Hydorthermal Carbonization (HTC): Valorisation of organic waste and sludges for hydrochar production and biofertilizers

The HTC process acts as an acceleration of the natural coal formation process, working at moderate pressure and temperature (20 bar and 210 ºC for the Ingelia process), allowing the dehydration of the organic matter and increasing the C-content up to 60 wt.%. [...] The analysis highlighted three major contributors to overall environmental impacts; electricity and thermal energy used in the process, CO2 produced in the process, and the organic content in the waste streams impacting the environment when applied to land. [...] The use of hydrochar as biofuel supports the substitution of fossil fuels and the reduction of the impact from the emissions derived from the transport of the HTC feedstocks. [...] Description of the system studied The study represents a ‘gate-to-gate’ LCA and as such the system boundary includes processes from raw material pumping to the operation of the HTC to disposal of waste stream. [...] The higher GW, FE and TE values within the study were mainly due to the higher levels of CO2 released in the process and the presence of organic contents in the waste streams.