Preparation and Phosphine Adsorption of Activated Carbon Prepared from Walnut Shells by KOH Chemical Activation

Abstract

Walnut-shell activated carbons (WSACs) with high surface area and predominant micropore development were prepared by KOH chemical activation. The effects of carbonization temperature, activation temperature, and ratio of KOH to chars on the pore development of WSACs and PH 3 adsorption performance of the modified walnut-shell activated carbons (MWSACs) were studied. Criteria for determining the optimum preparation conditions were pore development of WSACs and PH 3 breakthrough adsorption capacity of MWSAC adsorbents. The result shows that the optimum preparation conditions are a carbonization temperature of 700 • C, an activation temperature of 700 • C, and a mass ratio of 3. The BET surface area and the micropore volume of the optimal WASC are 1636m 2 /g and 0.641cm 3 /g, respectively. The micropore volume percentage of WSAC plays an important role in PH 3 adsorption when there is a slight difference in BET surface areas. High-surface-area WSACs with predominant micropores are suitable for PH 3 adsorption removal. The MWSAC adsorbent owns the biggest PH 3 breakthrough adsorption capacity (284.12mg/g) due to the biggest specific surface area, total pore volume, and micropore volume percentage. The MWSAC adsorbent will be a potential adsorbent for PH 3 adsorption removal from yellow phosphorus tail gas.

Physical and Chemical Properties of the Rice Straw Activated Carbon Produced from Carbonization and KOH Activation Processes

“…Biochar or charcoal are carbon-based materials produced by carbonization using heating process to increase carbon content of the starting material (Sumrit et al 2015). Charcoal can be produced from agriculture wastes such as paddy straw (Gao et al 2011), husk (Muniandy et al 2014), coconut waste (MohdIqbaldin et al 2013), peanut shell (Wu et al 2013), palm kernel shell (Rugayah et al 2014), walnut shell (Yu et al 2014), corn cob (Song et al 2013) and sugarcane (Srenscek-Nazzal et al 2013). Charcoal was the starting material to produce activated carbon (AC) which exhibits excellent absorption performance due to its high surface area, porosity and rich in active functional groups (Shamsuddin et al 2016).…”

Potassium hydroxide activation of activated carbon: a commentary

“…The mesoporous char-impregnated chemical activation is more favourable in the manufacture of activated carbon as compared to direct chemical activation. Pre-carbonization, executed in some studies [12,14], produces some advantages in the textural properties of the activated carbon, although KOH is a strong base which supports single step activation.…”

Recent advances in the use of walnut (Juglans regia L.) shell as a valuable plant-based bio-sorbent for the removal of hazardous materials

“…To study the adsorption of phosphine (PH 3 ), ACs were prepared from WS by the KOH and CA processes. 149 The adsorption of NH 3 -N in wastewater by MWS has also reported. An adsorbent was prepared by carbonizing WS using ZnCl 2 as the activating agent and was studied to its potential for liquid-phase adsorptive removal of NH 3 -N. 146 The removal of NO 3…”