Hydrogen is the lightest known gaseous element when studied under room temperature and standard pressures in the globe but a strong energy carrier. The process of decomposing water into its constituent components oxygen (O2) and the hydrogen gas (H2) which is achieved by passing an electric current via the water is called electrolysis.
The process set up involves the connection of two electrodes, the anode and the cathode to an electric power supply. The negatively charged electrode on to which the hydrogen electron adheres to is called the cathode and the positively charged electrode on to which oxygen molecules adheres to is the anode. These metal plates are made of inert substance like platinum or the stainless steel. During this process, the ratio of hydrogen moles generated is twice as much as the amount of oxygen moles so long as the faradaic efficiency is ideal (Hyfleet, n.d). In most cases however, the reaction generates less moles of the products because of reactions that may occur on the cells surface.
Pure water usually requires a lot of activation energy to overcome the covalent bond in the water molecules hence electrolysis in pure water can be considerably slow if the much electrical energy is not provided. If the process is found to be slow, an electrolyte can be added to the reaction to activate the reaction of the inert electrodes (Cohen, 2004, p.11).
The cathode reaction is a reduction process because the electrons on the cathode are donated to the hydrogen cations forming hydrogen gas. The reaction is as follows
Cathode 2H (aq) 2e- H2 (g). On the other hand, oxidation reaction takes place on the positively charged anode to result in the generation of the oxygen gas. The equation is as shown, Anode 2H2O (l) O2 (g) 4H (aq) 4e- . There are other forms of half reactions that take place, and are balanced by the base or acid although not all cases can be balanced by acid or base reaction. Cathode 2H2O(l) 2e- H2(g) 2 OH-(aq) (reduction reaction), while the anode reaction is 4OH-(aq) O2(g) 2H2O(l)4e- (oxidation reaction). When the two reactions are combined, they result into the following reaction equation Overall reaction 2H2O(l) 2H2(g) O2(g) (Kamarev, 2003).
Hydrogen can be generated both in small scale and in industrial generation.
The Hofmann voltmeter is one of the small scale electrolyte with platinum plates used as the anode and the cathode. The industrial electrolysis cells are also designed much like the Hofmann voltmeter, but it has very complex honeycombs or the platinum plates cathodes that can be used to generate large volumes of the hydrogen gas. Hydrogen is generated in large amounts especially if the intended use is for pure hydrogen like the oxyhydrogen flame torches, or when the oxygen requirements demand for pure oxygen (National Renewable Energy Laboratory, n.d). Otherwise, most of oxygen gas generated for industrial use is produced through the decomposition of hydrocarbons. Thus, hydrogen gas generated by hydrocarbons usually contains some impurities like the carbon monoxide among others (Pyle, Healy, Cortez, 1994, p.34). Majority of the hydrogen generated through electrolysis is achieved through the electrolysis of brine.
Other forms of electrolysis include the high temperature electrolysis. This gas may be used in the production of special chemical substances. The photo electrochemical process of splitting water is also another way of generating the gas. In addition to that, there is also the photoelectrobiological process of water splitting that is used industrial process to generate this gas. Apart form the electrolysis of water, fossil fuels are also decomposed to generate the gas.
The herber process is another large process through which the hydrocarbons are decomposed to generate oxygen. And advanced system of water electrolysis was developed under the European community commission funding by R D programme that came up with the alkaline water electrolysis system which they worked on for close to 10 years of research. The particular design that was introduced has features like, the low operational temperatures of 70 to 90 degree Celsius with a current density of (0.1to 0.3amperescm2). This is relatively low and desirable. The moderate temperature is less than 120 degree Celsius operating at high current density of (about 1amperecm2) and medium pressures among other characteristic features that are highly desirable in the market (Stojic, et al, 2003, p.317).
Hydrogen has many uses or applications like the storage of energy in form of battery. Space travel vehicles are equipped with the apparatus that can effectively use hydrogen as the fuel. Hydrogen is also used as a drying agent in the chemical industry.
Most of the hydrogen generated in many areas of the world is used in the purification or preservation of foods by the food processing firms. It is also commonly used in the treatment of metals during chemical process as well as the refining industries.
The principal user of hydrogen in the US is the NASA, the National Aeronautics and Space Administration which is used for space ships as fuel. The hydrogen is used in various forms like the liquid fuel (hydrogen) used in the space shuttles, hydrogen batteries for electrical appliances and the by product for pure drinking water. Hydrogen fuel cells can provide power enough to move and propel electric cars, and the larger ones can produce electricity enough to light in some remote areas. The fuel cells can be used as emergency source of electricity in the remotely located hospitals and residential areas (Edinger,Kaul, 2003, p.54). They can also be used to power cell phones, laptop computers and some high efficiency military apparatus.
