Message hydrocarbons, fuel, their types and purpose. Hydrocarbon fuel, its types and significance. Environmental impact

Fossil fuels are oil, coal, oil shale, natural gas and its hydrates, peat and other combustible minerals and substances from the group of caustobiolites, used mainly as fuel, mined underground or in open pits. Fossil fuels are formed from the fossilized remains of dead plants as they decompose anaerobically under heat and pressure in the Earth's crust over millions of years. Coal and peat are fuels formed as the remains of animals and plants accumulate and decompose. Fossil fuels are a non-renewable natural resource, having accumulated over millions of years. According to the Energy Information Administration (EIA), in 2007 the primary energy sources used were: oil - 36.0%, coal - 27.4%, natural gas - 23.0%, for a total of 86. 4% of all sources (fossil and non-fossil) of primary energy consumed in the world. It should be noted that non-fossil energy sources include: hydroelectric power plants - 6.3%, nuclear - 8.5%, and others (geothermal, solar, tidal, wind energy, wood and waste combustion) in the amount of 0.9%.

Oil is a natural oily flammable liquid consisting of a complex mixture of hydrocarbons and some other organic compounds. The color of oil is red-brown, sometimes almost black, although sometimes slightly yellow-green and even colorless oil is found; has a specific odor and is common in sedimentary rocks of the Earth. Oil has been known to mankind since ancient times. However, today oil is one of the most important minerals for humanity.

General scheme of oil refining In general, oil refining into petroleum products includes its preparation and the processes of primary and secondary processing. The purpose of preparing oil extracted from the subsoil is to remove mechanical impurities, dissolved salts and water from it and stabilize its composition. These operations are carried out both directly at oil fields and at oil refineries. Primary oil refining (primary processes) consists of dividing it into separate fractions (distillates), each of which is a mixture of hydrocarbons. Primary processing is a physical process and does not affect the chemical nature and structure of the compounds contained in oil. The most important of the primary processes is the direct race of oil. Secondary petroleum refining (secondary processes) is a variety of processes for processing petroleum products obtained by the direct race method. These processes are accompanied by destructive transformations of hydrocarbons contained in petroleum products and changes in their nature, that is, they are chemical processes.

Hydrocarbon Chemistry Many people believe that the crude oil pumped out of the ground is a mixture of different fuels, that they are all flammable and that there is essentially no difference between them. This is partly true, but let's figure out how, from a chemical point of view, gasoline differs from diesel fuel, kerosene, etc. Crude oil pumped out of the ground is not a fuel mixture at all, but a mixture of aliphatic hydrocarbons - substances consisting only of carbon and hydrogen atoms. The latter are connected to each other in chains of varying lengths. This is how hydrocarbon molecules are formed. This fact determines their physical and chemical properties. For example, the chain with one carbon atom (CH 4) is the lightest and is known as methane, a clear gas lighter than air. As the chains become longer, the hydrocarbon molecules become heavier and their properties begin to change noticeably. The first four hydrocarbons - CH 4 (methane), C 2 H 6 (ethane), C 3 H 8 (propane) and C 4 H 10 (butane) are all gases. They boil (evaporate) at temperatures of -107, -67, -43 and -18 degrees C. Chains starting from C 18 H 32 are liquids that have a boiling point starting from room temperature. So what is the real difference between gasoline, kerosene and diesel?

Carbon Chains in Petroleum Products Longer hydrocarbon chains have higher boiling points. Thanks to this property, hydrocarbons can be separated from each other. This process is called catalytic cracking, or simply distillation, and is what happens in an oil refinery. Here the oil is heated, and then the evaporated hydrocarbons are condensed, each into a separate container. Substances whose molecules have chains with C 5, C 6 and C 7 are all very light, easily evaporating, clear liquids called naphtha. It is used to make various solvents. Hydrocarbons with chains ranging from C7H16 to C11H24 are commonly blended and used to make gasoline. All of them evaporate at temperatures below the boiling point of water (100 o C). That's why, if you spill gasoline, it evaporates very quickly, literally before your eyes. Next comes kerosene. For its production, molecules from C 12 to C 15 are used.

Diesel and heating oil are made from even heavier hydrocarbons C 16 to C 19. Their boiling point is from 150 to 380 o C. Next come lubricating oils. They do not evaporate in any way at normal temperatures. For example, motor oil can run all day at 120 o C. Carbon molecules with C 20 are solids ranging from paraffin to bitumen, which is used to make asphalt and repair highways.

Hydrocarbon fuel, its types and significance

Hydrocarbon fuels are a mixture of hydrocarbons.

Installation diagram for determining the fractional composition of fuel. Hydrocarbon fuel is a liquid of complex composition, consisting of a large number of individual hydrocarbons. Such a liquid does not have a specific boiling point; the boiling process occurs in a certain temperature range. The characteristic points of the fractional composition are usually considered to be the initial boiling point, the boiling point of 10, 50, 90% of the fuel volume and the end boiling point.

Hydrocarbon fuels have the property of absorbing water from the air and dissolving it. The solubility of water in fuel is low and depends, other things being equal, on the temperature and chemical composition of the fuel. The most hygroscopic are aromatic hydrocarbons and especially benzene. Therefore, fuels rich in aromatic hydrocarbons have increased hygroscopicity.

Hydrocarbon fuel supplied at 260 C is cracked at 500 C in a pseudo-burnt bed; The technological scheme reactor - regenerator is used.

Hydrocarbon fuels are characterized by a high calorific value. The products of their complete combustion are mainly carbon dioxide and water. Only hydrogen, beryllium and boron have higher calorific values ​​than hydrocarbons. However, their use as fuels raises very complex problems that are not discussed here. In terms of operational properties, hydrocarbons as fuels have significant advantages.

Hydrocarbon fuels are characterized by high combustion speed and completeness. Thanks to this, the engine receives a high-density thermal charge for its operation in a very short period of time. With a well-organized process, the completeness of combustion of hydrocarbon fuels reaches 98% or more.

Hydrocarbon fuels differ little in the amount of air theoretically required for complete combustion - ranging from 13 9 to 15 0 kg / kg of fuel. Moreover, the higher the mass heat of combustion of the fuel (the higher the ratio of hydrogen to carbon), the more air is needed for its combustion.

Hydrocarbon fuels have the property of absorbing water from the air and dissolving it. The solubility of water in fuel is low and depends, other things being equal, on the temperature and chemical composition of the fuel. The most hygroscopic are aromatic hydrocarbons, and especially benzene. Therefore, fuels rich in aromatic hydrocarbons have increased hygroscopicity.

Hydrocarbon fuel, which is in a gaseous state at a temperature of 15 C and atmospheric pressure.

Hydrocarbon fuels without additives of non-hydrocarbon compounds have high physical stability.

Hygroscopicity of hydrocarbons. Hydrocarbon fuels have the property of absorbing water from the air and dissolving it.

Light hydrocarbon fuels transported in liquid form and used in gaseous form are called liquefied gas. It is widely used as a fuel in urban and rural areas.

Hydrocarbon fuels such as kerosene and the wide gasoline-naphtha-kerosene fraction have close limits for stable combustion in the engine.

For hydrocarbon fuels, the CP/HP ratio is determined taking into account the relative content of carbon and hydrogen in the working mass of the fuel.

For hydrocarbon fuels, this convergence in a first approximation (except for the region close to the region of maximum inert gas concentration) occurs in direct proportion to the change in inert gas concentration and mainly due to a shift in the upper limit.

Smokiness of combustion products D of TS-1 fuel at the exit from the combustion chamber of a gas turbine engine, depending on the pressure in chamber I (according to K.N. Erastov. Consumption of hydrocarbons and GT fuel burned without smoking, depending on pressure P [140]. Tendency hydrocarbon fuels to smoke is characterized by the height of the non-smoking flame, luminometric number and is determined directly during qualification tests of fuels in a model combustion chamber.

Comparison of the effectiveness of various methods for producing hydrogen. For hydrocarbon fuels, the only limitation is the minimum productivity, which still justifies the comparative complexity of the plant design. At the same time, installations using liquid petroleum products are of primary interest as they are the most universal.

Among hydrocarbon fuels, diesel fuels have the worst filterability under the same conditions, while gasoline has the best. The filterability of various fuels was studied using a setup simulating the fuel system of aircraft.

