Supercritical gasification of biomass

[Attero Dominatus]

Right now, the International Space Station simply allows waste to be vaporized upon reentry after it is loaded into the Progress capsules, but that is not an option for a long duration space voyage. For ships that travel between the earth and mars, ejecting trash will mean that it will fly along mostly the same trajectory, creating a navigational hazard. Ejection is not an option for medium and high orbits either, because there is no micro-dragging to create orbital decay.

Most waste from spaceship will be sewage sludge, left over food and scrap paper, because most containers and bags will be designed for re-use. Storing the garbage will consume space and burning it will cause major problems for the ship's air filters and mass ratio (incinerators have to be constructed of a steel alloy called Inconel because it is resistant to the acid gases produced from burning garbage).

Waste can be decomposed by placing it in water and raising the water's heat and pressure until it becomes a hybrid of liquid and gas called a supercritical fluid, which will seep through the waste material and hydrogenate it. This could produce hydrocarbons which can be used as rocket fuel.

www.energy.iastate.edu/renewable/biomass/cs/supercriticalwater.htm

[Floyd Looney]

Hhhmmm.... could this heating be done by solar energy? If space travel becomes common will there be unmanned waste recyclers? Could there be unmanned trash pods zooming back and forth?

[Attero Dominatus]

Aug 17, 2011 15:08:49 GMT -5 Floyd Looney said:

Hhhmmm.... could this heating be done by solar energy? If space travel becomes common will there be unmanned waste recyclers? Could there be unmanned trash pods zooming back and forth?

If close enough to the sun, yes. Using the sun to provide heat is not very good past mars though.

[Attero Dominatus]

My idea is to use the sun/local star when close, and waste heat from fusion or fission reactor when far. Since the ship is powered by nuclear fusion or fission, the hydrocarbons produced by the decomposition would be catalytically converted into methane and used for reaction control thrusters.

An alternative would be to use the hydrocarbons to form polymers and either use them as is for plastic or heat them in the absense of air to form carbon fibers for emergancy repair.

[Floyd Looney]

good ideas