Production of Fuel and Magnetic Carbon from Food Industry Wastes by Hydrothermal Carbonization
Project no. 23688 · Status: Kapanmış (Yayın bekleniyor) · 2022
Summary
<p>In the first part of this study, the usage of potato peel, pomegranate, and grape pomace from food industry wastes as fuel was investigated. For this purpose, hydrothermal carbonization was performed for all biomasses at 200, 225 and 250 °C at different holding times such as 30, 60, 120 and 240 minutes and after hydrothermal carbonization (HTC) solid (hydrocar) and liquid products were obtained. The ash contents, volatile matter amounts, fixed carbon amounts, fuel ratios, elemental compositions, higher heating values, energy efficiencies, combustion and fuel properties, metal contents, slagging and fouling indices of the obtained hydrocars were determined by recent techniques, while the total phenolic amounts and antioxidant activities of the aqueous phases were found investigated by Folin-Ciocalteu and TEAC methods, respectively.</p><p>When the HTC results are examined, the hydrochar yields decreased with increasing temperature. This decrease is due to the degradation of macromolecules in the structure of biomass and their transformation into liquid and/or gaseous products. Similarly, ash contents, fixed carbon contents, fuel ratios are increased with increasing temperature for potato peels and grape pomace, but the ash fraction was decreased at the same time. For pomegranate pomace, an increase was observed in all above mentioned parameters with increasing HTC temperature. With the increase in HTC temperature and time, the higher heating values, energy density ratios and energy efficiency values were increased for all hydrocars. These increases were in parallel with the increase in carbon amounts in hydrochars.</p><p>To find the fuel properties of hydrocars, van Krevelen diagrams were drawn, and these diagrams showed that all hydrochars had a similar property to peat and lignite coal. The combustion behavior of hydrochars was investigated by heating up to 900 °C with 20 °C/min heating rate under the air atmosphere in TGA and it was observed that the combustion of all hydrochars took place in two main steps. The total amount of phenolic compounds in the aqueous phases obtained from HTC were decreased with increasing HTC temperature and time for all samples, while it was found that the antioxidant activities of aqueous phases firstly increased then decreased with increasing HTC temperature.</p><p>In the second part of the study, the magnetic properties of pomegranate pomace, hydrocarch obtained from hydrothermal carbonization of pomegranate pomace and biochar obtained from pyrolysis of pomegranate pomace were investigated. For this purpose, first of all, pomegranate pomace, hydrochar obtained from the hydrothermal carbonization of the pomegranate pomace, and biochar obtained from the pyrolysis of the pomegranate pomace were mixed with iron sources- iron (III) chloride, red mud which is the waste of aluminum production, and chemical sludge which is the waste of wastewater treatment plants in different proportions then heated. The heat treatments were carried out at different temperatures and under different atmospheres such as nitrogen, carbon dioxide and water vapor. The yields, ash and metal contents, functional group analyzes with FT-IR, surface areas and surface properties, XRD analyzes, VSM (Vibrating sample magnetometer) analyzes, and saturation magnetization properties of the obtained magnetic carbons were investigated. According to the characterization results, the highest surface area was 356.96 m2/g belonged to the magnetic carbon coded ANP-KÇ-CO2, while the highest saturation magnetization was observed with 7.58 emu/g value for the sample coded ANP-ERM-CO2 with.</p><p>The use of the obtained magnetic carbons as adsorbent in order to remove Cr(VI) ion in wastewater was also investigated. This process was carried out at different pH (2-6), different adsorbent amounts (0.5-5 g/L) and different waiting times (30-240 min) to investigate the optimum conditions. The optimum conditions were found as pH 2, adsorbent amount 2 g/L and 4 hours. When the adsorption isotherms were examined, it was observed that the isotherms were compatible with the Langmuir model.</p>