Thermal decomposition of wheat straw pellets in a nitrogen environment: Characterization using thermogravimetric analyzer
Year: 2024
Type: article
Abstract: This experiment used a thermogravimetric (TG) analyzer within a nitrogen environment, investigating the thermal degradation patterns of wheat straw pellets (WSP) under temperatures ranging from 31 to 800 °C and varying heating rates (5, 10, and 20 °C/min). Two pellet types were considered: T 1 (100 % wheat straw) and T 2 (70 % wheat straw, 10 % sawdust, 10 % bentonite clay, and 10 % biochar). This study comprehensively analyzes WSP's thermal degradation , emphasizing model selection, composition effects, heating rate, and temperature. Results highlighted higher volatile matter content and calorific value in WSP. Model-free methods were applied to analyze TG/DTG profiles, revealing three distinct zones in WSP thermal decomposition: drying, devolatilization , and carbonization . Devolatilization, especially its 1st and 2nd steps, was extensively examined, with a significant mass loss (approx. 65 %) observed between 150 and 550 °C. Higher heating rates induced a shift in thermogravimetric profiles to elevated temperatures. Maximum mass loss rates during devolatilization ranged from 4.41 to 16.28 %/min for T 1 and 4.0–15.9 % for T 2 pellets. Temperature significantly influenced mass loss and reaction rates, whereas heating rates had a negligible impact. Thermodynamic properties indicated equilibrium reactions during pyrolysis for both T 1 and T 2 pellets. Additionally, increasing heating rates correlated with an upward trend in the reactivity index. The findings contribute valuable knowledge for optimizing biomass utilization in combustion and pyrolysis processes.
Authors: Bidhan Nath, Guangnan Chen, Les Bowtell, Elizabeth Graham
Language: English
Subfield: Biomedical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,210
OpenAlex ID: W4404136146