Impact of pyrolysis heating methods on biochars with enhanced CO2/N2 separation and their incorporation in 3D-printed composites

resumo

N-doped biochars, derived from chitosan sourced from waste crustaceous shells, were produced via microwave- assisted pyrolysis at temperatures ranging from 400 to 800 degrees C to enhance CO2 2 and N2 2 separation. Their performance was compared with biochars from conventional pyrolysis. Microwave-derived biochars exhibited superior CO2 2 adsorption capacity at 25 degrees C and 100 kPa (0.78 - 1.56 mmol g- 1 ) compared to conventionally produced ones (0.55 - 1.43 mmol g-- 1 ). Increasing the pyrolysis temperature up to 600 degrees C significantly improved biochar properties, including surface area, pore volume, and CO2 2 adsorption capacity. Microwave-derived biochar featured enhanced surface area, larger pore volumes, and unique morphologies, requiring, on average, 61 % less preparation time. The higher ultramicroporosity and N-species concentration correlated with superior performance in the biochar produced at 600 degrees C. In gas mixture experiments (20 % CO2 2 and 80 % N2) 2 ) under flow conditions, these biochars showed rapid adsorption/desorption rates due to enhanced macroporosity at samples produced at 600 and 800 degrees C, facilitating gas diffusion along the ultramicropores. Adsorption heat analysis indicated that the CO2 2 adsorption is predominantly driven by physisorption, supported by complete sample regeneration when applying N2 2 flux or increasing the temperature during desorption. The study also explores the feasibility of 3D-printing a composite using the most effective biochar and inorganic polymers sourced from waste, presenting potential benefits for industrial applications.

palavras-chave

PORE-SIZE CHARACTERIZATION; CARBON-DIOXIDE CAPTURE; MICROPOROUS ADSORBENTS; MICROWAVE PYROLYSIS; SLOW PYROLYSIS; ADSORPTION; ISOTHERMS; BIOMASS; PHASE

categoria

Engineering

autores

Correia, I; Ilkaeva, M; Castellino, M; Bocchini, S; Novais, RM; Mafra, L; Gonçalves, NPF; Lourenço, MAO

Grupos

G1 - Materiais Porosos e Nanossistemas
G4 - Materiais Renováveis e Economia Circular

Projectos

CICECO - Aveiro Institute of Materials (UIDB/50011/2020)

CICECO - Aveiro Institute of Materials (UIDP/50011/2020)

Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)

Unveiling CO2 chemisorption mechanisms in solid adsorbents via surface-enhanced ex(in)-situ NMR (NMR4CO2)

3D Printed Fouling-Resistant Photoactive Membranes for Wastewater Treatment (PURAQUA)

Rationale design of sustainable porous organosilicas for optimal CO2 uptake from biogas (GRACE)

Multifunctional bAuXite Inorganic polyMers for acid mine drainage treatment from PortUguese Mines (MAXIMUM)

agradecimentos

This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020 (DOI 10.54499/UIDB/50011/2020) , UIDP/50011/2020 (DOI 10.54499/UIDP/50011/2020) & LA/P/0006/2020 (DOI 10.54499/LA/P/0006/2020) , financed by national funds through the FCT/MCTES (PIDDAC) . This work has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 Research and Innovation Program (Grant Agreement 865974) . FCT is also acknowledged by M.I. and M.A. O.L. for Researcher positions (CEECIND/00546/2018 and CEECIND/01158/2021 (DOI: 10.54499/2021.01158.CEECIND/CP1659/CT0022) , respectively) . M.I. also acknowledges the Spanish Ministry of Science, Innovation and Universities for the "Beatriz Galindo" Scholarship (MU-23-BG22/00145) . N.G. and M.A.O.L acknowledge the funding from the European Union's Horizon Europe research and innovation program under the Marie Sklodowska-Curie Actions PF grant agreement No 101065059 and ERA-PF grant agreement No 101090287. R.N. would like to thank FCT project MAXIMUM (PTDC-CTM-CTM-2205-2020, DOI 10.54499/PTDC/CTM-CTM/2205/2020) .