Ethyl alcohol from sawdust. How to get alcohol or other liquid fuel from sawdust
In Soviet times, who still remembers, they joked a lot about alcohol made from sawdust. There were rumors that after the war, cheap vodka was made just on the basis of "sawdust" alcohol. In the people, this drink was called - "bitch".
In general, talk about the production of alcohol from sawdust arose, of course, not from scratch. Such a product was actually produced. It was called "hydrolytic alcohol". The raw material for its production was indeed sawdust, more precisely, cellulose extracted from the waste of the forestry industry. Speaking strictly scientifically - from non-food plant materials. According to rough calculations, about 200 liters of ethyl alcohol could be obtained from 1 ton of wood. This supposedly made it possible to replace 1.5 tons of potatoes or 0.7 tons of grain. Whether such alcohol was used in Soviet distilleries is unknown. It was produced, of course, for purely technical purposes.
It must be said that the production of technical ethanol from organic waste has long excited the imagination of scientists. You can find literature of the 19th century, where the possibilities of obtaining alcohol from a wide variety of raw materials, including non-food ones, are discussed. In the 20th century, this theme sounded with renewed vigor. In the 1920s, scientists in Soviet Russia even suggested making alcohol from… feces! There was even a playful poem by Demyan Bedny:
Well the time has come
Every day is a miracle:
Vodka is driven from shit -
Three liters per pood!
Russian mind will invent
To the envy of all Europe -
Soon the vodka will flow
Into the mouth from the very ass ...
However, the idea with feces remained at the level of a joke. But cellulose was taken seriously. Remember, in The Golden Calf, Ostap Bender tells foreigners about the recipe for "stool moonshine". The fact is that with cellulose they were already “chemizing” at that time. Moreover, it should be noted that it can be extracted not only from the waste of the forest industry. Domestic agriculture annually leaves huge mountains of straw - this is also an excellent source of cellulose. Do not waste good. Straw is a renewable source, one might say - free.
There is only one catch in this case. In addition to the necessary and useful cellulose, the lignified parts of plants (and straw is one of them) contain lignin, which complicates the whole process. Due to the presence of this very lignin in the solution, it is almost impossible to obtain a normal “mash”, since the raw material is not saccharified. Lignin inhibits the development of microorganisms. For this reason, “feeding” is required - the addition of normal food raw materials. Most often, this role is played by flour, starch or molasses.
Of course, you can get rid of lignin. In the pulp and paper industry, this is traditionally done chemically, such as by acid treatment. The only question is where to put it then? In principle, good solid fuel can be obtained from lignin. It burns well. Thus, the Institute of Thermal Physics of the Siberian Branch of the Russian Academy of Sciences has even developed an appropriate technology for burning lignin. But, unfortunately, the lignin that remains from our pulp and paper production is unsuitable as a fuel due to the sulfur it contains (the consequences of chemical processing). If we burn it, we get acid rain.
There are other ways - to process raw materials with superheated steam (lignin melts at high temperatures), to carry out extraction with organic solvents. In some places they do just that, but these methods are very costly. In a planned economy, where all costs were borne by the state, it was possible to work in this way. However, in a market economy, it turns out that the game, figuratively speaking, is not worth the candle. And when comparing costs, it turns out that the production of industrial alcohol (in modern terms, bioethanol) from traditional food raw materials is much cheaper. It all depends on how much you have such raw materials. Americans, for example, have an overproduction of corn. It is much easier and more profitable to use the surplus for the production of alcohol than to transport it to another continent. In Brazil, as we know, surplus sugarcane is also being used as feedstock for the production of bioethanol. In principle, there are not so few countries in the world where alcohol is poured not only into the stomach, but also into the tank of a car. And everything would be fine if some well-known world figures (in particular, the Cuban leader Fidel Castro) did not oppose such an “unfair” use of agricultural products in conditions when in some countries people suffer from malnutrition, or even die of hunger. .
