Hydrogen production apparatus, hydrogen production method, silicon fine particles for hydrogen production, and production method for silicon fine particles for hydrogen production

Abstract

An exemplary hydrogen production apparatus 100 according to the present invention includes a grinding unit 10 configured to grind a silicon chip or a silicon grinding scrap 1 to form silicon fine particles 2, and a hydrogen generator 70 configured to generate hydrogen by causing the silicon fine particles 2 to contact with as well as disperse in, or to contact with or dispersed in water or an aqueous solution. The hydrogen production apparatus 100 can achieve reliable production of a practically adequate amount of hydrogen from a start material of silicon chips or silicon grinding scraps that are ordinarily regarded as waste. The hydrogen production apparatus thus effectively utilizes the silicon chips or the silicon grinding scraps so as to contribute to environmental protection as well as to significant reduction in cost for production of hydrogen that is utilized as an energy source in the next generation.

1 . A hydrogen production apparatus comprising:
 a grinding unit configured to grind a silicon chip or a silicon grinding scrap to form silicon fine particles; and   a hydrogen generator configured to generate hydrogen by causing the silicon fine particles to contact with as well as disperse in, or to contact with or dispersed in water or an aqueous solution.   
     
     
         2 . The hydrogen production apparatus according to  claim 1 , further comprising:
 a surface oxide film remover configured to cause the silicon fine particles formed by the grinding unit to contact with an aqueous hydrofluoric acid solution or an aqueous ammonium fluoride solution; wherein   the hydrogen generator generates hydrogen by causing the silicon fine particles, which have been caused to contact with the aqueous hydrofluoric acid solution or the aqueous ammonium fluoride solution, to contact with as well as disperse in, or to contact with or dispersed in water or an aqueous solution.   
     
     
         3 . The hydrogen production apparatus according to  claim 2 , further comprising:
 a hydrophilization treatment unit configured to hydrophilize surfaces of the silicon fine particles having been caused to contact with the aqueous hydrofluoric acid solution or the aqueous ammonium fluoride solution; wherein   the hydrophilization treatment unit causes the surfaces of the silicon fine particles to contact with a surfactant or nitric acid.   
     
     
         4 . The hydrogen production apparatus according to  claim 1 , further comprising:
 an additional surface oxide film remover configured to cause the silicon fine particles extracted from the hydrogen generator to contact again with an aqueous hydrofluoric acid solution or an aqueous ammonium fluoride solution; and   an additional hydrogen generator configured to generate hydrogen by causing the silicon fine particles, which have been caused to contact again with the aqueous hydrofluoric acid solution or the aqueous ammonium fluoride solution by the additional surface oxide film remover, to contact with as well as disperse in, or to contact with or dispersed in water or an aqueous solution.   
     
     
         5 . The hydrogen production apparatus according to  claim 1 , further comprising:
 an adjuster configured to adjust at least one of hydrogen generation speed and a hydrogen generation amount by changing a hydrogen ion concentration index (pH) of the water or the aqueous solution in the hydrogen generator.   
     
     
         6 . A hydrogen production method comprising:
 a grinding step of grinding a silicon chip or a silicon grinding scrap to form silicon fine particles; and   a hydrogen generating step of generating hydrogen by causing the silicon fine particles to contact with as well as disperse in, or to contact with or dispersed in water or an aqueous solution.   
     
     
         7 . The hydrogen production method according to  claim 6 , further comprising:
 a surface oxide film removing step to be executed before the hydrogen generating step, of causing the silicon fine particles formed in the grinding step to contact with an aqueous hydrofluoric acid solution or an aqueous ammonium fluoride solution; wherein   in the hydrogen generating step, hydrogen is generated by causing the silicon fine particles, which have been caused to contact with the aqueous hydrofluoric acid solution or the aqueous ammonium fluoride solution, to contact with as well as disperse in, or to contact with or dispersed in water or an aqueous solution.   
     
     
         8 . The hydrogen production method according to  claim 7 , further comprising:
 a hydrophilization treatment step to be executed before the hydrogen generating step, of hydrophilizing surfaces of the silicon fine particles having been caused to contact with the aqueous hydrofluoric acid solution or the aqueous ammonium fluoride solution.   
     
     
         9 . The hydrogen production method according to  claim 6 , further comprising:
 an additional surface oxide film removing step to be executed during or after the hydrogen generating step, of causing the silicon fine particles to contact again with an aqueous hydrofluoric acid solution or an aqueous ammonium fluoride solution; and   an additional hydrogen generating step to be executed after the additional surface oxide film removing step, of generating hydrogen by causing the silicon fine particles to contact with as well as disperse in, or to contact with or dispersed in the water or the aqueous solution again.   
     
     
         10 . The hydrogen production method according to  claim 6 , wherein
 in the hydrogen generating step, at least one of hydrogen generation speed and a hydrogen generation amount is adjusted by changing a hydrogen ion concentration index (pH) of the water or the aqueous solution.   
     
     
         11 . The hydrogen production method according to  claim 8 , wherein
 in the hydrophilization treatment step, the surfaces of the silicon fine particles are caused to contact with a surfactant or nitric acid.   
     
     
         12 . The hydrogen production method according to  claim 6 , wherein
 the silicon fine particles have a crystallite diameter of 100 nm or less.   
     
     
         13 . The hydrogen production method according to  claim 6 , wherein
 the aqueous solution used in the hydrogen generating step has a pH value of 10 or more.   
     
     
         14 . A silicon fine particle for hydrogen production, having:
 an amorphous shape, a crystallite diameter of 100 nm or less, and a hydrophilic surface.   
     
     
         15 . The silicon fine particle for hydrogen production according to  claim 14 , having:
 a hydrophilic surface.   
     
     
         16 . The silicon fine particle for hydrogen production according to  claim 14 , including
 a silicon fine particle obtained by chemically treating a silicon fine particle that is formed by grinding a silicon chip or a silicon grinding scrap.   
     
     
         17 . A production method for silicon fine particles for hydrogen production, the method comprising:
 a grinding step of grinding a silicon chip or a silicon grinding scrap to form silicon fine particles.   
     
     
         18 . The production method for silicon fine particles for hydrogen production according to  claim 17 , the method further comprising:
 a surface oxide film removing step of causing the silicon fine particles formed in the grinding step to contact with an aqueous hydrofluoric acid solution or an aqueous ammonium fluoride solution.   
     
     
         19 . The production method for silicon fine particles for hydrogen production according to  claim 18 , the method further comprising:
 a hydrophilization treatment step of hydrophilizing surfaces of the silicon fine particles having been caused to contact with the aqueous hydrofluoric acid solution or the aqueous ammonium fluoride solution.   
     
     
         20 . The production method for silicon fine particles for hydrogen production according to  claim 19 , wherein
 in the hydrophilization treatment step, the surfaces of the silicon fine particles are caused to contact with a surfactant or nitric acid.   
     
     
         21 . The production method for silicon fine particles for hydrogen production according to  claim 17 , the method further comprising:
 a chemical treatment step of chemically treating the silicon fine particles that are formed by grinding the silicon chip or the silicon grinding scrap.   
     
     
         22 . A silicon fine particle for hydrogen production,
 the silicon fine particle being produced in accordance with the production method for silicon fine particles for hydrogen production according to  claim 17 .