Enhanced hydrogen production via staged catalytic gasification of rice husk using Ca(OH)2 adsorbent and Ce–Ni/γAl2O3 catalyst in a fluidized bed

• Published in: International journal of hydrogen energy 2023-05, Vol.48 (44), p.16630-16648
• Main Authors: Zeng, Xi, Fang, Mengxiang, Shan, Yidan, Lv, Tong, Cen, Jianmeng, Wang, Qinhui, Wang, Kaige
• Format: Article
• Language: English
• Subjects: Ca(OH)2 adsorbent; Ce–Ni/γAl2O3 catalyst; Fluidized bed; Hydrogen production; Rice husk; Staged catalytic gasification
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2022.12.218

Hydrogen production from rice husk was carried out via a two-stage system combining CLG (calcium looping gasification) using Ca(OH)2 adsorbent in a bubbling fluidized bed and catalytic reforming with Ce–Ni/γAl2O3 catalyst in a connected fixed bed. The results show that the maximum H2 concentration (69.16 vol%) and H2 yield (11.86 mmol g−1rice husk) are achieved at Ca/C (Ca(OH)2 to carbon molar ratio) = 1.5, H2O/C (H2O to carbon molar ratio) = 1.5, Tg (gasification temperature) = 500 °C, Tc (catalytic temperature) = 800 °C. The supplementation of fresh Ca(OH)2 at Ca/C of 0.5 during calcination helps to activate the regenerated CaO by hydration, maintaining its carbonation activity and CO2 adsorption. Ce–Ni/γAl2O3 catalyst promotes water gas shift (WGS), steam methane reforming (SMR), and C2–C3 hydrocarbons reforming, also exhibits excellent activity stability to maintain H2 concentration and H2 yield above 67.21 vol% and 11.67 mmol g−1rice husk, respectively, during 5 lifetime tests. •Staged catalytic gasification of rice husk in a fluidized bed for H2-rich gas.•Ca(OH)2 adsorbent promotes WGS and hydrocarbons reforming at a moderate temperature.•Fresh Ca(OH)2 supplement during calcination activates regenerated CaO by hydration.•Ce–Ni/γAl2O3 catalyst promotes WGS, SMR, and C2–C3 hydrocarbons reforming reactions.•Ce–Ni/γAl2O3 catalyst shows excellent activity stability with low carbon deposition. [Display omitted]