Effect of the Carbonization and Activation Process on the Adsorption Capacity of Rice Husk Activated Carbon

Abstract

In this study, rice husk was used as a precursor to prepare activated carbon using steam as a physical activation agent. Steam can be used to activate for almost all raw materials. This activation method was followed of the initial carbonization step. The study also investigated the effects of preparation parameters on the adsorption capacity of iodine (I) and methylene blue (MB). These parameters included the range of temperature and time in the carbonization and activation. The initial carbonization, done at temperatures up to 500°C in 60 min., was a highly exothermic process where the temperature was strictly controlled. The creation of the internal surface was done during the activation step with steam at temperatures 800 °C in 30 min., for which the BET (Brunauer, Emmett and Teller) specific surface area was up to 710.8 m 2 /g. Besides, the I and MB adsorption capacity of the activated carbon were the best that reached 866.0 ± 6.5 and 217.9 ± 1.0 mg/g, respectively, while the I and MB adsorption capacity of carbonization step only reached 311.7 ± 3.4 and 28.7 ± 0.8 mg/g, respectively. The entire synthetic procedure was simple, environmental-friendly and economical-effectively. The application prospect of the activated carbon prepared in this work was much more promising due to its high adsorptive capacity.

Adaptive neuro‐fuzzy inference system modeling of 2,4‐dichlorophenol adsorption on wood‐based activated carbon

“…Porosity, pore structure, pore size distribution, and specific surface area are very important in explaining the relationship between the solution and AC during adsorption. The properties of WbAC, such as specific surface area, pore volume, and pore size distribution, depend on various parameters including the activation method and process parameters used in the carbonization and activation steps . In this study, physically activated WbAC was used; the carbonized biomass was treated with water (steam) activating agents.…”

“…The advantages of physical activation are essentially its low cost and greener process: the chemicals involved (CO 2 , water, or air) are readily available and the technology is relatively simple and scalable. An economic assessment—though not carried out in this study—should play a key role in the cost of the starting raw material (e.g., waste/residue) and the desired physical and chemical properties in the final product and in the selection of the activation method . Physical activation with steam is generally performed at temperatures ranging between 600 and 900°C at the heating rates of 5–25°C/min .…”

Effects of chemical activating agents on physical properties of activated carbons – a commentary

“…Carbonization is pyrolysis of the material at high temperature (500 to 1,000°C) in an inert atmosphere. The aim is to liberate tar, hydrocarbons and volatiles to enrich the carbon content, at the same time creating an initial char porosity (Ma et al 2017). Activation has significant effects on the AC matrix, especially in the formation of the pore structure, giving rise to a high specific surface.…”

Obtaining lignocellulosic biomass-based catalysts and their catalytic activity in cellobiose hydrolysis and acetic acid esterification reactions

“…Physical activation involves the prior carbonization of a raw material with its further activation. 25 The most used physical activating agents are superheated water vapour, CO 2 , and oxygen or air, or a combination of all these agents. As a result, the activated biochars can be further used in various applications, such as activated carbon, soil amendments, carbon sequestration agents, and environmental adsorbents.…”