Cerestar's Barby plant
June 01, 1996
by Teresa Acklin
Company overcomes numerous challenges to build state-of-the-art wheat processing facility.
The largest wheat processing plant in the world looks almost like a set for a science fiction movie, with its gleaming towers and huge white dome suddenly looming up from the rolling plains that run for many miles along the banks of the River Elbe. The plant has a processing capacity of 400,000 tonnes a year, equivalent to the output of 80,000 hectares. All the wheat comes from surrounding farms within a 96-kilometer radius of the plant.
The site at Barby was originally developed for maize starch processing in the 1920s under the ownership of U.S. company CPC International's German subsidiary Deutsche Maizena. With a processing capacity of 250 tonnes per day, it was the largest in Europe.
Following World War II and the subsequent political changes leading to the formation of the German Democratic Republic, the Barby plant was nationalized. It was not until the fall of Communism in 1989 that the possibility of returning to starch manufacture in the area was considered.
For Cerestar, which already had ties with the site through its old links to CPC, Barby provided the opportunity for an important step in the economic and social integration of eastern Germany. The former CPC plant was still functioning, but Cerestar decided very quickly that it would not be possible to upgrade the existing plant and buildings or reduce staffing levels to meet present day standards.
The area itself, however, had many advantages. Through a combination of very good soil and climate, it was in the middle of one of the best quality wheat producing regions in northern Europe. It had access to water supplies uncontaminated by heavy industry or intensive farming and was on the bank of a river that could provide an additional means of transport in the future, as it was near an existing but unusable harbor in need of reconstruction.
The disadvantages were a cumbersome farming system consisting of large-scale co-operatives, a lack of infrastructure and bureaucratic and outdated local authorities unused to dealing with commercial organizations. The situation was further complicated by the fact that Cerestar needed access to water supplies on the other side of the river an area designated as a biosphere by the United Nations Educational, Scientific and Cultural Organization and therefore of outstanding natural and environmental importance.
Despite the problems, Cerestar decided to buy a 75-ha site next to the old CPC plant. The biosphere border on the opposite bank of the river was renegotiated so that wells could be sunk along the river bank. New trees were planted to create a border for the biosphere. The decision to build the plant was made in 1990, and the project was completed in February 1994, only one month behind schedule, at a cost of deutsche mark 370 million (U.S.$250 million).
Apart from the factory itself, the project involved the installation of nearly 10 kilometers of pipeline carrying water and the construction of a complete biological wastewater treatment plant, which supplies the needs of villages in the surrounding area. In the plant design, high priority was given to minimizing energy use and multiple utilization of water and steam for a system that needs 4,500 cubic meters of water a day. The water treatment plant and some of the pollution reducing equipment qualified for E.U. grants.
Construction also posed some special problems. The two descending-film evaporator driers, which are 24 meters long, 4 meters in diameter and weigh 95 tonnes each, had to be transported in one piece. The planners traveled more than 4,800 kilometers to find the best route that avoided narrow streets and low bridges.
The futuristic white dome that stores wheat feed used construction technology virtually unknown in Europe. It was built by inflating a white plastic bubble with compressed air and then spraying it with concrete, which was then reinforced with a steel frame providing a huge savings in costs and time.
In an intensive recruitment program, staff from the old plant were invited to apply for jobs with the new project. Of the original 3,800 applicants, many were unable to adapt to the very different work ethic and the use of new technology, and only 87 were finally selected. The plant now employs 185 people, most of whom are from Barby and the surrounding towns and villages.
The new Barby work teams received nearly U.S.$5.5 million in staff training at other Cerestar plants. The company operates the socio-technical system of multi-skilled operators, which not only gives workers a wider understanding of the plant operation, it dramatically reduces the number of staff needed.
At present, 80% of the wheat processed at Barby arrives by road. The old railway lines to the site were destroyed after reunification but are gradually being replaced by Cerestar. The river and harbor cannot be used commercially until they are dredged, but will be used increasingly in the future.
Apart from starch, high grade wheat feed and wheat gluten, the plant's principle output is a very flexible range of glucose and fructose syrups for the food, drink and confectionery industries. These products are designed to capitalize on the high-quality wheat supplies, uncontaminated water sources and Cerestar's latest technologies in microfiltration and enzyme processing.
The wheat mill itself, with a processing capacity of 1,200 tonnes per day, was built by Buhler Ltd., Uzwil, Switzerland, and is the largest in the world for the production of starch flour. It operates as a one-track line to give speed of processing with reduced operating equipment. One of the most important features of this section of the plant is the use of eight-roller mills to reduce the number of intermediate sifting steps during the mill grinding process.
The processes all are designed to maximize energy efficiency and minimize environmental effects. The main energy saving comes from the gas turbine, which is designed to achieve a system efficiency of 75% to 80%, compared with the conventional levels of 40%.
After initial separation of starch and bran, the wheat feed is dried in an airless drier, which works by evaporation and heat to reduce odor emissions. Solubles from the evaporation process are mixed with the bran to produce a high protein wheat feed which is pelleted to reduce dust problems and transport costs.
The separated flour is then mixed with water to make a dough. This is then diluted, and the wheat protein is separated into vital gluten, which is further washed and dried, and starch milk.
The starch milk is then separated into two streams. One is concentrated and dried for use in the paper industry and the other goes into six main product lines of glucose syrups. Tight controls of temperature and pH levels are maintained at all stages of these processes to avoid damaging the properties of the starch or protein.
Starch for the six product lines is liquified by heat, pressure and enzymes to produce six basic grades with different lengths of carbon chain molecules. The syrups first go through a rotating drum with a filter to remove insolubles.
At the next stage, new microfiltration techniques developed at Barby are used to further refine and purify the syrups. Immobile enzymes are fixed to resins to extract minerals and cut molecule size. This process marks a major advance in enzyme technology because the enzymes can be reused and the size of the stainless steel filtration tanks can be considerably reduced both making major cost savings.
The six main syrup lines are designed to give varying levels of sweetness and viscosity for different taste/mouth feel and structural properties. These can be custom-blended according to specific product requirements. Production is scheduled on a two-day run for each line, which combines flexibility with low cost believed to be the first time a total production line has been based on this concept.
This development in production technology means Cerestar can tailor products precisely to customers' specific requirements. Rather than working from a choice of standard materials customers can now specify exactly what they want the products to do and the plant's technology is used to meet their requirements.