A Study on the Production Characteristics of Hydrogen and Biochar Using the High-temperature Thermochemical Pyrolysis of Biomass

In this study, a CO2 negative hydrogen production technology was developed using biomass and plastic waste as raw materials. An indirect pyrolysis of biomass was carried out in an oxygen-free state by heating the reactor at a uniform temperature of 800 similar to 1,000 degrees C using flameless combustion. The biochar produced inside the reactor served as a catalyst for tar decomposition and biochar oven gas (BOG) production, which are production gases, through the cracking and adsorption process of input raw materials. The composition of the production gas was checked dependently on temperature and input raw materials, and it was confirmed that the higher the temperature and greater the amount of biochar in the reactor, the higher hydrogen concentration was achieved in BOG. BOG produced from coffee grounds and plastic waste contained more than 50% hydrogen in molar concentration, and the produced biochar contained carbon nanowires and hexagonal nanocarbon structures.