In general, meeting philanthropic wishes, scientists working in the field of bioethanol production should look for some more rational, more advanced technologies for processing non-food raw materials. Approximately ten years ago, specialists from the Institute of Solid State Chemistry and Mechanochemistry of the Siberian Branch of the Russian Academy of Sciences decided to take a different path - to use the mechanochemical method for these purposes. Instead of the well-known chemical processing of raw materials or heating, they began to use special mechanical processing. Why special mills and activators were designed. The essence of the method is as follows. Due to mechanical activation, cellulose passes from the crystalline state to the amorphous state. This makes it easier for the enzymes to work. But the main thing here is that the raw material in the process of mechanical processing is divided into various particles - with different (higher or lower) lignin content. Then, thanks to the different aerodynamic characteristics of these particles, they can be easily separated from each other using special devices.
At first glance, everything is very simple: grind - and that's it. But only at first glance. If everything was really so simple, then in all countries they would grind straw and other plant waste. In fact, it is necessary to find the right intensity here so that the raw material is separated into individual tissues. Otherwise, you will end up with a monotonous mass. The task of scientists is just to find the necessary optimum here. And this optimum, as practice shows, is quite narrow. You can also overdo it. That, I must say, is the work of a scientist in order to reveal the golden mean. Moreover, here it is necessary to take into account economic aspects - namely, to work out the technology so that the costs of mechanochemical processing of the feedstock (however cheap it may be) do not affect the cost of production.
Dozens of liters of wonderful alcohol have already been obtained in laboratory conditions. The most impressive thing is that alcohol is obtained from ordinary straw. And - without the use of acids, alkalis and superheated steam. The main help here is the “miracle mills” designed by the specialists of the Institute. In principle, nothing prevents us from moving on to industrial designs. But that is another topic.
Here it is - the first domestic bioethanol from straw! Still in bottles. Will we wait until they start producing it in tanks?
The general scheme for obtaining ethyl alcohol from hydrolysis "black molasses" is as follows. The crushed raw material is loaded into a multi-meter steel hydrolysis column lined with chemically resistant ceramics from the inside. A hot solution of hydrochloric acid is supplied there under pressure. As a result of a chemical reaction from cellulose, a product containing sugar, the so-called "black molasses", is obtained. This product is neutralized with lime and yeast is added there - molasses is fermented. Then it is heated again, and the released vapors condense in the form of ethyl alcohol (I don’t want to call it “wine alcohol”).
The hydrolysis method is the most economical way to produce ethyl alcohol. If 50 liters of alcohol can be obtained from one ton of grain by the traditional biochemical method of fermentation, then 200 liters of alcohol are expelled from one ton of sawdust, hydrolyzed into “black molasses”. As the saying goes: "Feel the benefits!" The whole question is whether "black molasses" as saccharified cellulose can be called a "food product", along with grain, potatoes and beets. Persons interested in the production of cheap ethyl alcohol think so: “Well, why not? After all, bard, as the remainder of “black molasses”, after its distillation goes to feed livestock, which means that it is also a food product. How can one not recall the words of F.M. Dostoevsky: "An educated person, when he needs it, can verbally justify any abomination."
In the 1930s, the largest starch plant in Europe was built in the Ossetian village of Beslan, which has been producing millions of liters of ethyl alcohol ever since. Then powerful factories for the production of ethyl alcohol were built throughout the country, including at the Solikamsk and Arkhangelsk pulp and paper mills. I.V. Stalin, congratulating the builders of hydrolysis plants, who during the war, despite the difficulties of wartime, put them into operation ahead of schedule, noted that this “makes it possible for the state to save millions of poods of grain”(Newspaper "Pravda" of May 27, 1944). 
Ethyl alcohol obtained from "black molasses", but, in fact, from wood (cellulose), saccharified by the hydrolysis method, if, of course, it is well purified, cannot be distinguished from alcohol obtained from grain or potatoes. According to current standards, such alcohol is of “highest purity”, “extra” and “luxury”, the latter is the best, that is, it has the highest degree of purification. Vodka prepared on the basis of such alcohol will not poison you. The taste of such alcohol is neutral, that is, “none” - tasteless, there are only “degrees” in it, it only burns the mucous membrane of the mouth. Outwardly, it is quite difficult to recognize vodka made on the basis of ethyl alcohol of hydrolytic origin, and various flavors added to such “vodkas” give them some difference from each other.
