life support, bio fuel - rambling

[KerbMav]

/ramblenumbers

To use it in a life support mod this might compare to 6 units of CO2 and 12 units of used/waste H2O(w) which would net you 1 unit of glucose for the plant/food and 6 units O2 and 6 units of fresh H2O(f).

/ramblecycle

So we would also need and basically be loosing water in the process, but as the body also receives water via food - especially in the case of fruits and vegetables - we could assume that a Kerbal metabolizes 1 unit of food and 1 unit of fresh water into 2 units of waste water. (*)

Simplified we could assume that - provided we have enough natural and/or artifical sunlight (simplified to the usage of electricity by the bio pods, also important for air circulation and automatic watering systems etc.) an autonomous ship would endlessly circulate:

6CO2 + 12 H2O(w) -> 6O2 + 6 H2O(f) + 6 units of food -> 6CO2 + 12 H2O(w) -> 6O2 + 6 H2O(f) + 6 units of food -> ...

Without implementing some kind of loss/inefficiency, the bio tank would be the holy grail of interplanetary travel - but maybe it should be?

(I will not go into calculating the exact molecular masses and how much energy a Kerbal's body can pull from 1 unit of glucose/food!)

/ramblefuel

Now, if we were to produce fuel, we would have to treat a bio fuel tank as a (gamewise) real tank filled with plant mass, which could be converted into fuel - but a not 100% full bio tank would loose an equal percentage of its ability to process CO2 and H2O(w) - at least until the bio mass has regenerated, which would/should also use up resources that would be lost to the cycle.

Alternatively fuel could be produced from the fruits instead of the plants itself.

/rambleconlusion

Whenever we use anything to create fuel - at least if we want to stay halfway realistic - we loose another resource or the basis to replenish a resource autonomously.

Basically we had to assume that it were possible to process:

fresh water + food + oxygen + Kerbal => waste water + carbondioxide + plants => fresh water + oxygen + fuel

Shortening this process would mean to feed a Kerbal snacks and have him put a fuel duct leading into the ships tank from his ... have a nice day!

(*) Yeah, I know, this is very simplified and most probably wrong!

(**) Which is mostly nonsense, as rockets almost always use oxygen and hydrogen, which could be generated from water directly with electric energy - the specific impulse of this is better then using ethanole/biofuel and oxygen.

[seanth]

See also

http://forum.kerbalspaceprogram.com/threads/53009-0-21-BioMass-Renewable-Bio-Fuel-Modules

and