How to make gasoline from coal

Definition of the term synthetic fuel code

The term "synthetic fuel" has several different meanings and can include different types of fuel. The traditional definition established by the "International Energy Agency" defines "synthetic fuel" as any liquid fuel derived from coal or natural gas. The US Energy Information Association defines synthetic fuel in its 2006 annual report as a fuel derived from coal, natural gas, biomass, or animal feed by chemical conversion to synthetic oil and/or synthetic liquid products. Numerous definitions of synthetic fuels include fuels produced from biomass, as well as from industrial and municipal waste.
On the one hand, "synthetic" means that the fuel is produced artificially. Unlike synthetic fuels, conventional fuels are usually obtained by separating crude oil into separate fractions (distillation, rectification, etc.) without chemical modification of the components. However, various chemical processes can also be used in the production of traditional fuels. Under the concept of "synthetic" it can be emphasized, on the other hand, that the fuel was produced by chemical synthesis processes, that is, the production of higher-level compounds from several lower compounds. This definition applies in particular to XtL fuels, in which the feedstock is first decomposed into a synthesis gas of lower compounds (H 2 , CO, etc.) in order to obtain higher hydrocarbons (Fischer-Tropsch synthesis). However, even with conventional fuels, chemical processes can be part of the manufacturing process. For example, hydrocarbons with too long carbon chains can be broken down into shorter chain products, such as those found in gasoline or diesel fuel, through so-called cracking. As a result, depending on the definition, it may not be possible to clearly distinguish between conventional and synthetic fuels. Although there is no exact definition, the term "synthetic fuel" is usually limited to XtL fuel.
The difference between synthetic and alternative fuels lies in the way the fuel is used. That is, an alternative fuel may require a more serious modification of the engine or fuel system, or even the use of an unconventional type of engine (for example, steam).

Main products of coal

The most conservative estimates suggest that there are 600 items of coal products. Scientists have developed various methods for obtaining coal processing products. The processing method depends on the desired end product. For example, in order to obtain pure products, such primary products of coal processing - coke oven gas, ammonia, toluene, benzene - use liquid flushing oils. In special devices, products are sealed and protected from premature destruction. The processes of primary processing also involve the method of coking, in which coal is heated to a temperature of +1000 ° C with completely blocked access to oxygen. At the end of all the necessary procedures, any primary product is additionally cleaned. The main products of coal processing:

naphthalene
phenol
hydrocarbon
salicylic alcohol
lead
vanadium
germanium
zinc.

Without all these products, our life would be much more difficult. Take the cosmetic industry, for example, it is the most useful area for people to use coal processing products. Such a product of coal processing as zinc is widely used for the treatment of oily skin and acne.Zinc, as well as sulfur, is added to creams, serums, masks, lotions and tonics. Sulfur eliminates existing inflammation, and zinc prevents the development of new inflammations. In addition, therapeutic ointments based on lead and zinc are used to treat burns and injuries. An ideal assistant for psoriasis is the same zinc, as well as clay products of coal. Coal is a raw material for the creation of excellent sorbents that are used in medicine to treat diseases of the intestines and stomach. Sorbents, which contain zinc, are used to treat dandruff and oily seborrhea. As a result of a process such as hydrogenation, liquid fuel is obtained from coal at enterprises. And the combustion products that remain after this process are an ideal raw material for a variety of building materials with refractory properties. For example, this is how ceramics are created.