However, not everything is as good as it seems at first glance. Geneticists conducted research: one batch of experimental mice was added to the diet of real (grain) vodka, the other - hydrolytic, from wood. Mice that used the "bitch" died much faster, and their offspring degenerated. But the results of these studies did not stop the production of pseudo-Russian vodkas. It's like a popular song: “After all, if vodka is not driven from sawdust, then what would we have from five bottles ...”
There is a growing demand for biofuels - combustible liquids made from renewable biological resources. One of them is wood. Is it possible to obtain fuel from wood that is not inferior to oil?
The first thing to understand is that it is precisely gasoline or kerosene that cannot be made from wood. It does not decompose into straight chain hydrocarbons, of which petroleum products are mainly composed. However, this does not mean that substances that can replace petroleum products cannot be obtained from it.
Some people love the stool
First on the list, of course, is alcohol. Two different types of alcohol can be obtained from wood. The first, which is called woody, is scientifically methyl alcohol. This substance is very similar to the usual ethyl alcohol, both in combustibility and in smell and taste. However, methyl alcohol differs in that it is very poisonous, and ingestion of it can lead to fatal poisoning. At the same time, it is a high-quality motor fuel, its octane number is even higher than that of ethyl alcohol, and much higher than that of ordinary gasoline.
The technology for obtaining methyl alcohol from wood is very simple. It is obtained by dry distillation, or pyrolysis. More precisely, it is one of the components of the liquid - a mixture of oxygen-containing organic substances that are separated from freshly expelled wood resin. However, the yield of alcohol thus obtained is too low to be used as a fuel. This makes this technology of fuel production unpromising.
However, ethyl alcohol can also be obtained from wood, in much larger quantities. This alcohol - the so-called hydrolysis - is obtained by the decomposition of cellulose, the main component of wood, with the help of sulfuric acid. Rather, when cellulose decomposes, sugars are obtained, which in turn can be processed into alcohol in the usual way. This method of obtaining ethyl alcohol is very common in industry; it is the hydrolysis method that produces almost all technical alcohol used for non-food purposes.
Ethyl alcohol can be used both directly instead of gasoline and as an additive to gasoline. By means of such additives, various grades of biofuels are obtained, which are popular, in particular, in countries such as Brazil.
Obtaining ethyl alcohol by hydrolysis of wood is somewhat less economically profitable than obtaining it from various agricultural crops. However, the advantageous side of this method of obtaining biofuel is that it does not require the allocation of agricultural areas for "fuel" crops that do not provide food products, but allows the use of forestry areas for its production. This makes the production of biofuel ethanol from wood a rather practical technology.
And turpentine is good for anything
The disadvantage of ethanol as a fuel is its low calorific value. When used in engines in its pure form, it gives either less power or more consumption than gasoline. Mixing alcohol with substances with a high calorific value helps to solve this problem. And not necessarily these are products from oil: turpentine, or turpentine, is quite suitable as such an additive.
Turpentine is also a product of wood processing, and more specifically, coniferous: pines, firs, larches and others. It is widely used as a solvent, and its most purified varieties are used in medicine. However, the timber processing industry produces a large amount of the so-called sulfate turpentine as a by-product - the lowest grade containing toxic impurities, not only inapplicable in medicine, but also finds very limited use in the chemical and paint and varnish industries.
At the same time, turpentine of all wood processing products is most similar to an oil product, more precisely, to kerosene. It has a very high calorific value and can be used as fuel in kerosene stoves, lamps, and kerosene gases. It is also suitable as a motor fuel, however, for a short time: if it is poured into tanks in its pure form, the engines soon fail due to tarring.
However, turpentine can be used as a fuel not in its pure form, but as an additive to ethanol. Such an additive does not greatly reduce the octane number of ethyl alcohol, but increases the heat of combustion. Another positive side of this biofuel manufacturing technology is that turpentine denatures alcohol, making it unsuitable for ingestion as alcohol. And the social consequences of the widespread introduction of undenatured alcohol as a fuel can become very severe.
