MASS AND ENERGY-BALANCE FOR SOLID-STATE FERMENTATION

Elemental balance equations for four main elements: carbon, hydrogen, oxygen and nitrogen for solid state fermentation have been presented. The heat balance has been derived from enthalpies of combustion. It has been shown that there are proportional relations between generated heat and amount of emitted carbon dioxide as well as between generated heat and change in the dry bed mass. Results of experimental investigations of growth of Aspergillus niger in a mixture of wheat bran and beet pulp agree with theoretical predictions. Coefficients of proportionality between generated heat and produced carbon dioxide as well as between heat generated and change in the dry bed mass have been experimentally found to equal 455 kJ/mol CO2 and 16,6 kJ/g respectively. Proportionality coefficients have also been calculated from average biomass composition, average biomass yield and measured composition and heat of combustion of solid medium. Results of the calculation agree well with experimental data.