Direction of use	Brands, groups and subgroups
1. Technological
1.1. Layer coking	All groups and subgroups of brands: DG, G, GZhO, GZh, Zh, KZh, K, KO, KSN, KS, OS, TS, SS
1.2. Special pre-coking processes	All coals used for layered coking, as well as grades T and D (subgroup DV)
1.3. Producer gas production in stationary type gas generators:
mixed gas	Brands KS, SS, groups: ZB, 1GZhO, subgroups - DGF, TSV, 1TV
water gas	Group 2T, as well as anthracite
1.4. Production of synthetic liquid fuels	GZh brand, groups: 1B, 2G, subgroups - 2BV, ZBV, DV, DGV, 1GV
1.5. semi-carbonization	Brand DG, groups: 1B, 1G, subgroups - 2BV, ZBV, DV
1.6. Production of carbonaceous filler (thermoanthracite) for electrode products and foundry coke	Groups 2L, ZA, subgroups - 2TF and 1AF
1.7. Production of calcium carbide, electrocorundum	All anthracites, as well as a subgroup of 2TF
2. Energy
2.1. Pulverized and stratified combustion in stationary boiler plants	Weight brown coals and athracites, as well as hard coals not used for coking. Anthracites are not used for flare-layer combustion
2.2. Burning in reverberatory furnaces	Brand DG, group i - 1G, 1SS, 2SS
2.3. Combustion in mobile heat installations and use for communal and domestic needs	Grades D, DG, G, SS, T, A, brown coal, anthracites and hard coal not used for coking
3. Production of building materials
3.1. Lime	Marks D, DG, SS, A, groups 2B and ZB; grades GZh, K and groups 2G, 2Zh not used for coking
3.2. Cement	Grades B, DG, SS, TS, T, L, subgroup DV and grades KS, KSN, groups 27, 1GZhO not used for coking
3.3. Brick	Coals not used for coking
4. Other productions
4.1. Carbon adsorbents	Subgroups: DV, 1GV, 1GZhOV, 2GZhOV
4.2. active carbons	ZSS group, 2TF subgroup
4.3. Ore agglomeration	Subgroups: 2TF, 1AB, 1AF, 2AB, ZAV

Coal

The processing of this type of raw material is carried out in three directions: hydrogenation, coking and incomplete combustion. Each of these types involves the use of a special technological process.

Coking involves the presence of raw materials at a temperature of 1000-1200 o C, where there is no oxygen access. This process allows for the most complex chemical transformations, the result of which will be the formation of coke and volatile products. The first in a cooled state is sent to metallurgy enterprises. Volatile products are cooled, after which coal tar is obtained. There are still many uncondensed substances left. If we talk about why oil is better than coal, then it should be noted that much more finished products are obtained from the first type of raw material. Each of the substances is sent to a specific production.

At the moment, even the production of oil from coal is carried out, which makes it possible to obtain much more valuable fuel.

Coal appeared on planet Earth about 360 million years ago.Scientists called this segment of our history the Carboniferous or Carboniferous period. At the same time, the appearance of the first terrestrial reptiles, the first large plants, is also recorded. Dead animals and plants decomposed, and a colossal amount of oxygen actively contributed to the acceleration of this process. Now on our planet there is only 20% oxygen, and at that time animals breathed deeply, because the amount of oxygen in the atmosphere of Carbon reached 50%. It is this amount of oxygen that we owe to the modern wealth of coal deposits in the bowels of the Earth. But coal is not everything. Due to various types of processing, a huge amount of various useful substances and products are obtained from coal. What is made from coal? That is what we will talk about in this article.

Solid and gaseous fuels edit edit code

In some third world countries, wood and charcoal are still the main fuel available to the population for heating and cooking (about half of the world's population lives this way). This in many cases leads to deforestation, which in turn leads to desertification and soil erosion. One of the ways to reduce the dependence of the population on wood sources is the introduction of the technology of briquetting agricultural waste or household waste into fuel briquettes. Such briquettes are obtained by pressing the slurry obtained by mixing waste with water on a simple lever press, followed by drying. This technology, however, is very labor intensive and requires a source of cheap labor. A less primitive option for obtaining briquettes is to use hydraulic pressing machines for this.

Some gaseous fuels can be considered options for synthetic fuels, although such a definition can be controversial, since engines using such fuels need to be seriously modified. One of the widely discussed options for reducing the contribution of motor vehicles to the accumulation of carbon dioxide in the atmosphere is the use of hydrogen as a fuel. Hydrogen engines do not pollute the environment and emit only water vapor. Hydrogen-oxygen fuel cells use hydrogen to directly convert the energy of a chemical reaction into electrical energy. Since hydrogen is obtained either by methods that require a large consumption of electricity, or by the oxidation of hydrocarbon fuels, the environmental and, even more so, the economic advantages of such fuels are highly controversial.

Full article Hydrogen energy.

