HYDROGEN PRODUCTION – Current Methods to Extract Hydrogen
Because pure hydrogen does not occur naturally on Earth in large quantitie. Hence it takes a substantial amount of energy in industrial hydrogen production. There are different ways to produce it, such as electrolysis and steam-methane reforming process, etc. In electrolysis, electricity is run through water to separate the hydrogen and oxygen atoms. This method can use wind, solar, geothermal, hydro, fossil fuels, biomass, nuclear, and many other energy sources.
Obtaining hydrogen from this process is being studied as a viable way to produce it domestically at a low cost. Steam-methane reforming, the current leading technology for producing hydrogen.Hydrogen in large quantities extracted from methane. However, this reaction causes a side production of carbon dioxide and carbon monoxide. These gases are greenhouse gases and contribute to global warming and other drastic effects.
CURRENT METHODS OF EXTRACTION OF HYDROGEN
Hydrogen is locked up in enormous quantities in water, hydrocarbons, and other organic matter. One of the challenges of using hydrogen as a fuel comes from being able to efficiently extract hydrogen from these compounds. Currently, steam reforming, or combining high-temperature steam with natural gas, accounts for the majority of the hydrogen produced.
Hydrogen can also be produced from water through electrolysis, but this method is much more energy intensive. Once extracted, hydrogen is an energy carrier (i.e. a store for energy first generated by other means). The energy can be delivered to fuel cells and generate electricity and heat, or burned to run a combustion engine.
In each case hydrogen is combined with oxygen to form
VARIOUS METHODS OF HYDROGEN PRODUCTION
|Methods of extraction||Process||Implementation|
|Steam reforming of methane gas||In presence of nickel catalyst & at 973-1373K:
CH4(g) + H2O(g) = CO(g) + 3H2(g)
Next reaction at lower temperature:
|Current major source of hydrogen|
|Hydrogen from coal (Gasification)||At high temperature and pressure:
Coal + H2O(g) + O2 = syngas
Syngas is H2 + CO + CO2 + O2(g)
|Current method of mass hydrogen production|
|Electrolysis of water||Electric current passed through water:
2H2O(l) = 2H2(g) + O2(g)
|Not in widespread use due to cost of electricity|
|Solar – Hydrogen system||Electric current passed through water:
2H2O(l) = 2H2(g) + O2(g)
|Not in widespread use due to cost of renewable energy sources|
ADVANTAGES AND DISADVANTAGES OF VARIOUS METHODS OF HYDROGEN PRODUCTION
|Steam reforming of methane gas||-65 to 75% efficiency
-Economical (least expensive method)
|Hydrogen from coal (Gasification)||-Large supplies of coal
-Carbon sequestration would raise costs
|Electrolysis of water||Depend on electricity source||-Input into production may require more energy than released
-Produces CO2emissions if coal is energy source
|Solar – Hydrogen system||-No emissions