CO2 uptake by activated hydrochar derived from orange peel (Citrus reticulata): Influence of carbonization temperature

K R Deepak; Sooraj Mohan; P Dinesha; Rajasekhar Balasubramanian

doi:10.1016/j.jenvman.2023.118350

CO₂ uptake by activated hydrochar derived from orange peel (Citrus reticulata): Influence of carbonization temperature

J Environ Manage. 2023 Sep 15:342:118350. doi: 10.1016/j.jenvman.2023.118350. Epub 2023 Jun 9.

Authors

K R Deepak¹, Sooraj Mohan², P Dinesha³, Rajasekhar Balasubramanian⁴

Affiliations

¹ Department of Mechanical and Industrial Engineering, Manipal Institute of Technology, Manipal Academy of Higher Education, Manipal, 576104, India.
² Department of Mechanical Engineering, National Institute of Technology Goa, Farmagudi, Ponda, Goa, 403401, India.
³ Department of Mechanical and Industrial Engineering, Manipal Institute of Technology, Manipal Academy of Higher Education, Manipal, 576104, India. Electronic address: dinesha.p@manipal.edu.
⁴ Department of Civil and Environmental Engineering, College of Design and Engineering, National University of Singapore, 117576, Singapore.

PMID: 37302173
DOI: 10.1016/j.jenvman.2023.118350

Abstract

In this study, activated hydrochar was prepared from orange peel (OP) waste using KOH for the first time for potential environmental applications. The influence of hydrothermal carbonization temperature (180 °C, 200 °C, and 220 °C) on the CO₂ adsorption capacity of OP-derived activated hydrochar (OP-180, OP-200, and OP-220) was investigated. Scanning electron microscope (SEM) images revealed that the activated OP hydrochar has high microporosity, a desired attribute for effective adsorption. The yield and the oxygen content of the hydrochar decreased with the increasing process temperature whereas the carbon content showed an increase. Fourier-transform infrared spectroscopy showed the presence of various functional groups including ketone, aldehydes, esters, and carboxyl in the hydrochar. CO₂ adsorption isotherm was determined for all hydrochar samples. At 25 °C and 1 bar, OP-220 showed the highest CO₂ uptake at 3.045 mmol/g. The use of OP waste for CO₂ adsorption applications contributes to carbon neutrality and a circular economy.

Keywords: Activated carbon; Biomass; CO(2); Char; Climate action; Hydrothermal carbonization.

MeSH terms

Biomass
Carbon
Carbon Dioxide
Citrus sinensis*
Citrus*
Temperature

Substances

Carbon Dioxide
Carbon