Transforming Sugarcane Bagasse and Vinasse Wastes into Hydrochar in the Presence of Phosphoric Acid: An Evaluation of Nutrient Contents and Structural Properties
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Sugarcane bagasse and vinasse are wastes generated at large scales by the Brazilian sugarcane industry. Therefore, new waste treatment and management practices are essential for a sustainable industrial growth and here we purpose the hydrothermal carbonization (HTC) to converts wet biomass into carbon-based solids.
HTC of a mixture of sugarcane bagasse and vinasse was conducted at different temperatures, reaction times and phosphoric acid percentages. The chemical, structural and morphological properties of the hydrochars were evaluated by elemental analysis (CHNS), nutrient quantification (P, Ca, Mg, K), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM).
In the presence of phosphoric acid, the hydrochar yield increased as the ash content increased due to phosphate precipitates, as observed by XRD. The yield of the hydrochar decreased and the carbon and nitrogen content increased when the temperature increased from 180 to 230 °C. Hydrochars are amorphous and compositionally similar to lignites. The FTIR spectra showed bands at approximately 1700 and 1600 cm−1 in the hydrochar due to carboxylation and aromatization of the products, respectively. The presence of carboxylic acids is important due to their ability to interact with cations and hydrophilic molecules. Additionally, nutrients such as P, N, K, Ca, and Mg were concentrated in the hydrochar as inorganic phases.
HTC applied to sugarcane bagasse and vinasse wastes produces hydrochars primarily containing carbon, nitrogen, and other nutrients as inorganic phases. Hydrochars could potentially be used as an agricultural fertilizer.
KeywordsHydrothermal carbonization Sugarcane bagasse Vinasse Phosphoric acid
The authors are grateful to Central Analítica – UFC/CT–INFRA/MCTI–SISNANO/Pro-Equipamentos CAPES for providing the scanning electron microscopes and the Laboratório de Sucroquímica e Química Analítica – UNESP/IBILCE for providing the infrared spectrometer. O. P. F and M. C. B. also acknowledge support from CNPq (Grants 478743/2013-0 and 445487/2014-3) and FUNCAP (PRONEX PR2-0101-00006.01.00/15). We also appreciate the financial support and scholarship from FAPESP (Grants 2013/21776-7 and 2014/22400-3).
- 3.Rolim, M.M., Lyra, M.R.C.C., Duarte, A.S., Medeiros, P.R.F., Silva, E.F.F., Pedrosa, E.M.R.: Influência de uma lagoa de distribuição de vinhaça na qualidade da água. Revista Ambiente Água 8, 155–171 (2013)Google Scholar
- 5.Libra, J.A., Ro, K.S., Kammann, C., Funke, A., Berge, N.D., Neubauer, Y., Titirici, M.M., Fuhner, C., Bens, O., Kern, J.: Hydrothermal carbonization of biomass residuals: a comparative review of the chemistry, processes and applications of wet and dry pyrolysis. Biofuels 2(1), 89–124 (2011)CrossRefGoogle Scholar
- 8.Xue, Y., Gao, B., Yao, Y., Inyang, M., Zhang, M., Zimmerman, A., Ro, K.: Hydrogen peroxide modification enhances the ability of biochar (hydrochar) produced from hydrothermal carbonization of peanut hull to remove aqueous heavy metals: Batch and column tests. Chem. Eng. J. 200, 673–680 (2012)CrossRefGoogle Scholar
- 16.ASTM: Standard Test Method for Chemical Analysis of Wood Charcoal. Method D1762-84. ASTM International, Pennsylvania (2013)Google Scholar
- 17.EPA: Soil and waste pH. Method 9045D. Environmental Protection Agency, Washington, DC (2004)Google Scholar
- 21.EPA: Acid Digestion of Sediments, Sludges and Soils. Method 3050B. Environmental Protection Agency, Washington, DC (1996)Google Scholar
- 22.APHA: Standard Methods for the Examination of Water and Wastewater, 21st edn. American Public Health Association, American Water Works Association, Water Environment Federation, Washington, DC (2005)Google Scholar
- 33.van Krevelen, D.W.: Coal: Typology–Physics–Chemistry–Constitution. Elsevier, Amsterdam (1993)Google Scholar
- 41.Nakamoto, K.: Infrared and Raman Spectra of Inorganic and Coordination Compounds. John Wiley & Sons, Hoboken (2009)Google Scholar