Bioorganic activated carbon from cashew nut shells for H2 adsorption and H2/CO2, H2/CH4, CO2/CH4, H2/CO2/CH4 selectivity in industrial applications
Jarosław Serafin, Bartosz Dziejarski, Óscar Javier Fonseca-Bermúdez, Liliana Giraldo, Rocío Sierra, Marta Gil‐Bonillo, Ghulam Farid, Juan Carlos Moreno-Piraján
Abstract
This research explores the production of activated carbon (AC) from cashew nut shells using a potassium hydroxide (KOH) activation method, with a focus on its application in high-pressure gas adsorption. Among the synthesized samples, AC850 demonstrated the highest efficiency, displaying a specific surface area of 1972 m 2 /g and total and micropore volumes of 0.847 cm 3 /g and 0.724 cm 3 /g, respectively. The bioorganic activated carbon exhibited significant sorption capabilities for H 2 , with uptake values of 13.34 mmol/g (2.69 wt%) at 10 bar and 25 °C, and a H 2 /CH 4 selectivity range between 43.4 and 2.6. Calculations were also conducted for selectivity in a mixture of three gases (H 2 , CO 2 , and CH 4 ) in industrial settings. Advanced characterization methods such as N 2 /CO 2 adsorption isotherms, FT-IR, Raman spectroscopy, SEM, and TGA were employed to analyze the structural and chemical properties of the produced AC, including its functional groups and molecular structure. The research underscores the potential of utilizing agricultural waste, particularly cashew nut shells, to develop efficient materials for H 2 storage and purification. The high-pressure adsorption capability and eco-friendly nature of the manufactured activated carbon make it suitable for both environmental and industrial applications. • Activated carbon from cashew shells is explored for high-pressure H 2 adsorption. • A 1972 m 2 /g surface area is featured by AC850, excelling in H 2 sorption. • AC's structural, chemical traits are revealed, crucial for H 2 storage. • Exceptional H 2 sorption is demonstrated by the AC, with uptake reaching 13.34 mmol/g at 10 bar and 25 °C. • In industrial gas mixture separation, H 2 shows the highest selectivity, followed by CO 2 and CH 4 .