Could you explain it in a bit more detail? Then again, I'm tired and need a nap- so maybe that's also a factor...

True, but Hydrogen is my propellant which I try to get as much as possible of. CO2 is similar to Nitrogen in NTR performance with the nasty habit of cluttering the exhaust with Sut, so it would only be use when landing on a gravity well (like a planet or moon). Another issue with Urea is that it's solid, which it not very convenient when you want to transport it, except when you operate near the sun and it becomes liquid.

Urea-electrolysis is useful mainly because urea is the main component of urine. I.e. it has synergy with any life-support system. The idea was that if players have TAC Life Support installed they could use this to turn their Kerbals' waste into usable propellants...

Normally, you're going to get a combination of N2, H2, and CO3- which will normally spontaneously decay and give rise to CO2 gas, a process that can be accelerated with catalysts, heating etc...

http://www.rsc.org/chemistryworld/News/2009/July/02070902.asp

Methinks the modder doth like his thermal rockets too much. Nitrogen and Carbon Dioxide both have quite high ISP's compared to any chemical rocket when you put them through an electric thruster. And with an electric thruster, you're probably going to want to use heavier, lower ISP propellants like these for the extra Thrust they provide anyways, as electric thrusters aren't exactly known for their amazing Thrust/MW...

For Planet/Mun landings Ammonia seems very intresting as you can both use the Low Isp Nitrogen and High Isp Hydrogen, but if your already in orbit and only needs to make transfers, Pure Hydrogen is probably still king because of it's High Isp.

If you're already in orbit, electric thrusters are king because of their incredible ISP. And if you're using an electric thruster, you're going to want to use the denser/heavier propellants anyways for the extra Thrust/MW they provide... (it may come at the expense of ISP- but your ISP is still going to blow any chemical or thermal alternative out of the water anyways- and it's worth it for actually getting usable thrust-levels with your electric thrusters...)

Speaking of electric thrusters... Are you looking into the ISP-display bug and fuel-flow bugs for them? I can't exactly send my spacecraft hurtling (or crawling) across the solar system with electric thrusters when they show up as having 0 seconds ISP in the VAB/SPH (making mission-planning impossible) and then say they don't access to any propellant even when the plasma thruster is sitting *right on top of* a big old LqdNitrogen tank...

Regards,

Northstar

Edited by Northstar1989

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Keep in mind that per-mol of Urea you decompose, you have insufficient O2 to make all CO2 - you're going to end up with extra C that has to go with something - unless we let pure C dust be an intermediate resource (like alumina) and let it be used for various reactions noted above. It could also have synergy with the life support mods (to be used in the greenhouses?)

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Uploaded Version 0.7.26 for Kerbal Space Program 0.90 Released on 2015-03-16

  • Added Ammonia Electrolysis with overflow limiter
  • LiquidHydrogen is Hydrogen Resource when NFT Propulsion is installed

Oh cool, you're adding ISRU reactions already! I thought you were going to wait for me to figure out how to draw up some code for them!

In that case, here are a list of reactions we should strongly consider including- I can provide more details and chemical formula (or, eventually, code- once I figure out how to create it for the KSP ISRU system...) for any/all you're willing to add:

(1) Sabatier Reaction run with onboard resources only- so players can run orbital refineries around Duna with Carbon Dioxide collected by Propulsive Fluid Accumulators and Hydrogen shipped from much more infrequent launches from surface water-mining outposts on Duna (this is MUCH faster and more efficient than having to produce all your Methane and LOX on the surface and THEN launch it to orbit, as you don't have to accelerate any of your Carbon or Oxygen to orbit if you scoop it from the edge of the atmosphere while already in orbit...)

(2) The Reverse Water Gas Shift Reaction. Converts Carbon Dioxide into Carbon Monoxide and Water. The water can then be electrolyzed to recover the Hydrogen- allowing you to run this reaction ad-infinitum to isolate Oxygen from Carbon Dioxide scooped from Duna's atmosphere with a Propulsive Fluid Accumulator... The Carbon Monoxide could either be thrown away (hey, it's no loss if you basically have an unlimited source of Carbon Dioxide readily available) or stored for the Fischer-Tropsch Process...

(3) Direct Carbon Dioxide Electrolysis (also known as Solid Oxide CO2 Electrolysis, or SOCE in typical NASA-lingo...) Converts Carbon Dioxide into solid carbon (graphite) and Oxygen. Doesn't work so well in space (such as with Carbon Dioxide form a Propulsive Fluid Accumulator) as the graphite tends to gook up the reactor, but provides a great (and faster and more energy-efficient) way to isolate Oxygen directly from any atmosphere containing Carbon Dioxide. The suggested way of clearing out the graphite (and what would be done by NASA in the designs they've considered) is to blast the equipment with more hot Carbon Dioxide regularly- which will convert the graphite and some of the Carbon Dioxide into Carbon Monoxide (the requirement for this cleaning-process means that this reaction should really only work inside the atmosphere, though... Not necessarily on the ground- it would also work with a plane flying at high altitude or a high-powered rocket "flying" well inside the upper atmosphere...)

(4) Fischer-Tropsch Process: converts Carbon Monoxide and Hydrogen into Kerosene and Water. Very useful on Duna with RealFuels, *if* we add a Carbon Monoxide resource. Enough said...

(5) Methane Pyrolysis: got excess methane? Want to get your Hydrogen back? No problem! Just stick it inside this handy insulated heating-chamber, heat it up to a good few hundred degrees in the absence of Oxygen, wait a while, and voila! You will have graphite and usable Hydrogen-gas. You have to dispose of the Methane, but this really shouldn't be too much of a problem when it's in a big solid chunk (and there are no catalysts or electrodes you have to worry about it fouling up) inside a sealed tank like this...

