Syngas/H2 production from bioethanol in a continuous chemical-looping reforming prototype

Chemical-looping reforming (CLR) allows H-2 production without CO2 emissions into the atmosphere. The use of a renewable fuel, bioethanol, in an auto-thermal CLR process has the advantage to produce H-2 with negative CO2 emissions. This work presents the experimental results obtained in a continuously operating CLR unit (1 kW(th)) using ethanol as fuel. Two NiO-based oxygen carriers were used during more than 50 h of operation. The influence of variables such as temperature, water-to-fuel and oxygen-to-fuel molar ratios was analysed. Full conversion of ethanol was accomplished and carbon formation was easily avoided. A syngas composed of approximate to 61 vol.% H-2,H-approximate to 32, vol.% CO, approximate to 5 vol.% CO2 and approximate to 2 vol.% CH4 was reached at auto-thermal conditions for both materials. Gas composition was closed to the given by the thermodynamic equilibrium. These results demonstrate the technical viability of H-2/syngas production by using bioethanol in an auto-thermal CLR process. (C) 2015 Elsevier B.V. All rights reserved.