Corn cob biomass residues: Synergies between thermochemical processes for biofuel production and adsorbent materials for the bioenergy sector

Abstract

This research uses corn cob (CC), a renewable material, to make biofuels. The energy conversion was done by conventional and flash pyrolysis (750–850 °C), showing how the process affects the yield and properties of the biofuels. The CC stood out for their high carbon content (48.19 %) and low ash content (1.16 %). Flash pyrolysis increased the gaseous fraction (69.8 %) and the concentration of combustible gases (higher heating value (HHV) = 16.31 MJ/kg). Research has also been carried out on the production of activated carbons from CC char to separate gas mixtures, store gas or upgrade biogas. Higher temperatures and/or amounts of activator improved their textural properties (BET surface area and total pore volume up to 1982 m²/g and 0.820 cm³/g). These adsorbents are highly effective in CO₂ adsorption, with a capacity of up to 15.3 mmol/g at 3 MPa for that obtained with KOH at 700 °C and 2:1 wt ratio. They are good at absorbing methane at 3 MPa with a maximum of 8.8 mmol/g when prepared with KOH at 800 °C and 2:1 wt ratio. Hydrogen adsorption was limited. The potential of CC for biofuel production through pyrolysis and the development of adsorbents applicable to the bioenergy sector have been proven.