Garba Kabir, Mohammed Habu Iyodo, Isa Yusuf Makarfi
Department of Chemical Engineering, Abubakar Tafawa Balewa University, P.M.B 0248, Bauchi, Nigeria.
Department of Chemical Engineering, University of Maiduguri, P.M.B 1069, Maiduguri, Nigeria.
Heliyon. 2024 Jul 10;10(14):e34435. doi: 10.1016/j.heliyon.2024.e34435. eCollection 2024 Jul 30.
Metal oxides as catalysts alter the properties of the pyrolysis vapor secondary reactions during the thermal decomposition of several biomass leading to high-value bio-oils. This study aimed to investigate the thermal decomposition characteristics of (CS) shells that were treated with various metal oxides (ZnO, CuO, FeO/FeO, and FeO) using pyrolysis. The study also sought to identify pyrolysis reaction parameters (kinetics and thermodynamics parameters) that are not widely documented. Thermogravimetric pyrolysis was carried out at different heating rates, and the undocumented pyrolysis kinetic parameters were determined using the Flynn-Wall Ozawa method (FWO) according to American Standard Testing and Materials (ASTM) 6441 guidelines for assessing biomass decomposition. The metal oxide-treated CS shells lost significant weight between 62 and 67 wt% during the thermogravimetric pyrolysis, lower than 75 wt% of the CS shell. The average activation energies (E) for pyrolysis of the ZnO, CuO, FeO/FeO, and FeO treated CS shells were 203.04, 155.35, 338.85, and 219.92 kJ/mol, respectively in contrast to that of the untreated CS-shell. The Bayesian Information Criteria revealed that the diffusion kinetics of the Gistling-Brounshtein model best describes the pyrolysis of the shell mixed with metal oxides. The metal oxides affected the CS shells' pyrolysis kinetic parameter (E), which can promote pyrolysis vapor upgrading to encourage the widespread use of metal oxides in pyrolysis for bioenergy and chemical recovery.
金属氧化物作为催化剂，在几种生物质的热分解过程中会改变热解蒸汽二次反应的特性，从而生成高价值生物油。本研究旨在通过热解研究用各种金属氧化物（氧化锌、氧化铜、氧化亚铁/氧化铁和氧化亚铁）处理过的（CS）壳的热分解特性。该研究还试图确定尚未广泛记录的热解反应参数（动力学和热力学参数）。在不同加热速率下进行热重热解，并根据美国材料与试验协会（ASTM）6441评估生物质分解的指南，采用弗林-沃尔-小泽方法（FWO）确定未记录的热解动力学参数。在热重热解过程中，经金属氧化物处理的CS壳失重显著，在62%至67%（重量）之间，低于CS壳的75%（重量）。与未处理的CS壳相比，氧化锌、氧化铜、氧化亚铁/氧化铁和氧化亚铁处理的CS壳热解的平均活化能（E）分别为203.04、155.35、338.85和219.92千焦/摩尔。贝叶斯信息准则表明，吉斯林-布朗施泰因模型的扩散动力学最能描述与金属氧化物混合的壳的热解。金属氧化物影响了CS壳的热解动力学参数（E），这可以促进热解蒸汽升级，从而鼓励在热解中广泛使用金属氧化物以实现生物能源和化学回收。
