AGRANA Opens First-of-its-Kind Biogas Plant in Kaposvar, Hungary

16/11/07 In 2007 at the site of the Kaposvár sugar factory in Hungary, international sugar, starch and fruit group AGRANA installed a large-scale biogas facility that to date is unique in the European sugar industry. The capital invested was HUF 1.7 billion, or about EUR 6.8 million.

The biogas power plant, which took seven months to build, began operation a few days after the start of this year’s sugar beet campaign. The feedstock consists of the spent beet pulp produced during sugar beet processing, as well as of beet syrup. These organic by-products now supply a large portion of the energy needs of the sugar plant. In times of rising energy prices and a difficult market environment for the sugar industry in the European Union, the utilisation of energy from by-products through a biogas plant represents highly advanced technology and an attractive alternative to the traditional energy source of natural gas.

“The biogas plant in Kaposvár is an important example of how the right expertise can strengthen the competitiveness of the European sugar industry,” said AGRANA’s CEO Johann Marihart at the opening of the new facility in Kaposvár. The biogas technology creates similar self-sufficiency in energy supply for sugar beet processing as is achieved in sugar cane mills. Sugar cane residue (bagasse) from which the juice has been expressed is the corresponding energy source for cane sugar mills. The anaerobic fermentation of beet pulp employed in the AGRANA biogas plant generates a similar energy equivalent in beet sugar factories.

As biogas from beet pulp replaces fossil energy, the process also substantially improves the CO2 balance of sugar production at Kaposvár. About 860 tonnes of beet pulp per day is fed into the plant’s fermentation process, corresponding to roughly one-half of the factory’s daily output of beet pulp. This results in the production of 110,000 cubic metres of biogas per day. In the sugar plant’s boilers, this biogas is used to generate thermal energy during the beet campaign. Biogas has a methane content of about 55%, in contrast to natural gas, which is about 96% methane. The amount of biogas used by the Kaposvár sugar factory is thus equivalent to about 60,000m3 of natural gas per day, representing 40% of the mill’s daily energy requirement. The biogas plant thus saves this amount of natural gas. It therefore prevents a total of about 10,000 tonnes of CO2 emissions in the course of a campaign. For the next stage of expansion, 75% substitution for natural gas is planned.