Yogesh Badgujar, Nandini Ajgaonkar, Hitesh S. Pawar
High Resolution Image Download MS PowerPoint Slide Continued fossil fuel depletion has accelerated the search for sustainable, clean energy solutions, positioning abundantly available biomass as a compelling pathway to meet global energy demand. The present study explores the use of an inexpensive transition metal-loaded TiO 2 catalyst for catalytic thermoliquefaction (mCTL) of the organic biodegradable municipal solid waste to produce carbon-dense mCTL oil at nonstringent reaction conditions. Various transition metal catalysts are synthesized as TiO 2 -loaded catalysts from their nitrate precursors and evaluated for mCTL. Of the synthesized catalysts (Cr/TiO 2, Ni/TiO 2, Fe/TiO 2, Co/TiO 2, and Cu/TiO 2 ), Co/TiO 2 shows excellent performance in terms of biomass conversion (>68%) and mCTL oil yield (>58%) without formation of char and gaseous byproducts at 200 °C. The optimized conditions using Co/TiO 2 provide biomass conversion (>84%) and mCTL oil yield (>77%) at 250 °C in 60 min. Various surface-morphological and analytical characterization techniques are explored to elucidate the catalyst's physicochemical and surface features. The synthesized Co/TiO 2 exhibits the presence of Co 2 O 3 and Co 3 O 4 with a crystalline phase and uniform Co loading on TiO 2 . Surface area analysis reveals a mesoporous structure with a specific surface area of 16.93 m 2 g −1 and pore diameters ranging from 8 to 16 nm. The obtained mCTL oil was characterized by acid number, elemental analysis, infrared spectroscopy, GC-MS, and HPLC, confirming the presence of a wide range of hydrocarbons, including acids, esters, alcohols, etc. Catalyst recyclability tests over five consecutive runs demonstrate consistent mCTL process performance. Additionally, environmental metrics, including the E-factor, process mass intensity (PMI), and water and carbon footprints, indicated the sustainability of the mCTL process, highlighting its strong potential to produce next-generation fuels, chemicals, and value-added products from municipal waste. Thus, cobalt was found to be a more efficient metal to promote the mCTL process, which may be because of its excellent balance of redox activity, hydrogenation ability, C−O bond cleavage efficiency, and thermal stability.