Expert: Dr. Henry Boyter, Jr. - 10/25/2004

Question
What can extract hydrogen and oxygen out of tha air? I am designing a new Humanitarian emergency package that includes a completely clean water device so that it can save those either in drought or flood.  (haitian flood water reeks of the dead and is unethical to be recycled for drinking water), thus I ask what can attract hydrogen and oxygen in air or any other components that make up basic drinking water?  

Answer
Gases are removed from the air by chilling with liquid nitrogen or liquid helium.  These methods are very expensive and are not reasonable for the purpose you seek.  Then you have to convert it to water by some means.  You could just apply reactions to the air itself to make the water.  But again, equipment and energy are required.  Instead, why not just extract the water out of the air.  Much cheaper.  For flood areas, you can just filter the water from the flood and except for a pump, no real special equipment is needed (it can be pumped by hand).  Drought is a different subject.  Here an absorbant of some type could remove the water from the air and then it could be squeezed out.  Pretty inefficient.

The problem with all these is energy.  If an energy source was not required, hydrogen and oxygen would just be falling out of the air as water at room temperature and pressure.