Carbonized biowaste presents a promising route to producing energy materials in a low carbon or even carbon negative way, given that the precursor material (i.e. plant material) relies on the conversion of atmospheric CO2 to sugar molecules. By treating cellulose, starch or other sugar molecules at high temperature (230 oC) and pressure in aqueous solution, an amorphous high carbon material is formed. This hydrothermal carbon (HTC) can be further modified to produce parts for battery anodes, water purification filters, supercapacitors, fuel cells and catalyst supports. Here we propose to examine the hydrogen group of the HTC carbon material before and after heat treatment at relatively low temperatures to better understand the nature of the disordered carbon material.