Effect of Nickel-Modified Hematite on the Conversion of Volatile and Char during Chemical Looping Gasification of Wood-Based Panel Waste

Abstract

Nickel modification is a promising method to improve the reactivity of hematite in chemical looping gasification (CLG), but the effect of nickel-modified hematite on the conversion of volatiles and char remained unclear. In this work, thermogravimetric and CLG experiments of wood-based panel waste were applied to explore the conversion of volatile and char over nickel-modified hematite. Compared with original hematite, Ni-modified hematite exhibited higher weight loss during thermogravimetric experiments under a H 2 atmosphere (29.41− 31.00%), indicating that the nickel modification improved the oxidation capacity of hematite. The higher oxidation capacity of nickel-modified hematite can further promote the conversion of C/ H element in char, leading to a higher weight loss of wood-based panel waste over nickel-modified hematite (54.14−57.79%) than that over original hematite (52.48%) in thermogravimetric experiments. However, the reaction between oxygen carrier and wood-based panel waste concentrated in the char conversion stage, resulting in the negligible inhibition effect of nickel-modified hematite on HCN and NH 3 emission during the devolatilization stage. The total gas yield, valid gas yield, and carbon conversion rate in CLG over OC-Ni10 were higher than those over original hematite. Overall, the Ni-modified hematite can further promote the char conversion of WBPW to syngas during the CLG process.