Lignin waste - into income!
Such a component of wood as lignin is considered of little use. Its use in industry is much less widespread than that of cellulose. Despite the fact that it finds application in the production of building materials and in the chemical industry, more often it is simply burned directly at the timber and chemical industry. However, as it turns out, more diverse products can be obtained from lignin pyrolysis than from cellulose pyrolysis.
Lignin consists mainly of aromatic rings and short straight hydrocarbon chains. Accordingly, during its pyrolysis, predominantly hydrocarbons are obtained. However, depending on the pyrolysis technology, it is possible to obtain both a product with a high content of phenol and related substances, and a liquid resembling petroleum products. This fluid is also suitable as an ethanol additive for biofuel production.
Technologies and installations for pyrolysis have been developed that can consume both lignin from dumps and wood waste not separated into lignin and cellulose. Better results are obtained when mixing lignin or wood waste with garbage consisting of discarded plastic or rubber: the pyrolysis liquid is more oily.
Peaceful atom and sawdust
Another technology for obtaining biofuel from wood was developed quite recently by Russian scientists. It belongs to the field of radiochemistry, that is, chemical processes occurring under the influence of radioactive radiation. In the experiments of scientists from the Institute of Chemistry. Frumkin's sawdust and other wood waste were subjected to simultaneous exposure to strong beta radiation and dry distillation, and the heating of the wood was carried out precisely with the help of super-strong radiation. Surprisingly, under the influence of radiation, the composition of the products obtained during pyrolysis has changed.
In the pyrolysis liquid obtained by the "radioactive" method, a high content of alkanes and cycloalkanes, that is, hydrocarbons contained mainly in oil, was found. This liquid turned out to be much lighter than oil, comparable, rather, with gas condensate. Moreover, the examination confirmed the suitability of this liquid for use as a motor fuel or processing into high-quality fuels, such as motor gasoline. We think that this does not deserve special mention, but let's clarify for the sake of calming the fears of radiophobes: beta radiation is not capable of causing induced radioactivity, therefore the fuel obtained in this way is safe and does not exhibit radioactive properties itself.
What to recycle
It is clear that it is preferable to use not whole tree trunks for biofuel production, but wood processing waste, such as sawdust, wood chips, twigs, bark, and even the same lignin that goes to dumps and furnaces. The output of these wastes per hectare of felled forest is, of course, lower than wood in general, but we should not forget that they are obtained as a by-product in the production processes that are already underway at many enterprises in the country, respectively, production wastes are cheap and for them there is no need to cut down or plant additional forest areas for felling.
In any case, wood is a renewable resource. Ways to restore forest areas have long been known, and in many regions of the country there is even an uncontrolled overgrowth of abandoned agricultural land with forests. One way or another, the Russian Federation is not one of the countries where forest conservation should be treated with all due diligence; the areas of our forest and its potential for self-restoration are quite enough to fully load the timber processing industry, the production of biofuels, and many other industries.
The production of alcohol from potatoes, grain, molasses, and sugar beet requires the consumption of large quantities of these valuable raw materials. Replacing such raw materials with cheaper ones is one of the sources of saving food products and reducing the cost of alcohol. Therefore, the production of technical ethyl alcohol from non-food raw materials has recently increased significantly: wood, sulfite liquors and synthetically from ethylene-containing gases.
Production of alcohol from wood
The hydrolysis industry produces a number of products from plant wastes containing cellulose, in particular from wood wastes: ethyl alcohol, fodder yeast, glucose, etc.
In hydrolysis plants, cellulose is hydrolyzed with mineral acids to glucose, which is used for fermentation into alcohol, yeast growth and release in crystalline form. There are hydrolysis plants of various profiles: hydrolysis-alcohol, hydrolysis-yeast, hydrolysis-glucose. The hydrolysis industry is of great economic importance; it is due to the fact that valuable products are obtained from low-value plant waste. In particular, 170-200 liters of ethyl alcohol are obtained from 1 ton of absolutely dry coniferous wood, the production of which would require 0.7 tons of grain or 2 tons of potatoes.
