Microwave assisted and conventional hydrothermal treatment of waste seaweed: Comparison of hydrochar properties and energy efficiency

Sepideh Soroush; Frederik Ronsse; Jihae Park; Stef Ghysels; Di Wu; Kyoung-Woong Kim; Philippe M Heynderickx

doi:10.1016/j.scitotenv.2023.163193

Microwave assisted and conventional hydrothermal treatment of waste seaweed: Comparison of hydrochar properties and energy efficiency

Sci Total Environ. 2023 Jun 20:878:163193. doi: 10.1016/j.scitotenv.2023.163193. Epub 2023 Mar 31.

Authors

Sepideh Soroush¹, Frederik Ronsse², Jihae Park³, Stef Ghysels², Di Wu¹, Kyoung-Woong Kim⁴, Philippe M Heynderickx⁵

Affiliations

¹ Centre for Environmental and Energy Research (CEER)-Engineering of Materials via Catalysis and Characterization, Ghent University Global Campus, 119-5 Songdomunhwa-Ro, Yeonsu-Gu, Incheon 406-840, South Korea; Department of Green Chemistry and Technology, Faculty of Bioscience Engineering, Ghent University, 653 Coupure Links, Ghent B-9000, Belgium.
² Department of Green Chemistry and Technology, Faculty of Bioscience Engineering, Ghent University, 653 Coupure Links, Ghent B-9000, Belgium.
³ Lab of Plant Growth Analysis, Ghent University Global Campus, 119-5 Songdomunhwa-Ro, Yeonsu-Gu, Incheon 406-840, South Korea.
⁴ School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, South Korea.
⁵ Centre for Environmental and Energy Research (CEER)-Engineering of Materials via Catalysis and Characterization, Ghent University Global Campus, 119-5 Songdomunhwa-Ro, Yeonsu-Gu, Incheon 406-840, South Korea; Department of Green Chemistry and Technology, Faculty of Bioscience Engineering, Ghent University, 653 Coupure Links, Ghent B-9000, Belgium. Electronic address: Philippe.Heynderickx@Ghent.ac.kr.

PMID: 37003343
DOI: 10.1016/j.scitotenv.2023.163193

Abstract

Waste seaweed is a valuable source for converting into value-added carbon materials. In this study, the production of hydrochar from waste seaweed was optimized for hydrothermal carbonization in a microwave process. The produced hydrochar was compared with hydrochar synthesized by the regular process using a conventional heating oven. The results show that hydrochar produced with a holding time of 1 h by microwave heating has similar properties to the hydrochar produced in a conventionally heated oven for 4 h (200 °C and water/biomass ratio 5): carbon mass fraction (52.4 ± 3.9 %), methylene blue adsorption capacity (40.2 ± 0.2 mg g^-1) and similar observations on surface functional groups and thermal stability were made between hydrochars produced by both methods. The analysis of energy consumption showed microwave assisted carbonization consume higher energy in compare to conventional oven. The present results suggest that hydrochar made from waste seaweed and using the microwave technique could be an energy-saving technology for producing hydrochar with similar specifications to hydrochar produced by conventional heating methods.

Keywords: Biomass; Hydrochar; Microwave; Waste seaweed.