The thermal conductivity of hydrocarbon fuels depends on the chemical composition and temperature.

The thermal conductivity of hydrocarbon fuels depends on their chemical composition and at 0 C and atmospheric pressure lies in the range 0 115 - 0 125 W / (m - K). With increasing temperature, the thermal conductivity of fuels decreases; pressure has little effect. Alkanes of normal structure have the greatest heat capacity. As branching increases and the C:H ratio increases, the heat capacity of hydrocarbons decreases. Alcohols have a high heat capacity. As the pressure increases, the heat capacity decreases slightly.

For hydrocarbon fuels (without an anti-knock additive), it has been observed that the combustion rate varies in proportion to the octane number.

The heat capacity of hydrocarbon fuels at 20 C and atmospheric pressure is 1 6 - 2 0 kJ / kg K.

The thermal conductivity of hydrocarbon fuels at 0 C and atmospheric pressure varies within the range of 0 115 - 0 125 W / m K.

The calorific value of hydrocarbon fuels varies within rather narrow limits.

Fractions obtained during the distillation of crude oil.

Sources of hydrocarbon fuels are crude oil and natural gas. Oil and gas fields are usually located nearby and are found in many countries around the world.

The era of cheap hydrocarbon fuels, which ensured unprecedented rates of economic growth in industrialized countries, is a thing of the past forever.

In hydrocarbon fuels, during their storage, chemical changes occur mainly due to the oxidation and further transformations of the most unstable hydrocarbons. In this case, oxidation products of a resinous nature are formed and the fuel becomes unsuitable for use in engines.

The highest calorific value of certain elements. The heat of combustion of hydrocarbon fuels depends on the chemical composition and structure of the individual hydrocarbons included in the fuel, and for hydrocarbons of various groups is in the range of 9500 - 10,500 kcal/kg. In table Table 4 shows the values ​​of the heat of combustion per unit of mass and volume for elements that have the highest heat of combustion compared to other elements of the periodic system.

The calorific value of hydrocarbon fuels can be calculated using various empirical formulas.

Dependence of combustion stability limits on the chemical composition of hydrocarbons. During the combustion of hydrocarbon fuels, the release of dispersed particles of carbonaceous substances, similar in composition to carbon, is observed. Solid particles formed during combustion are carried away with combustion products and, at high concentrations, can be noticeable in the form of smoke. Some of the solid emissions are deposited on the surfaces of the combustion chamber in the form of soot. The formation of carbon deposits in an engine depends on the following properties of the fuel: fractional and chemical composition, density, content of resinous substances, sulfur and other impurities. In addition, carbon formation depends on the design of the combustion chamber and the completeness of the combustion process.

One firefighter saves another caught in toxic smoke during a fire in a closed warehouse. When hydrocarbon fuels are burned at low temperatures, light hydrocarbons, aldehydes (such as formaldehyde) and organic acids can be formed. Significant amounts of nitrogen oxide are formed at high temperatures - as a result of the oxidation of nitrogen contained in the atmosphere, and at low combustion temperatures of fuel, which contains a lot of nitrogen. If the fuel contains chlorine, hydrogen chloride is formed. Polymer plastic materials pose a particular danger.

The molecular weight of hydrocarbon fuels is determined mainly by the cryoscopic method and, in rare cases, the method of measuring vapor density is used.

Sulfur compounds of hydrocarbon fuels, including diesel, are converted mainly into hydrogen sulfide during the steam conversion process. Thermodynamic calculations performed for some reactions of hydrogen sulfide with solid reagents in order to determine the degree of conversion of hydrogen sulfide under conditions of high concentrations of water vapor showed that the most favorable reagent for capturing hydrogen sulfide from wet gas is zinc oxide. The degree of absorption of hydrogen sulfide by zinc oxide, even under conditions of high concentrations of water vapor (about 50%) at a temperature of 800 - 900 C, remains significant (52%), and calcium oxide does not chemisorb hydrogen sulfide under the same conditions.

Oxidation catalysis

Catalysis of the oxidation of hydrocarbon fuels by metal ions involves the generation of radicals that determine the development of oxidation chains and require additional consumption of an antioxidant to remove newly formed peroxide radicals from the reaction sphere.

To obtain hydrocarbon fuels with increased thermal stability, methods have been proposed that use the treatment of petroleum distillates with sulfuric acid and molecular sieves. Molecular sieves selectively release polar compounds that impair its thermal stability.

When hydrocarbon fuels come into contact with metals, especially at elevated temperatures, deposits form on the surface of the latter.

The conditions for using hydrocarbon fuels in rocket engines and in supersonic aircraft differ significantly. From the tank, pressurized with gasified nitrogen, the fuel enters the centrifugal pump, from where, through the main valve, it enters the inner space of the engine. Part of the fuel after the main fuel valve is taken into the automatic workflow control system, where there are units with friction pair gaps of 17 - 20 microns.

Scheme of a thermal air gasifier for gasoline. Steam conversion of hydrocarbon fuels is more complex in design. This is due to the need to have an additional capacity for water, a system for its supply and dosing.

Energy characteristics of fuels for jet engines. The energy characteristics of hydrocarbon fuels for jet engines can be increased by irradiating them with radioactive radiation. During radiation exposure, the molecular weight of the fuel increases.

The energy characteristics of hydrocarbon fuels for jet engines are limited by the fact that, along with hydrogen, which has the highest calorific value of 28,700 kcal/kg, they contain carbon, the calorific value of which is low - 7,800 kcal/kg. By replacing carbon with higher-calorie elements, such as beryllium (14,970 kcal/kg) and boron (14,170 kcal/kg), broad opportunities are opened for obtaining promising high-energy fuels for jet engines.

The acid number of hydrocarbon fuels and oils is very low. Acids, and especially hydroxy acids, which accumulate in fuels and oils during operation, are an extremely undesirable impurity.

When choosing a hydrocarbon fuel, it is necessary to consider several properties of hydrocarbons. These include the amount of heat released for each gram of fuel burned; The benefit of high enthalpy of combustion may be lost if the fuel required is high molecular weight.

The calorific value of hydrocarbon fuels depends on the elemental composition, which in turn is related to the group composition.

During the combustion of hydrocarbon fuels, the release of dispersed particles of carbonaceous substances, similar in composition to carbon, is observed. The solid particles formed during combustion, apparently as a result of pyrolysis of the fuel to coke, are carried away with the combustion products and, at high concentrations, can be noticeable in the form of smoke. Some of the coke emissions are deposited on the surfaces of the combustion chamber, turbine blades and other parts in the form of soot. The formation of carbon deposits primarily depends on the combustion conditions of the fuel and its chemical composition, in particular on the carbon and hydrogen content.

thermal conductivity hydrocarbon fuel hydrogen

Types of hydrocarbon fuels

Aromatic hydrocarbons are organic compounds consisting of carbon and hydrogen and containing benzene nuclei. The simplest and most important representatives of A. u. - benzene (I) and its homologues: methylbenzene, or toluene (II), dimethylbenzene, or xylene, etc. To A. u. also include benzene derivatives with unsaturated side chains, for example styrene (III). There are many known A.u. with several benzene nuclei in the molecule, for example diphenylmethane (IV), diphenyl C6H5--C6H5, in which both benzene nuclei are directly linked to each other; in naphthalene (V) both rings share 2 carbon atoms; such hydrocarbons are called A.u. with condensed nuclei.

Basic source of obtaining A. serve as coking products. coal From 1 t Kam.-Ug. resins can be isolated on average: 3.5 kg of benzene, 1.5 kg of toluene, 2 kg of naphthalene. The production of A. is of great importance. from fatty petroleum hydrocarbons (see Flavoring of petroleum products). For some A.u. Purely synthetic methods are of practical importance. Thus, ethylbenzene is produced from benzene and ethylene, the dehydrogenation of which leads to styrene:

According to the chemical properties of A. u. differ sharply from unsaturated alicyclic compounds; they are classified as an independent large class of organic compounds (see Aromatic compounds). Under the action of sulfuric acid, nitric acid, halogens and other reagents in A. hydrogen atoms are replaced and aromatic sulfonic acids, nitro compounds, halobenzenes, etc. are formed. These compounds serve as intermediate products in the production of dyes, medicines, etc. Styrene easily forms a practically important polymer - polystyrene. The oxidation of naphthalene produces phthalic acid o-C6H4 (COOH)2, which serves as the starting product in the production of many dyes, glyphthalic resins, and phenolphthalein.

