Synergic consideration of competitiveness and ecology in biogas production and use

Abstract

A biotechnological investment producing biogas from the by-products of sugar industry was put in operation at the Kaposvár Sugar Factory of Hungarian Sugar Ltd in 2007. The project essentially contributed to the survival of the Kaposvár Sugar Factory, as the only one Hungarian plant, in the worsening contention in producing beet sugar. In addition, the favourable environmental effects of the investment support the long-term sustainable and successful activity of the factory. The investment involved the building of two extremely large fermentors of 12000 m3 useful volume, with the connected feeding and mechanical equipment, as well as gas system. Depending on the dry matter content, the biogas plant is able to receive 800-1000 t raw material daily. Based on the pilot studies, the biogas production of 110.000 m3 / day was supposed with 55-60% methane content. This amount replaces 60-65.000 m3 natural gas in heating of the evaporators of the sugar factory. The test operation of the biogas plant in 2007 has been followed by the normal operation since 2008 September. The obtained results exceeded the expectations, regarding both the quantity and the quality of the produced biogas. Daily production reached the value of 140.000 m3 with an average methane content of 53%. The methane equivalent of 76-77.000 m3 covered more than 50% of the factory’s energy demand.