Preparation of KOH and Steam Two-step Activated Carbons from Coconut Shell Char and Their Adsorption Properties

Sakazaki, Taiga; Yoshimura, Kazuhiro; Machida, Motoi

doi:10.2488/jwrs.56.251

Cited by 4 publications

(3 citation statements)

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“…The specific surface area initially rapidly increased with the increase in KOH solution concentration and increased more slowly roughly after the concentration exceeded 2 M. It reached 2549 m 2 /g at a concentration of 4.5 M. The mechanism of reaction of activation with KOH has been explained in several different ways by various researchers [14][15][16][17][18] . Using common factors presented in all their articles, Sakazaki et al proposed the following reaction formulas [7] . Firstly, the following reaction (2) progresses at 630˚C and K 2 CO 3 is generated.…”

Section: Resultsmentioning

confidence: 99%

“…Of these, activation with KOH is attracting particular attention because of its effects of producing numerous micropores and of drastically increasing specific surface area [4][5][6] . It has also been reported that combined use of physical and chemical activation can contribute to further increases in specific surface area and to controlling pore size [7] . While many other reports on activation treatment methods have been published, there are only a limited number of reports on the activation of coffee grounds.…”

Section: Introductionmentioning

confidence: 99%

“…While many other reports on activation treatment methods have been published, there are only a limited number of reports on the activation of coffee grounds. Although KOH used for activation is strongly alkaline, in most of published papers, the amount of KOH used was 4 times as much as that of the material to be carbonized [7] . Using too much KOH can cause a number of problems such as increasing producing costs and corroding equipment.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Effects of Activation with CO<sub>2</sub>/KOH on the Pore Structures of Coffee Grounds-derived Carbon

Kikuchi

Yamashita

Sakuragawa

2012

Trans. Mat. Res. Soc. Japan

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In this study, coffee grounds were carbonized through activation with carbon dioxide (hereinafter referred to as CO 2 ) or potassium hydroxide (hereinafter referred to as KOH), and the effects of the respective activation conditions on the pore structures of the carbon obtained were investigated. The specific surface area of the sample carbonized in a CO 2 stream at 850˚C was 752 m 2 /g and that of the sample impregnated with KOH and carbonized was 2549 m 2 /g when the concentration of KOH was 4.5 M. In the sample carbonized in a CO 2 stream, the pores formed were 0.8, 1, and 3.1 nm in size, which were enlarged with the increase in treatment temperature and started to include numerous mesopores. In the sample impregnated with KOH and carbonized, the pores formed were 0.7 nm and 1 to 1.1 nm in size, which were slightly enlarged with the increase in concentration of KOH. It was confirmed that for coffee grounds, activation with KOH had an effect of increasing specific surface area and that CO 2 activation had an effect of increasing pore size.

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