(alkanes) have a branched structure; paraffinic hydrocarbons of normal structure have the lowest octane number. Petroleum fuels produced by catalytic reforming and cracking have higher octane numbers than those obtained by direct distillation.

To increase the octane number of fuels, high-octane components and anti-knock additives are used. Many of them (for example, MTBE) evaporate more easily than gasoline, which leads to an interesting effect in cars with a leaky gas tank - as fuel is consumed and the additive evaporates, the octane number of gasoline remaining in the tank decreases by several units. This leads to a slight ringing sound at full engine power (not equipped with a knock sensor). The vast majority of modern injection engines have knock sensors that allow the use of any gasoline with an octane number of 91-98; engines with a high compression ratio can be filled with gasoline with an octane number of at least 95 or even 98.

Organic compounds consisting of carbon and hydrogen and containing benzene nuclei. The simplest and most important representatives of A. u. - benzene (I) and its homologues: methylbenzene, or toluene (II), dimethylbenzene, or xylene, etc. To A. u. also include benzene derivatives with unsaturated side chains, for example styrene (III). There are many known A.u. with several benzene nuclei in the molecule, for example diphenylmethane (IV), diphenyl C6H5--C6H5, in which both benzene nuclei are directly linked to each other; in naphthalene (V) both rings share 2 carbon atoms; such hydrocarbons are called A.u. with condensed nuclei.

Basic source of obtaining A. serve as coking products. coal From 1 t Kam.-Ug. resins can be isolated on average: 3.5 kg of benzene, 1.5 kg of toluene, 2 kg of naphthalene. The production of A. is of great importance. from fatty petroleum hydrocarbons (see Flavoring of petroleum products). For some A.u. Purely synthetic methods are of practical importance. Thus, ethylbenzene is produced from benzene and ethylene, the dehydrogenation of which leads to styrene

According to the chemical properties of A. u. differ sharply from unsaturated alicyclic compounds; they are classified as an independent large class of organic compounds (see Aromatic compounds). Under the action of sulfuric acid, nitric acid, halogens and other reagents in A. Hydrogen atoms are replaced and aromatic sulfonic acids, nitro compounds, halobenzenes, etc. are formed.

Paraffin hydrocarbons

All alkanes of normal structure, up to C33H68, were isolated from oil. C5 - C16 are liquids, C17 and more are solids.

When implementing the technological process, one should take into account their tendency, under certain conditions, to form associates.

Intermolecular interactions of high molecular weight (HM) alkanes are caused by hydrogen bonds of the C-H...C type with an energy of 2-4 kJ/mol and dispersion forces.

With decreasing temperature, the number of hydrocarbon molecules in the paraffin associate increases, because the paraffin chain changes from a zigzag shape to a straightened, linear one, and in this state the paraffin molecules are prone to intermolecular interaction (IMI) and form supramolecular structures.

The temperature at which associate formation begins increases with increasing molecular weight of hydrocarbons:

N-pentane - -60°C;

N-hexadecane - +80°C.

The lower the temperature, the greater the number of hydrocarbon molecules in the associate:

N-hexadecane at 20°C - 3 molecules.

H-octane at -50°C - 31 molecules.

This is explained by the weakening of the thermal motion of hydrocarbon molecules with decreasing temperature and the increasing energy of the MMV of alkanes with increasing chain length. The intensity of the MMV of alkanes is significantly lower compared to hydrocarbons of other classes present in petroleum systems.

Paraffin supramolecular structures can exist in an oil system only at low temperatures and are completely disaggregated as the temperature rises.

State educational institution

Higher professional education

"PETERSBURG

STATE UNIVERSITY OF COMMUNICATIONS"

Department of Metal Technology

ABSTRACT

Fuel

Is done by a student Khomich D.A.

( signature, date )

Faculty ______________ group ___________

Accepted the report

Lukina L.G.

(signature, date)

Velikie Luki

Maintaining…………………………………………………………………………………….…..3

History of development………………………………………………………...………4

Fuel characteristics……………………………………………………………..6

Fuel types

1. solid……………....………………………………………………………7

   liquid………………………………………………………………………………….10

   Gaseous…………………………………………………………….13

   Atypical fuels……………………………………………………………..18

Development prospects. Biofuels…………………………….20

Use of alcohols as fuel. …………………22

Conclusion………………………………………………………………………………...24

Introduction

The history of human development is closely connected with the production and use of energy. Already in the ancient world people used

thermal energy for heating a home, cooking, making household items, tools, etc. from copper, bronze, iron and other metals.

Since ancient times, coal and oil have been known - substances that produce a large amount of heat when burned. Now the wording is "fuel"

includes all substances that, when burned, give a large amount

heat that is widespread in nature and (or) produced industrially. Fuel includes oil and petroleum products (kerosene, gasoline, fuel oil, diesel fuel), coal, natural combustible gas,

wood and plant waste (straw, husks, etc.), peat, oil shale, and currently substances used in nuclear reactors at nuclear power plants and rocket engines.

Thus, fuel classification can be carried out, for example, according to

its state of aggregation: solid (coal, peat, wood, shale),

liquid (oil and petroleum products) and gaseous (natural gas). Also

fuel types can also be divided according to their origin: vegetable,

mineral and industrial products.

History of development

Even our distant ancestors warmed themselves by fires. The flame also served for lighting and cooking. The fire was supported by wood, and it was they, these pieces of wood, that for a long time were the main type of fuel for humanity. With the help of firewood, the inhabitants of the Earth solved many problems: they warmed themselves, cooked food, and even began to smelt metals (However, for this, firewood was first turned into charcoal). The tree played such a decisive role in the life of society that “wandering” cities remain in history. For example, the capital of Ethiopia - Addis Ababa - in past times constantly moved from place to place as residents cut down the surrounding forests.

But centuries passed, there were more and more people on the planet, and less and less forests. And in the 19th century, England, the most advanced industrial country of that time, suffered a fuel crisis. There was no longer enough firewood on the island for the needs of the population and industry. It was urgent to find a replacement for them. The search, however, was short-lived. People have known for a long time that coal and oil can also burn well. True, it is one thing to know, and another thing to use this knowledge in practice. After all, coal and oil must be found and extracted. Yes, and you also need to be able to drown them. Let's say, coal just from a match will not light up like brushwood. And ordinary furnaces for oil are not suitable at all.

But need will teach you everything. In the same England, and then in other countries of the world, over time they learned to burn with coal even better than with wood. Of course, this did not mean at all that the firewood was immediately forgotten. They are needed even to light coal. And in those places where forests were abundant, firewood was still widely used. Thus, in Russia at the beginning of the 20th century, firewood provided more than half of all energy, one quarter came from coal, and one sixth from oil.

In those days, illuminating gas was obtained by processing coal. But already at the beginning of the 20th century they realized that the gas that comes out of the bowels of the Earth burns no worse. Further proof of this is the gas stoves that still exist in many homes to this day.

In 1910, as statistics show, the majority of fuel in the world was already coal - 65%. Firewood came after it, and oil came in last place. Its share in the world fuel balance was only 3%, and natural gas was not used at all.

After another quarter of a century, the share of coal fell to half, while the share of oil in the fuel balance increased to 15%. Many countries around the world have begun to use natural gas.

Even more significant changes took place in Russia. Already during the first five-year plans, the country began to rapidly increase the pace of coal production. V.I. Lenin called coal “the bread of industry,” and the country did not want to keep its developing industry on a starvation diet. Every year the coal industry showed an increase of more than 100%. From 1930 to 1940, coal production tripled: from 70 to 220 million tons per year. Similar rates continued in the first post-war years. During the five-year period from 1950 to 1955, an increase of 170 million tons was achieved.

And yet, despite such rapid growth of the coal industry, it gradually lost its leading position.

In the 70s, oil confidently took first place in the fuel balance - about 35%. The share of hard coal decreased to 30%. Natural gas took third place – about 20%. Then came firewood - 10%. Other energy sources, including water and nuclear power plants, provided only 5% of the energy.

