Experimental and Theoretical Studies on CO ₂ Storage Behaviour of Rice Husk–Based Activated Biochar and Its Mixture With Bitumen

ABSTRACT Fossil‐based fuels led to the excessive increase in atmospheric CO 2 leading to global warming and climate change. One of the methods to overcome the issue is CO 2 capture and sequestration. In this view, in the present work, an activated rice husk biochar (ARHBC) was synthesized due to its excellent CO 2 capture properties. In addition, a mixture was prepared with bitumen and 6% ARHBC to study the adsorption isotherm and reaction kinetic behaviour for road construction application. The adsorption isotherms and reaction kinetics for ARHBC as well as the mixture were measured at various temperatures like 298–328 K with the supply pressure till 5 bar, using in‐house fabricated Sievert's apparatus. The CO 2 storage of 0.33, 0.05 and 0.02 g/g of ARHBC, mixture and bitumen, respectively, was observed at 5‐bar supply and ambient temperature. In addition, physical characterizations like BET, SEM, FTIR and TGA were carried out to understand the CO 2 capture behaviour of adsorbents. Thereafter, the adsorption isotherms were modelled using the Langmuir isotherm model, whereas the reaction kinetics were modelled using the pseudo–second‐order kinetic model and validated successfully with experimental data. The coefficient of correlation and normalized standard deviation indicate that the predicted isotherm and kinetic data closely correspond with the experimental values. Later, the adsorption isotherms of ARHBC were predicted for higher equilibrium pressure of 100 bar, which is observed to be similar to isotherms reported in literature.