Determination of combustion characteristics and kinetic parameters of Ulva lactuca and its biochar

Abstract

Utilization of macroalgae, which accumulated in the coastal area and considered as waste by municipals, for biofuel production is a good solution putting forward for both waste management and meeting the renewable energy requirement. This study aims to investigate the use of Ulva lactuca collected from the Marmara Sea coast as a raw material for solid biofuel production. Therefore, in this study, the combustion characteristics of Ulva lactuca and its biochar were investigated by the thermogravimetric method, and kinetic parameters were determined by using Kissinger-Akahira-Sunose (KAS) and Flynn-Wall-Ozawa (FWO) methods. When the obtained thermograms are examined, it was observed that the combustion of raw seaweed occurs in three phases, while the combustion of biochars occurs in two phases. As a result of the calculations, the combustion activation energies of macroalga and its biochar were found to be approximately 261 kJ/mol and 146 kJ/mol, respectively, using the KAS method. It was found that the values calculated using the FWO method were similar to the KAS method. These data show that biochar requires less energy than raw algae during combustion.