Contributions of hemicellulose, cellulose and lignin to the mass and the porous properties of chars and steam activated carbons from various lignocellulosic precursors

Abstract

a b s t r a c tIn this study, contributions of hemicellulose, cellulose and lignin to the mass and the porous properties of chars and activated carbons from various lignocellulosic materials were studied. A predictive calculation was established using the experimental results obtained for the three components separately to evaluate the carbonization and activation yields and their respective contributions to the chars and to the subsequent activated carbons of various precursors in term of weight fraction. These equations were validated. The results showed that lignin can be considering as being the major contributor of all chars and activated carbons. Besides, the evolution of the mean pore size versus the specific porous volume showed that each component contributes to the porosity of chars and activated carbons whatever is its weight contribution.

Bioprocesses for biofuels: an overview of the Brazilian case

“…The plant cell wall is composed mainly by polymers as cellulose, lignin, and hemicellulose. In general, cellulose polymer is the most abundant, representing from 34% to 50% of dry weight, followed by hemicellulose (19% to 34%) and lignin (11% to 30%) [22]. The proportion of each polymer in lignocellulosic biomass varies considerably among plant species as well as within the same species, being dependent on the tissue type, environmental factors, and developmental stage [23].…”

Microwave-assisted pretreatment technologies for the conversion of lignocellulosic biomass to sugars and ethanol: a review

“…Because of the rich carbon content of lignin, lignocellulosic biomass is a better choice to be used as precursor for producing activated carbon [4]. Activated carbon derived from lignocellulosic biomass is widely used for waste water treatment, air pollution treatment, chemical processes, and adsorption of volatile organic compounds [5]. Activated carbon is a well-known adsorbent due to its unique and versatile properties, namely high surface area, microporous structure, and favorable pore size, which allow access of gases/liquids into the internal pore surface and a high degree of surface reactivity [6].…”

Influence of thermal treatment conditions on efficiency of PFA/MCM-48 composite and CMK-1 carbon replica in adsorption of volatile organic compounds

“…uniform composition, high carbon yield and low ash content) compared to the ACs prepared from the natural feedstock [12,13]. During the production of ACs, carbonization of a raw material, performed in the temperature range of 600-900°C under an inert atmosphere, is often followed by physical activation (for example, treatment with steam or CO 2 ) and/or chemical activation (for example, reaction with KOH, ZnCl 2 or H 3 PO 4 ), resulting in a development of surface area and pore volume of formed ACs as well as changes in their surface composition [14][15][16][17][18][19][20]. A majority of ACs is microporous solids with very narrow channels, which can cause diffusion limitations restricting an access to inner adsorption centres and making ACs unregenerable [21][22][23][24].…”