Dimethyl etherEdit | edit code

Dimethyl ether is obtained by dehydration of methanol at 300–400°C and 2–3 MPa in the presence of heterogeneous catalysts—aluminosilicates. The degree of conversion of methanol into dimethyl ether is 60%, into zeolites - almost 100%. Dimethyl ether is an environmentally friendly fuel without sulfur content, and the emission of nitrogen oxides in the exhaust gases is 90% less than gasoline. The cetane number of a dimethyl diesel engine is more than 55, while that of a classic oil one is from 38 to 53. The use of dimethyl ether does not require special filters, but it is necessary to remake the power systems (installation of gas-cylinder equipment, adjustment of mixture formation) and engine ignition. Without alteration, it is possible to use it on cars with LPG engines with a 30% methanol content in the fuel.

The combustion heat of DME is about 30 MJ/kg, for classical petroleum fuels it is about 42 MJ/kg. One of the features of the use of DME is its higher oxidizing power (due to the oxygen content) than that of conventional fuel.

In July 2006, the National Development and Reform Commission (NDRC) (China) adopted the standard for the use of dimethyl ether as a fuel. The Chinese government will support the development of dimethyl ether as a possible alternative to diesel fuel.In the next 5 years, China plans to produce 5-10 million tons of dimethyl ether per year.

Cars with engines running on dimethyl ether are being developed by KAMAZ, Volvo, Nissan and the Chinese company Shanghai Automotive.

Oil

If we continue to understand what is obtained from coal and oil, then it is worth mentioning the diesel fraction of oil refining, which usually serves as fuel for diesel engines. Fuel oil contains high-boiling hydrocarbons. By means of reduced pressure distillation, various lubricating oils are usually obtained from fuel oils. The residue that exists after the processing of fuel oil is commonly called tar. From it, a substance such as bitumen is obtained. These products are intended for use in road construction. Mazut is often used as a boiler fuel.

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NYMEX West Texas Intermediate oil prices

During the Second World War, Germany to a large extent, up to 50% in some years, satisfied its fuel needs by creating production facilities for processing coal into liquid fuel. According to "Hitler's personal architect" Albert Speer, Germany was technically defeated on May 12, 1944, when 90% of the factories producing synthetic fuel were destroyed due to massive Allied bombing.

Similarly, South Africa, with the same goals, created the Sasol Limited enterprise, which during the apartheid era helped the state's economy to function successfully despite international sanctions.

In the US, producers of such fuels often receive government subsidies, and therefore sometimes such companies produce "synthetic fuels" from a mixture of coal and biowaste. Such methods of obtaining government subsidies are criticized by the "greens" as an example of the abuse of features of the tax system by corporations. Synthetic diesel fuel produced in Qatar from natural gas has a low sulfur content and is therefore blended with conventional diesel fuel to reduce the level of sulfur in such a mixture, which is necessary for marketing diesel fuel in those US states where there are especially high requirements for fuel quality (for example, in California).

Synthetic liquid fuels and gas from solid fossil fuels are now produced on a limited scale. Further expansion of the production of synthetic fuels is constrained by its high cost, which significantly exceeds the cost of oil-based fuels. Therefore, the search for new economical technical solutions in the field of synthetic fuels is now being intensively conducted. The search is aimed at simplifying known processes, in particular, at reducing the pressure during coal liquefaction from 300–700 atmospheres to 100 atmospheres and below, increasing the productivity of gas generators for processing coal and oil shale, and also developing new catalysts for the synthesis of methanol and gasoline based on it.

Now the use of Fischer-Tropsch technology is possible only if oil prices are stable above $50-55 per barrel.

Ethers

Ethers are colorless, mobile, low-boiling liquids with a characteristic odor.
Methyl tertiary butyl ether (MTBE) is currently considered the most promising antiknock agent. In Russia, it is allowed to add it to automotive fuels in an amount of up to 15%. The limitations are caused by the features of operational characteristics: relatively low calorific value and high aggressiveness towards rubbers. According to road test results, unleaded gasolines containing 7-8% MTBE outperform leaded gasolines at all speeds. The addition of 10% MTBE to gasoline increases the octane number according to the research method by 2.1-5.9 units, and 20% - by 4.6-12.6 units, and therefore it is more effective than such well-known additives as alkyl gasoline and methanol .
The use of fuel with methyl tert-butyl ether slightly improves the power and economic performance of the engine. MTBE is a colorless transparent liquid with a pungent odor. The boiling point is 54-55°C, the density is 0.74 g/cm3. The octane number by this method is 115-135 points. World production of MTBE is estimated at tens of millions of tons per year.

