Influence of the blend nickel/porous hydrothermal carbon and cattle manure hydrochar catalyst on the hydrothermal gasification of cattle manure for H^sub 2^ production

This study presents the optimized hydrothermal gasification (HTG) and hydrothermal carbonization (HTC) of Cattle Manure (CM) and Cattle Feed (Canola Stalks) for hydrogen-rich gas, bio-oil and porous carbonaceous catalyst support production as a potential procedure to handle cattle wastes and produce valuable energy carriers. Our main objective in the present research was to produce H2-rich gas from the wastes of dairy cattle in the presence of the efficient catalyst supported on a support that was prepared from the cattle feed. Therefore, with the aim of improving one of the momentous dimensions in the sustainable development that is the environmental protection, considerable efforts were focused on the maximum exploration of dairy cattle waste materials. Three operating parameters of temperature (380–440 °C), reaction time (5–30 min), and feed concentration (2.5–3.5 wt%) were examined and their optimized levels were found to be 440 °C, 20 min, and 2.5 wt%, respectively. The hydrothermal gasification was performed using Ni catalyst supported on activated carbon canola stalks (ACCs), CM hydrochar that was produced via the HTC and further ZnCl2 chemical activation of canola stalks, and the combination of ACCS and hydrochar (called blend) catalysts under the optimized conditions. The impact of catalyst supports on the distribution of gaseous products was assessed by various techniques and accordingly, the blend catalyst increased the H2 and total gas yields by the factors of 1.73 and 1.66, respectively. Furthermore, the bio-oil of the HTG process was also collected and analyzed using GC/MS analysis and it was found that the CM bio-oil is rich in phenol and its derivatives, furans, Nitrogen-containing compounds, and aromatic molecular structures.