Costa, Joana R.Capeto, Ana PaulaPereira, Carla F.Pedrosa, Sílvia S.Mota, Inês F.Burgal, João da SilvaPintado, Ana I.Pintado, Manuela E.Oliveira, Catarina S. S.Costa, PatríciaMadureira, Ana Raquel2022-12-282022-12-282022-122079-4991http://hdl.handle.net/10400.14/39668Ashes from sugarcane by-product incineration were used to synthesize silica powders through alkaline hot extraction, followed by ethanol/acid precipitation or the sol–gel method. Both production methods allowed amorphous spherical silica microparticles with sizes ranging from 1–15 μm and 97% purity to be obtained. Water absorption ranged from 135–155 mL/100 g and 150–250 mL/100 g for precipitated silica and silica gel, respectively, while oil absorption ranged from 305 to 390 and from 250 to 350 mL/100 g. The precipitation with ethanol allowed the recovery of 178 g silica/kg ash, with a lab process cost of EUR 28.95/kg, while the sol-gel process showed a yield of 198 g silica/kg ash with a cost of EUR 10.89/kg. The experimental data suggest that ash from sugarcane by-products is a promising source to be converted into a competitive value-added product, minimizing the environmental impact of disposal problems.engAmorphous silicaCircular economyCosmetic ingredientProcess developmentSpherical microparticlesjournal article10.3390/nano1223420185143654406PMC973933136500824000896204900001