Uses of Hydrogen in the Industry
Hydrogen is a colorless, odorless, flammable, non-toxic and flammable gas at atmospheric temperature. Due to its properties, hydrogen is one of the main starting factors used substance in chemical industries. It is the basic building block in manufacturing of ammonia (Ramachandran, & Raghu, 5).
Hydrogen is used mainly in the manufacturing of two chemical components, which are ammonia and methanol. These chemical components are made industrially. The manufactured ammonia is used in fertilizer manufacturing industries while methanol is used in the manufacturing of polymers. Hydrogen is also used in oil refining industries for reforming oils to obtain a high-quality grade of petrol and in the removal of sulfur substances from petroleum. It, therefore, forms an important element in oil refinery industries.
Hydrogen is used as fuel in industries due to its high calorific importance. The combustion of hydrogen generates a lot of energy that is useful in the industry. Some automobiles are designed to use hydrogen as a primary source of fuel. An example in the industry of such automobile is a forklift. Many forklifts use hydrogen as a source of fuel.
Hydrogen is also mostly used in food industries where by it is used in the manufacturing of hydrogenated vegetable oils that includes the butter and margarine. During this process, hydrogen is combined with the vegetable oil to produce solid fats by the use nickel as a catalyst.
Hydrogen is also used in welding companies for welding torches that are used during the melting of steel. It is mixed with inert gasses to get a reducing atmosphere required in the metallurgical industry. Due to its reducing agent, hydrogen is used in chemical industries for metal extraction. For instance, hydrogen is required for treating mined tungsten to remove the impurities in them and make them pure (Ramachandran, & Raghu, 12).
This element is also used in the production of methyl alcohol. The methyl alcohol produced is put into different uses that include the production of ink, paints, and varnishes. Methyl alcohol is not meant for humans and is toxic if consumed. Hydrogen has isotopes that are used in the nuclear fuel industry. For instance, the deuterium is used as a neutron moderator where the atom is split for fusion reaction. Hydrogen bomb has been known as one of the bombs that result from nuclear fusion. It results in release of a lot of energy, which if used well can result in several benefits.
Hydrogen is also known to be used in pharmaceutical industries in the manufacturing of vitamins and other related pharmaceutical substances. This element is also essential in the float glass manufacturing industries. In this industry, hydrogen is used to avoid the oxidation of the huge tin bath. Oxidation of the tin bath could result in production of glass that has porosities.
In the electronic industries, hydrogen is used to carry the most active trace elements such as phosphine during the manufacture of semiconducting layers in incorporated circuits. Due to its high thermal conductivity and low friction resistance, hydrogen is used in large power plants to cool the generators. Generators in thermal power plants need to be cooled and hydrogen provides a good option for cooling unlike other compounds used for cooling such as water. Hydrogen is a light gas and due to this property, it is used by the scientists with the air balloons which are filled with hydrogen (Ramachandran, & Raghu, 45).
How PSA Works
Pressure Swing Adsorption (PSA) is a process that is used to separate a specific gas from a mixture of gases under specific pressure. The affinity of that gas to the adsorbent and its molecular properties are the parameters utilized by this technology in achieving its desired effect. The technology operates at nearly ambient temperatures and is totally different from gas techniques which apply cryogenic distillation techniques. At high pressure, the target gas will be adsorbed by use of one of the following commonly used adsorptive materials; molecular sieves, activated carbon, bone char and zeolites. For the adsorbed materials to be desorbed the unit will then swings to a lower pressure (Choi et al, 18).
The Pressure Swing Adsorption relies on the fact that different gases under high pressure will be attracted to the solid surfaces and this is what is termed as adsorption process. The solid surfaces that adsorb the gas are those of specific adsorptive materials called adsorbents. The higher the pressure of the gases, the higher the volume of the gas that will be adsorbed onto the solid surfaces. When the pressure of the gas or gas mixture ids reduced the adsorbed gas will detach itself from the solid surfaces. The releasing of the gas from the solid surfaces is termed as desorption. This process uses the knowledge that different gases are attracted to different solid surfaces with varying strength under high temperature (Ruthven, & Knaebel, 45).
A good example that demonstrates well how this PSA process works is displayed well when air under high pressure is passed through a zeolite packed bed. The zeolite packing will preferentially attract nitrogen and not oxygen from the air. The nitrogen proportion in the air will be partly or fully be attracted to the zeolite packing and the gas coming out of the packing bed will be highly enriched with oxygen and less or no nitrogen. The adsorptive effects of the packet-bed will reduce with time when in use and after some time its efficiency will be very low and regeneration will be required. Regeneration is the act of removing the nitrogen attracted by the zeolite packing by reducing the system pressure. After regeneration, the packet-bed will be ready for another cycle of production of air enriched in oxygen.
Apart from the ability of the adsorbents used in PSA to preferentially attracts other gases and leave others, the adsorbents for PSA are always very porous materials selected based on their surface areas that are large. Adsorbents that have a widely recognized use in the PSA systems are; zeolite, alumina, silica gel, molecular sieves, and activated carbon. Adsorptive surfaces of these adsorbents are very large to enable adsorption of a high volume of the preferred gas. The adsorbed gas thickness on these surfaces will contain one or more molecules layers of the gas. Molecular sieves use their molecule size characteristic to exclude different gas molecules due to their molecular sizes. The larger molecules will not be allowed to pass through the sieves while the smaller ones will be able to pass through the sieves. This will restrict the ability of the larger molecules to be adsorbed by the sieves (Choi et al, 18).
The PSA process is used as a substitute to the cryogenic distillation techniques. It is also used as the primary source of medical oxygen to the hospitals. Large-scale production of hydrogen gas for the production of ammonia and use in oil refineries uses the PSA processes to remove carbon dioxide in the final step of the production process. Recycle streams of hydrocracking and hydro-treating process units, produces hydrogen sulphide from the hydrogen feed. This hydrogen sulphide must be removed from the process. Oil refineries always utilize PSA in removing these hydrogen sulphide. The quality of biogas generated can be upgraded to that of the natural gas by use of the PSA process. Carbon dioxide in the biogas will be adsorbed and the gas coming out of the packed-bed column will have a higher methane ratio (Choi et al, 34).
Works Cited
Choi, W. K., Kwon, T. I., Yeo, Y. K., Lee, H., Song, H. K., & Na, B. K. (2003). Optimal operation of the pressure swing adsorption (PSA) process for CO2 recovery. Korean Journal of Chemical Engineering, 20(4), 617-623.
Ramachandran, Ramakrishnan, and Loc H. Dao. "Pressure swing adsorption." U.S. Patent No. 5,365,011. 15 Nov. 1994.
Ruthven, Douglas Morris, Shamsuzzaman Farooq, and Kent S. Knaebel. Pressure swing adsorption. Vol. 480. New York: VCH publishers, 1994.
