ABSTRACT
This study evidenced the potential of simple sugars and vinasse to produce hydrogen (H2). The process showed a significant footprint (64 - 97 kg CO2/kg H2) but a carbon capture unit reduced the emissions to 1 kg CO2/kg H2. From the best operating conditions identified in this work, a sequential-parallel system with H2 yields above 1.5 (mol H2/mol glucose) is self-energy sustainable. After a short acclimation period the H2 flow rate was increased by 1.5 whereas energy surplus and footprint were reduced 24 and 35 %, respectively. Acclimation dropped water use from 1.7 to 0.70 (kg water/kg H2). An acidogenic-methanogenic process fueled by vinasse could be merged to a bioethanol facility because some of the units are available. Hydrogen derived from vinasses had lower biogenic emissions (0.9 kg CO2/kg H2) and the bioprocess is self-energy sustainable.
