Green approach to production of porous char adsorbents via oxidative carbonization in fluidized catalyst bed

A green and energy-efficient technique for production of porous carbon-mineral chars from agricultural wastes (rice husk, wheat bran) and sedimentary carbonaceous feedstocks (high-ash peat, coal) was developed. It is based on partial combustion in fluidized bed of a deep oxidation catalyst at low temperatures (465 – 600$^\circ$C). This technique yields porous chars with an elevated mineral content that depends on a feedstock used, and gaseous products of complete oxidation. It was found that the obtained chars have developed porosity with BET specific surface area of ca. 50 – 170 m$^2$g$^{-1}$, pore volume of 0.05 – 0.17 ml $\cdot$ g$^{-1}$, and ash content of 16 – 79 wt.%. They were additionally characterized by TGA and FTIR. Their testing as adsorbents for heavy metal ions (by the example of Cu$^{2+}$) and organic dyes (by the example of methyl green) revealed that their adsorption capacities are comparable to those of chars produced by the conventional pyrolytic approaches.