Nowadays, oil and gas occupy the first places - they provide more than two-thirds of the fuel balance.

Why did this happen? After all, there is still plenty of coal today: its proven reserves amount to 1075 billion tons - 87.5% of all fuel reserves of the planet. The whole point is that oil and gas are more convenient to use. Here is just one example: grimy stokers threw coal into the firebox with shovels; Liquid and gaseous fuels are easily supplied using pumps through pipes, and burned using nozzles and burners. These amenities are especially visible in transport. Today, almost all of the fuel demand for ships and diesel locomotives, airplanes and cars, tractors and motorcycles is met by oil and gas. And this trend is likely to continue for a long time. Because oil and gas burn better than any other fuel. So, when 1 kg of oil is burned, 46 thousand kJ are released, when 1 m 3 of gas is burned - about 38 thousand kJ, while 1 kg of coal produces, at best, only 29 thousand kJ. In other words, the heat of combustion of oil is approximately 1.5 times higher than that of coal, and more than two times higher than the heat of combustion of wood. And this also has to be taken into account.

Fuel characteristics

The properties of a fuel depend mainly on its chemical composition. The main element of any fuel of natural origin is carbon (its content ranges from 30 to 85% of the mass). IN

The fuel composition also includes H, O, N, S, ash, water.

The practical value of fuel is determined by the amount of heat

released upon complete combustion. Thus, when burning 1 kg of wood, heat is released equal to 10.2 MJ, coal - 22 MJ,

gasoline - 44 MJ. This value directly depends on the content in the fuel

carbon and hydrogen and vice versa - from the content of oxygen and nitrogen.

Another important characteristic of fuel is its heat output, estimated by the value of the maximum temperature that can theoretically be obtained with complete combustion of the fuel in air. At

When burning wood, for example, the maximum temperature does not exceed 1600 degrees, coal - 2050, gasoline - 2100.

Fuel types

1.Solid

Solid fuels are combustible substances, the main component of which is carbon. Solid fuels include coal and brown coals, oil shale, peat and wood. The properties of the fuel are largely determined by its chemical composition - the content of carbon, hydrogen, oxygen, nitrogen and sulfur. Solid rocket fuel is a solid substance or a mixture of individual substances that can burn without air access, thereby creating engine jet thrust. Depending on the processing method, solid fuels can be divided into two groups: natural and refined. Natural solid fuels include coal, brown coal, peat, wood and straw. Coal and peat are sediments formed as a result of the decay and decomposition of plants in ancient times under the influence of high pressure and lack of oxygen.

Wood

Wood consists predominantly of organic substances (99% of the total mass). The elemental chemical composition of wood of different species is almost the same. Absolutely dry wood contains on average 49% carbon, 44% oxygen, 6% hydrogen, 0.1-0.3% nitrogen. When wood is burned, its inorganic part remains - ash. Ash contains calcium, potassium, sodium, magnesium and other elements. The listed chemical elements form the main organic substances: cellulose, lignin and hemicelluloses.

Oil shale

http://allfuel.ru/c887.html Oil shale, a mineral from the group of solid caustobioliths, produces a significant amount of resin (close in composition to oil) during dry distillation. Oil shales consist of predominant mineral (calcite, dolomite, hydromicas, montmorillonite, kaolinite, feldspars, quartz, pyrite, etc.) and organic parts (kerogen), the latter accounting for 10-30% of the mass of the rock and only in the shales of the highest quality reaches 50-70%. The organic part is a bio- and geochemically transformed substance of protozoan algae that has retained its cellular structure (thallomoalginite) or lost it (colloalginite); As an impurity, the organic part contains altered remains of higher plants (vitrinite, fusainite, lipoidinite). Depending on the ratio of algal and humus components, oil shale is divided into sapropelite and humitosapropelite. The first group of oil shale differs from the second in its increased content of hydrogen (8-10%) and low content of humic acids (0.5%) in the organic mass. Sapropelite oil shale has an increased yield of resins up to 20-30% and a calorific value of up to 14.6-16.7 MJ/kg (3500-4000 kcal/kg). These indicators in humite-sapropelite G. s. lower with equal content of mineral impurities. In world practice of extraction and use of hydrocarbons. The range of the most important indicators is very wide.

Sapropel

http://allfuel.ru/c888.html Sapropel is a substance of biological origin, formed under fresh water during bacterial processes with low oxygen availability. Depending on the composition of the organic and mineral parts, sapropels are divided into several types. In addition to calcium, iron, phosphorus, sapropel contains biologically active substances - vitamins, growth stimulants, hormones, antibiotics and others.

Peat

http://allfuel.ru/c889.html Peat is a combustible mineral; formed by the accumulation of plant remains that have undergone incomplete decomposition in swamp conditions. A swamp is characterized by the deposition on the soil surface of incompletely decomposed organic matter, which later turns into peat. The peat layer in swamps is at least 30 cm (if less, then these are wetlands). Contains 50-60% carbon. Heat of combustion (maximum) 24 MJ/kg. It is used comprehensively as fuel, fertilizer, thermal insulation material, etc.

Coal

http://allfuel.ru/c890.html There are: brown coals, hard coals, anthracites and graphites. It is interesting that in Western countries there is a slightly different classification: respectively, lignites, subbituminous coals, bituminous coals, anthracites and graphites (not used in thermal power engineering). 1.Brown coals. They contain a lot of water (43%) and therefore have a low calorific value. In addition, they contain a large amount of volatile substances (up to 50%). They are formed from dead organic residues under load pressure and under the influence of elevated temperature at depths of about 1 kilometer. 2. Coals. They contain up to 12% moisture (3-4% internal), therefore they have a higher calorific value. They contain up to 32% volatile substances, due to which they ignite well. They are formed from brown coal at depths of about 3 kilometers. 3. Anthracite. Almost entirely (96%) consists of carbon. They have the highest heat of combustion, but do not ignite well. They are formed from coal when pressure and temperature increase at depths of about 6 kilometers. Mainly used in the chemical industry.

Tar sands

http://allfuel.ru/c891.html Tar sands - fossil fuel, org. part of which is natural bitumen. According to the bitumen content, they are divided into rich, or intensive (more than 10% by weight of bitumen), medium (5-10%) and lean (up to 5%). Bitumen is divided into several types: malts, asphalts, solid fusible substances, asphaltites, kerites. The content of resinous-asphaltene substances in these types of bitumen is 35-60, 60-75, 75-90 and more than 90%, respectively. Over 25 chemical elements were found in bitumen.

Powder

http://allfuel.ru/c892.html Gunpowder - solid mixtures of organic and/or inorganic compounds capable of burning stably (without going into explosion or detonation) over a wide external range. pressure (0.1-1000 MPa). Powder-energy sources are used to impart to projectiles and missiles the required flight speed to the target. Gunpowder is characterized by the heat of combustion at constant volume, the volume of gaseous products u0 and efficiency. For barrel systems, performance is expressed by the work produced by the gaseous products of the explosion of 1 kg of gunpowder, the so-called gunpowder force.

2.Liquid

Liquid fuels are complex chemical compounds of flammable and non-flammable substances. The main chemical elements that make up any liquid fuel are carbon C, hydrogen H, oxygen O, nitrogen N and sulfur S. In addition to these elements, liquid fuel contains moisture and non-combustible minerals that form ash during combustion. Liquid fuels include: petroleum products produced by distillation of crude oil; creosote, which is a product of low-temperature coking and sublimation of coal; synthetic oils resulting from the liquefaction of coal; other types of liquid fuels, for example those produced from plants.

Oils

http://allfuel.ru/c913.html Oils are liquids (organosilicon fluids, esters of phosphoric, adipic and other acids, polyalkylene glycols, etc.), used mainly as lubricants, coolants, and components of greases. Depending on what makes up the base of oils, they can be divided into three types: mineral (mineral), synthetic (synthetic, full synthetic) and semi-synthetic (teil synthetic, semi-synthetic). The basis of mineral motor oils are purified oil fractions of petroleum. Next, at least 5-6 different additives are added to the base oil (10-15% or more of the total volume), giving it the necessary new properties or significantly improving its natural qualities.

