Microwave plasma pyrolysis for the valorization of VFA extracts from HTC process water

Volatile fatty acids (VFAs) in HTC liquors are a promising but underutilized resource for energy production. This study examines the recovery of VFAs from HTC process water via liquid–liquid extraction and the co-pyrolysis of the recovered stream with methane in a microwave plasma reactor to produce syngas. Experimental analysis at the HYDROPYR pilot of the BioFairNet project, has provided the real VFA composition in the HTC liquor. The experimental results are used as input in a newly-developed thermodynamic model (implemented in MATLAB-Cantera) and simulation were performed for 1000–2500 K. The model results at 1500 K, simulate syngas production with >99.9 mol% of H2/ CO in the gaseous phase, and the simultaneous production of carbon black. Ongoing work will incorporate reaction kinetics and techno-economic analysis to inform scale-up for municipal wastewater-treatment applications.