Enhanced H2 production via catalytic steam reforming of acetic acid as bio-oil model compound using asymmetric-structured nickel hollow fiber membrane

An intensified membrane reactor offers promising near future solution for converting ‘carbon-neutral’ bio-oil to hydrogen (H 2 ). This work reports the development of two membrane reactor configurations made from asymmetric-structured nickel (Ni) hollow fiber membranes (ANHFMs), i.e., catalytic membrane reactor (CMR) and catalytic membrane micro-reactor (CMMR) for steam reforming of bio-oil, represented by acetic acid as bio-oil model compound. In CMR and CMMR, the dense Ni thin film in ANHFM serves as an H 2 -selective permeation membrane, which allows H 2 permeation out of the reaction chamber while added Ni/Al 2 O 3 functions as an efficient catalyst bed. CMMR is a new configuration developed here, that relies on the presence of fine catalyst particles on the microchannels within the porous substrate inside hollow fiber, deposited using special coating process. CMR, in contrast, adopts conventional membrane reactor configuration, with catalyst particles packed outside hollow fiber. Although both CMMR and CMR demonstrated higher carbon gasification efficiency and H 2 yield due to in situ H 2 removal, the former showed higher H 2 separation efficiency relative to the latter, especially at higher liquid hourly space velocity (LHSV). Notably, CMMR displayed performance that is close to the target required for industrial H 2 separation, i.e., H 2 recovery of ∼72 % at 1000 °C and an LHSV of 59.84 h −1 . The performance of CMMR for steam reforming of bio-oil model compound consisting of acetic acid, acetone, and ethanol was also tested, which was comparable to the performance of acetic acid alone. CMMR may thus play significant role for enabling hydrogen economy via biomass conversion pathway. • Two distinct asymmetric-structured Ni hollow fiber membrane reactors are developed. • In CMR, catalysts are outside fiber and in CMMR, they are in fiber's microchannels. • CMR and CMMR are tested for steam reforming of acetic acid, key bio-oil component. • CMMR demonstrates high H 2 recovery of ∼72 % at 1000 °C and an LHSV of 59.84 h −1 . • Steam reforming of bio-oil model (ethanol, acetone & acetic acid) was also tested.