Accurate Study on the Supercritical Water Gasification of Black Liquor: an Experimental Campaign in Continuous Operation Mode

The scope of this work was to provide an assessment of weak black liquor conversion into bio-syngas by means of SCWG process. At this aim, a continuous fed system operating at 250 bar and in the temperature range 600-750°C has been used. These temperatures are higher than the usual temperature range of SCWG, which involves additional interest in the following result. The results showed that both hydrogen and methane concentration increases with temperature, reaching 42%vol/vol and 23%vol/vol at 750°C, respectively. As opposite, CO2 concentration decreased with temperature (from 43% to 34%). The carbon conversion efficiency (CCE) increased from 650°C to 700°C, showing a slight decrease at 750°C. As a consequence, the cold gas efficiency (CGE) reached the maximum value (57%) at 700°C. At these conditions, the lower heating value of the bio-syngas was 13 MJ/Nm3, this result raises the potential of this process for energy purposes. These results, obtained by means of