Katarzyna Szambelan

Water and energy saving bioprocess for bioethanol production from corn grain applying stillage liquid part recirculation

The distillery stillage is a major and arduous byproduct generated during ethanol production in distilleries. The liquid part of this stillage was proved that can be recycled in the ethanol production from corn, without disturbing the fermentation process. The corn seeds were fermented employing the conventional non-pressure method for gelatinizing as well as including a novelty: Recirculation system of distillery stillage liquid part instead of process water. The efficiency of fermentation and main chemical parameters of stillage were estimated. The liquid part of stillage was recycled 28 times. At these conditions distillery yeast Saccharomyces cerevisiae efficiently produced ethanol yielding 79.80% of the theoretical, keeping the vitality and quantity on the same level. However, recirculation of the liquid part of stillage caused protein and potassium increase in the wet cake what makes this product more attractive for fodder supplementation. It was proven that the addition of stillage liquid fraction to the mashing process instead of process water and 28 recirculation cycles in ethanol production from corn constitutes the way which could significantly reduce the water and energy consumption, what essentially reduce whole general production costs without ethanol efficiency decreasing.

The comprehensive analysis of sorghum cultivated in Poland for energy purposes: Separate hydrolysis and fermentation and simultaneous saccharification and fermentation methods and their impact on bioethanol effectiveness and volatile by-products from the grain and the energy potential of sorghum straw

The aim of this work was to study the potential of sorghum crop cultivated in European climate as an energy material. The investigation showed strong interaction between the fermentation method and the sorghum cultivar. It was also noted that the cultivar with the highest grain yield showed the highest yield of ethanol per hectare, achieving 1269 L/ha in SHF (separate hydrolysis and fermentation) and 1248 L/ha in SSF (simultaneous saccharification and fermentation). Chromatographic analysis of raw spirits showed that smaller amounts of impurities are formed in the SSF process than in the SHF process. The calorific value of sorghum straw was also measured, and amounted to 16,050-16,840 kJ/kg. The results have demonstrated the high value of sorghum as grain for bioethanol production and as straw as a valuable feedstock for forming pellets or briquettes.