Green Biorefinery – Production of Amino Acids from Grass Silage Juice using an Ion Exchanger Device at Pilot Scale

The use of grass biomass in biorefineries offers sustainable routes to gain bulk and fine chemicals, such as amino acids from biobased resources. In 2008, the Green Biorefinery Upper Austria has been established to extract amino acids and lactic acid from grass silage at pilot scale. After pressing the grass and pre-treating the grass silage juice by different state of the art membrane technologies, the amino acids were purified and separated using an ion exchanger device. To guarantee higher loadings and throughputs per batch run at the ion exchanger device, a displacement chromatography was applied. Using the present device 6 to 10 kg amino acids per batch run were yielded. By monitoring the displacement step, the separation into three different amino acid product fractions was implemented. Additionally, different process parameters, such as flow rates or different amino acid concentrations in the feed were investigated to find out possible correlations and to increase the yield per batch run. Considering the investigated process conditions, it was found out that the ratio between amino acids and inorganic cations in the feed influences the yield per batch run.