Hydrogen

Hydrogen Production

Most of the hydrogen produced today is made by steam reforming of natural gas. For the near term, this method of production will continue to dominate gasification of coal and partial oxidation of oil.

Hydrogen can be produced from a variety of feedstock using a variety of process technologies. Feedstock options include fossil resources such as coal, natural gas, petroleum and renewable resources such as biomass, sunlight and wind.

The choice of production methods will vary depending on the availability of feedstock resources, the quantity of hydrogen required and the required purity of hydrogen.

There is a wide range of processes for producing hydrogen economically and in an environmentally friendly way.

These processes are divided into three major areas:

Thermo chemical production technologies

• Natural gas steam reforming:
  Worldwide 48% of hydrogen is produced from natural gas, 30% from oil, 18% from coal and the remaining 4% via water electrolysis.


• Partial oxidation / ceramic membrane reactor:
  A very promising method.


• Biomass Gasification and pyrolysis:
  Agriculture residues and wastes or biomass specifically grown for energy users as switch grass are suited for hydrogen production via pyrolysis or gasification

Electrolytic production technologies

• Water electrolysis:
  Provides a small percentage of the world hydrogen, supplying applications for hydrogen with high purity or prime power.


• Reversible fuel cells / electrolyzers:
  Operating the proton exchange membrane (PEM) fuel cell 'in reverse' can produce hydrogen in high purity

Photolytic production technologies

• Photo-biological:
  A bioreactor can use light (sunlight or artificial light) to produce hydrogen with the help of microorganisms. By employing catalysts and engineered systems, hydrogen production efficiency could reach over 20%.


• Photo-electrolysis:
  In the long term the most promising technology for hydrogen production is the direct light-induced splitting of water without any use of electricity. A recent photolytic cell has been obtained with very high efficiency for the production of hydrogen. Systems based on nano-crystalline materials and conducting polymers have yielded revolutionary applications. This process offers the prospect of cheap fabrication together with other attractive features, such as flexibility. The phenomenal recent progress in fabrication and characterizing nano crystalline materials has opened up whole new vistas of opportunity unthinkable before.