How to look at energy issues

Hello! The three elements of human survival and development: matter, energy and information. Therefore, the history of energy development directly affects the history of human development.

The most decisive elements in our human survival and development are three: ? matter, energy and information.

The material that makes up our world, the information that determines our survival activities, and the energy that sustains us and enables us to develop, all of these activities are carried out through the consumption of energy.

All energy comes from energy, and human beings cannot live without energy. Energy is the main basis for human survival, life and development. Energy science and technology, the development of energy utilization in the progress of human society has been playing an important role.

Milestones in energy development It can be said that every milestone in the development of energy utilization is accompanied by a huge leap in human survival and social progress. Over the past thousands of years, in the history of human energy use, roughly experienced such four milestone development stage: the use of fire in primitive society, the ancestors ushered in the dawn of civilization under the light of fire; 18th century the invention of the steam engine and the use of greatly improved productivity, leading to the industrial revolution in Europe; 19th century the use of electricity, greatly promoting the development of social and economic development, changed the face of human life; the 20th century to nuclear energy as the main source of energy, the development of human life, the development of human life, the development of human life, the development of human life, the development of human life, the development of human life. face; the 20th century to nuclear energy as the representative of the use of new energy, so that mankind into the microcosm of the atom, began to use the energy within the atom.

Future energy requirements:

There are enough reserves to meet the needs of human survival and development, and will not cause environmental pollution affecting human survival.

Future energy requirements: The future of human society will continue to depend on energy and its sustainable development. Therefore, we must have a clear understanding of the structure and reserves of energy on the earth now, and develop the energy utilization technology that must be developed in order to make the survival of human beings sustained permanently.

And the energy we depend on for survival is inexhaustible? The answer is: no, and yes. In fact, after entering the 21st century, mankind's current technology can be developed energy resources will face a serious shortage of crisis, today's coal, oil and natural gas and other fossil fuel resources are increasingly depleted, and even can not be maintained for decades. Therefore, sustainable alternative energy sources must be sought. Nearly half a century of peaceful uses of nuclear energy has made nuclear energy the only realistic large-scale alternative to limited fossil fuels in the new energy family. Moreover, in the future, if the complete utilization of nuclear energy can be realized, the energy resources of mankind will be infinite.

In addition to the three major factors of matter, energy and information, the requirements of human beings for security are becoming more and more important. Security includes social security, health security and environmental security. Their relationship with energy is also very close. The energy now utilized has caused a great deal of environmental pollution problems, seriously affecting the survival of mankind. Therefore, the future requirement for energy will not only be sufficient reserves, but also clean energy. Relative to other fossil energy sources, the peaceful use of nuclear energy has fully proved that nuclear energy is one of the clean energy.

u Definition and sources of energy

What is energy? The Encyclopedia of Science and Technology says: "Energy is a resource from which energy such as heat, light, and power can be obtained"; Encyclopedia Britannica says: "Energy is a term that includes all fuels, flowing water, sunlight, and wind, which humans can use appropriate means of conversion to provide themselves with the energy they need. Energy is a term that includes all fuels, running water, sunlight, and wind, which man can make available to himself by suitable means of conversion. As can be seen, energy is a source of interconvertible energy in many forms. In short, energy is a material resource in nature that can provide energy for human beings.

The source of energy: energy from celestial bodies outside the Earth (such as solar energy), the Earth itself contains energy (such as geothermal, nuclear energy), the Earth and other celestial bodies interact with the energy generated (such as tides).

And energy is the source from which it is generated. : Energy sources are usually categorized according to their form and mode of application. They are generally categorized as: solid fuels, liquid fuels, gaseous fuels, hydroelectric energy, electrical energy, solar energy, biomass energy, wind energy, nuclear energy, ocean energy and geothermal energy. Of these, the first three categories are collectively known as fossil fuels or fossil energy. These energy sources, which have been recognized by mankind, can be converted into various forms of energy needed by people under certain conditions. For example, firewood and coal, heated to a certain temperature, can be combined with oxygen and release a large amount of heat energy, which can be used directly for heating, can also be used to produce steam to drive the turbine, and then drive the generator, so that the heat energy into mechanical energy, and then into electrical energy. The electricity is sent to factories, organizations and households, and can be converted into mechanical energy, light energy or heat energy.

