Textural Characteristics of Coconut Shell-Based Activated Carbons with Steam Activation

Abstract

Activated carbons were prepared from coconut shells by using carbonization at 600 °C for 2 h followed by water steam activation. Effects of activation temperature, hold time and water steam amount on the yield, BET surface area and micropore volume of activated carbons were evaluated. The pore structure of the activated carbon was characterized by N2 adsorption at 77K. Surface area, micropore volume and pore size distribution (PSD) of the carbons were determined by the Brunauer–Emmett–Teller (BET) equation, Dubinin–Astakhov (DA) and the Non-Local Density Functional Theory (NLDFT) methods, respectively. The results show that activated carbons with specific surface area of 1500 m2/g and pore size lower than 2 nm can be produced at 900 °C for 1~2 h. Hold time could be reduced by increasing steam amount and activation temperature, but micropore was enlarged and yield was decreased. Increasing hold time could produce more micropores when steam amount and activation temperature were more appropriate. Pore size distribution shows that activated carbons are microporous dominant.

A Review on the Transformation of Furfural Residue for Value-Added Products

“…Some strategies can reduce this negative effect. For example, the oxidation gas introduced into the thermal carbonization process can effectively remove the residual material and carry out selective oxidation on the highly reactive sites in the FR, which further expands the pore diameter of the carbon structure [83,84]. Microwave and other auxiliary means can also accelerate the internal thermal activation process of activated carbon, which effectively expands the carbonization aperture [85,86].…”

Screen printed carbon electrode from coconut shell char for lead ions detection

“…The activation of coconut shell char yielded 32.6 % of the initial weight. Degradation of cellulose, hemicellulose, lignin, and unstable components in coconut shells allowed the weight loss (Wang et al, 2013). During activation, cellulose, and hemicellulose decomposition occur, increasing carbon's porosity, enhancing the oxidizing agent's diffusion into particles, and oxidizing lignin within the char (Zhou et al, 2018).…”

Eliminating Luck and Chance in the Reactivation Process: A Systematic and Quantitative Study of the Thermal Reactivation of Activated Carbons

“…The addition of carbon dioxide leads to a pore opening at a later stage of the activation process, which involves widening of the narrow microporosity, whereas the addition of water vapor widens the microporosity from the early stage of the activation process [11]. Despite being widely considered one of the most efficient processes, thermal reactivation suffers from several drawbacks such as incomplete desorption or pyrolysis due to an insufficient reactivation temperature, overactivation, and/or mass loss (low yield) due to unfavorable conditions, an undesirable reduction in particle size, or fouling (blocking of the pores) [12][13][14]. Further, reactivation under non-optimized conditions leads to excess energy consumption, making the process economically and ecologically less efficient.…”