The adsorption capacity of chemically reduced graphene (CRG) in selective removal of diethanolamine (DEA) from a mixture of methyldiethanolamine (MDEA) in aqueous solutions was evaluated and compared with commercially available activated carbons using batch studies. Four equilibrium isotherm models such as Langmuir, Freundlich, Temkin, and Dubinin-Radushkevish and three different kinetics models such as Pseudo-first order, Pseudo-second order and Intra-particle diffusion were applied. The maximum uptake capacity for DEA using CRG at 296 K (250.0 mg/g) was high compared to two selected activated carbons (1.05 and 0.559 mg/g). The adsorption of DEA was found to be spontaneous and endothermic process with all the adsorbents.