Evaluation of the energetic and environmental potential of the hydrothermal carbonization of biowaste: Modeling of the entire process chain

This study outlines the entire process chain related to an industrial-sized hydrothermal carbonization (HTC) plant, which treats the organic fraction of municipal solid waste. A parameter study, carried out in laboratoryscaled experiments, was used to create a model starting with the substrate preparation and ending with the production of electricity. It was designed to be infinitely variable with respect to different reaction intensities within certain boundary conditions. Contrary to previous research endeavors, all components related to the HTC process and modules for the post-treatment of co-products including heat recovery and process water treatment were integrated. Based on this model, the claim that HTC-char is a more environmentally friendly energy carrier than lignite was investigated. In the realm of a life cycle assessment, a GWP of 0.45-0.70 kg CO2,Eq/kWh(el) was revealed for the electricity production from HTC-char. It, thus, outcompetes the electricity production from lignite (1.05-1.40 kg CO2,Eq/kWh(el)).