Techno-economic assessment of hydrogen production based on dual fluidized bed biomass steam gasification, biogas steam reforming, and alkaline water electrolysis processes

In this paper, three CO2-neutral H-2 production processes were investigated. The three employed technologies were dual fluidized bed (DFB) biomass steam gasification, biogas steam reforming (BSR), and alkaline electrolysis (AEL) powered by renewable electricity with their necessary downstream separation and purification process steps. Aspen Plus process simulations were carried out in order to calculate the mass and energy balances of the three processes. In addition, a techno-economic assessment was carried out for a fictitious business producing H-2 at a rate of 90 kg h(-1) in Austria in 2016. This assumption was used so that the economic feasibility of these investigated processes could be directly compared. The simulation results show that the DFB biomass steam gasification process has a higher H-2 conversion rate (51.4%) but a lower fuel based H-2 production efficiency (38.9%) than the BSR process (27.2% and 47.0%, respectively). Moreover, the alkaline electrolysis process shows the highest energy based H-2 conversion efficiency at about 66%. The results of the economic assessment show that the DFB biomass steam gasification process has investment costs of 12.1 MEUR followed by the biogas steam reforming process with investment costs of 9.9 MEUR. The alkaline electrolysis process has investment costs of 4.4 MEUR. However, the after tax H-2 break-even price of the DFB process is the lowest with 0.148 EUR kWh(-1). The BSR process has an after tax H-2 break-even price of 0.152 EUR kWh(-1) and the AEL process has an after tax H-2 breakeven price of 0.191 EUR kWh(-1). The net present value (NPV) calculations reveal that the BSR process has the highest NPV, followed by the AEL process and the DFB biomass steam gasification process. However, the NPV of all three processes are very similar. In general, all three H-2 production processes perform at the same level based on the results of the process simulation and the chosen economic assumptions. (C) 2017 Elsevier Ltd. All rights reserved.