The hydrolysis industry processes wood in a complex manner, as a result of which, in addition to ethyl alcohol, other valuable products are obtained at the hydrolysis-alcohol plants: furfural, lignin, liquid carbon dioxide, fodder yeast.
Raw materials for hydrolysis production
The raw material for hydrolysis production is wood in the form of various wastes from the forestry and woodworking industries: sawdust, wood chips, shavings, etc. The moisture content of wood ranges from 40 to 60%. Sawdust processed by hydrolysis plants usually has a moisture content of 40-48%. Wood solids include cellulose, hemicelluloses, lignin and organic acids.
Wood hemicelluloses consist of hexosans: mannan, galactan and pentosans: xylan, araban and their methylated derivatives. Lignin is a complex substance of the aromatic series, its chemical composition and structure have not yet been established.
The chemical composition of absolutely dry wood is given in table 1.
Table 1 - Chemical composition of absolutely dry wood
In addition to wood, vegetable waste from agriculture is also used as a raw material for the hydrolysis industry: sunflower husk, corn cob, cotton husk, cereal straw.
The chemical composition of plant waste from agriculture is presented in Table 2.
Table 2 - Chemical composition of plant waste from agriculture Technological scheme of complex wood processing
The technological scheme of complex wood processing consists of the following stages: wood hydrolysis, neutralization and purification of the hydrolyzate; fermentation of hydrolytic wort, distillation of hydrolytic mash.
The crushed wood is subjected to hydrolysis with dilute sulfuric acid when heated under pressure. During hydrolysis, hemicellulose and cellulose decompose. Hemicelluloses are converted into hexoses: glucose, galactose, mannose and pentoses: xylose and arabinose; cellulose to glucose. Lignin remains as an insoluble residue during hydrolysis.
Hydrolysis of wood is carried out in a hydrolysis apparatus - a steel cylindrical vessel. As a result of hydrolysis, a hydrolyzate is obtained containing about 2-3% fermentable monosaccharides and an insoluble lignin residue. The latter can be used directly in the production of building boards, in brick production, when grinding cement, as a fuel; after appropriate processing, lignin can be used in the production of plastics, rubber industry, etc.
The resulting hydrolyzate is sent to the evaporator, where the vapor is separated from the liquid. The released steam is condensed and used to isolate furfural, turpentine and methyl alcohol from it. Then the hydrolyzate is cooled to 75-80°C, neutralized in the neutralizer with milk of lime to pH 4-4.3 and nutritional salts for yeast (ammonium sulphate, superphosphate) are added. The resulting neutralizate defend to release from the precipitation of calcium sulfate and other suspended particles. The settled precipitate of calcium sulphate is separated, dried, fired and alabaster is obtained, which is used in construction equipment. The neutralizate is cooled to 30-32°C and sent for fermentation. The hydrolyzate thus prepared for fermentation is called must. Fermentation of hydrolytic wort is carried out in a continuous way in fermentation tanks. In this case, the yeast continuously circulates in the system; yeast is separated from the mash on separators. The carbon dioxide released during fermentation is used to release liquid or solid carbon dioxide. A mature mash containing 1.0-1.5% alcohol is sent for distillation and rectification to a brew distillation apparatus and ethyl alcohol, methyl alcohol and fusel oil are obtained. The stillage obtained after distillation contains pentoses and is used for growing fodder yeast.
