Analysis of the Structure and Slow-Release Performance of Seaweed Biochar Treated by Hydrothermal Carbonization Pretreatment Coupled with Medium–High Temperature Pyrolysis

作者：Jikai Lu, Bing Wang, Yifan Qiao, Kenji Ogino, Hongyu Si, Yan Li · 发表于：ACS Sustainable Chemistry & Engineering · 年份：2025 · DOI：10.1021/acssuschemeng.5c02279 · 被引用次数：6 · 研究领域：Catalysis and Hydrodesulfurization Studies、Thermochemical Biomass Conversion Processes、Adsorption and biosorption for pollutant removal

Seaweed biomass is a kind of marine waste carbon resource with rapid growth and rich elements, but the problem of high-water content makes seaweed face high energy consumption in the process of development and utilization. In this study, a new process of hydrothermal carbonization pretreatment coupled with medium–high temperature pyrolysis was proposed, in which seaweed biomass was preliminarily hydrolyzed by liquid bubble water. Cancel the filtration and drying of hydrothermal intermediate products, and complete pyrolysis in medium–high temperature anaerobic environment. The existence of moisture in hydrothermal intermediate products may promote the water–gas reaction during pyrolysis, resulting in the formation of hollow carbon spheres on the surface of biochar and their rupture into “gourd” pore structure (with small opening but large internal space). Compared to traditional pyrolytic biochar, the biochar produced in this study exhibits similar surface functional groups and atomic bonding states, along with a hierarchical porous structure featuring micropores, mesopores, and macropores. While retaining the basic structure and characteristics of traditional pyrolytic biochar, the slow-release amount of readily available nutrients was reduced by 2.76–45.65%, demonstrating improved slow-release performance. Additionally, the total energy consumption during production decreased by 6.18–6.25%, the overall yield increased by 2.19–2.35 times, and the energy cost per gram was redu...