Effect of Formaldehyde to Phenol Ratio in Phenolic Beads on Pore Structure, Adsorption and Mechanical Properties of Activated Carbon Spheres

Arjun Singh; Sanjeevan Aggrawal; Darshan Lal

doi:10.14429/dsj.69.12821

Arjun Singh Terminal Ballistics Research Laboratory, Chandigarh, DRDO Chandigarh
Sanjeevan Aggrawal DRDO-Defence Materials and Stores Research and Development Establishment, Kanpur - 208 013, India
Darshan Lal DRDO-Defence Materials and Stores Research and Development Establishment, Kanpur - 208 013, India

DOI: https://doi.org/10.14429/dsj.69.12821

Keywords: Phenolic beads, activated carbon spheres, physical activation, mechanical, adsorption properties.

Abstract

Phenolic beads (PBs) prepared from different formaldehyde to phenol (F/P) molar ratios were used as polymeric precursor for activated carbon. Activated carbon spheres (ACSs) have been produced from PBs via the physical activation process using carbon dioxide (CO2) as activating agent at 950 °C for different burn-off. The prepared ACSs were investigated for nitrogen adsorption, surface morphology and compressive strength by means of BET surface area analyser, scanning electron microscopy (SEM) and carbon and sphere tester techniques. The results indicated that the effects of F/P ratio observed, especially variation in the adsorption and mechanical properties. It was found that ACSs obtained from F/P ratio one showed the superior adsorption properties, possessed a high BET surface area in a range of 836 m2 g-1 to 3694 m2 g-1 with high pore volume (0.47 cm3 g-1 - 2.47 cm3 g-1) and 73-97 per cent microporosity. The BET surface area and pore volume increased, while the microporosity gradually decreased, with increasing the extent of burn-off. Compressive strength decreased with increasing F/P ratio as well as the extent of burn-off. ACSs upheld improved compressive strength (from 160 N mm-2 to 9 N mm-2) than those obtained from F/P ratio 2 and 3 in PBs. SEM studies of ACSs demonstrated well developed pore structure.

Author Biographies

Arjun Singh, Terminal Ballistics Research Laboratory, Chandigarh, DRDO Chandigarh

Dr Arjun Singh received his PhD in Chemistry from Panjab university, Chandigarh. Presently, he is working as Scientist in DRDO-Terminal Ballistics Research laboratory, Chandigarh. he has research experience in fluoropolymer, phenolic resins, activated carbon, high energetic materials, synthesis of energetic composite, etc.
In the current study, he designed the experiments and contributed by preparation of ACSs and evaluation of compressive strength. he had also interpreted of adsorption data and drafted the manuscript.

Sanjeevan Aggrawal, DRDO-Defence Materials and Stores Research and Development Establishment, Kanpur - 208 013, India

Mr Sanjeevan K. Agrawal received his MSc in Chemistry and working as Technical Officer at the DRDO-Defence Materials & Stores and Research and Development Establishment, Kanpur. his areas of interest are scale of activated carbon spheres, characterisation of porous carbons and test methodologies for chemical protective suit.
In the present work, he contributed the characterisation of activated carbon spheres for adsorption properties by using surface area analyser.

Darshan Lal, DRDO-Defence Materials and Stores Research and Development Establishment, Kanpur - 208 013, India

Mr Darshan Lal received his BE (Chemical Engineering) and he is working as Scientist ‘F’ at the DRDO-Defence Materials and Stores Research and Development Establishment, Kanpur. his areas of research are scale up of activated carbon spheres, production of carbon materials, development of chemical protective suit and process development of activated carbons.
In the present study, he was involved in overall guidance, critical suggestions and approval of manuscript.

References

Reference:

Bansal R C, Donnet J B and Stoeckli H F 1988 Activated Carbon. New York: Marcel Dekker, 259-333.

Shi H 1996 Activated carbons and double-layer capacitance. Electrochimica Acta 41(10):1633-1639.

Liu X and Osaka T 1996 All-solid-state electric double-layer capacitor with isotropic high-density graphite electrode and polyethylene oxide/LiClO4 polymer electrolyte. J ElectrachemSoc 143 (12):3982-3986.

Kotz R and Carlen M 2000 Principles and applications of electrochemical capacitors. ElectrachimActa 45(15-16): 2483-2498.

Weng T C and Teng H 2000 Characterization of high porosity carbon electrodes derived from mesopore pitch for electric double layer capacitors. J ElectrochimSoc 148(40): 368-73.

Kan Y, Yue D, Wu Y and Gao B 2017 Preparation and characterization of activated carbons from waste tea by H3PO4 activation in different atmospheres for oxytetracycline removal. J Taiwan Inst. Chem. Eng. 71: 494-500.