{TAIL ~ Hydrogen production apparatus} with {HEAD ~ solution feed control} to eliminate build up of products on a solid reactant 
{ TAIL ~ Hydrogen production apparatus } with { HEAD ~ solution feed control } to eliminate build up of products on a solid reactant
TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH