The Steam-Methane Reforming Process Purifies Hydrogen
Hydrogen, the most abundant element in the Universe (also the lightest) is actually rare to find in a pure form here on Earth. This is due to hydrogen’s willingness to bond with other atoms and molecules. Despite its abundance it needs to be separated from these other atoms and molecules in order to be available in a pure form.
Hydrogen is useful to humans and is useful in some important industries. Pure hydrogen is primarily used to make ammonia (which is in turn used to make fertilizer) and methanol (which is usually turned into fuel). However it needs to be separate from all of the atoms and molecules it likes to bond to in order to be of any industrial use to humans.
95% of purified hydrogen produced today is made from the Steam-Methane Reforming Process. This process produces hydrogen from a hydrogen generating source, this is usually natural gas or oil, however other sources can be used.
Molecular sieve’s role in producing hydrogen doesn’t occur until the end of the steam-methane reforming process. Before molecular sieve gets used the feed stock(most likely natural gas) must go through a hydrodesulfurization process, a steam reforming process, a heat recovery process and a CO conversion process. These processes further breakdown the complex molecular structure of the feedstock preparing it for the final stage for hydrogen purification.
The final stage in purifying hydrogen is to use a Pressure Swing Adsorption (PSA) process.The PSA process will use either a 5A molecular sieve, which is usually used to create high purity hydrogen or a 13X molecular sieve to adsorb larger hydrocarbons and other impurities if they are there.
5A specializes in separating straight and branch chained hydrocarbons from one another. 13X molecular sieve will specialize in removing any additional C02 or NH3 if there is any remaining at this point, it will depend on what you used as a feed stock.
There are over 200 Hydrogen producing plants in the world, most of them should be listed in the link below. Hydrogen plays an important role in various industrial and scientific applications and molecular sieve plays an important role in making it pure.
List of Hydrogen Plants: http://bit.ly/wsYzKM