Energy comes in all shapes and sizes on the planet we live on. In total there are three initial sources.

Solar energy

Earth

Energy from celestial bodies external to the Earth (mainly solar energy) The vast majority of the energy needed by humans comes directly or indirectly from the sun. It is the various plants that convert solar energy into chemical energy stored within the plant through photosynthesis. Fossil fuels such as coal, oil, and natural gas were also formed by ancient plants and animals buried in the ground over long geologic ages. They are essentially solar energy fixed by ancient organisms. In addition, hydroelectric energy, wind energy, wave energy, and ocean current energy are also converted from solar energy.

Energy contained in the Earth itself Usually refers to energy associated with heat within the Earth and energy associated with atomic nuclear reactions.

The energy associated with the heat inside the Earth is called geothermal energy. Hot springs and magma spewed out by volcanic eruptions are manifestations of geothermal heat. The Earth can be divided into three layers: the crust, the mantle and the core, which is a large heat reservoir. The Earth's crust is the layer on the surface of the Earth, generally ranging from a few kilometers to 70 kilometers thick. Below the crust is the mantle, which is mostly molten magma and is 2,900 kilometers thick. Volcanic eruptions are generally eruptions of this magma. Inside the Earth is the core, which has a temperature of 2,000 degrees at its center. It can be seen that the Earth's geothermal resource storage is also very large.

The energy source associated with the reaction of atomic nuclei is precisely the nuclear energy that this book will introduce. Changes in the structure of the atomic nucleus can release a large amount of energy, called atomic nuclear energy, referred to as nuclear energy, commonly known as atomic energy. It comes from nuclear fission energy resources when fission reactions occur, such as uranium and plutonium stored in the earth's crust, and fusion energy resources when fusion reactions occur, such as deuterium, tritium, lithium, etc., stored in the oceans. These substances release energy when they undergo atomic nuclear reactions. Currently the largest use of nuclear energy is for electricity generation. In addition, it can be used as other types of power sources, heat sources, etc.

Energy from planetary gravity Refers to the energy that is formed as a result of the Earth's interaction with celestial bodies such as the Moon and the Sun. The regular movement of the Earth, the Moon, and the Sun causes periodic changes in their relative positions, and the gravitational pull between them causes the sea to rise and fall, resulting in the formation of tidal energy. Compared with the two types of energy mentioned above, the amount of tidal energy is very small. The world's tidal energy is equivalent to about 3 billion tons of coal per year, and the actual availability of only the shallow sea area that part of the annual equivalent of about 60 million tons of coal.

u Energy structure and reserves

What energy resources are available to us on Earth? How long will they last? What should we do about them?

Types of energy :

Primary energy: natural energy resources such as coal, oil, nuclear energy, etc.;

Secondary energy: artificially created energy resources such as gasoline, electricity, steam, etc.

Primary and secondary energy sources Energy sources are divided into two main categories, natural energy (primary energy) and artificially created energy (secondary energy), according to the way in which they are generated. Natural energy refers to energy resources that exist in nature in their natural form and have not been processed or converted, such as coal, oil, natural gas, nuclear fuel, wind, water, solar energy, geothermal energy, ocean energy, tidal energy, etc.; Artificial energy refers to energy resources that are directly or indirectly converted from primary energy into other types and forms, such as gasoline, gasoline, kerosene, diesel fuel, electricity, steam, hot water, hydrogen, laser, etc.

Conventional energy and new energy sources Among them, the energy sources that have been widely utilized by human beings and have played an important role in human life and production are called conventional energy sources, which usually refer to four kinds of energy, such as coal, petroleum, natural gas, and hydroelectric energy. And only recently by human development and utilization, pending further research and development of energy resources called new energy, relative to conventional energy, in different historical periods and scientific and technological level, new energy has different content. In today's society, new energy usually refers to nuclear energy, solar energy, wind energy, geothermal energy, hydrogen and so on.

