A Simple Method to Synthesize Novel Mesoporous Carbon–silica Composites from the By-product of Ethanol Production

Carbon-silica composites with mesoporous structures were synthesized from low-cost materials by conventional heating. The carbon source used was vinasse, a by-product of ethanol production molasses, while Na2SiO3 and K2SiO3 utilized as low cost abundantly available silica sources alternatives to tetraethyl orthosilicate (TEOS). simple preparation method adopted follows: vinasse dehydrated 50% H2SO4 (1:2 in weight ratio) produce carbon, after which the added ratio vinasse:silica 0.8:1, 0.2:1 0.5:1 for Na2SiO3, TEOS, respectively. mixture stirred heated at 80 °C 6 h, washed water, dried 120 3 h obtain carbon-silica composites. Composites characterized N2 adsorption-desorption, Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), moisture content, ash slurry pH, point zero charge (pHPZC) bulk density. exhibited BET (Brunauer–Emmett–Teller) surface areas 443, 354 570 m2/g average pore diameters 5.20, 5.52 7.63 nm when using respectively, sources. highly mesoporous, accounting around 71-80% total volume. FTIR showed presence Si–O–Si bond all According TGA results, adsorbents thermally stable up 700 °C. pH pHPZC each composite very similar acidic character (slurry 2.63–6.80 2.95–7.00). density 560–660 kg/m3, higher than some commercial activated carbons. These results indicated that prepared promising functional use potential adsorbents.