Performance evaluation of sorption enhanced chemical-looping reforming for hydrogen production from biomass with modification of catalyst and sorbent regeneration.

Process simulation of sorption enhanced chemical-looping reforming for hydrogen production from biomass was investigated. Corn stover was converted to bio-oil via pyrolysis prior to sorption enhanced chemical-looping reforming (SE-CLR). NiO was used as a catalyst and oxidizing agent and CaO was used as a CO 2 sorbent which are cycled between the reduction and oxidation reactors. Modification of the process to incorporate a step for catalyst and sorbent regeneration was examined and compared with conventional sorption enhanced chemical-looping reforming process. By modifying the SE-CLR process with the recirculating of solids from the air reactor directly to the reformer, a maximum bio-oil conversion rate of 92%, a maximum hydrogen production yield of 153.4 g H 2 /kg corn stover, and a maximum hydrogen purity of 77% v/v can be obtained with a circulated NiO to bio-oil molar ratio ( CNB ) of 12.3; a circulated CaO to bio-oil molar ratio ( CCB ) of 125.2; and where the ratio of solids recovered by the air reactor from the calcination reactor ( α ) was set as 1, and the ratio of solids flowing directly from the air reactor to the reformer ( β ) was set as 0.02. The split of a fraction of solids streams to feed directly back to the reformer offers a great impact process control as operating conditions can be broadened. [ABSTRACT FROM AUTHOR]