Hydrogen generator

Abstract

A hydrogen gas generator generates hydrogen gas by mixing two reactants. The generator has a reaction chamber for receiving a solid reactant. The chamber has a reaction product separator impermeable to the solid reactant and a biasing means for biasing reactant products against the separator. The generator also has a liquid reactant dispenser for storing a liquid reactant and is fluidly coupled to the reaction chamber, such that dispensed liquid reactant reacts with the solid reactant in the reaction chamber to produce hydrogen gas and a waste product that are substantially permeable through the separator. The generator also has a product collector coupled to the reaction chamber for collecting hydrogen gas and waste product that have passed through the separator.

1 . A hydrogen gas generator comprising: 
 (a) a reaction chamber for receiving a solid reactant, the chamber having a reaction product separator impermeable to the solid reactant and a biasing means for biasing reactant products against the separator;    (b) a liquid reactant dispenser for storing a liquid reactant and fluidly coupled to the reaction chamber, such that dispensed liquid reactant reacts with the solid reactant in the reaction chamber to produce hydrogen gas and a waste product that are substantially permeable through the separator; and,    (c) a product collector coupled to the reaction chamber for collecting hydrogen gas and waste product that have passed through the separator.    
     
     
         2 . A hydrogen gas generator as claimed in  claim 1  further comprising a hydrogen gas separator located in the product collector and which is permeable to hydrogen gas and impermeable to the waste product.  
     
     
         3 . A hydrogen gas generator as claimed in  claim 2  wherein the hydrogen gas separator is a gas separation membrane.  
     
     
         4 . A hydrogen gas generator as claimed in  claim 1  wherein the biasing means is a spring.  
     
     
         5 . A hydrogen gas generator as claimed in  claim 1  wherein the solid reactant is sodium borohydride powder.  
     
     
         6 . A hydrogen gas generator as claimed in  claim 5  wherein the sodium borohydride powder is compacted into a pill form.  
     
     
         7 . A hydrogen gas generator as claimed in  claim 6  wherein the separator is a screen having a mesh size that is smaller than the sodium borohydride grain size.  
     
     
         8 . A hydrogen gas generator as claimed in  claim 1  wherein the liquid reactant is an acidic solution.  
     
     
         9 . A hydrogen gas generator as claimed in  claim 8  wherein the acid solution has a pH of 2 or less.  
     
     
         10 . A hydrogen gas generator as claimed in  claim 1  wherein the liquid reactant is citric acid solution.  
     
     
         11 . A hydrogen gas generator as claimed in  claim 1  further comprising an outer shell enclosing the reaction chamber, liquid reactant dispenser and product collector, wherein at least part of the shell is sufficiently transparent to view the amount of solid reactant remaining in the generator.  
     
     
         12 . A hydrogen gas generator as claimed in  claim 1  wherein the liquid reactant dispenser is a bag, and the generator further comprises an inner bag enclosing the reaction chamber and product collector, the inner bag being located within the dispenser bag.  
     
     
         13 . A method of generating hydrogen gas comprising: 
 (a) biasing a solid reactant towards a reaction product separator that is impermeable to the solid reactant;    (b) dispensing a liquid reactant to the solid reactant to produce a hydrogen gas and a waste product that are substantially permeable through the separator; and    (c) applying sufficient pressure to pass the hydrogen gas and waste product through the separator.    
     
     
         14 . A method as claimed in  claim 13  further comprising after (c), separating the hydrogen gas from the waste product.