Production of sugar from sugar beet: technology description

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

Sugar production is the prerogative of large factories. After all, the technology is quite complex. Raw materials are processed on continuous production lines. As a rule, sugar production facilities are located in close proximity to sugar beet cultivation sites.

Product description

Sugar is essentially a pure carbohydrate (sucrose) that tastes sweet and pleasant. It is well absorbed and ensures the normal functioning of the body (visual and hearing acuity, an important nutrient for brain cells, takes part in the formation of fats). Abuse of the product leads to the development of diseases (caries, excess weight, etc.).

Raw materials for production

Traditionally in our country this product is made from sugar beets. Sugar production requires a large supply of raw materials.

Beetroot is a representative of the haze family. Grows for two years, culture is resistant to drought. During the first year, a root grows, and then during the second year it developsstem, flowers and seeds appear. The mass of the root crop is 200-500 g. The mass fraction of hard tissue is 75%. The rest is sugar and other organic compounds.

Beet harvesting takes 50 days. At the same time, plants operate an average of 150 days a year. To provide raw materials for the sugar industry, beets are stored in so-called kagat (large piles).

Sugar beet storage technology

Beets are laid in layers in piles on previously prepared areas. If the storage technology is violated, the beets will germinate and rot. After all, roots are living organisms. A characteristic of germination is the index of the ratio of sprouts to the mass of the entire fruit. Under conditions of high temperature and high humidity, the beets begin to germinate already on the fifth day of storage. At the same time, the beets, which are located in the upper part of the pile, germinate most intensively. This is an extremely negative phenomenon, which leads to a decrease in the efficiency of sugar production. To minimize losses from germination, the tops of the fruits are cut off during harvesting, and the crop itself in the piles is treated with a special solution.

It is important to store the fruits in piles carefully, trying not to damage them. After all, damaged areas of the fetus are a weak point that is affected first of all, and then he althy tissues.

The development of bacteria is significantly affected by temperature and humidity levels. Maintaining the recommended air composition and temperature1-2 °C, then the processes of decay slow down (sometimes do not develop).

The beets that are being stored are extremely polluted (soil, grass). Dirt impairs air circulation in the pile, provokes rotting processes.

Therefore, it is recommended to wash the beets and store them washed. In recent years, special devices have been widely used to blow out weeds, straw and dirt.

Beet yield

One of the most important tasks is to increase the yield of sugar beets. It depends on many factors. Sugar production directly depends on the volume of collection, as well as on the technological quality of raw materials.

First of all, the technological qualities of cultivated beets depend on the seeds used. Modern technologies allow to control biological and other characteristics. Seed quality control allows you to significantly increase the yield per hectare of sown area.

The method of growing beets is also important. A significant increase in yield is observed with the so-called ridge cultivation method (yield growth ranges from 15 to 45%, depending on the climatic characteristics of the region). The essence of the method is as follows. In autumn, special machines pour ridges, so that the earth actively absorbs and accumulates moisture. Therefore, in spring, the earth ripens quickly enough, creating favorable conditions for sowing, growth and development of fruits. In addition, beets are much easier to harvest: the soil density of the ridges is relatively low.

It is curious that this technology was proposed by the Soviet scientist Glukhovsky in the distant 20s of the last century. And relatively recently, the method was introduced in advanced countries.

Despite the great effectiveness, this technology has not found wide application. The reason for this is the lack and high cost of special equipment. The production of sugar from beets therefore has prospects for development and reaching a new technological level.

Beets should be harvested before frost. Deliveries to enterprises of dug out beets can be carried out according to the flow principle or by the flow-transshipment method. In order to reduce the loss of sucrose during long-term storage at transshipment bases, the fruits are covered with straw.

Production process

An average sugar plant in Russia is capable of processing several thousand tons of raw materials (sugar beets). Impressive, isn't it?

Production is based on complex chemical processes and reactions. The essence is the following. To obtain sugar crystals, it is necessary to isolate (extract) sucrose from raw materials. Then sugar is separated from unnecessary substances and a ready-to-eat product (white crystals) is obtained.

Sugar production technology consists of the following operations:

• cleaning from dirt (washing);
• receiving chips (chopping, grinding);
• sucrose extraction;
• juice filtration;
• thickening (evaporation of moisture);
• boiling mass(syrup);
• separation of molasses from sugar;
• drying sugar.

Sugar beet washing

When raw materials arrive at the sugar plant, they end up in a kind of bunker. It can be located both underground and outside. With a powerful directed jet of water, the sugar beet is washed out of the hopper. Root crops fall on the conveyor, during the movement of which the raw materials are pre-cleaned from all kinds of debris (straw, grass, etc.).

Crushing root crops

Producing sugar from beets is impossible without grinding them. So-called beet cutters come into play. The output is thin strips of sugar beets. In sugar production technology, the way the pieces are cut is very important: the larger the surface area, the more efficiently the sucrose is separated.

Sucrose extraction

The beet chips are fed through the conveyor into the diffusion apparatus with auger. Sugar is separated from the chips with warm water. The chips are fed through the auger, and warm water flows towards it, which extracts the sugar. In addition to sugar itself, water also carries along other soluble substances. The process is quite effective: at the output, the pulp (the so-called beet chips) contains only 0.2-0.24% sugar by mass fraction. Water, saturated with sugars and other organic substances, becomes cloudy and foams strongly. This liquid is also called diffusion juice. The most complete processing is possible only when the raw material is heated to 60 degrees. At this temperature, the proteins coagulate and do not stand out from the beets. Sugar production doesn't end there.