Alcohols

http://allfuel.ru/c914.html Alcohols are an organic compound containing one or more OH hydroxyl groups at saturated carbon atoms in the molecule. Based on the number of these groups, they distinguish between one- (sometimes the term “alcohols” refers only to monohydric alcohols), two- (glycols), three- (glycerols) and polyhydric alcohols. Alcohols containing two OH groups on one carbon atom are usually unstable. Some of these compounds, such as those stabilized by intramolecular hydrogen bonds, are stable. Alcohols may contain CHO and CO, COOH, CN.

Liquid rocket fuel

http://allfuel.ru/c915.html Rocket Fuel is a substance that undergoes chemical, nuclear or thermoelectric reactions. Liquid rocket fuel consists of fuels such as KEROSENE, liquid HYDROGEN or HYDRAZINE (N 2 H 4), which reacts with an oxidizing agent, such as liquid OXYGEN. Solid rocket fuel contains fuel and oxidizer in the form of powders. Nuclear rocket fuel contains URANIUM and PLUTONIUM. Varieties of ionic rocket fuel include the metal CESIUM, which, when boiling, releases ions into an electric field that accelerates them to high speeds.

Ethers

Essential oils are a mixture of liquid odorous volatile substances isolated from plant materials (distillation, extraction, pressing). Most essential oils are highly soluble in gasoline, ether, lipids and fatty oils, waxes and other lipophilic substances, and very poorly soluble in water. The solubility of essential oils in alcohol strongly depends on its strength (it decreases noticeably in the presence of water). Ethers are organic substances with the formula R-O-R1, where R and R1 are hydrocarbon radicals. It should, however, be taken into account that such a group may be part of other functional groups of compounds that are not ethers. Esters are organic compounds, derivatives of carboxylic or mineral acids, in which the hydroxyl group -OH of the acidic function is replaced by an alcohol residue.

Emulsions

http://allfuel.ru/c917.html Emulsions are dispersed systems in which the dispersion medium and the dispersed phase are in a liquid state. Emulsions are usually coarse systems. Emulsions are microheterogeneous systems consisting of two practically mutually insoluble liquids, which are very different from each other in the nature of their molecules.

Synthetic fuels

http://allfuel.ru/c918.html Synthetic liquid fuels are flammable liquids obtained synthetically and used in internal combustion engines. Synthetic liquid fuel is synthesized from a mixture of CO and CO 2 produced from natural gases and coal; the process is carried out at elevated temperatures and pressures and in the presence of catalysts - Ni, Co, Fe, etc. (Fischer and Tropsch method). Depending on the process conditions, the resulting liquid. t. contains various amounts of paraffin and olefin hydrocarbons, mainly of normal structure.

Petroleum fuels

http://allfuel.ru/c1859.html Oil is a flammable oily liquid with a specific odor, widespread in the sedimentary shell of the Earth, and is the most important mineral resource. It is formed together with gaseous hydrocarbons, usually at depths of more than 1.2-2 km. Near the earth's surface, oil is converted into thick malta, semi-solid asphalt, etc. Oil consists of various hydrocarbons (alkanes, cycloalkanes, arenes - aromatic hydrocarbons - and their hybrids) and compounds containing, in addition to carbon and hydrogen, heteroatoms - oxygen, sulfur and nitrogen . Oil varies greatly in color (from light brown, almost colorless, to dark brown, almost black) and in density - from very light (0.65-0.70 g/cm3) to very heavy (0.98-1 .05 g/cm3). Reservoir Oil, located in deposits at considerable depth, is saturated with gaseous hydrocarbons to varying degrees. The chemical composition of oil is also diverse. Therefore, talking about the average composition of Oil or “average” Oil can only be conditional. The elemental composition fluctuates the least: 82.5-87% C; 11.5-14.5% N.; 0.05-0.35, rarely up to 0.7% O; 0.001-5.3% S; 0.001-1.8% N. Low-sulfur oil predominates (less than 0.5% S), but about 1/3 of all oil produced in the world contains more than 1% S.

Gaseous.

Gaseous fuels are divided into natural and artificial and are a mixture of combustible and non-flammable gases containing some water vapor and sometimes dust and tar. The amount of gaseous fuel is expressed in cubic meters under normal conditions, and the composition is expressed as a percentage by volume. The composition of the fuel is understood as the composition of its dry gaseous part. The most common gaseous fuel is natural gas, which has a high calorific value. The basis of natural gases is methane, the content of which in gas is 76.7-98%. Other gaseous hydrocarbon compounds are included in the gas composition from 0.1 to 4.5%. Combustible gases include: hydrogen H2, methane CH4, other hydrocarbon compounds CmHn, hydrogen sulfide H2S and non-flammable gases, carbon dioxide CO2, oxygen O 2, nitrogen N 2 and a small amount of water vapor H 2 O. The indices m and n at C and H characterize compounds of various hydrocarbons, for example, for methane CH 4 m = 1 and n = 4, for ethane C 2 H 6 m = 2 and n = 6, etc.

Propane

Propane is liquefied petroleum gas (transported under pressure of 10-15 atmospheres). Methane is natural gas (in a car under a pressure of 200-250 atmospheres). Because of this pressure difference, the two fuels require different cylinders. For propane, a metal cylinder with a wall thickness of 4-5 mm is sufficient, but for methane cylinders are needed much thicker. This places restrictions on the use of methane in passenger cars. Methane requires durable cylinders that can withstand such pressure. To lighten the weight of the cylinders, they are made of metal-plastic.

Butane

http://allfuel.ru/c894.html Butane or butyl hydrogen, C 4 H 10, is the simplest saturated hydrocarbon, starting from which modern theories allow for the possibility of isomerism, that is, the existence of two or more chemical modifications, the percentage composition and particle size of which are the same, and the distribution of the elementary atoms that make up the particle , various. For the formula C 4 H 10, the existence of two isomers is possible: normal butane or diethyl, CH 3 CH 2. CH 2 CH3, and isobutane or trimethylmethane CH(CH3)3. Formed by the action of dry zinc metal on ethyl iodide C 2 H 5 J; it is a gas that easily condenses when strongly cooled into a liquid that boils at 1°; it reacts slowly with chlorine. Its presence is indicated in American oil. Isobutane is obtained by the action of zinc on tertiary butyl iodide JC(CH3)3 in the presence of water, and iodine is replaced by hydrogen; the gas, difficult to condense into a liquid boiling at - 17°, reacts very easily with chlorine, forming with it tertiary butyl chloride ClC (CH3)3.

Methane

http://allfuel.ru/c895.html Methane CH4 is a colorless and odorless gas, almost twice as light as air. It is formed in nature as a result of decomposition without air access of the remains of plant and animal organisms. Therefore, it can be found, for example, in swampy reservoirs and coal mines. Methane is contained in significant quantities in natural gas, which is now widely used as fuel in everyday life and in industry.

Natural gas

Natural gas is a mixture of gases formed in the bowels of the earth during the anaerobic decomposition of organic substances. Refers to minerals. It is often an associated gas during oil production. Natural gases consist of methane, ethane, propane and butane, sometimes containing impurities of low-boiling liquid hydrocarbons - pentane, hexane, etc.; they also contain carbon dioxide, nitrogen, hydrogen sulfide and inert gases.

Coal bed methane

http://allfuel.ru/c897.html Coalbed methane is found in coal-bearing sediments. Coal bed methane is formed through biochemical and physical processes during the conversion of plant material to coal. Causes explosions in coal mines. Coal bed methane is a cleaner and more efficient fuel than coal. It can be extracted as an independent mineral, and as a by-product obtained in the process of degassing mines before coal mining. In the process of mine degassing, the cost of methane production plays a secondary role. Degassing means used in Russian mines extract from 20 to 30% of the total volume of methane released.

Mine gas

http://allfuel.ru/c898.html Firemine gas is a flammable gas released in coal mines, less often in salt, metal ore and sulfur mines. R. is colorless, lighter than air, since it consists mainly of methane, it also contains nitrogen, neon, argon, hydrogen, carbon dioxide, traces of ethane, propane, ethylene and other hydrocarbons. Occurs in mineral deposits as a result of the decomposition of organic substances under the influence of microorganisms, heat, pressure, and sometimes radiation.

Marsh gas

http://allfuel.ru/c899.html Swamp gas is a colorless gas with a very faint odor, the simplest hydrocarbon formed in stagnant water from the decay of plant debris. It is formed during the fermentation of fiber and other plant residues in swamp mud without air access under the influence of bacteria. Contains methane CH4 and small amounts of N2 and CO2.

