One of the important steps in carbon capture and storage (CCS) is the absorption of carbon dioxide (CO2) from flue gases by aqueous solutions of amines. This process is susceptible to severe corrosion of plant equipment which is typically mitigated by using corrosion resistant materials or corrosion inhibitors or the combination of both. With more stringent environmental regulations on chemical use, treatment and disposal, there is a pressing need to replace inorganic heavy metal corrosion inhibitors that are commonly used in this process with environmentally friendly inhibitors that provide comparable inhibition performance. In this work, two organic compounds, namely dimercaptosuccinic acid (DMSA) and triethylenetetramine (TETA) were selected as potential alternative corrosion inhibitors. DMSA contains thiol (-SH) functional group while TETA possesses amine (-NH2). They are biodegradable and less toxic than monoethanolamine (MEA), a commonly used amine in this process. Their inhibition performance on carbon steel (AISI 1018) was evaluated by a series of electrochemical and weight loss corrosion experiments carried out in a simulated CO2 absorption process using an aqueous solution of MEA. The results showed that both DMSA and TETA were effective corrosion inhibitors. Based on electrochemical experimental results, the inhibition efficiency of DMSA could reach 99% under both static and dynamic conditions. TETA also performed well with inhibition efficiencies of up to 90% under static and 85% under dynamic conditions. Their inhibition performance was found to increase with inhibitor concentration and solution temperature and slightly decrease with solution velocity. The post-analysis of adsorption isotherm and Arrhenius plots suggested that the inhibitors underwent spontaneous physical adsorption that followed Langmuir adsorption isotherm to form a protective monolayer on the metal surface. Such interaction with metal surface could be also predicted by the quantum chemical analysis using the density functional theory (DFT). The energy gap (ΔE) of DMSA and TETA are lower than that of MEA, suggesting that DMSA and TETA have more affinity to react with iron than MEA. The inhibition performance was also verified in weight loss tests over an extended test duration of 21 days, in which DMSA and TETA gave inhibition efficiencies of 82% and 89%, respectively.