(6) The REAL Anthraquinone Process. OK, there is already a reaction with this name in KSP-Interstellar, but it doesn't have the correct chemistry for the name... The ACTUAL process works by combining Hydrogen and Oxygen gas directly, rather than by combining Oxygen and water. An important distinction when you're somewhere like Duna orbit where you (should) have unlimited access to Oxygen via Propulsive Fluid Accumulators, but very limited access to Hydrogen, and want to make a bunch of Hydrogen Peroxide for your RCS system... We can keep the old process if you want, we just need to give it a different (more appropriate) name.

(7) It's called Hydrazine, not Monopropellant. OK, this one is pretty self-explanatory, but if you're using RealFuels and combining Hydrogen Peroxide (see above) and Ammonia to make Monopropellant, it should produce "Hydrazine", not "Monopropellant". Having an actual tank full of Hydrazine is also important for the reactions below...

(8) Need hypergolics? We've got you covered! There are actually 3 different hypergolic fuels (MMH, UDMH, and Aerozine) in RealFuels, but I'm just going to lump them all under the same entry here for brevity, as well as the production of their shared oxidizer (NTO- i.e. N2O4). One of the fuels (Aerozine) is actually just a 50/50 blend of the other two (and can be easily produced as such with the right conversion-reaction in-game) and is only its own resource as the other two are easy to blend, but impossible to separate back apart again once mixed... MMH and UDMH, meanwhile, are just Hydrazine with either one or two methyl-groups tacked on, respectively. So if you have a source of Methane available (Sabatier Reaction anyone?), Hydrazine (see above), and an ISRU refinery- then you can just combine the Methane and Hydrazine to get MMH or UDMH and a volume of Hydrogen as by-product equal to half the volume of Methane you put in... Really not that complicated as far as ISRU reactions go. Neither is NTO (properly, N2O4- "NTO" is just common shorthand for it, the same way HTP is for high-purity Hydrogen Peroxide...) To get NTO all you have to do is combine one part Nitrogen gas and two parts Oxygen gas together (there are some catalysts and co-catalysts involved, but we don't really need to care about them, as they are not consumed by the reaction...) VOILA! You have an unlimited quantity of highly-dense fuels that will never boil-off and will spontaneously ignite when mixed with NTO- perfect for your offworld refueling bases! Just don't let Jeb anywhere near the fuel-tanks or he might try to mix the two just to see a large explosion... :D

Ummm, I think these are enough reactions for now. Even *MY* brain hurts from this much chemistry and research in such a short period of time... I'd love to know if you''re willing to work with me to get these resources added to KSP-Interstellar, FreeThinker. Figuring out creative and efficient ways to utilize the environment to your best advantage is half the fun of ISRU! (It's a bit like legos- you have this reaction that does this, and that reaction that does that- but how do you select the right reactions and design your mission-plan to get the propellant you want as efficiently as possible? For instance, do you set up a surface-base on the ground, or use Propulsive Fluid Accumulators from orbit?)

Regards,

Northstar

- - - Updated - - -

Keep in mind that per-mol of Urea you decompose, you have insufficient O2 to make all CO2 - you're going to end up with extra C that has to go with something - unless we let pure C dust be an intermediate resource (like alumina) and let it be used for various reactions noted above. It could also have synergy with the life support mods (to be used in the greenhouses?)

Ummm, I already addressed this before just today. See my comments above. The Urea is dissolved in water (in fact, that's what the "(aq)" stands for below...) You just end up combining the excess Carbon with some of the Oxygen that is produced from breaking down a bit of that water in the process... (make sure to see the paper I linked to there and HERE) To be precise, this is what the net reaction looks like:

CO(NH2)2 (aq) + H2O --> N2 + 3 H2 + CO2

The water is broken down indirectly, though reaction of the urea with hydroxide ions (OH-), which naturally form in water. I'm not going to get into a complex discussion of pH and why this is exactly, only needless to say that it happens and the sub-reaction looks like this:

CO(NH2)2 (aq) + 6 OH- --> N2 + 5 H2O + CO2

Read the paper I linked for more details- the precise balance of electron-transfer and such, for instance... Here's that link one more time:

http://www.suttonfruit.com/pics/urea_electrolysis.pdf

I'm kind of getting sick of repeating this, because I had to explain the exact same thing earlier today, as well as to players several weeks ago in the development of KSP-I Extended, the last time I mentioned urea-electrolysis, as well as on the TAC Life Support Thread where I suggested urea-electrolysis, and I think also on the Regolith thread as well IIRC (don't ask me why I mentioned it there). So please make sure to read the link I posted, and educate your fellow players about the relevant chemistry if they have any questions about it as well, so I don't have to keep repeating myself... :P

Regards,

Northstar

Edited by Northstar1989

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(1) Sabatier Reaction run with onboard resources only- so players can run orbital refineries around Duna with Carbon Dioxide collected by Propulsive Fluid Accumulators and Hydrogen shipped from much more infrequent launches from surface water-mining outposts on Duna (this is MUCH faster and more efficient than having to produce all your Methane and LOX on the surface and THEN launch it to orbit, as you don't have to accelerate any of your Carbon or Oxygen to orbit if you scoop it from the edge of the atmosphere while already in orbit...)

I already implemented this. The depending on the availability of resources, it will either get the resources from the atmosphere or from local resources

Edited by FreeThinker

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