Comparison of strategies for H2 production by biomass fast pyrolysis and in line conventional steam reforming or sorption enhanced steam reforming
Pablo Comendador, Jon Álvarez, Aitor Arregi, Maider Amutio, Martı́n Olazar, Gartzen López
Abstract
H 2 is expected to play a crucial role in the energy transition as fuel, energy vector and building block. Therefore, different routes for producing renewable H 2 are currently under study. In this context, biomass thermochemical conversion is encouraging, with the two-step pyrolysis and in line steam reforming (PY-SR) being an outstanding alternative. The aim of this study is to further develop this alternative by coupling the steam reforming with in situ CO 2 capture, i.e., pyrolysis and in line sorption enhanced steam reforming (PY-SESR). A commercial Ni-based material and dolomite were used as catalyst and sorbent, respectively. PY-SR and PY-SESR were compared in terms of their performance when varying the reforming temperature (450–750 °C) and the Steam to Biomass (S/B) ratio (0.5–3). PY-SR led to best results in terms of H 2 production (0.1086 g H2 g −1 biomass ) and H 2 purity (65.2 mol %) at a temperature of 600 °C and a S/B ratio of 3. PY-SESR yielded optimal results concerning H 2 production (0.1180 g H2 g −1 biomass ) and H 2 purity (99.8 mol %) at temperatures in the 525–600 °C range and S/B ratios between 1 and 3. Therefore, PY-SESR approach allowed lowering the reforming temperature and S/B ratio, as well as widening the range of optimal conditions and improving the performance of PY-SR. In short, PY-SESR process led to the maximization of biomass conversion to H 2 by producing a highly pure H 2 stream with lower energy requirements. Additionally, negative emissions are attained by integrating CO 2 capture in the processing of a carbon-neutral feedstock, such as biomass.