Main content area

Meso/Macroporous Silica from Miscanthus, Cereal Remnant Pellets, and Wheat Straw

Ahmad Alyosef, Hallah, Schneider, Denise, Wassersleben, Susan, Roggendorf, Hans, Weiß, Michael, Eilert, André, Denecke, Reinhard, Hartmann, Ingo, Enke, Dirk
ACS sustainable chemistry 2015 v.3 no.9 pp. 2012-2021
Miscanthus, X-radiation, X-ray diffraction, adsorption, agricultural wastes, biomass, carbon, combustion, drying, energy crops, fluorescence, furnaces, heat treatment, macropores, mercury, microstructure, nitrogen, organic compounds, pellets, porous media, scanning electron microscopy, silica, sulfuric acid, temperature, thermal analysis, washing, wheat straw
In the present study, the possibility of extracting biogenic silica from various European biomass materials was investigated. High-purity biogenic silica (>90 wt % SiO₂) was obtained from energy crops (miscanthus), agro wastes (wheat straw), and other crop residues (cereal remnant pellets). Three different morphological forms of biogenic silica materials (ash) were obtained by a thermo-chemical treatment of these biomass sources. The wet biomass materials were leached using 5 M sulfuric acid for a defined period of time. After washing and drying the biomass materials, the leached samples were subjected to a heat treatment in a furnace with three sequential temperatures and time stages to determine the minimum combustion temperature of the organic compounds in the biomass materials. The final products were characterized by X-ray diffraction, X-ray fluorescence, carbon content analysis, differential thermal analysis, low temperature nitrogen adsorption, mercury intrusion porosimetry, and scanning electron microscopy. The obtained silica materials had a microstructure composed of accessible, interconnected, and intraparticle meso- and macropores with sizes ranging from 3 to 1500 nm.