As potential antiknock agents, it is possible to use ethyl tert-butyl ether, tert-amyl methyl ether, as well as methyl ethers obtained from olefins C₆-WITH₇.

Properties of some ethers.

Ether	Formula	VERY	MHMM	OC_Wed	T_kip, °С
MTBE	CH₃-O-C(CH₃)₃	118	110	114	55
ETBE	C₂H₅-O-C(CH₃)₃	118	102	110	70
MTAE	CH₃-O-C(CH₃)₂C₂H₅	111	98	104,5	87
DIPE	(CH₃)₂CH-O-CH(CH₃)₂	110	99	104,5	69

To obtain AI-95 and AI-98 gasolines, MTBE additives or its mixture with tert-butyl alcohol, which is called Feterol - the trade name Octane-115, are usually used. The disadvantage of such oxygen-containing components is the volatilization of esters in hot weather, which leads to a decrease in the octane number.

Liquid fuel from gases

It is hard to imagine that from such simple substances as carbon monoxide (that is, carbon monoxide) and hydrogen, complex organic compounds, the most diverse types of liquid fuel, can be obtained.

To obtain liquid fuel, you need to have a mixture of these gases, in which for each part of carbon monoxide there would be two parts of hydrogen. This mixture is obtained in special apparatus - gas generators. A mixture of water vapor and air is blown through a layer of hot coke. Oxygen in the air combines with carbon to form carbon monoxide. This process is called coal gasification. When water molecules decompose, hydrogen is released. A mixture of hydrogen and carbon monoxide is sent to refrigerators. From here, the so-called water gas goes to the reactor. At a temperature of 200°, under the influence of the most active catalysts—cobalt or nickel—carbon monoxide and hydrogen enter into a chemical combination. Complex heavy substances are formed from a large number of light gas molecules.

Catalysts not only contribute to the formation of simple compounds of carbon and hydrogen, but also affect a further complication - the polymerization of molecules: carbon atoms are connected in chains, rings, overgrown with hydrogen atoms. A wide variety of hydrocarbons reappear - from light gases (starting from methane) to solid, high-melting paraffins containing up to 100 carbon atoms in each molecule. Approximately 60% of the initially taken gas mixture passes into liquid fuel. This is artificially prepared oil, not much different from ordinary, natural oil.

Let's enter the workshop where fuel synthesis takes place. Iron apparatuses are surrounded by intricate weaves of thick pipes. The shop is quiet and deserted. Special devices automatically control the process, they themselves record the temperature and pressure. Interestingly, the process of formation of liquid fuel takes place at ordinary atmospheric pressure and a temperature of only about 200 °. When synthesizing fuel from gases, expensive equipment is not needed to create high pressures and temperatures. This favorably distinguishes synthesis from coal hydrogenation.

Soviet industry is now producing hundreds of thousands of diesel engines running on mixtures of high-boiling heavy oil fuel.

There are more and more powerful 25-ton trucks - dump trucks, motor ships, excavators and other vehicles that are equipped with diesel engines. The automobile and tractor park is being increased.

The production of artificial diesel fuel is also constantly growing.

So chemists control the processes, getting the right grade of fuel.

The advantages of this method open up great prospects for it. Liquid fuel can be obtained from any, even the lowest grade brown coal.

Pre-gasification of the fuel makes it possible to obtain gasoline from oil shale and even peat, not to mention the use of natural gas for this purpose. In 1951-1955, new plants were built for the production of synthetic liquid fuel from coal, shale and peat. Only in the Estonian SSR, on the basis of local oil shale, the output of such fuel will increase by 80% over the five-year period.

S. Gushchev
Rice. B, Dashkov and A. Katkovsky
magazine "Technology - Youth" No. 7, 1954

Better than nature

Back at the end of the last century, N. D

Zelinsky drew attention to the difference in the structure of oil molecules. Most of the molecules of high-quality Baku oil are closed rings of carbon atoms, to which hydrogen atoms are attached on the sides.