Biogas

http://allfuel.ru/c900.html Biogas is a gas produced by methane fermentation of biomass. The decomposition of biomass into components occurs under the influence of 3 types of bacteria. In the food chain, subsequent bacteria feed on the waste products of the previous ones. The first type is hydrolytic bacteria, the second is acid-forming, the third is methane-forming. Not only bacteria of the methanogen class, but all three species are involved in the production of biogas. Biogas is a mixture of gases in which methane (55-65%) and carbon dioxide (35-45%) predominate. Biogas is formed during the anaerobic decomposition of manure, straw and other organic waste. As a source of energy, Biogas is obtained in special installations (digesters), in which the biomass of residues of crop and livestock products, manure, feces, etc. is fermented.

Landfill gas

http://allfuel.ru/c901.html Landfill gas is a gas formed as a result of anaerobic decomposition of organic municipal waste. Garbage rotting occurs under the influence of bacteria belonging to two large families: acidogens and methanogens. Asidogens produce the primary decomposition of waste into volatile fatty acids, methanogens process volatile fatty acids into methane CH4 and carbon dioxide CO2. As a result, landfill gas consists of approximately 50% methane CH4, 50% CO2, including small impurities of H3S and organic matter.

Methane hydrate

http://allfuel.ru/c902.html Methane hydrate is a crystalline clathrate structure made of water and methane. The relevance of a comprehensive study of methane hydrate is due to the fact that it is widespread in nature and is considered as a promising source of fuel. According to some estimates, the world's reserves of methane hydrate can provide twice as much energy as can be obtained from fossil fuels.

Hydrogen

http://allfuel.ru/c903.html Hydrogen is a colorless gas, tasteless and odorless, in appearance no different from air. It was first noticed by Paracelsus in the first half of the 16th century; but only Lemery, at the end of the 17th century, distinguished Hydrogen from ordinary air, showing its flammability. Cavendish studied this substance in more detail in the last century. It is the lightest gas: one liter of Hydrogen, at 0° and 760 mm. pressure, weighs 0.089538 g. for latitude 45° and at sea level. Density relative to air is 0.06949, i.e. Hydrogen is almost 141/2 times lighter than air; thanks to this, it is retained for some time in a vessel with the open neck facing downwards, and flies away very quickly when the vessel is brought to its normal position.

Compressed Natural Gas (CNG)

Compressed natural gas CNG is almost pure methane. It is transported through gas pipelines and used for heat and power plants, industrial enterprises, as well as for domestic purposes. Methane flows through the gas pipeline at a pressure of 50–70 AT. And the apartments are supplied under low pressure, slightly above atmospheric pressure.

Solid fuel gasification products

http://allfuel.ru/c905.html Gasification of fuels, the transformation of solid or liquid fuels into flammable gases through incomplete oxidation with air (oxygen, water vapor) at high temperature. In gasification, fuel is obtained mainly from combustible products (carbon monoxide and hydrogen). Any fuel can be gasified: fossil coal, peat, fuel oil, coke, wood, etc. Gasification of fuel is carried out in gas generators; The resulting gases are called generator gases. They are used as fuel in metallurgical, ceramic, glass furnaces, in household gas appliances, internal combustion engines, etc. In addition, they serve as raw materials for the production of hydrogen, ammonia, methanol, artificial liquid fuel, etc.

Mixtures

Gaseous fuel is a mixture of combustible and non-flammable gases. The combustible part consists of saturated (?СnH3n+2) and unsaturated (?СnH3n) hydrocarbons, hydrogen H2, carbon monoxide CO, and hydrogen sulfide (H2S). Non-combustible elements include nitrogen (N2), carbon dioxide (CO2) and oxygen (O2). The compositions of natural and artificial gaseous fuels are different. Natural gas is characterized by a high content of methane (CH4), as well as small amounts of other hydrocarbons: ethane (C2H6), propane (C3H8), butane (C4H20), ethylene (C2H4), and propylene (C3H6). In artificial gases, the content of flammable components (hydrogen and carbon monoxide) reaches 25-45%; in ballast, nitrogen and carbon dioxide predominate - 55-75%.

1. Atypical fuels

Rocket fuel is a substance or a combination of substances that represents a source of energy and working fluid for a rocket engine. Rocket fuel must satisfy the following basic requirements: have a high specific impulse, high density, the required state of aggregation of components under operating conditions, must be stable, safe to handle, non-toxic, compatible with structural materials, have raw materials, etc. Nuclear fuel that is used in nuclear reactors to carry out a nuclear fission chain reaction. There is only one natural nuclear fuel - uranium, which contains fissile 235U nuclei, ensuring the maintenance of a chain reaction (nuclear fuel), etc. “raw material” 238U nuclei, capable of capturing neutrons and transforming into new fissile 239U nuclei, which do not exist in nature; secondary fuel.

Nuclear fuel

http://allfuel.ru/c919.html Nuclear fuel is the various chemical and physical forms of URANIUM and PLUTO used in NUCLEAR REACTORS. Liquid fuels are used in homogeneous reactors; heterogeneous reactors use various forms of fuel - pure metals and alloys, as well as oxides and carbides. Nuclear fuel must have high thermal conductivity, be resistant to radiation damage and be accessible for production. Serves to generate energy in a nuclear reactor. Usually it is a mixture of substances (materials) containing fissile nuclei (for example, 239Pu, 235U). Sometimes nuclear fuel is also called nuclear fuel.

Fusion fuel

Fusion fuel - relating to nuclear reactions at ultra-high temperatures. Thermonuclear installation. Thermonuclear weapons. Fusion fuel. Thermonuclear reaction (a reaction of the fusion of atomic nuclei of light elements, occurring at ultra-high temperatures and accompanied by a huge release of energy. Thermonuclear reaction is a reaction of the fusion (fusion) of light atomic nuclei into heavier ones, occurring at ultra-high temperatures and accompanied by the release of a huge amount of energy.

Rocket fuel

http://allfuel.ru/c921.html Rocket fuel is a substance, combination, or mixture of substances used in rocket engines of a wide variety of designs and principles of operation to obtain jet thrust and accelerate the rocket. The concept of rocket fuel currently has a very broad interpretation, since with the development of rocket technology and the development of rocket engines based on various principles, new ways of accelerating working bodies have emerged. For example, a nuclear rocket engine, ion, etc. Therefore, the concept of rocket fuel as a kind of flammable liquid and oxidizer will not reflect the entire possible range of rocket fuels, from chemical one- and two-component, to nuclear and thermonuclear, as well as the use of antimatter. Rocket fuel is divided into various groups, types and types, and the same division takes place when considering individual types of rocket fuels.

5. Development prospects. Biofuels.

The world is increasingly talking about the need to replace oil, coal and gas with biofuels. Echoes are already reaching Russia, where, however, few people yet understand what it really is. In the press you can sometimes find stories about miraculous substances that do not pollute the environment at all and are more effective than gasoline, kerosene and diesel fuel.

In reality, there is nothing fundamentally new in biofuels. Biofuels have been used for thousands of years and remain the only source of heat and cooking for many. Firewood has been and remains the main biofuel, and its environmental friendliness is not at all obvious - just remember about uncontrolled deforestation. However, now the word “biofuel” rarely means firewood. As a rule, we are talking about more high-tech products obtained from agricultural crops or waste from processing plant and animal raw materials. They are fine with renewability, but the situation with harmful emissions is a little more complicated. Proponents say biofuels produce less air pollution, while opponents counter that burning biofuels emits the same products as burning fossil fuels.

The truth, as usual, lies in the middle. Indeed, during the combustion of both fuels, mainly carbon dioxide, water and several impurities are formed, many of which are harmful: carbon monoxide, nitrogen oxides, hydrocarbons, etc. The greatest attention is usually paid to harmful exhaust components and one of the culprits of the greenhouse effect - carbon dioxide.

One of the main advantages of biofuels is the reduction of greenhouse gas emissions. This, however, does not mean that the combustion of biofuels produces less carbon dioxide (although this is possible). When biofuels are burned, carbon that was previously absorbed by plants is returned to the atmosphere, so the planet's carbon balance remains unchanged. Fossil fuels are a completely different matter: the carbon in their composition remained “conserved” in the bowels of the earth for millions of years. When it enters the atmosphere, the concentration of carbon dioxide increases.

