A one-step self-sustained low temperature carbonization of coconut shell biomass produced a high specific surface area biochar-derived nano-adsorbent

Abstract

A one-step self-sustained carbonization of coconut shell biomass, carried out in a brick reactor at a relatively low temperature of 300-500°C, successfully produced a biochar-derived adsorbent with 308 m 2 /g surface area, 2 nm pore diameter, and 0.15 cm 3 /g total pore volume. The coconut shell biochar qualifies as a nano-adsorbent, supported by scanning electron microscope images, which showed well-developed nano-pores on the surface of the biochar structure, even though there was no separate activation process. This is the first report whereby coconut shell can be converted to biochar-derived nano-adsorbent at a low carbonization temperature, without the need of the activation process. This is superior to previous reports on biochar produced from oil palm empty fruit bunch.

Surface Functionalization of Biochar from Oil Palm Empty Fruit Bunch through Hydrothermal Process

“…A large amount of biomass can be processed in one or two steps with a relatively high yield of 20-40% [1] and only be limited with the size of the reactor used. Reports have shown that a large variety of biomass from different sources such as soft/hardwoods [2], fibers [3], shells [4], and even byproducts of fermentation [5] and wastewater treatment processes [6] can be used as feedstock for biochar production. Biochar can be used in a variety of situations mainly in wastewater treatment [7] and soil conditioning [8] due to its inherent adsorptive capabilities.…”

Coconut shell and husk biochar: A review of production and activation technology, economic, financial aspect and application

“…In self-sustained carbonization, the carbonization temperature is maintained by itself while the combusting biomass is changed into biochar inside the reactor (Idris et al, 2015a(Idris et al, , 2015bSamsudin et al, 2019). Dried biomass is fed into a self-sustained carbonization reactor, which is primarily made of high-temperature resistance bricks.…”

“…Pyrolysis is widely used to produce coconut shell biochar ( Adorna et al, 2020 ; Baharum et al, 2020 ; Behera et al, 2020 ; Khuenkaeo and Tippayawong, 2020 ; Nuryana et al, 2020 ; Pituya et al, 2016 ; Sari et al, 2020 ; Windeatt et al, 2014 ), whereas gasification is an alternative technology used ( Atienza et al, 2020 ; Millán et al, 2021 ). Self-sustained carbonization is the most current method to produce coconut shell biochar ( Samsudin et al, 2019 ). As for coconut husk, by far, pyrolysis is the only technology selected for coconut husk biochar production ( Isidoria et al, 2018 ; Suman and Gautam, 2017 ; Windeatt et al, 2014 ).…”

“…Pyrolysis thermally degrades biomass at elevated temperature in an oxygen-free condition to produce biochar, bio-oil and synthetic gas ( Lee et al, 2019 ; Narzari et al, 2015 ), whereas gasification directly converts biomass into synthetic gas and yields a small amount of biochar ( Sikarwar and Zhao, 2017 ). Self-sustained carbonization involves the combustion of biomass while the carbonization temperature is sustained on its own during the biomass transformation into biochar ( Samsudin et al, 2019 ). Among these thermochemical processes, pyrolysis is reportedly having a lower biochar production cost (272 USD ton −1 ) in comparison to gasification (380 USD ton −1 ) ( Brown et al., 2011 ; Meyer et al., 2011 ).…”

A Review on the Application of Granular Filter Media and the Utilization of Agro-Industrial Wastes for Stormwater Quality Improvement

“…AC can be efficient through an activation with acid or heat control [89], affecting the lignin content and pore volume at a specific temperature [47]. Interestingly, a coconut shell with high SSA processed using only one-step low-temperature carbonization without activation was successfully experimented [90]. Another study demonstrated that biochar and activated biochar from coconut fibre is highly porous with micropores that aid the adsorbent [91].…”