The high quality of the fuel primarily depends on such a cyclic structure of molecules. Grozny oil contains less naphthenes - cyclic hydrocarbons. It is dominated by molecules of the methane series, stretched in the form of chains of atoms. Gasoline, obtained from Grozny oil, when compressed in engine cylinders, detonated, spontaneously exploded much earlier than the moment when an ignition spark jumped between the electrodes of the candle.

This phenomenon caused a lot of trouble for both chemists and motor builders, who always sought to increase the power of motors. The power and efficiency of the engine depends primarily on how strongly the pistons in the cylinder compress the combustible mixture. The compression ratio (that is, the ratio of the volume of the entire cylinder to the volume of the combustible mixture that is extremely compressed in the cylinder) is one of the most important characteristics of the engine. The higher the compression ratio, the more powerful and economical the engine. If, for example, the compression ratio of an automobile engine is increased from 5.25 to 10.3, then the car, moving at a speed of 40 km / h, will consume half as much fuel and cover twice as much distance on one tank of gasoline.

But here's the problem: ordinary gasoline vapors cannot withstand high compression and detonate. The engine quickly overheats, begins to knock, as if it is about to fall apart. Its power drops sharply.

During detonations, the piston rings and the piston crown burn out, and the bearings are destroyed.

These properties of the fuel are evaluated by the so-called octane number. If they say that the octane number of fuel is 60, this means that its detonation properties are the same as those of a mixture containing 60% isooctane and 40% heptane. These two substances were taken as a standard not by chance: isooctane resists detonation very well (its octane number was therefore equated to 100), while heptane, on the contrary, detonates more easily than all other liquid hydrocarbons (its octane number was taken as 0).

It turned out a kind of scale, according to which you can find out how it detonates, whether one or another grade of gasoline is of high quality.

The higher the octane number of gasoline, the more you can compress the combustible mixture in the cylinders without fear of detonation, the more powerful and economical the engine. At first, aircraft engines ran on gasoline with an octane rating of 50-55. The use of gasoline with an octane rating of 87 in aviation made it possible to increase engine power by 30-35%, the appearance of 100-octane gasoline helped to increase engine power by another 15-30%. In other words, modern engines have become almost twice as powerful as the "old" engines with such a volume of cylinders.

It would seem that the quality of 100-octane gasoline is the limit set by nature itself. But this limit, like many others, has been overcome by science, armed with advanced technology. Modern aircraft fly on gasoline with an octane rating well above 100. There is no oil in the world that contains gasoline of such high quality. Such gasoline can only be obtained artificially - by synthesis.

The synthesis of hydrocarbons has long been a tempting goal for many generations of chemists. Academician N. D.Zelinsky wrote in 1931: “When a chemist gets acquainted with the structure of petroleum hydrocarbons and studies their properties, he cannot help but be surprised at how easily nature has created these amazing forms that are so difficult to prepare synthetically.”

Today, high-quality liquid fuels are obtained from low-quality gasolines and gases by rearranging straight chains into branched and annular structures.

Waste-to-fuel processing in Russia

In January 2019, President Vladimir Putin signed a decree on the creation of the Russian Ecological Operator company, which will become the country's single waste operator in the form of a public law company (PPC); the functions of the founder will be carried out by the Ministry of Natural Resources. The operator will be involved in state programs for waste management and attract investors for waste disposal projects.

Innovation

Waste processing complexes:
For the first time in the framework of domestic research, the task was set (2011) combine disparate advanced developments across many industries.
Several options for environmentally friendly, high-tech waste processing complexes that are competitive on the world market will be developed.Optimization of raw materials, heat, gas flows will ensure the maximum production of liquid fuel fractions and building materials - without any technological waste, except for catalytically purified waste gases.
As a result of processing, profitable products will be produced: fuel, additives, building materials.

At the 1st stage, it is planned to complete the experimental line for research, testing, certification and patenting.
This work will be carried out jointly with the Skolkovo Foundation, of which Rusekoil is a member.

Planned construction of mobile or stationary processing complexes consisting of 1-5 lines of the same type with an annual processing volume of 50-250 thousand tons of prepared MSW (newly formed and landfill), sorting "tails", sludge, peat, coal sludge, wood waste and other organic matter.
As a result of processing, commercial products will be produced:

diesel fuel
chemical products: (benzene, toluene and nefras or combined fraction of BTK),
cement,
aerated concrete.