To provide information about operational parameters at batch configurations such as, the effect of inoculum, addition of nutrients, pH control and substrate concentration to improve hydrogen and ethanol production
According to the results, the selected inoculum was sludge from an aerobic wastewater treatment plant and an aerobic pretreatment. Also, it was necessary to provide nutrients addition and pH control. The substrate concentration that improves hydrogen and ethanol production is in a range of 40 to 70 g glycerol/L. Finally, the results coming from the analysis of the type of inoculum and pretreatment were also used for a continuous system.
The aim of the deliverable 2.1 is to further develop a bioprocess for hydrogen (H2) and ethanol (EtOH) production from crude glycerol increasing the ethanol production up to 40 gl-1. This amount was estimated according to a statistical model based on the production of more than 26 gL-1 of ethanol by preliminary fed-batch fermentation. The bioprocess is based on a selected microbial mixed cultures (called GCL inoculum) which is a functional consortium characterized by Klebsiella spp. (~60%) and Escherichia spp. (~32%)genera, both playing the role of hydrogen and ethanol producers. Working under non sterile conditions using mixed cultures, which are more robust of a pure culture, may lower the operational costs of ethanol production. Continue reading