文献类型：期刊文献

英文题名：Molecular Structure and Formation Mechanism of Hydrochar from Hydrothermal Carbonization of Carbohydrates

作者：Shi, Ning Liu, Qiying He, Xiong Wang, Gui Chen, Ni Peng, Jiayu Ma, Longlong

第一作者：Shi, Ning

通信作者：Shi, N[1];Shi, N[2];Shi, N[3]

机构：[1]Guizhou Inst Technol, Sch Chem Engn, Guiyang 550003, Guizhou, Peoples R China;[2]Chinese Acad Sci, Guangzhou Inst Energy Convers, Guangzhou 510640, Guangdong, Peoples R China;[3]Guangdong Prov Key Lab New & Renewable Energy Res, Guangzhou 510640, Guangdong, Peoples R China

第一机构：贵州理工学院化学工程学院

通信机构：corresponding author), Guizhou Inst Technol, Sch Chem Engn, Guiyang 550003, Guizhou, Peoples R China;corresponding author), Chinese Acad Sci, Guangzhou Inst Energy Convers, Guangzhou 510640, Guangdong, Peoples R China;corresponding author), Guangdong Prov Key Lab New & Renewable Energy Res, Guangzhou 510640, Guangdong, Peoples R China.|贵州理工学院化学工程学院;贵州理工学院;

年份：2019

卷号：33

期号：10

起止页码：9904-9915

外文期刊名：ENERGY & FUELS

收录：;EI(收录号：20194007494065);Scopus(收录号：2-s2.0-85072804963);WOS:【SCI-EXPANDED(收录号:WOS:000492113000047)】；

基金：This research received support from the Academic New Seedling Plan Project of Guizhou Institute of Technology (Qjan Ke He [2017]5789-08), the National Natural Science Foundation of China (51576199), and the Natural Science Foundation of Guangdong Province (2017A030308010).

语种：英文

外文关键词：Aldehydes - Aliphatic hydrocarbons - Byproducts - Carbohydrates - Carbonization - Condensation - Condensation reactions - Ketones - Organic solvents

摘要：Hydrochars are solid byproducts formed during the liquid-phase biorefinery process and could be used to generate functional carbonaceous materials, but the detailed molecular structure and the formation mechanism are still unclear. Herein, the formation of hydrochars from liquid-phase carbonization of biomass-derived compounds including glucose, fructose, xylose, ribose, dihydroxyacetone (DHA), 5-hydroxymethylfurfural (HMF), furfural (FF), and pyruvaldehyde (PRV) in water and inert polar organic solvents ethyl acetate (EAC) and tetrahydrofuran (THF) was studied. The carbohydrates were found to generate hydrochars in both water and the organic solvents, while the HMF and FF could generate hydrochars only in water. The a-carbonyl aldehydes, including PRV, 3-deoxyglucosone, and 2,5-dioxo-6-hydroxyhexanal (DHH), formed during the decomposition of carbohydrates were proposed to be the key primary precursors for hydrochar formation. The molecular structures of the hydrochars were characterized by elemental analysis, Fourier transform infrared analysis, and solid-state C-13 NMR analysis to confirm that the molecular formula of the hydrochars all could be approximately expressed as (C3H2O)(n), and the molecular structures of the hydrochars all consisted of polyaromatic hydrocarbon, phenolic, furanic, and aliphatic framents and a small amount of carbonyl/carboxyl groups. The presence of the polyaromatic hydrocarbon and phenolic fragments in the hydrochars suggested that aldol condensation played a critical role for hydrochar formation. By regarding the aldol condensation of alpha-carbonyl aldehydes as the initial step for hydrochar formation, we deduced the polymerization routes of these a-carbonyl aldehydes and found that the a-carbonyl aldehydes all could undergo aldol condensation followed by acetal cyclization and etherification to form polymers (C3H2O)(n) rich in furanic framework or undergo aldol condensation followed by a 1,2-hydride shift, intramolecular aldol condensation, and dehydration to generate polymers (C3H2O)(n) rich in the phenolic framework. One molecular structure containing polyaromatic hydrocarbon, phenolic, furanic, and aliphatic fragments is proposed for the hydrochars.