JAUE2022-041: Life Cycle Assessment of Influencing Factors in Reed Hydrochar Preparation

Abstract

Hydrothermal carbonization technology has attracted more and more attention due to its economic and environment-friendly application in the efficient conversion of biomass resources. In this study, hydrothermal carbonization of reed was conducted in a hydrothermal reactor under laboratory conditions. The factors that modulated the hydrochar yield and efficiency of methylene blue adsoption such as temperature, residence time, and solid-liquid ratio were investigated. Scanning electron microscopy and Fourier transform infrared spectroscopy were used to characterize the structure of reed hydrochar. The experimental results indicated that the order of the factors affecting hydrochar yield was as follows: residence time > maximum temperature > solid-liquid ratio. The order of factors that modulated adsorption was: solid-liquid ratio > maximum temperature > residence time. The optimum conditions for hydrochar production were reaction temperature at 260℃, a residence time of 2 h, and solid-liquid ratio of 1:10. The optimum conditions for methylene blue adsorption were reaction temperature at 260℃, residence time of 1 h, and a solid-liquid ratio of 1:10. Characterization analysis revealed a pore structure at the surface of the hydrochar comprising carbon microspheres and multilayer structure. The surface also had a high number of oxygen-containing functional groups. The environmental impact of the reed hydrochar preparation process was evaluated using the life cycle assessment approach. The SimaPro 9.2.0.2 software was used to model the environmental impact of the reed hydrochar production process for optimization of the production parameters from an ecological perspective.