Diffusing Juice Purification

From the liquid it is necessary to remove the smallest suspended particles of beets and dissolved organic substances. Technologically, up to 40% of by-products can be removed. Whatever is left accumulates in the molasses and is only removed at the final stage of production.

Juice heated up to 90°C. Then it is processed with lime. As a result, proteins and other substances that are in the juice precipitate. This operation is performed on special equipment within 8-10 minutes.

Now you need to remove the lime. This process is called saturation. Its essence is as follows: the juice is saturated with carbon dioxide, which enters into a chemical reaction with lime, forming calcium carbonate, which precipitates, absorbing various pollutants. The transparency of the juice increases, it becomes lighter.

The juice is filtered, heated to 100 °C and re-saturated. At this stage, a deeper purification from impurities is carried out, after which the juice is again sent for filtration.

Juice must be discolored and thinned (not so viscous). For this purpose, sulfur dioxide is passed through it. Sulfurous acid is formed in the juice - a very strong reducing agent. Reaction with water produces a certain amount of sulfuric acid, releasing hydrogen, which in turn brightens the juice.

After coarse and pure saturation, the output is 91-93% of the original volume of high-quality,bleached juice. The percentage of sucrose in the resulting volume of juice is 13-14%.

Evaporation of moisture

Produced in two stages using special equipment. For the production of sugar at the first stage, it is important to obtain a thick syrup with a solids content of 65-70%. The resulting syrup undergoes additional purification and is again subjected to the evaporation procedure, this time in special vacuum devices. It is necessary to obtain a viscous thick substance with a sucrose content of 92-93%.

If you continue to evaporate water, the solution becomes supersaturated, crystallization centers appear and sugar crystals grow. The resulting mass is called massecuite.

The boiling point of the resulting mass is 120 °C under normal conditions. But further boiling is carried out in a vacuum (to prevent caramelization). In conditions close to vacuum, the boiling point is much lower - 80 °C. This mass at the stage of evaporation in a vacuum apparatus is “alloyed” with powdered sugar. What stimulates the growth of crystals.

Separation of sugar from molasses

Sugar mass goes to centrifuges. There the crystals are separated from the molasses. The liquid that comes out after separating the sugar crystals is green molasses.

Sugar crystals linger on the mesh of the centrifuge drum, which are treated with hot water and steamed to whiten. In this case, the so-called white molasses is formed. This is a solution of sugar and the remains of green molasses in water. White molasses undergoes secondary processing invacuum machines (to minimize losses, improve production efficiency).

Green molasses goes to another apparatus for boiling. As a result, the so-called second massecuite is obtained, from which yellow sugar is already obtained. It dissolves in juice after the first cleaning.

Drying sugar

The sugar production cycle is not yet complete. The contents of the centrifuge are removed and sent to dry. After the centrifuge, the moisture content of the sugar is approximately 0.5% and the temperature is 70°C. In a drum-type dryer, the product is dried to a moisture content of 0.1% (this is largely ensured by the residual temperature after the centrifuges).

Waste

The main waste products of sugar production from sugar beets are pulp (the so-called root shavings), fodder molasses, filter-press mud.

Beet pulp is up to 90% by weight of raw materials. Serves as good feed for livestock. It is unprofitable to transport pulp over long distances (due to high humidity, it is very heavy). Therefore, it is purchased and used by farms located near sugar production facilities. To prevent damage to the pulp, it is processed into silage.

In some sugar beet sugar factories, the shavings are pressed (up to 50% of moisture is removed) and then dried in special chambers. As a result of such processing, the mass of pulp, ready for use as intended and transported over long distances, is no more than 10% of its original mass.

Melassa –fodder molasses - obtained after processing the second massecuite. Its volume is 3-5% of the mass of the feedstock. It is 50% sugar. Feed molasses is an important component in the production of ethyl alcohol, as well as in the production of animal feed. In addition, it is used in yeast production, in the manufacture of citric acid and even medicines.

The volume of filter-press mud reaches 5-6% of the mass of unprocessed raw materials. Used as a fertilizer for agricultural soils.

Production of refined sugar

The production of refined sugar is usually located at the sugar factories themselves. As part of such plants, there are special workshops. But third-party organizations that buy granulated sugar from factories can also produce refined sugar. According to the method of obtaining refined sugar, it can be cast and pressed.

The sequence of technological operations in the production of refined sugar is as follows.

Sugar is dissolved in water. The thick syrup is processed to remove various coloring substances. After purification, the syrup is boiled in a vacuum chamber, and the first refined massecuite is obtained. In order to eliminate yellowness, ultramarine is added to the vacuum chamber (0.0008% by weight of the syrup, no more). The process of boiling is similar to the process of boiling when obtaining sugar.

Refined massecuite needs to be spaced. A thick mass is formed (slurry with a moisture content of 3%, no more), which is pressed. The result is a refined sugar that takes the form of a press. To get refined in the formheads, massecuite is poured into the appropriate forms. At the bottom of the mold there is a special hole through which the remaining solution flows out. Wet refined sugar is dried with hot air until the moisture index decreases to a value of 0.3-0.4%. Then it remains only to wait until the sugar lumps cool, cut (if necessary) and pack.