This study aims to investigate the energetic behavior as well as the behavior of formed gases, taking into account the inorganic content in the supercritical water gasification (SCWG) of microalgae for different process conditions. Two different salt separation cases and different process conditions including varying inorganic content of microalgae have been studied. In addition, the behavior of inorganic elements has been investigated by means of phase partitioning and compound formation in different process equipment of a conceptual SCWG plant. The results show that the process is thermally more efficient when the reactor temperature is lower and when the dry microalgae concentration in the feed is higher. The increase in the mass fraction of the inorganic content of microalgae enhances the formation of CH4 and H2 and decreases the thermal energy requirement of the reactor.