section_path: Production/Steam reforming
section_name: Steam reforming
paragraph_text: Steam reforming
  
  Hydrogen is mainly produced by steam methane reforming (SMR), the reaction of water and methane. Thus, at high temperature (1000–1400 K, 700–1100°C or 1300–2000°F), steam (water vapor) reacts with methane to yield carbon monoxide and H.
  
  Steam reforming is also used for the industrial preparation of ammonia.
  
  This reaction is favored at low pressures, Nonetheless, conducted at high pressures (2.0 MPa, 20 atm or 600 inHg) because high-pressure H is the most marketable product, and pressure swing adsorption (PSA) purification systems work better at higher pressures. The product mixture is known as " synthesis gas " because it is often used directly for the production of methanol and many other compounds. Hydrocarbons other than methane can be used to produce synthesis gas with varying product ratios. One of the many complications to this highly optimized technology is the formation of coke or carbon:
  
  Therefore, steam reforming typically employs an excess of H O. Additional hydrogen can be recovered from the steam by using carbon monoxide through the water gas shift reaction (WGS). This process requires an iron oxide catalyst:
  
  Hydrogen is sometimes produced and consumed in the same industrial process, without being separated. In the Haber process for ammonia production, hydrogen is generated from natural gas.