Conversion of brewed tea waste into hydrochar and activated carbon

Feasibility of hydrochar and activated carbon production from brewed tea waste was investigated in this study. Brewed tea waste was hydrothermally carbonised in subcritical water to obtain hydrochar as energy feedstock. Hydrothermal carbonisation experiments were performed at different process temperatures to determine its effect on fuel properties and combustion behaviour of resultant hydrochar. Increasing the process temperature yielded less amount of hydrochar. Higher calorific value and lower burnout temperature was observed for hydrochar. Hydrothermal carbonisation could remove only 25%-35% of initial ash in biomass and could not remove CaO in brewed tea waste. Hence, hydrochar had high slagging risk during combustion, which was only slightly lower than that of feedstock. On the other hand, hydrochar had lower fouling risk due to removal of K2O. ZnCl2 activation of hydrochar produced an activated carbon with high surface area and acceptable porosity

Conversion of poultry wastes into energy feedstocks

WOS: 000383827700058PubMed ID: 27440220In this study, conversion of wastes from poultry farming and industry into biochar and bio-oil via thermochemical processes was investigated. Fuel characteristics and chemical structure of biochars and bio-oils have been investigated using standard fuel analysis and spectroscopic methods. Biochars were produced from poultry litter through both hydrothermal carbonization (sub-critical water, 175-250 degrees C) and pyrolysis over a temperature range between 250 and 500 degrees C. In comparison to hydrothermal carbonization, pyrolysis at lower temperatures produced biochar with greater energy yield due to the higher mass yield. Biochars obtained by both processes were comparable to coal. Hydrothermal liquefaction of poultry meal at different temperatures (200-325 degrees C) was conducted and compared to optimize its process conditions. Higher temperatures favored the formation of bio-crude oil, with a maximum yield of 35 wt.% at 300 degrees C. The higher heating values of bio-oils showed that bio-oil could be a potential source of synthetic fuels. However, elemental analysis demonstrated the high nitrogen content of bio-oils. Therefore, bio-oils obtained from hydrothermal liquefaction of poultry meal should be upgraded for utilization as a transport and heating fuel. (C) 2016 Elsevier Ltd. All rights reserved.TUBITAK by National/International Research Projects Supporting Program [BIDEB 2209-A]We would like to thank TUBITAK for financial support by BIDEB 2209-A National/International Research Projects Supporting Program for University Students