However, this is expensive to generate and are not widely used but only as an emergency power source. There are known cases of buses and other automobiles that are currently using hydrogen as fuel source in the U.S. They store it as liquid hydrogen or in gaseous form on board and then change it to electricity by the use of a motor cell. The most overriding problem in the automobile industries is that despite the ability to generate the hydrogen in cars, it is unfortunate that there are only few refueling stations (Haughland, Raland, 1999,p.19). Specialists are however trying to install the refueling stations and more cars for a number of agencies that order to use these types of cars.
Another use of hydrogen is the hydrogen gas sensors and alarms. It is needed by many companies to be used as the feed stock for their machinery because it has a high compression energy that allows it to react chemically with processing materials, hence the generation of new products. It may also be used in those processing conditions that need be protected from oxidation. The food and beverages industries are the best consumers of the gas in the hydrogenation of fatty acids that are not saturated and in the production of solid fats (Shimizu, et al, 2006, p.421). The solid fats could be required in products such as margarine, cottonseed, fish, and corn among others.
The chemical industry is yet another consumer of hydrogen especially in the production of large quantities of ammonia, hydrogen peroxide, solvents, methanol and polymers. The hydrogenation of cosmetic oils, and oils used in the generation of insulators, ointments, plastics, and soaps also involves the use of hydrogen gas.
The energy sector is not to be left behind in the use of hydrogen because majority of the new innovations which require the use of environmental friendly emissions are now employing the use of the gas. The fuel cells are an example of its uses. The petroleum refineries are also using hydrogen as a catalyst in the processing of the petroleum or crude oils to its constituent components. The medical authorities are using hydrogen in the generation of medicinal products and vitamins. The metal industry also creates a reducing agent for metal reaction by mixing hydrogen and inert gases (Mandin, et al, p.3). The formation of alloys in most cases requires a reducing atmosphere for suitable reactions.
In the electronics industry, it uses the gas for advertisements, the production of semiconductors and power source for electrical appliances for products like cell phones. It is also used to fuel rockets in the aviation appliances.
In conclusion, although many uses of hydrogen have been discussed, it should be noted that the industrial electrolysis processes are expensive. This means that it is only when large amounts of pure hydrogen are needed or pure oxygen when this process is done. The generation of large volumes of hydrogen gas has been left with the fossil fuels decomposition of generally the hydrocarbons genesis of the gas.
The process set up involves the connection of two electrodes, the anode and the cathode to an electric power supply. The negatively charged electrode on to which the hydrogen electron adheres to is called the cathode and the positively charged electrode on to which oxygen molecules adheres to is the anode. These metal plates are made of inert substance like platinum or the stainless steel. During this process, the ratio of hydrogen moles generated is twice as much as the amount of oxygen moles so long as the faradaic efficiency is ideal (Hyfleet, n.d). In most cases however, the reaction generates less moles of the products because of reactions that may occur on the cells surface.
Pure water usually requires a lot of activation energy to overcome the covalent bond in the water molecules hence electrolysis in pure water can be considerably slow if the much electrical energy is not provided. If the process is found to be slow, an electrolyte can be added to the reaction to activate the reaction of the inert electrodes (Cohen, 2004, p.11).
The cathode reaction is a reduction process because the electrons on the cathode are donated to the hydrogen cations forming hydrogen gas. The reaction is as follows
Cathode 2H (aq) 2e- H2 (g). On the other hand, oxidation reaction takes place on the positively charged anode to result in the generation of the oxygen gas. The equation is as shown, Anode 2H2O (l) O2 (g) 4H (aq) 4e- . There are other forms of half reactions that take place, and are balanced by the base or acid although not all cases can be balanced by acid or base reaction. Cathode 2H2O(l) 2e- H2(g) 2 OH-(aq) (reduction reaction), while the anode reaction is 4OH-(aq) O2(g) 2H2O(l)4e- (oxidation reaction). When the two reactions are combined, they result into the following reaction equation Overall reaction 2H2O(l) 2H2(g) O2(g) (Kamarev, 2003).
Hydrogen can be generated both in small scale and in industrial generation.
The Hofmann voltmeter is one of the small scale electrolyte with platinum plates used as the anode and the cathode. The industrial electrolysis cells are also designed much like the Hofmann voltmeter, but it has very complex honeycombs or the platinum plates cathodes that can be used to generate large volumes of the hydrogen gas. Hydrogen is generated in large amounts especially if the intended use is for pure hydrogen like the oxyhydrogen flame torches, or when the oxygen requirements demand for pure oxygen (National Renewable Energy Laboratory, n.d). Otherwise, most of oxygen gas generated for industrial use is produced through the decomposition of hydrocarbons. Thus, hydrogen gas generated by hydrocarbons usually contains some impurities like the carbon monoxide among others (Pyle, Healy, Cortez, 1994, p.34). Majority of the hydrogen generated through electrolysis is achieved through the electrolysis of brine.
