In recent years,more and more attention has been paid to the hydrothermal carbonization(HTC)of biomass,due to the rising energy crisis combined with growing environment concerns.Hydrochar is a solid residue from HTC of biomass and has abundant carbon content.However,a post-activation step is required for a high performance porous carbon,due to the fact that hydrochar possesses limited porosity and surface area.It is well documented that the porosity of hydrochar could be significantly enhanced by chemical activator,such as H3PO4,NaOH,KOH,K2CO3 and ZnCl2.Recently,considerable progress has been made toward understanding the effects of activation conditions(such as activation temperature,the kinds and amounts of activator)on the porosity of hydrochar based porous carbon.The hydrochar based porous carbon exhibit high ability for removal of contaminants from aqueous solution and capture of gas(such as CO2,H2 and CH4),due to its abundant porosity and narrow microporous distribution.Undoubtedly,the properties of hydrochar(such as aromaticity,polarity,thermal recalcitrance)are obviously influenced by HTC conditions(such as peak temperature and retention time).For example,increases in aromaticity and recalcitrance occur with increasing peak temperatures.Unfortunately,the effect of hydrochar properties on the porosity of its resultant porous carbon is unknown.Hence,to fully understand the affecting factor of porosity development of hydrochar based porous carbon,more attention must be paid to the hydrochar properties.