Study of Activated Carbons by Pyrolysis of Mangifera Indica Seed (Mango) in Presence of Sodium and Potassium Hydroxide

J C Moreno-Piraján,L Giraldo

doi:10.1155/2012/909747

Abstract

Activated carbons (ACs) were prepared by pyrolysis of seeds mango in presence of sodium and potassium hydroxide (chemical activities). Seeds mango from Colombian Mango cultives were impregnated with aqueous solutions of NaOH and KOH following a variant of the incipient wetness method. Different concentrations were used to produce impregnation ratios of 3:1 (weight terms). Activation was carried out under argon flow by heating to 823 K with 1 h soaking time. The porous texture of the obtained ACs was characterized by physical adsorptions of N2at 77 K and CO2at 273 K. The impregnation ration and hydroxide type had a strong influence on the pore structure of these ACs, which could be easily controlled by simply varying the proportion of the hydroxides used in the activation. Thus, the development of porosity for precursors with low structural order (high reactivity) is better with NaOH than KOH, whereas the opposite is observed for the highly ordered ones. Variable adsorption capacities and porosity distributions can be achieved depending on the activating agent selected. In general, KOH produces activated carbons with narrower micropore distributions than those prepared by NaOH.

Highlights

Chemical activation is one of the possible methods to produce activated carbons (ACs)[1,2,3,4,5,6]
The chemical activation usually takes place at a temperature lower than that used in physical activation, it can improve the pore development in the carbon structure because the effect of chemicals
The isotherms are type Ia for the AC activated with potassium hydroxide, CMK92316 with a small development of mesopores, and type Ib for CMK112316

Summary

Introduction

Chemical activation is one of the possible methods to produce activated carbons (ACs)[1,2,3,4,5,6]. We report on the porous texture characteristics of ACs prepared by NaOH and KOH activation of seeds mango. We will show that carbon adsorbents with high surface areas and pore volumes can be obtained from this material, and that development of the porous structure can be modulated by of the hydroxides type use in the activation chemical.

Results

Conclusion