Fuel potential and properties of grape pomace hydrochar

Abstract

Increasing fossil fuel depletion that leads to air pollution and global warming have become serious environmental problem. For this reason, a numerous of alternative biofuels have been developed and investigated as potential energy sources to substitute them. One of promising and highly effective technology for conversion of wet and waste biomass into multi-functional materials is a hydrothermal carbonization. In this study grape pomace was hydrothermally carbonized at different temperatures (180, 200 and 220 °C). Produced hydrochars were characterized in order to investigate its potential application as an alternative and energy-efficient renewable fuels. The carbon, fixed carbon, sulphur and volatile matter contents were determined in all hydrochar samples. Obtained results showed that temperatures play significant role on the structural characteristics of produced materials. As expected, the carbon content and fixed carbon content in hydrochars were increased with temperature increasing. Higher yields of carbon and fixed carbon observed in hydrochars indicated that intensive carbonization of biomass occurred. On the contrary, sulphur and volatile matter content were decreased. Observed reduction may be a result of dehydration and decarboxylation of grape pomace during hydrothermal treatment. These reductions are highly beneficial and improve the efficiency of solids’ direct combustion. Decreased volatile matter content can potentially reduce the release of inorganic vapours and pollutant emission during combustion, while decreased sulphur content preventing generation and emission of harmful sulphur oxides, SOx, compared to the parent biomass. The present study showed that hydrothermal carbonization mproved fuel qualities and potential of grape pomace hydrochars among different reaction temperatures.