Loading...
Optimization of hydrothermal carbonization of Rhizoclonium riparium macroalgae using response surface methodology for high-performance solid biofuel production
Author(s)
Chanpee, Sirayu
Jadsadajerm, Supachai
Manatura, Kanit
Wongrerkdee, Sutthipoj
Kaewtrakulchai, Napat
Date Issued
January 1, 2026
Type
Article
Abstract
Hydrothermal carbonization (HTC) was adopted as a promising approach for improving fuel quality for several high-moist biomass. In this study, the Rhizoclonium riparium macroalgae (RMA), an abundant marine alga in an aquaculture pond, was successfully converted into hydrochars as a sustainable solid biofuel. The Box Behnken design (BBD) was applied for the HTC experiment to investigate the individual and interactive effects of operating parameters, including HTC temperature, reaction time, and water ratio, on hydrochar physicochemical characteristics and fuel properties. The response surface optimization (RSM) revealed maximum mass yield (MY) of 79.1%, higher heating value (HHV) of 23.6 MJ/kg, and energy yield (EY) of 94.4%. The RSM-BBD of process parameters and their HTC effects showed that the decreasing MY and EY were significantly due to the HTC temperature and residence time. From ANOVA analysis, temperature, time, and water ratio were the most significant parameters responding to MY, HHV, and EY. The optimal conditions for hydrothermal carbonization (HTC) of RMA as a solid biofuel were determined to be a temperature of 200 °C, a duration of 2 h, and a water-to-biomass ratio of 1:1, producing the highest energy yield (EY) of 95.3%. Utilizing RSM-BBD to investigate HTC parameters for hydrochar production is a suitable effort for technical scalability.
Citation
Biomass Conversion and Biorefinery, 16(1), 2026