Synthetic gasoline: description, characteristics, performance, production methods

2024 Author: Howard Calhoun | [email protected]. Last modified: 2023-12-17 10:16

Science and progress allow you to create things that have never been seen before, which many could not even think of. Take, for example, such a relatively new development as synthetic gasoline. Many people know that this fuel is obtained by distillation from oil. But it can also be synthesized from coal, wood, natural gas. The production of synthetic gasoline, although it cannot fully replace the conventional route of production, still deserves to be studied. Therefore, its history will be considered, as well as ways to obtain it.

Introduction

It is difficult to imagine modern civilization without motor fuel - diesel, kerosene, gasoline. Cars, planes, rockets, water transport work for them. But the amount of oil in the bowels is limited. Not so long ago, it was believed that humanity would soon inevitably face a shortage of fuel. But it turned out,it's not all that sad. New technologies are being developed to extract hard-to-recover reserves, and alternative options are emerging. We can also mention green energy and increasing the efficiency of resource use (modern small cars easily manage 4-6 liters of fuel per hundred kilometers, although at the beginning of our millennium they required about 10). And high-quality fuel, as it turned out, can be obtained from various non-petroleum raw materials.

How did it all start?

We need to start with events that took place more than 150 years ago. It was then that commercial oil production began. Since then, humanity has used up more than half of the so-called light raw materials. Initially, oil was used as a source of thermal energy. In our time, this approach is not economically viable. When the automobile era came, the products of fractionation of oil became widespread in the role of motor fuel. At the same time, the more raw materials were depleted, the more profitable it became to look for an alternative.

What is oil? This is a mixture of hydrocarbons, and more specifically, cycloalkanes. What are they? The simplest alkane is known to many as methane gas. In addition, there are nitrogenous and sulfurous impurities in oil. And if it is properly processed, then you can get a lot of different materials. For example, take the well-known gasoline. What does he represent? In fact, this is a low-boiling oil fraction formed by short-chain hydrocarbons with an amountatoms from five to nine. Gasoline is the main fuel for passenger cars as well as small aircraft. The next highlighted type is kerosene. It is more viscous and heavy. It is formed from hydrocarbons in which there are from 10 to 16 atoms. Kerosene is used in jet aircraft and engines. An even heavier fraction is gas oil. It is used in diesel fuel, which is a mixture with kerosene.

Scientific search for an alternative

Although the main fractions are obtained from oil, it turned out that other carbon raw materials can also be used for this purpose. This problem was solved by chemists as early as 1926. Then the scientists Fischer and Tropsch discovered the reduction of carbon monoxide under atmospheric pressure. It was found that liquid and solid hydrocarbons can be formed from a gas mixture in the presence of catalysts. In terms of their chemical composition, they were close to products obtained from oil. The result of chemical research was called "synthesis gas". It turned out pretty easy. So much so that it can be repeated at home by any person who has not skipped chemistry and physics at school. It was obtained by passing water vapor over coal (this is its gasification) or by converting ordinary natural gas (it consists mainly of methane). In the second case, metal catalysts were additionally used. It should be noted that synthesis gas can be created not only from methane and coal. A promising direction is now considered to be work on enzymatic andthermochemical processing of vegetable raw materials waste. We should also not forget about the conversion of biogas, that is, volatile substances obtained from the decomposition of organic waste.

How has the application evolved?

Nazi Germany excelled in this regard. During World War II, she had significant problems in terms of fuel supply. Therefore, entire complexes were created that processed coal into liquid fuel. And the synthetic gasoline of the Third Reich made its significant contribution, quite strongly postponing the fall of this terrible state. Then the method of chemical liquefaction of coal was used until pyrolysis fuel was obtained. By the end of the war, Nazi Germany managed to reach the level of 100,000 barrels of synthetic oil per day. In more usual terms, this is more than 130 tons! The use of coal is expedient due to the similar chemical composition. So, in it the hydrogen content is 8%, while in oil it is 15%. If you create a certain temperature regime and saturate the coal with hydrogen in a significant volume, then it will go into a liquid state. This process is called hydrogenation. In addition, it can be accelerated and increased in volume if catalysts are used: iron, tin, nickel, molybdenum, aluminum and many others. All this makes it possible to isolate various fractions and use them for further processing.

Synthetic gasoline is produced in Germany now. After World War II, South Africa followed suit. ThenChina, Australia and the United States began to join. It should be noted that we also have the potential for the development of this area.

About falling and rising

In the Soviet Union, even before the start of the Second World War, there were searches for a possible extraction of gasoline from brown coal. But, alas, it was not possible to obtain results suitable for industrial production. After the end of the conflict, the price of oil fell, and with it, the need for synthetic fuel disappeared. Now, due to the decrease in oil reserves, this area is experiencing a rebirth. The production of synthetic gasoline is becoming more and more widespread, often meeting with support from the state. For example, in the United States, manufacturers of such fuels can count on government subsidies. Despite all the prerequisites, liquid fuels are produced on a limited scale. The fact is that the expansion of existing capacities is limited by the high cost, which significantly exceeds what is obtained from conventional raw materials. For example, synthetic gasoline in Germany can be made from water and carbon dioxide, but in just a year it will cost a new car. And all because of the high cost of installation. The main direction of work is the search for economic technical solutions. For example, the issue of pressure reduction for coal liquefaction is open. Now it is necessary to create 300-700 atmospheres, and the search is carried out to achieve a value of 100 and below. Also relevant are the issues of increasing the productivity of generators, the development of new catalysts (more efficient). Yes, and we should not forget that there is not so much high-quality natural coal. Therefore, it is considered more promising to obtain it from gas. What are the opportunities here?

