Effect of hard and soft structure of different biomasses on the porosity development of activated carbon prepared under N2/microwave radiations. Issue 3 (September 2015)

• Record Type: Journal Article
• Authors: Mechati, Fedia; Bouchelta, Chafia; Medjram, Mohamed Salah; Benrabaa, Rafik; Ammouchi, Nesrine
• Is Part Of: Journal of environmental chemical engineering. Volume 3:Issue 3(2015:Sep.)
• Page Start: 1928
• Page End: 1938
• Publication Date: 2015-09
• Subjects: Activated carbon -- Microwaves activation -- Pyrolysis -- Hard vegetables wastes -- Soft vegetables wastes -- Adsorption -- Methylene blue; Chemical engineering -- Environmental aspects -- Periodicals; Environmental engineering -- Periodicals; Chemical engineering -- Environmental aspects; Environmental engineering; Periodicals; 660.0286
• DOI: 10.1016/j.jece.2015.07.007
• Languages: English
• ISSNs: 2213-2929

Abstract

Graphical abstract: Highlights: MW reduce time activation until 6 min instead of 4 h in the conventional activation. Also, energy is saved because activation time is reduced. Hard ACs have a best porous structure than the soft one. Best adsorption capacities of hard ACs from MB than the soft one. Abstract: In this work, we have prepared different activated carbons with high adsorbing capacity, first from hard precursors as apricot and peach stones and secondly from soft precursors as peel orange and grape stalk. The vegetables wastes were chemically treated with sulfuric acid, pyrolyzed under nitrogen flow, and activated in microwave apparatus under nitrogen flow in various operating conditions. The obtained activated carbons were characterized by different methods, thermogravimetric analysis (TGA), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and nitrogen adsorption (BET). The prepared materials have been evaluated as an adsorbents for methylene blue removal from aqueous solutions. The results show that the hard materials have better porous structure than the soft one ( S BET 529 and 518 m 2 /g, total pore volume 0.26 and 0.25 cm 3 /g and microporous volume of 0.19 and 0.20 cm 3 /g for apricot and peach stones, respectively). The use of microwave as an activation method has considerably reduced the consumed energy and activation time compared with the conventional method. In fact, the optimum microwave powers vary from 400 to 650 W, and radiations time from 3 to 6 min. The isotherm data could be well described by Langmuir equation.