1-World Energy Supplying Trend
From the beginning, "energy" is known as driving force in human communities and its importance and effect on human life became clearer as he progressed. After fire discovery, primitive man, used trees' leaves, branches, trunks, etc. for providing his energy requirements. Actually, for long time what is known as plant biomass, has been used as human required energy resource. It can be said this period was the age of energy supplying on the basis of biomass sources or "biomass economy".
With the discovery of coal and its combustion properties, it was exploited as a new energy resources and its use was developed as thermal energy source. This trend accelerated by the invention of steam engines which brought about a great evolution in industry and was one of the reasons of the Industrial Revolution. It should be said that the development of railway transportation with the employing of steam locomotives has affected the florescence of the age of the utilization of coal energy, a great deal. In fact, this period is the age of energy supplying by the use of coal, or 'coal economy".
When oil was discovered, its advantages over coal were cleared especially in transportation. Gradually, the consumption of coal decreased as the usage of crude oil increased so high that during short period, much of the human required energy sources were supplied by crude oil and its derivatives. On the basis of this fast trend, crude oil was known as the most important resource for energy supply. Therefore, this period should be named as "petroleum economy" undoubtedly.
Crude oil resources are limited and it is not possible to continue this accelerated consuming trend for longer time. It is necessary to use alternative resources that have the same combustion properties. Thus, the use of the gases extracted with crude oil is widespread. These gases are simply converted to liquid (LNG). It become possible to use these vast sources of natural gas in urban gas piping network, supplying the power plants' fuel, and using as vehicles' fuel. These trends decentralize the use of crude oil in energy supply and change the balance toward natural gas. In this way, the age of energy supplying is formed based on the natural gas.
All of these energy sources including biomass, coal, crude oil and its derivatives, and natural gas are used through combustion and produce so many kinds of emissions to environment. The major of these emissions are CO, CO2, NOx, sulphur oxides, and suspended particles. Their concentrations and extensions in environment are based on their resources and proportional to fossil fuels consumptions. This unrestrained utilization trend leads to environmental pollution. Some of these pollutants, e.g., CO and NOx affect human health, directly. The others, e.g., CO2 with increasing the green house effects, increase the global temperature and produce unusual environmental changes such as, ice melting in Arctic and Antarctic, oceans' surface elevations, and dangerous storms.
2- The Reasons for the Hydrogen Economy Approach
There are some reasons why politicians and experts in energy and environment fields are eager to start this movement toward the establishment of this novel economy, e.g., "hydrogen economy". These reasons are:
- Limitation of fossil fuels' resources.
- Destructive environmental effects of the growing fossil fuel utilizations.
- Fossil fuels Increasing price.
- Political quarrels and their effects on the trends of stable energy systems.
- This novel energy economy will represent the energy security, environmental protection, and rise of the energy system's efficiency. In this way, hydrogen is one of the best choices as an energy carrier through this novel energy system.
Hydrogen is the most abundant element in and outside the earth and can be isolated by a variety of processes. In an ideal energy system based on hydrogen, as mentioned above, hydrogen is produced by the electricity that is generated via renewable sources such as wind, solar, and geothermal energies. The electricity is used to electrolysis water and produced hydrogen and oxygen. The produced hydrogen should be storage and then, transport to consumers. Its ultimate consumers are of very different natures and include small and portable electrical devices and equipments (like cell phones and laptops) and electrical power and transportation industries. According to this approach, many experts believe that hydrogen is the ultimate fuel for human civilization. Human will experience the hydrogen economy in near future and it is not boasting!
Hydrogen chemical energy is converted to electrical energy by a device called "fuel cell"., There are different kinds of fuel cells based on their applications and structures. In fact, through an energy system based on hydrogen, the importance of fuel cells is such that they are evaluated as propellant force of the development trend of this system. In hydrogen economy, in addition to technologies of fuel cells that consume hydrogen, the main components are the technologies of production, storage, supply, and transport of hydrogen. Although, it is useful to achieve to the hydrogen economy by the use of renewable resources but it is not take place by an immediate jump. There are some technical and economical problems that make it impossible to change the present system rapidly. Therefore, the achievement to hydrogen economy dose not takes place in near future.
There is need to establish a chain of infrastructures in order to support hydrogen economy. These infrastructures are in different fields of hydrogen production, storage, transport, and supply together with technologies of hydrogen consuming in fuel cells. It is apparent that each of these related technologies will not develop by the same speed because of related economical and technical problems. Taking in to account the capabilities of natural gas for producing hydrogen (more than 90% of produced hydrogen in world is getting from natural gas, now) developing of natural gas infrastructure will be helpful in establishing the hydrogen economy.
In medium range discipline, the hydrogen economy will be organize based on the combination of centralized and/or decentralized hydrogen production from renewable resources and fossil fuel sources like natural gas, coal, etc. and transportation of hydrogen in the form of natural gas in pipe lines or especial trucks. In this transient period the use of fuel cells that can directly or indirectly consume hydrogen, natural gas, and methanol will be develop. By the same time the infrastructures of production, storage, supply, and use of hydrogen will be advanced.
As stated before, natural gas is considered as one of the main promoters in establishing and developing of hydrogen economy. It has the required infrastructures that are suitable for using directly or indirectly (via reformer) in some fuel cells. It is essential to do something about the produced CO2 during the converting of natural gas or other fossil fuels to hydrogen. It is suggested that this gas must be storage at the dept of the caverns or oceans’ bed. It is need to say that methanol is capable for using in some of fuel cells applied for charging the portable electric device such as cell phones or laptops.
In brief, although there are many advantages in establishing and gaining the infrastructures of hydrogen economy, it dose not happens at once. A series of activities is required to accomplish this novel technology. They are R&D activities, prototype manufacturing, pilot plants construction, cost reductions, and culturization.
Last Update: Friday 12 December 2008 Time: 15:57