Produced from natural gas

This is especially true due to existing transport problems. So, if you transport natural gas, then the cost of this will be 30-50% of the cost of the final product. Therefore, its processing immediately near the place of extraction into high-quality gasoline and diesel fuel is very relevant. This puts forward a number of requirements for the compactness of installations. If end products are obtained through the methanol stage, then such a process is convenient due to the fact that it takes place in a single reactor. But a lot of energy is required, which is why synthetic fuel is twice as expensive as oil. An alternative to this common method was proposed by the Institute of Petrochemical Synthesis of the Russian Academy of Sciences. It involves working with another intermediate - dimethyl ether. It is not difficult to work in this way if the proportion of carbon monoxide in the resulting synthesis gas is increased. The production of synthetic gasoline in this case is an additional and rather environmentally friendly fuel. Especially it showed itself well when starting cold engines due to its high cetane number. And for the production of gasoline, this option is not bad. So, you can make fuel with an octane rating of 92. Synthetic gasoline from natural gas at the same time has fewer harmful impurities than those that can be found in those made from oil. The installation proposed by the Russian Academy of Sciences offers a scheme of operation, according to which, the higher the reaction temperature, the moreperformance.

Can you do it all yourself?

Despite the fact that alternative energy is considered a relatively young science, it is not a problem to repeat its achievements within one household. Therefore, yes, it is quite possible to create synthetic gasoline with your own hands. Moreover, given the specifics of the conditions in which one has to exist, it is possible to rely on wood, coal and biogas. Which of them to give preference to at home - everyone decides for himself.

As the simplest, the most relevant is the question of how to get synthetic gasoline from wood with your own hands. Many consider it solely as a building material or raw material for toys. But it is worth remembering at least wood alcohol, and it becomes clear that the potential exists. How to get synthesis gas in this case? It is necessary to take wood (or its waste, what exactly is not important). At home, you can make a device from three parts, each of which will perform its function. Initially, it is necessary to ensure their drying and heating to a temperature of 250-300 degrees Celsius. Then comes the turn of pyrolysis. Here the temperature should rise to 700 degrees. And the final stage is gas generation. It starts steam reforming. The process takes place at a temperature of 700-1000 degrees. The result is a very pure synthesis gas. Additional intervention is not required. Next, we use catalysts, and synthetic gasoline is ready!

Make from coal

And one more small point that was not mentioned before - when working at home, the installations, for sure, will turn out to be quite large. Therefore, it is not recommended to place them in an apartment. But creating them in your own home or near it is a very real thing.

Synthetic gasoline can be obtained from coal through the influence of steam. Its gasification is the easiest and most feasible way for home use. So let's get started. Initially, for greater efficiency and an increase in the speed of the process, coal must be crushed. Then it is saturated with hydrogen. Then it is necessary to create a temperature of 400-500 degrees Celsius and a pressure of 50-300 kg/cm2. And we are waiting for the moment of transition to the liquid state. If no solvent is used, then only 5-8% of the total mass of coal will become so. Then comes the turn of catalysts. Suitable for coal: molybdenum, nickel, cob alt, tin, aluminum, iron, as well as their compounds. Any kind of raw material can be used for gasification. Brown, stone - everything will do. Although its quality affects the conversion efficiency. Previously, the designation of the amount of carbon was given and the figure was called 8%. This is not entirely true. Depending on the brand and quality, the value can range from 4% to 8%. And for the minimum suitability of subsequent processing and separation of gasoline, it is necessary to achieve a value of 11% (better than 15%). Initially, not the fact that everything will work out. Especially if you skipped lessons in physics andchemistry. Nevertheless, synthetic gasoline from coal can be successfully made and used.

Working with biogas

This is a rather unusual and extravagant approach, but it works. Its beauty is also in the fact that as a fuel it has a wider application than just synthetic gasoline. True, it takes up a lot of space. So, for example, one cubic meter of biogas is equivalent to 0.6 liters of gasoline. If you use it not in a compressed state, then even taking it to the eyeballs on a truck, you won’t be able to drive more than a hundred or two kilometers. Therefore, how to synthesize the desired gasoline from it? This is possible due to the fact that, in fact, it is methane with small impurities. That is practically what you need. Synthesis, however, is problematic. After all, something new and at the same time simple has not been invented here. That is, we have to work on the creation of synthesis gas, and from it to ensure the formation of gasoline. This is done (according to the most common scheme) through methanol. Although you can work through dimethyl ether. When it comes to methanol, you should always remember that it is extremely dangerous. The situation is complicated by the fact that it has the smell of alcohol, and the boiling point is 65 degrees Celsius. In general, working with fuel synthesis is not a child's play. Therefore, it will not be superfluous to learn chemistry and physics if this knowledge is not available. In short, synthetic gasoline is obtained by distillation of gas and a condenser. This method is not fast, but if there is a good theoretical background, it is not difficult. But without knowledge it is impossible to workrecommended. After all, pure methanol is the highest octane fuel, and therefore dangerous. And the engine of an ordinary car will not “digest” it - it is not designed for this.

Conclusion

That's how to get synthetic fuel. It should be noted that these are not toys, but a flammable activity. Therefore, without proper theoretical preparation, one should not engage in such a matter. After all, this would be a direct violation of safety rules. And they, it should be remembered, are always written in blood.