Figure 1 - Technological scheme of integrated wood processing at hydrolysis-alcohol plants When processing according to this scheme, from 1 ton of absolutely dry coniferous wood, the following quantities of marketable products can be obtained:
- Ethyl alcohol, l ………………….. 187
- Liquid carbon dioxide, kg …………….. 70
- or solid carbon dioxide, kg ……… 40
- Feed yeast, kg…………….. .. 40
- Furfural, kg …………………………….9.4
- Turpentine, kg ……………………………0.8
- Thermal insulation and building ligno-plates, m 2 .... 75
- Building alabaster, kg ……..225
- Fusel oil, kg ………………..0.3
Production of alcohol from sulfite liquors
In the production of cellulose from wood using the sulfite method, sulfite liquor is obtained as a waste - a brown liquid with the smell of sulfur dioxide. The chemical composition of sulfite liquor (%): water - 90, dry matter - 10, including lignin derivatives - lignosulfonates - 6, hexoses - 2, pentoses -1, volatile acids, furfural and other substances - about 1. For a long time sulfite liquors released into the rivers, they polluted the water and destroyed the fish in the reservoirs. At present, we have a number of plants for the complex processing of sulphite liquor into ethyl alcohol, fodder yeast and sulphite-distillery concentrates. The production of alcohol from sulfite liquors consists of the following stages: preparation of sulfite liquor for fermentation, fermentation of sulfite lye wort, distillation of mature sulfite mash.
The preparation of sulfite liquor for fermentation is carried out according to a continuous scheme. The lye is blown with air to remove volatile acids and furfural, which delay the fermentation process. The blown liquor is neutralized with milk of lime and then kept to coarsen the precipitated crystals of calcium sulfate and calcium sulfide; while adding nutrient salts for yeast (ammonium sulphate and superphosphate). Then the lye is settled. The settled sediment - sludge - is lowered into the sewerage, and the clarified liquor is cooled to 30-32°C. The liquor prepared in this way is called wort. The wort is sent to the fermentation section and fermented in the same way as wood hydrolysates, or the moving head method is used. The movable packing is called the cellulose fibers remaining in the liquor. The fermentation method with a movable nozzle is based on the property of some yeast races to be sorbed on the surface of cellulose fibers and form flakes of fibrous yeast mass, which quickly and completely settles to the bottom of the vat in a mature mash. Fermentation is carried out in a fermentation battery, which consists of head and tail tanks. In the fermenting wort, cellulose fibers with adsorbed yeast are in continuous motion under the influence of the released carbon dioxide. The fermented mash comes from the head vat to the tail vat, where the fermentation process ends, and the fibers with yeast settle to the bottom. The settled yeast-fiber mass is returned by a pump to the head vat, where the wort is simultaneously fed, and the mature mash containing 0.5-1% alcohol is sent to the distillation apparatus and ethyl alcohol, methyl alcohol and fusel oil are obtained. The vinasse obtained after distillation contains pentoses and serves as a nutrient medium for growing fodder yeast, which is then separated, dried and released as dry yeast. The vinasse after separating the yeast containing lignosulfonates is evaporated to a solids content of 50-80%. The resulting product is called sulfite-bard concentrate and is used in the production of plastics, building materials, synthetic tanning agents for leather, in foundry and road construction.
A valuable aromatic substance, vanillin, can be obtained from sulphite-bardy concentrates.
The technological scheme for the complex processing of sulfite liquors into ethyl alcohol, fodder yeast and sulfite-bard concentrates is shown in Figure 2.
Figure 2 - Process flow diagram for the processing of sulphite liquors into alcohol During the processing of sulphite liquors, in terms of 1 ton of spruce wood, the following is obtained:
- Ethyl alcohol, l ……………….. 30-50
- Methyl alcohol, l …………………… 1
- Liquid carbon dioxide, l ………….. 19-25
- Dry fodder yeast, kg …. 15
- Sulfite-bardine concentrates with a moisture content of 20%, kg .... 475
Synthetic alcohol production
The raw material for the production of synthetic ethyl alcohol is the gases of oil refineries, which contain ethylene. In addition, other ethylene-containing gases can be used: coke oven gas obtained from coal coking and associated petroleum gases.
Currently, synthetic ethyl alcohol is produced in two ways: sulfuric acid hydration and direct ethylene hydration.
Ethylene sulfate hydration
The production of ethyl alcohol by this method consists of the following processes: the interaction of ethylene with sulfuric acid, in which ethyl sulfuric acid and diethyl sulfate are formed; hydrolysis of the resulting products with the formation of alcohol; separating alcohol from sulfuric acid and purifying it.
