In Austria, sugar is produced from home-grown sugar beet. After being harvested in autumn, the beet is taken from the field to be processed in AGRANA’s sugar factories in Tulln or Leopoldsdorf. The sugar beets are processed into high-quality sugar, either for the end consumer (Wiener Zucker) or for the industry.
In Austria, sugar is produced from home-grown sugar beet. After being harvested in autumn, the beet is taken from the field to be processed in AGRANA’s sugar factories in Tulln or Leopoldsdorf. The beet is cleaned and reduced to small pieces before the sugar is then extracted from the cuttings. The resulting syrup is then thickened and crystallized. Finally, the sugar crystals are separated from the syrup in centrifuges. The finished sugar is then automatically packed and sent on its way to the consumer as an important luxury food article.
Would you like to know more about our sugar beet? Then discover our brochure „From beet to sugar” – it contents interesting facts and figures about our sugar beet and sugar production. Or experience the production process from the perspective of our sugar beet.
THE SUGAR BEET PLANT (beta vulgaris saccharifera) is a biennial plant belonging to the goosefoot family. The taproot, the so-called beet, which is used to produce sugar, forms during the growing phase in the first year. A flower and seeds form during the growing phase of the second year. This relies on the sugar stored in the beet. With a sugar concentration of 16 to 20%, the sugar beet offers the highest yield among sugar-producing plants (sugar beet and sugar cane). The water content is around 75%.
Leaves of the sugar beet
With the aid of solar energy and the chlorophyll in its leaves, the sugar beet plant converts carbon dioxide from the air, water and minerals in the soil into sugar. This process is called photosynthesis. The sugar beet foliage is left on the fields during harvesting.
HEAD OF THE SUGAR BEET
The head of the sugar beet plant, from where the leaves branch off, contains many non-sugar materials and therefore needs to be removed during harvesting.
ROOT OF THE SUGAR BEET
The sugar produced during photosynthesis is stored in the root of the sugar beet. The lighter areas are those in which the concentration of sugar is particularly high.
After being washed carefully and temporarily stored in the beet bunker, the sugar beet are subsequently processed.
1. Slicing
Slicing machines cut the beets into strips known as cossettes which have an average sugar Content of between 16 and 20%.
2. Raw Juice production
The sugar is extracted from the cossettes by means of hot water (around 70 °C) in a diffuser, with the cossettes moving in the opposite direction to the water flow (counter-flow-principle), in a process known as extraction. The raw juice or liquor obtained contains around 98% of the sugar in the sugar beet as well a organic and inorganic constituents (so-called non-sugars) from the beet.
3. Juice purification
The non-sugars in the raw Juice are bound and extracted by means of the natural substances lime (CaO) and carbonic acid gas (CO2) which are produced in the site's own lime kiln.
4. Filtration
The flocculatable insoluble non-sugars and the lime are filtered off in filter units. The filtrate is known as thin juice and the filter residue as carbonation-lime. This is an important soil improver and fertilzer which is spread on the fields.
5. Thick juice production
The thin juice is evaporated in hour-long steaming process to produce thick juice. The operation of on-site power plants provides the considerable quantities of energy needed for sugar production. The steam produced in the high-pressure boilers is used in the turbogenerators to produce electricity. The waste steam from the turbines is used as process heat (cogeneration) in order to heat the evaporator station.
6. Crystallisation
The thick juice is thickened further in the boiling-pans under vacuum. The crystallisation process is triggered by adding (spiking) the thick juice with finely ground sugar. Further evaporation allows the crystals to grow to the desired size.
7. Centrifugal
The sugar crystals are seperated from the syrup by means of centrifuging. The separated syrup is subjected to a further two crystallisation process.
8. Sugar
The pure, crystal-clear sugar appears White when subjedted to white light. White sugar contains at least 99.7% sucrose. The remainder is in effect moisture
9. Sugar drying
White sugar is dried in an air stream, cooled and stored in silos. In its many forms and packaged in numerous different household and industrial volumes, sugar is an important nutritional and semi-luxury food stuff which then makes its way to the end consumer.
10. Molasses
The syrup separated off during the final crystallisation step is known as molasses. The molasses contains the non-crystallised sugar (6-9% of the sugar content of the beet) as well as the soluble non-sugars from the sugar beet. Molasses is a valuable ingredient for the baking yeast and animal feed industry as well as for the production of alcohol.
11. Pellets
The cossettes from the sugar juice is derived in the extraction tower are mechanically pressed and, following the addition of molasses, dried in a drying tunnel before being pelleted and sold as animal feed.
Sugar cane is obtained from sugar cane shoots called ‘sets’ that are ready for harvest after eleven to eighteen months. Each shoot can be harvested up to seven times before it has to be replaced. Harvesting is done either mechanically or by hand. The dried leaves, called ‘trash’, are often burned away first to make the subsequent processing easier.
The cultivated cane must be processed as soon as possible after being harvested in order to obtain the sugar and to prevent sugar being broken down by microorganisms. Raw cane sugar is thus produced in factories that are located close to the growing area. The sugar cane is cleaned, compressed and ground, before being sprayed with hot water to extract the juice. This juice is then filtered, concentrated by means of pressurized steam, and then crystallized. It is then passed through centrifuges to separate it from the remaining syrup.
At this stage, the sugar is partly clean and exists in a crystallized, microbiologically stable form. As a commodity it can now be stored and transported to refineries around world.
The most important stages in refining raw cane sugar are:
Besides producing sugar from sugar beet, AGRANA also refines raw sugar from sugar cane to make white sugar at its plants in Romania and Hungary. The plant in Bosnia-Herzegovina is operated purely as a raw sugar refinery. In order to supply its raw sugar refineries in the EU, AGRANA sources raw sugar from the so-called least developed countries, with the facility in Brčko/Bosnia-Herzegovina being supplied with raw sugar from the global market, mainly from Brazil.
