Mechanism of K/Ni Etching for Biochar-H_(2)O Gasification  

作　　者：Zhenyu Cheng Dongdong Feng Qi Shang Yijun Zhao Wenda Zhang Shaozeng Sun 

机构地区：[1]School of Energy Science and Engineering,Harbin Institute of Technology,Harbin 150001,China

出　　处：《Journal of Harbin Institute of Technology(New Series)》2024年第3期1-18,共18页哈尔滨工业大学学报（英文版）

基　　金：Sponsored by the National Natural Science Foundation of China(Grant No.52276180);the Natural Science Foundation of Heilongjiang Province(Grant No.YQ2022E026).

摘　　要：Biomass-H_(2)O gasification is a complex thermochemical reaction,including three processes of volatile removal:homogeneous/heterogeneous reforming,biochar gasification and etching.The rate-determining step is biochar-H_(2)O gasification and etching so the DFT is carried out to see the catalytic role of different metal elements(K/Ni)in the zigzag biochar model.The calculation results show that the gasification of biochar-H_(2)O needs to go through four processes:dissociative adsorption of water,hydrogen transfer(hydrogen desorption,hydrogen atom transfer),carbon dissolution and CO desorption.The energy barrier indicated that the most significant step in reducing the activation energy of K is reflected in the hydrogen transfer step,which is reduced from 374.14 kJ/mol to 152.41 kJ/mol;the catalytic effect of Ni is mainly reflected in the carbon dissolution step,which is reduced from 122.34 kJ/mol to 84.8 kJ/mol.The existence of K causes the edge to have a stronger attraction to H and does not destroy theπbonds of biochar molecules.The destruction ofπbonds is mainly due to the role of H free radicals,while the destruction ofπbonds will lead to easier C-C bond rupture.Ni shows a strong attraction to O in OH,which forms strong Ni-O chemical bonds.Ni can also destroy the aromatic structure directly,making the gasification easier to happen.This study explored the catalytic mechanism of K/Ni on the biochar-H_(2)O gasification at the molecular level and looked forward to the potential synergy of K/Ni,laying a foundation for experimental research and catalyst design.

关 键 词：BIOCHAR Potassium-nickel catalysis H_(2)O gasification etching Quantum chemistry Transition state theory 

分 类 号：TK6[动力工程及工程热物理—生物能]