Hydrogen-Rich Gas Production from Two-Stage Catalytic Pyrolysis of Pine Sawdust with Nano-NiO/Al2O3 Catalyst

Tao Xu,Xiuren Zheng,Jue Xu,Yongping Wu

doi:10.3390/catal12030256

Tao Xu, Xiuren Zheng + Show 2 more

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https://doi.org/10.3390/catal12030256

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Journal: Catalysts	Publication Date: Feb 24, 2022
Citations: 17	License type: CC BY 4.0

Affiliation: Xi'an University of Science and Technology

Abstract

Hydrogen production from biomass pyrolysis is economically and technologically attractive from the perspectives of energy and the environment. The two-stage catalytic pyrolysis of pine sawdust for hydrogen-rich gas production is investigated using nano-NiO/Al2O3 as the catalyst at high temperatures. The influences of residence time (0–30 s) and catalytic temperature (500–800 °C) on pyrolysis performance are examined in the distribution of pyrolysis products, gas composition, and gas properties. The results show that increasing the residence time decreased the solid and liquid products but increased gas products. Longer residence times could promote tar cracking and gas-phase conversion reactions and improve the syngas yield, H2/CO ratio, and carbon conversion. The nano-NiO/A12O3 exhibits excellent catalytic activity for tar removal, with a tar conversion rate of 93% at 800 °C. The high catalytic temperature could significantly improve H2 and CO yields by enhancing the decomposition of tar and gas-phase reactions between CO2 and CH4. The increasing catalytic temperature increases the dry gas yield and carbon conversion but decreases the H2/CO ratio and low heating value.

Highlights

Hydrogen is a promising alternative energy source for the future because of its abundant resources, high energy conversion, and clean application [1,2,3]
The main objective of this study is to study the high-temperature catalytic pyrolysis performance of pine sawdust for hydrogen-rich gas production using nano NiO/γ-Al2O3 as a catalyst in a two-stage moving bed
The pyrolysis experiments of pine sawdust were performed at 850 ◦C without using catalysts or a catalytic bed

Summary

Introduction

Hydrogen is a promising alternative energy source for the future because of its abundant resources, high energy conversion, and clean application [1,2,3]. Hydrogen production from biomass is an attractive way to solve the energy shortage and environmental pollution problems. The two pathways for hydrogen-rich gas from renewable biomass are as follows: thermochemical conversion and biological conversion [8,9]. The thermochemical conversion is a feasible option in terms of economic and technological considerations. The main thermochemical processes include pyrolysis, gasification, supercritical water gasification, and chemical looping [10,11,12]. Pyrolysis is one of the most promising thermochemical processes that can co-produce high-value solid, liquid, and gas products, including hydrogen [13]

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