Other forms of electrolysis include the high temperature electrolysis. This gas may be used in the production of special chemical substances. The photo electrochemical process of splitting water is also another way of generating the gas. In addition to that, there is also the photoelectrobiological process of water splitting that is used industrial process to generate this gas. Apart form the electrolysis of water, fossil fuels are also decomposed to generate the gas.
The herber process is another large process through which the hydrocarbons are decomposed to generate oxygen. And advanced system of water electrolysis was developed under the European community commission funding by R D programme that came up with the alkaline water electrolysis system which they worked on for close to 10 years of research. The particular design that was introduced has features like, the low operational temperatures of 70 to 90 degree Celsius with a current density of (0.1to 0.3amperescm2). This is relatively low and desirable. The moderate temperature is less than 120 degree Celsius operating at high current density of (about 1amperecm2) and medium pressures among other characteristic features that are highly desirable in the market (Stojic, et al, 2003, p.317).
Hydrogen has many uses or applications like the storage of energy in form of battery. Space travel vehicles are equipped with the apparatus that can effectively use hydrogen as the fuel. Hydrogen is also used as a drying agent in the chemical industry.
Most of the hydrogen generated in many areas of the world is used in the purification or preservation of foods by the food processing firms. It is also commonly used in the treatment of metals during chemical process as well as the refining industries.
The principal user of hydrogen in the US is the NASA, the National Aeronautics and Space Administration which is used for space ships as fuel. The hydrogen is used in various forms like the liquid fuel (hydrogen) used in the space shuttles, hydrogen batteries for electrical appliances and the by product for pure drinking water. Hydrogen fuel cells can provide power enough to move and propel electric cars, and the larger ones can produce electricity enough to light in some remote areas. The fuel cells can be used as emergency source of electricity in the remotely located hospitals and residential areas (Edinger,Kaul, 2003, p.54). They can also be used to power cell phones, laptop computers and some high efficiency military apparatus.
However, this is expensive to generate and are not widely used but only as an emergency power source. There are known cases of buses and other automobiles that are currently using hydrogen as fuel source in the U.S. They store it as liquid hydrogen or in gaseous form on board and then change it to electricity by the use of a motor cell. The most overriding problem in the automobile industries is that despite the ability to generate the hydrogen in cars, it is unfortunate that there are only few refueling stations (Haughland, Raland, 1999,p.19). Specialists are however trying to install the refueling stations and more cars for a number of agencies that order to use these types of cars.
Another use of hydrogen is the hydrogen gas sensors and alarms. It is needed by many companies to be used as the feed stock for their machinery because it has a high compression energy that allows it to react chemically with processing materials, hence the generation of new products. It may also be used in those processing conditions that need be protected from oxidation. The food and beverages industries are the best consumers of the gas in the hydrogenation of fatty acids that are not saturated and in the production of solid fats (Shimizu, et al, 2006, p.421). The solid fats could be required in products such as margarine, cottonseed, fish, and corn among others.
The chemical industry is yet another consumer of hydrogen especially in the production of large quantities of ammonia, hydrogen peroxide, solvents, methanol and polymers. The hydrogenation of cosmetic oils, and oils used in the generation of insulators, ointments, plastics, and soaps also involves the use of hydrogen gas.
The energy sector is not to be left behind in the use of hydrogen because majority of the new innovations which require the use of environmental friendly emissions are now employing the use of the gas. The fuel cells are an example of its uses. The petroleum refineries are also using hydrogen as a catalyst in the processing of the petroleum or crude oils to its constituent components. The medical authorities are using hydrogen in the generation of medicinal products and vitamins. The metal industry also creates a reducing agent for metal reaction by mixing hydrogen and inert gases (Mandin, et al, p.3). The formation of alloys in most cases requires a reducing atmosphere for suitable reactions.
In the electronics industry, it uses the gas for advertisements, the production of semiconductors and power source for electrical appliances for products like cell phones. It is also used to fuel rockets in the aviation appliances.
In conclusion, although many uses of hydrogen have been discussed, it should be noted that the industrial electrolysis processes are expensive. This means that it is only when large amounts of pure hydrogen are needed or pure oxygen when this process is done. The generation of large volumes of hydrogen gas has been left with the fossil fuels decomposition of generally the hydrocarbons genesis of the gas.
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