Production  of  Hydrogen.  313 
PRODUCTION  OF  HYDROGEN  BY  THE  IRON  CONTACT 
METHOD.1 
By  Harry  L.  Barnitz,  Ph.G. 
One  of  the  methods  that  has  found  favor  in  recent  years  for  the 
production  of  hydrogen  in  installations  of  large  commercial  capacity 
is  the  so-called  "  iron  contact  method." 
The  generating  elements  employed  by  this  method  are  coke  and 
water,  and  through  them  hydrogen  can  be  produced  of  almost 
"  chemical  purity,"  i.  e.,  of  a  purer  grade  than  by  many  other  tech- 
nical processes  for  large  production  excepting  electrolytical. 
The  iron  contact  method  is  cyclic  with  respect  to  the  "  iron  con- 
tact mass  " ;  that  is,  this  iron  contact  mass  is  used  over  and  over 
again.  If  red  hot  iron  is  siprayed  with  a  jet  of  steam,  the  iron  is 
oxidized  and  forms  iron  oxide,  while  hydrogen  is  liberated.  If  the 
iron  oxide  thus  produced  is  treated  with  reducing  gases,  such  as 
generator  gas,  water  gas  or  illuminating  gas,  the  iron  oxide  is  re- 
converted into  sponge  iron. 
All  these  reducing  gases  consist  chiefly  of  a  mixture  in  varying 
quantities  of  carbonic  oxide,  hydrogen  and  hydrocarbons. 
For  instance,  the  commonly  employed  water  gas,  which  is  easily 
produced  by  means  of  coke  and  steam  in  producers  of  large  working 
capacity  (say  up  to  100  cubic  meters  per  hour),  gives  a  theoretical 
mixture  of  50  per  cent.  CO  and  50  per  cent.  H.  In  practice,  how- 
ever, this  gas  always  contains  large  quantities  of  impurities,  em- 
anating from  the  coke  during  the  process  of  generation,  averaging 
about  6  per  cent.  N,  4  per  cent.  CO  and  2-3  per  cent,  hydrocarbons 
and  sulphides. 
The  reactions  used  in  the  iron  contact  process  may  be  repre- 
sented by  the  following  formulae : 
(1)  Oxidation:  Fe  +  H20  =  FeO  +  H2. 
(2)  Reduction:  2FeO  +  H2  +  CO  =  2Fe  +  H20  +  C02. 
It  will  be  observed  that  equation  (2)  is  exactly  the  reverse  of 
equation  (1)  at  least  as  far  as  steam  is  concerned. 
The  reaction  takes  place  at  the  surface  of  the  "contact  mass." 
Only  where  the  fresh  gases  enter,  a  powerful  and  far-reaching  re- 
1  Reprinted  from  Metallurgical  and  Chemical  Engineering,  Vol.  XVI, 
No.  10,  May  15,  1917. 
Am.  Jour.  Pharm.  j 
July,  1917.  i 