The raw materials for sulfuric acid hydration are gases containing 47-50% by weight. ethylene, as well as gases with a lower ethylene content. The process is carried out according to the scheme below.
Figure 3 - Technological scheme for the production of synthetic alcohol by the method of sulfuric acid hydration Ethylene interacts with sulfuric acid in the reaction column, which is a vertical cylinder. Inside the column are capped plates with overflow glasses. An ethylene-containing gas is supplied to the lower part of the column by a compressor, and 97-98% sulfuric acid is supplied to the column from above for irrigation. The gas, rising up, bubbles on each plate through the liquid layer. Ethylene reacts with sulfuric acid according to the following reactions:
A mixture of ethylsulfuric acid, diethylsulfate and unreacted sulfuric acid flows continuously from the reaction column. This mixture is cooled in a refrigerator to 50 ° C and sent for hydrolysis, in which the following reactions occur:
The monoethyl sulfate obtained from the second reaction is subjected to further decomposition with the formation of another molecule of alcohol.
Direct hydration of ethylene
The technological scheme for the production of ethyl alcohol by the direct hydration of ethylene is presented below.
Figure 4 - Flow chart of direct hydration of ethylene in the production of ethyl alcohol The raw material for the direct hydration process is a gas with a high content of ethylene (94-96%). Ethylene is compressed by a compressor up to 8-9 kPa. Compressed ethylene is mixed with water vapor in certain proportions. The interaction of ethylene with water vapor is carried out in a contact apparatus - a hydrator, which is a vertical steel hollow cylindrical column in which a catalyst (phosphoric acid deposited on aluminosilicate) is located.
A mixture of ethylene and water vapor at 280-300°C under a pressure of about 8.0 kPa is fed into the hydrator, which maintains the same parameters. When ethylene interacts with water vapor, in addition to the main reaction of the formation of ethyl alcohol, side reactions occur, resulting in diethyl ether, acetaldehyde, and ethylene polymerization products. Synthesis products carry away a small amount of phosphoric acid from the hydrator, which can subsequently have a corrosive effect on equipment and pipelines. To avoid this, the acid contained in the synthesis products is neutralized with alkali. The synthesis products after neutralization are passed through a salt separator, and then cooled in a heat exchanger and water-alcohol vapors are condensed. Get a mixture of water-alcohol liquid and unreacted ethylene. Unreacted ethylene is separated from the liquid in a separator. It is a vertical cylinder, in which baffles are installed, which sharply change the speed and direction of the gas flow. Ethylene is removed from the separator to the suction line of the circulation compressor and sent for mixing with fresh ethylene. Water-alcohol solution flowing from the separator contains 18.5-19% vol. alcohol. It is concentrated in a stripping column and in the form of vapors is directed to a distillation column for purification. Alcohol is obtained with a strength of 90.5% vol. Synthetic alcohol plants use the method of direct hydration of ethylene.
The production of synthetic alcohol, regardless of the method of its production, is much more efficient than the production of alcohol from food raw materials. To obtain 1 ton of ethyl alcohol from potatoes or grain, it is necessary to spend 160-200 man-days, from oil refining gases only 10 man-days. The cost of synthetic alcohol is about four times less than the cost of alcohol from food raw materials.
Today, quite a lot of people are engaged in the manufacture of homemade liqueurs, however, some drinks require the presence of an alcohol element. The production of alcohol at home is not very laborious. To do this, you need to know and take into account some aspects and principles for the manufacture of methyl alcohol.
First of all, the presence of grain is required for the manufacture of methanol. In the role of grain crops in this case, corn, wheat can act. You can also use potatoes and starch. But, as you know, in interaction with a substance, starch does not give any reaction. In order to produce a chemical element, the sugaring method is used. And in order to sugar it, certain enzymes are needed, they are present in the malt. By making ethanol from grain without chemical impurities, the yield of a natural product is observed.
Methanol production technology
The technology for the production of an alcohol chemical at home can consist of several stages.
