Abstract
Waste seaweed that is collected at coastal regions of maritime provinces in Canada is creating ecological problems as it promotes an anoxic event, which produces nearly zero dissolved oxygen in water along with hydrogen sulfide emission. The work done in this study attempts to address this issue by producing a coal-like solid hydrochar and nutritious liquid slurry (processed water) by employing a rather recent thermo-chemical process called hydrothermal carbonization (HTC) on the seaweed. The HTC was carried out in a batch reactor system for three different reaction temperatures, 180 °C, 200 °C, 220 °C, and three different reaction times, 30, 60, and 120 min. Each of the produced hydrochars was characterized by different analytical methods. The effects of the process conditions on the yield and the properties of the hydrochar and process water were examined. The hydrochar produced at 220 °C and 120 min showed the highest carbon content (48.5%) and heating value (18.93 MJ/kg). The energy density and carbon to nitrogen (C/N) ratio in the hydrochar increased significantly as compared to raw seaweed. Moreover, HTC reduced the ash yield and volatile compounds of the seaweed. Thus, hydrochar can be used as a fuel for direct combustion, in soil remediation, or in carbon sequestration applications.
Highlights
Biomass is a collective term to describe organic materials from plants or animals, and their derived wastes [1,2,3]
The maximum heating value of 18.93 MJ/kg was obtained for the hydrochar produced at a reaction temperature of 220 ◦C and a reaction time of 120 min
Atomic ratios (H/C and oxygen to carbon (O/C)) for hydrochar decreased with increasing reaction conditions
Summary
Biomass is a collective term to describe organic materials from plants or animals, and their derived wastes [1,2,3]. The higher carbon content, heating value, and energy density and the lower inorganic matter, improved hydrophobicity, and modified microcrystalline structure and morphology as compared to raw biomass could lead to the broad application of hydrochar in various fields, including the energy, catalyst, adsorbent, and medical fields [8,22,23]. Heidari et al [11] summarized the challenges in the development of HTC, which include limited knowledge of the reaction kinetics of the HTC process, finding applications for process water along with hydrochar, and continuous feeding of biomass against high pressure. The Chief Administrative Officer (CAO) of Summerside stated about this waste seaweed that “It is a bio-resource, and there is a potential we hope for energy production, biofuel, value-added products, nutraceuticals, other forms of fertilizers or chemicals” [38]. The value-added product could substitute petroleum-based fuels and/or materials and support the development of a bioeconomy [39]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