In terms of harmful emissions, biofuels are somewhat superior to oil fuels. Most studies show that biofuels provide reductions in carbon monoxide and hydrocarbon emissions. In addition, biofuels contain virtually no sulfur. At the same time, the emission of nitrogen oxides increases slightly; in addition, with incomplete combustion of many biofuels, aldehydes enter the atmosphere. But, in general, in terms of the level of harmful emissions, biofuels are superior to oil fuels.

There are many types of biomass fuels available. This includes biogas - methane, produced by the decomposition of organic residues (for example, manure) by bacteria, and solid fuels, but most of the talk is about biofuels for cars: ethanol and “biodiesel”.

Moreover, if we take the current price per barrel of oil (about $100), then unclaimed opportunities open up for the production of alternative fuels, which until now were simply unprofitable due to their high cost. The more than doubling of oil prices over the past three years should have, one way or another, made a number of projects that had previously been shelved until better times profitable.

Oil is not the only raw material for producing high-octane organics for our car engines. Of course, you can’t put a windmill on a car, just like a nuclear or thermonuclear reactor; batteries for operating as a source of energy for a car engine, which have recently been significantly improved in terms of capacity, still do not yet provide an ideal solution.

Since nature, storing fossil types of organic matter for the future, did not provide for the large number of the human race and its greed, humanity will have to turn its gaze to the organic matter growing around and independently come up with ways to create fuel from improvised and, if possible, renewable sources.

A logical solution for the near future is to search among alternative methods for the synthesis of high-octane organics, without the use of depleting fossil resources. There are many such methods, one of the most popular due to the relatively low cost of production is the production of alcohol using renewable natural resources, that is, from biomass from the garden. The alcohol obtained in this way can be poured into the tank in its pure form, or it can be mixed with petroleum distillation products for additional savings. Everything would be fine, but there are a limited number of places with a suitable climate where you can grow corn and wheat for distillation into alcohol fuel with sufficient profitability.

In fact, algae are the same organic matter, perfect for producing biodiesel fuel, except that they provide an excellent yield of biomass per square meter of cultivated area - unlike “land” plants; does not contain sulfur and other toxic substances - unlike oil; finally, it is perfectly decomposed by microorganisms and, most importantly, provides a high percentage of ready-to-use fuel: for some types of algae - up to 50% of the original mass!

6.Use of alcohols as fuel.

The use of alcohols as fuel for automobile engines is not new. The developers of the first internal combustion engines paid no less attention to alcohol engines than to gasoline engines. Alcohols have high octane numbers - more than 100 units, but a lower calorific value compared to petroleum fuels (when fuel burns, less energy is released, power decreases, and fuel consumption increases).

The beginning of large-scale oil production made the use of alcohol as a motor fuel unprofitable. Alcohol fuels have become a niche product: for example, the engines of speedway motorcycles and many sports karts run on methyl alcohol. Alcohol automobile fuel is somewhat popular in Brazil, where there are no large oil reserves, but there are ideal conditions for growing sugar cane and producing cheap alcohol from it.

In addition to ethanol and methanol, other alcohols are proposed to be used as motor fuels. BP and Du Pont are betting on butanol.

The greatest attention is now paid to ethyl alcohol. In scientific, technical and economic news feeds, messages about plans to build new factories appear almost every day. Sugar cane does not grow in the United States, so corn must be the main source of bioethanol. However, the matter is not limited to the “Queen of the Fields”: it is planned to use everything - from potatoes and wheat to various organic wastes. A number of countries are planning to export bioethanol to the United States and other countries interested in switching to alcohol fuel. Brazil plans to replace up to 10% of the world's gasoline consumed with cane alcohol by 2025.

Gasoline engines are generally not suitable for using alcohol fuels, although design changes to convert them to alcohol are minimal. It is often possible to limit ourselves to the use of alcohol-resistant materials and the installation of elements for separating water condensate. Currently, many leading automakers produce universal engines that can run on gasoline, alcohol, or mixtures thereof. When using mixtures of gasoline with a small amount of alcohol (up to 10%), the fuel is usually suitable for conventional gasoline engines.

It is mixed fuels that are currently the most popular in the world. Gasoline-ethanol mixtures are usually designated by the letter E (for ethanol) and a number indicating the alcohol content as a percentage. The most common fuel is E10 or gasohol, containing 10% ethanol. It is widely used in Denmark, Thailand and other countries. In the United States, E10 fuel is gaining popularity due to restrictions on the use of esters in gasoline that have come into force.

Conclusion.

Despite the huge variety of fuels, the main sources of energy remain oil, natural gas, and coal. The state of affairs 100 years ago was illuminated by Mendeleev. The first two fossil fuels will run out in the near future. Petroleum fuels are of particular value for vehicles (the main consumers of energy), due to their ease of transportation, so research is currently underway on the use of coal for the production of liquid fuels, including motor ones. Nuclear fuel reserves are also huge, but its use imposes high safety requirements and high costs for preparation, operation and disposal of fuel and associated materials.

World consumption of fossil fuels is about 12 billion tce. in year. According to the BP Statistical review of World Energy, fossil fuel consumption was:

In the European Union (EU-15) - 1396 million tons of oil equivalent (2.1 billion t.e.)

• 45% - oil, 25% - gas (natural), 16% - coal, 14% - nuclear fuel

In the USA - 2235 million tons of oil equivalent (3.4 billion tons of oil equivalent)

• 40% - oil, 27% - gas (natural), 26% - coal, 8% - nuclear fuel

Share of renewable energy sources in energy balances

Europe - 5%

According to rough estimates, Russia's energy consumption is 1.3 billion tce. in year.

6% - nuclear fuel

4% - renewable sources

Over the past 20 years, global energy consumption has increased by 30% (and this growth is likely to continue due to the growing demand of booming countries in the Asian region). In developed countries, over the same period, the consumption structure has changed significantly - part of coal has been replaced by more environmentally friendly gas (Europe and especially Russia, where the share of gas in consumption was up to 40%), and the share of nuclear energy has also increased from 4% to 10%.

Characteristics and kinds risk." Completed by student: Shalabina A.A. ... as a result of excessive consumption of materials, raw materials, fuel, energy, as well as for... low supply discipline, interruptions in fuel and electricity; physical and mental...

Fuel in the structure of energy resources

Coursework >> Physics

And brown coals are the most common species fuel, ensuring reliable energy development. 2. ... oxygen and nitrogen content. Another important characteristic fuel- its heat output, estimated by the maximum...

Many people believe that the crude oil pumped out of the ground consists of a mixture of different types of fuels, that they are all flammable and, in fact, there is no difference between them. This is partly true, but let's figure out how, from a chemical point of view, gasoline differs from diesel fuel, kerosene, etc.

The crude oil pumped out of the ground is not a fuel mixture at all, but a mixture of aliphatic hydrocarbons - substances consisting only of carbon and hydrogen atoms. The latter are connected to each other in chains of varying lengths. This is how hydrocarbon molecules are formed. This fact determines their physical and chemical properties. For example, the chain with one carbon atom (CH 4) is the lightest and is known as methane, a clear gas lighter than air. As the chains become longer, the hydrocarbon molecules become heavier and their properties begin to change noticeably.

The first four hydrocarbons - CH 4 (methane), C 2 H 6 (ethane), C 3 H 8 (propane) and C 4 H 10 (butane) are all gases. They boil (evaporate) at temperatures of -107, -67, -43 and -18 degrees C. Chains starting from C 18 H 32 are liquids that have a boiling point starting from room temperature. So what is the real difference between gasoline, kerosene and diesel?

Carbon chains in petroleum products

Longer hydrocarbon chains have higher boiling points. Thanks to this property, hydrocarbons can be separated from each other. This process is called catalytic cracking, or simply distillation, and is what happens in an oil refinery. Here the oil is heated, and then the evaporated hydrocarbons are condensed, each into a separate container.

Substances whose molecules have chains with C 5, C 6 and C 7 are all very light, easily evaporating, transparent liquids called naphtha. It is used to make various solvents.