The Age of Coal

Changes in Energy Structure Historically, along with the discovery of new fossil resources and large-scale exploitation and application, the world's energy consumption structure has gone through several transformations. in the 18th century, coal was used as a substitute for firewood, and by the mid-19th century, coal had already gradually taken over the dominant position. in the 1920s, with the discovery of petroleum resources and the development of the petroleum industry, a second transformation of the world's energy structure took place, i.e., the discovery of oil resources and the development of the petroleum industry. In the 1920s, with the discovery of petroleum resources and the development of the petroleum industry, the world's energy structure underwent a second transformation, that is, from coal to oil and natural gas, to the 1960s, oil and natural gas has gradually known as the dominant energy source, shaking the dominant position of coal. However, the outbreak of two oil crises since the 1970s began to shake the dominant position of oil in energy. At the same time, most of the chemical energy reserves are diminishing, and accompanied by many environmental pollution problems.

While the human demand for energy is increasing day by day. For example, the main forms of energy Earth's energy reserves are estimated

Coal: ~200 years

Oil, natural gas: ~50 years

Nuclear energy: infinity

One of the increasing consumption of electricity every year. According to statistics, if the population doubles every 30 years, the demand for electricity will have to double every eight years.

So, at the end of the 20th century, the energy structure began to undergo a third shift, that is, from the oil-centered energy system began to coal, nuclear and other renewable energy sources and other diversified energy structure. In particular, with the passage of time, the proportion of nuclear energy will continue to grow and will gradually replace oil and natural gas as one of the major large-scale energy sources.

Storage of chemical energy How many more years of coal, oil, and natural gas are left for mankind to exploit and utilize? According to the World Energy Conference, the world's proven recoverable coal reserves*** amount to 15,980 billion tons, which are expected to be mined for another 200 years. Proven recoverable oil reserves*** amount to 121.1 billion tons, which can be exploited for 30 to 40 years. Proven recoverable natural gas reserves *** counted 119 trillion cubic meters, is expected to be exploited for 60 years. It must be pointed out that coal, oil and other direct combustion used to produce electricity and heat is too bad, not to mention the possible environmental pollution, they are still very good chemical raw materials it!

Hydro and new energy potential What about hydro? We know that water power can be developed and utilized in the long term. However, in those countries and regions where there is a large area of water shortages, hydroelectric resources are not abundant how to do? Besides, there is a seasonal problem with hydro energy. All these make water energy can not become the only main force in the world energy structure. Among the new energy sources, solar energy is inexhaustible, but the cost is too high, and in view of the current technological development, it is unlikely that it will be rapidly developed and widely used within a generation. The same is true of other new energy sources. Some other energy sources are similar to water energy, their scale is limited by the environment, seasons, geographic location and other conditions, such as wind energy, tidal energy, geothermal energy and so on.

Fissile Nuclides

The only three atoms that are susceptible to fission are uranium-235 (U235), plutonium-239 (Pu239), and uranium-233 (U233). Whereas the only naturally occurring fissionable element is uranium-235, plutonium-239 can be produced from uranium-238, and uranium-233 can be produced from thorium-232 (Th232).

Fusible nuclear reactions

Deuterium (D2)-tritium (D3) reactions. Deuterium and tritium are both isotopes of the hydrogen atom. Deuterium occurs naturally, while tritium is extremely rare and must be produced artificially (e.g., from lithium).

Nuclear energy - an infinite source of energy Nuclear energy is divided into two types: fission energy and fusion energy. Currently, only fission energy is being used for peaceful purposes. Controlled fusion energy utilization technology is being overcome.

Composition of natural uranium

Natural uranium accounts for 99.3% of the difficult to fission uranium-238, only 0.714% of the fissile uranium-235. uranium-238 can be absorbed by a neutron into a fissile plutonium-239.

