Preparation of nitrogen-doped activated carbon from bio-oil residue for efficient CO2 adsorption

An efficient strategy for the resourcezation of waste bio-oil residue was developed to fabricate nitrogen -doped activated carbon (NAC) as CO2 adsorbent. The NAC was produced by in -situ nitrogen -doped carbonization and K(2)CO(3 )activation, using urea as nitrogen source. The effects of activation temperature, mass ratios of urea to bio-oil residue (U/O ratio) and K(2)CO(3 )to char (K/C ratio) on the physicochemical properties and CO2 adsorption performance of NAC were investigated. Under the conditions of activation temperature of 750 C, U/O ratio of 1 and K/C ratio of 3, the as -prepared NAC exhibited the greatest CO2 adsorption performance with an excellent CO2 adsorption capacity of 6.22 mmol/g at 1 bar and 0 C, which was much higher than that without nitrogen doping (2.21 mmol/g). In addition, the CO2/N-2 selectivity of NAC was 14.3 and the adsorption capacity loss was below 1% after 5 consecutive cycles, revealing promising potentials in carbon capture applications.