Hydrothermal Carbonization of Ulva Lactuca (Chlorophyta) for Hydrochar Production

抄録

Hydrothermal carbonization is an environmentally benign approach to producing hydrochar from wet biomass owing to no need for a pre-drying process. This study aims to examine the effect of temperature and time on hydrochar characteristics from the hydrothermal carbonization of Ulva lactuca. The hydrothermal carbonization was performed using a batch reactor. The effect of temperature was performed at 180, 200, and 220 °C. Meanwhile, the holding times varied between 30, 60, and 90 min. The results showed that the hydrothermal process could significantly affect carbon and oxygen contents in macroalgae, but it was not the case for hydrogen, nitrogen, and sulfur content. It might be because the mild temperature condition of the hydrothermal process could not enhance the formation of the hydrogen, nitrogen, and nitrogen gas. The hydrothermal carbonization can increase the energy contents of U. lactuca by over 42%. The highest HHV of 21.07 MJ/kg was achieved at 220 °C which is comparable to typical low-ranked coals.