As the development of nuclear fission energy one of the main raw materials of uranium, the world's proven uranium reserves of about 4.9 million tons, thorium reserves of about 2.75 million tons. Thorium reserves of about 2.75 million tons. If well utilized, it can be used for 2400-2800 years.

The fusion reaction is mainly from deuterium - tritium nuclear reaction, deuterium from a large number of seawater, tritium can come from lithium. Therefore, the fusion fuel is mainly deuterium and lithium, seawater deuterium content of 0.03 grams / liter, it is estimated that the amount of seawater on the earth is about 13.8 billion billion meters 3, so the world's deuterium reserves of about 4 billion tons; lithium reserves on the earth, although less than the deuterium is much less than more than 200 billion tons, with which to make tritium, enough to meet the needs of mankind on the fusion energy. The energy released by these fusion fuels is ten million times greater than the energy released by the total amount of energy available in the world. At the current level of world energy consumption, the deuterium and tritium available on Earth for atomic fusion could last mankind hundreds of billions of years. If mankind has realized the deuterium - tritium controlled fusion, nuclear fuel can be said to be "inexhaustible, inexhaustible", mankind will fundamentally solve the energy problem, which is the current nuclear scientists are diligently seeking so. Fusion energy is not only abundant, but also safe and clean. Fusion produces much less radioactivity than fission.

Experts predict that nuclear energy will become an inexhaustible and durable source of energy for mankind in the future.

1.2 A Dirty Planet and Clean Nuclear Power

Highlights of this section: Questions answeredThe following questions are asked: How long will existing energy sources last? Can energy be utilized without polluting the environment? Is nuclear energy really sustainable?

u Sustainable development of energy

It is necessary to find sources of energy that can guarantee an adequate supply in the long term without causing environmental pollution.

At present, the problems faced by mankind are: depletion of energy resources; serious environmental pollution.

Energy utilization and environmental sustainability

Energy crisis

Currently, some of the world's conventional energy reserves can only last half a century (such as oil), the most can be sustained for one or two hundred years (such as coal) human survival needs.

Today, almost all industrialized countries are faced with two closely related challenges to sustainable development: ensuring a satisfactory long-term energy supply and reducing the impact of human activities on the environment. The sustainable development of energy use and the environment has become an important issue for the future survival of mankind and the continuation of civilization.

Crisis of energy supply Today's world population has exceeded 6 billion, more than twice as many as at the end of the last century, while energy consumption has statistically increased by more than 16 times. No matter how many people talk about "conserving" and "utilizing solar energy" or "drilling more oil or gas wells" or "discovering more and more large coal fields "The supply of energy has never been able to keep up with human demand for energy. Currently, the world's energy consumption is dominated by fossil resources, of which a few countries such as China are dominated by coal, while most other countries are dominated by oil and natural gas. According to the current consumption, experts predict that oil and natural gas can only last for less than half a century at most, and coal can only last for one or two hundred years. So no matter which conventional energy structure, mankind is facing an increasingly serious energy crisis.

Smoky thermal power plants

Pollution of the environment by energy On the other hand, the process of utilizing fossil energy in particular also has a direct impact on the Earth's environment, causing the atmosphere and water resources to suffer serious pollution. The five main pollutants in the atmosphere are: oxides of nitrogen (such as NO and NO2), sulfur dioxide (SO2), various suspended particulate matter, carbon monoxide (CO) The main sources of atmospheric pollution

Currently the world's worst atmospheric pollution comes from the increase in the amount of carbon dioxide in the atmosphere caused by the burning of fossil energy. The main consequences are: acid rain, the greenhouse effect and the destruction of the ozone layer.

and hydrocarbons (such as CH4, C2H6, C2H4, etc.). There are three main sources: ① the burning of fossil fuels such as coal and oil; ② the exhaust from automobile emissions; ③ the exhaust from industrial production (e.g., various chemical plants, coking plants, etc.). And among them, thermal power plants burning fossil fuels are the largest stationary source of pollution.

u Nuclear energy is a sustainable energy source