Below are the most basic ones:
- Methanol production with malt. Grains of cultivated plants must be germinated in small dishes, while they are scattered in one layer, up to about three centimeters. Remember that pre-sprouted grains must be treated with a solution of potassium permanganate. After processing, the seeds are placed in a container and moistened with water. It should be borne in mind that the presence of sunlight, or the sufficiency of light, directly depends on the rate of grain germination. A polyethylene material or thin glass should be covered over the container, that is, it should be sufficiently transparent. If there is a decrease in the amount of water, it must be added.
- Next step: starch processing. To begin with, we extract starch from the product that is selected for the manufacture of ethanol. In this case, it's potatoes. Slightly spoiled potatoes must be boiled until a paste begins to form from the water. Next, we wait until the product has cooled down, in the meantime we grind the malt. Next, mix the two products. Next, the starch splitting procedure takes place, it must be carried out at a temperature of at least 60 ˚ C. Now the mixture is placed in a bowl with hot water and left for 1 hour. After the time has elapsed, the product is completely cooled.
- fermentation stage. As you know, fermentation is characterized by the presence of alcohol containing elements. However, it is impossible to call Braga an alcoholic drink. After the mixture has cooled, yeast is added, which can react even at room temperature. However, if the temperature rises higher, the fermentation of the product will naturally occur faster. With significant heat, the fermentation procedure will end after three days. At the same time, a mild smell of grain can be felt from the product.
- The next step is distillation. With what is it produced? For this, a special apparatus for the production of alcohol at home is used.
- The final stage is the purification technology. We can say that methyl alcohol is ready, but it is noticed that the liquid is not transparent. That is why cleaning is done. It is carried out by adding a solution of potassium permanganate. In this form, we leave methyl alcohol for one day, then filter it - the product is ready.
As you can see, the technology for making homemade alcohol is quite simple and does not require additional effort.
Production of ethanol substance from sawdust
In recent years, fossil raw materials that can be used to make ethyl alcohol have significantly decreased. There is a shortage of grain. However, the production of alcohol from sawdust is not the worst option, since this raw material is constantly updated over the years.
However, the manufacture of the substance from sawdust requires some skills, and in addition, the manufacturer must have special equipment, without which it will be laborious to produce ethanol. The production of alcohol from sawdust at home is very popular, so it does not require high costs.
As you know, your own manufactured ethanol is not compared with the factory version. Products made in economic conditions are of higher quality, because each ingredient is distinguished by its uniqueness. It is much easier to produce alcohol from sawdust!
How to produce an alcoholic product at home?
The production of ethyl alcohol at home is carried out using a special apparatus. This device is able to carry out the procedure for the splitting of certain elements, as well as to carry out chemical reactions between them. Ordinary equipment for the manufacture of alcoholic beverages may look like mini factories. You can make any kind of alcoholic beverages in them.
It is quite simple to study the technology for the preparation of ethyl substance, while the product is of high quality. What can be obtained from this? Firstly, these are high-quality alcoholic products, and secondly, their own costs are fully recovered, this requires a special apparatus.
For example, if sugar is used in an amount of 20 kg, up to 12 liters of alcohol come out of it. The percentage of methanol reaches up to 96%. From this calculation, 25 half-liter bottles of vodka come out. In addition, the electricity that the device consumes will be spent about 25 kW.
Such equipment is capable of using all loaded products for their intended purpose. The undrinkable product yield from the first treatment can be used as a cleaner for glass surfaces and windows. Also, such a device can be installed independently, using the necessary diagrams and drawings. Such equipment can easily cope with the production of methyl alcohol.
Equipment for the production of alcoholic products has some principles of its work. The device has a special neck that fills the tank with the necessary liquid. Braga can act in the form of such a liquid. With the help of heating burners, the product is heated to the boiling point. After that, the apparatus and equipment must be transferred to normal mode.
Further, cooling takes place through the refrigeration compartment with additional purification of steam from unnecessary impurities. The purified substance enters the tank, and the vapors enter the refrigerator, where they are cooled to a liquid state. The apparatus for the production of alcohol is able to develop the established standard. The result of this procedure is alcohol of high quality preparation.