Hydrocarbons with chains ranging from C 7 H 16 to C 11 H 24 are usually mixed and used to make gasoline. All of them evaporate at temperatures below the boiling point of water (100 o C). That's why, if you spill gasoline, it evaporates very quickly, literally before your eyes.

Diesel and heating oil is made from even heavier hydrocarbons - C 16 to C 19. Their boiling point is from 150 to 380 o C.

Carbon molecules with C20 are solids ranging from paraffin to bitumen, which is used to make asphalt and repair highways.

All these substances are obtained from crude oil. The only difference is the length of the carbon chain. When buying diesel fuel, you get fuel consisting of a mixture of certain hydrocarbons. In addition, this mixture contains various chemical additives that change some properties. For example, thickening point or flash point.

Thus, the same mixture of hydrocarbons can become both summer and winter diesel fuel. It all depends on the additives!

How it works?

In real life, having fuel is not enough. In order to perform useful work: to heat a house, to move you in a car for some distance, to transfer cargo, you need to burn fuel in an internal combustion engine. It doesn’t matter what kind of engine it is - diesel or gasoline, it’s all about the fuel itself. Namely, in burning it.

Combustion is a process of decay that releases energy. What can disintegrate in fuel? Chemical bonds. It turns out that the more connections and the longer the chain, the better. The way it is! This fact explains the higher efficiency of diesel fuel compared to gasoline.

It should also be remembered that at the time of combustion, carbon is oxidized and CO 2 is formed - carbon dioxide. This is a harmful substance that causes the same greenhouse effect on Earth. There are more carbon atoms in diesel fuel, and there are even more in plastic. That's why you shouldn't burn these substances unless absolutely necessary.

), in 2007 the following primary energy sources were used: oil - 36.0%, coal - 27.4%, natural gas - 23.0%, in total the share of fossil fuels was 86.4% of all sources (fossil and non-fossil) consumed primary energy in the world. It should be noted that non-fossil energy sources include: hydroelectric power plants - 6.3%, nuclear - 8.5%, and others (geothermal, solar, tidal, wind energy, wood and waste combustion) in the amount of 0.9%.

a brief description of

Oil

Oil is a natural oily flammable liquid consisting of a complex mixture of hydrocarbons and some other organic compounds. The color of oil is red-brown, sometimes almost black, although sometimes slightly yellow-green and even colorless oil is found; has a specific odor and is common in sedimentary rocks of the Earth. Oil has been known to mankind since ancient times. However, today oil is one of the most important minerals for humanity.

Coal

Fossil coal

Coal is a type of fossil fuel formed from parts of ancient plants underground without oxygen. The international name for carbon comes from lat. carbō ("coal"). Coal was the first fossil fuel used by humans. It enabled the industrial revolution, which in turn contributed to the development of the coal industry, providing it with more modern technology. Coal, like oil and gas, is an organic substance that has undergone slow decomposition through biological and geological processes. The basis for the formation of coal is plant residues. Depending on the degree of conversion and the specific amount of carbon in coal, four types are distinguished:

• brown coals (lignites);

In Western countries, there is a slightly different classification - lignites, subbituminous coals, bituminous coals, anthracites and graphites, respectively.

Oil shale

Oil shale is a mineral from the group of solid caustobiolites, which during dry distillation produces a significant amount of resin (close in composition to oil). Shales were mainly formed 450 million years ago on the seabed from plant and animal remains. Oil shale consists of predominant mineral (calcite, dolomite, hydromicas, montmorillonite, kaolinite, feldspars, quartz, pyrite and others) and organic parts (kerogen), the latter makes up 10-30% of the mass of the rock and only reaches the highest quality shale 50-70%. The organic part is a bio- and geochemically transformed substance of protozoan algae, which has retained its cellular structure ( thallomoalginitis) or lost it ( colloalginitis); As an impurity, the organic part contains altered remains of higher plants (vitrinite, fusainite, lipoidinite).

Natural gas

Gas hydrates

Peat

The main components of oil, as well as gas, were formed at a time when organic residues had not yet been completely oxidized, and carbon, hydrocarbons and similar components were present in small quantities. Sedimentary rocks covered the remains of these substances. Temperature and pressure increased, and liquid hydrocarbon accumulated in the voids of the rocks.

Fossil coal mining

Mankind has long used mines to extract coal from great depths. The deepest mines in the Russian Federation extract coal from a depth of just over 1,200 meters. Coal-bearing deposits, along with coal, contain many types of georesources that have consumer significance. These include host rocks as raw materials for the construction industry, groundwater, coal bed methane, rare and trace elements, including valuable metals and their compounds. The use of jets as a destruction tool in the executive bodies of shearers and roadheaders is of particular interest. At the same time, there is a constant growth in the development of equipment and technology for the destruction of coal and rocks with high-speed jets of continuous, pulsating and pulsed action.

Consumption rates

Coal was the first fossil fuel used by humans. It allowed for the industrial revolution, which, in turn, contributed to the development of the coal industry, providing it with more modern technology.

During the 18th century, the amount of coal produced increased by 4,000%. By 1900, 700 million tons of coal were mined per year, then it was the turn of oil. Oil consumption has been growing for about 150 years and reached a plateau at the beginning of the third millennium. Currently, the world produces more than 87 million barrels per day, or about 5 billion tons per year.

Recoverable reserves (reserves)

Published calculations estimate coal reserves at about 500 billion tons, and the amount of recoverable oil on Earth is about two trillion barrels. According to Hubbert's theory, due to the fact that oil is a non-renewable resource, sooner or later its global production will reach its peak (the term Peak Oil denotes the maximum world oil production that has been or will be achieved). US oil production peaked in 1971 and has been declining since then. The International Energy Agency (IEA), in its World Energy Outlook 2004, noted in particular: “Fossil fuels currently account for the majority of global energy consumption and will continue to do so for the foreseeable future. Although supplies are currently high, they will not last forever.”

Proved reserves according to 2005-2006 data:

Fossil fuel production according to 2006 data:

Proven reserves (years of production at current rate) remaining in the Earth (2006):

• fossil coal: 148 years;
• oil: 43 years;
• natural gas: 61 years.

Meaning

Most fossil fuels are burned to produce electricity, water heating and residential heating. Fossil coal, peat, and oil shale have long been used by humans in economic activities. Natural gas was considered a by-product of oil production, but is now becoming a highly valuable fossil natural resource. In addition, in the modern world, fossil fuels are used as motor fuels, lubricants and raw materials for organic synthesis.

Environmental impact

CO 2 emissions

Burning fossil fuels releases carbon dioxide (CO2), a greenhouse gas that persists in the atmosphere for centuries and is the largest contributor to global warming. Climatic research has reliably established a close to linear relationship between the magnitude of global warming and the amount of carbon dioxide CO 2 accumulated in the atmosphere. To limit global warming to 2°C with the intended chance of success, it is necessary to set a cap on future cumulative CO 2 emissions, which therefore represent the finite largest total global resource. The CO 2 emissions budget, based on the goal of preventing unacceptable global warming, means that 60-80% of fossil fuel reserves must remain intact, which requires an immediate and dramatic reduction in current rates of fossil fuel production and combustion.

At the same time, global financial markets largely ignore the need to limit CO 2 emissions. Fossil fuel production continues to be subsidized by many governments, and large amounts of money continue to be spent on exploring new reserves. Investors tend to believe that all carbon reserves can be mined and commercialized.

Since 2012, a number of environmental groups have been waging a global campaign to boycott investments in fossil fuels, the logic of which its initiators formulate as follows: “if it is wrong to destroy the climate, then it is wrong to profit from this destruction.” The campaign is rapidly expanding and has received official support from the UN. Several multinational investors (for example, France's largest insurance company AXA) have announced complete disinvestment of their funds from coal mining.

The role of natural gas emissions

Natural gas, the majority of which is methane, is also a greenhouse gas. The greenhouse effect of one methane molecule is approximately 20-25 times stronger than that of a CO 2 molecule, therefore, from a climate point of view, burning natural gas is preferable to releasing it into the atmosphere.

Other impacts

Enterprises of the Russian fuel and energy complex account for half of the emissions of harmful substances into the air, more than a third of polluted wastewater, and a third of solid waste from the entire national economy. The planning of environmental measures in areas of pioneering development of oil and gas resources is of particular relevance.