Two-step hydrothermal conversion of biomass waste to humic acid using hydrochar as intermediate

作     者：Yuchao Shao Jun Zhao Yuyang Long Wenjing Lu Yuchao Shao;Jun Zhao;Yuyang Long;Wenjing Lu

作者机构：School of EnvironmentTsinghua UniversityBeijing 100084China Department of BiologyInstitute of Bioresource and AgricultureHong Kong Baptist UniversityHong Kong 999077China Zhejiang Provincial Key Laboratory of Solid Waste Treatment and RecyclingInstrumental Analysis CenterSchool of Environmental Science and EngineeringZhejiang Gongshang UniversityHangzhou 310012China 

出 版 物：《Frontiers of Environmental Science & Engineering》 (环境科学与工程前沿（英文）)

年 卷 期：2023年第17卷第10期

页      面：17-26页

核心收录：

学科分类：0710[理学-生物学] 081704[工学-应用化学] 07[理学] 08[工学] 0817[工学-化学工程与技术] 070303[理学-有机化学] 0703[理学-化学] 0836[工学-生物工程] 

基　　金：supported by the Key R&D Program of Ningxia Hui Autonomous Region(China)(No.2020BFG02001) The authors are thankful to Hong Kong Environment Conversion Fund(China)(No.46/2020) 

主　　题：Biowaste Hydrochar Humic acid Hydrothermal parameter Unsaturation 

摘      要：Converting biomass materials to humic acid is a sustainable method for humic acid production and achieve biomass valorization. A two-step hydrothermal treatment method was adopted in this study to produce humic acid from corn stalks. In the first step of the process, hydrochar was prepared at different hydrothermal temperatures and pH values. Their chemical properties were then analyzed, and the hydrochar-derived humic acids were produced under alkaline hydrothermal conditions (denoted as HHAalk). The hydrochar, prepared under high temperature (200 °C) and strong acidic (pH 0) conditions, achieved high HHAalk yields (i.e., 67.9 wt% and 68.8 wt% calculated based on weight of hydrochar). The sources of HHAalk formation were as follows: 1) production in the hydrochar preparation stage, and 2) increment under the alkaline hydrothermal treatment of hydrochar. The degree of hydrochar unsaturation was suggested as an indicator for evaluating the hydrochar humification potential under alkaline hydrothermal conditions. This study provides an important reference for the preparation of suitable hydrochar with high hydrothermal humification potential.