eng Oriental Scientific Publishing Company Biosciences Biotechnology Research Asia 0973-1245 2025-06-25 22 2 723 731 10.13005/bbra/3397 54919 article Nirali Patel 1 Kaushal Patel 1 Department of Mathematics, Veer Narmad South Gujarat University, Surat, India The primary function of the human respiratory system is gas exchange, encompassing the exchange of various gases. This work focuses on analyzing the transport of carbon monoxide ( ) within the human body. We have divided the human body into two compartments: alveolar and pulmonary capillaries. A mathematical model is required to derive the fractional pressure of carbon monoxide from the air.  In this work, we study the lung compartment model for carbon monoxide exchange during human respiration. Our objective is to create a classical differential model for the volume of carbon monoxide present in the alveolar and capillary compartments of the lungs. We also numerically solve the concentration of carbon monoxide in the hemoglobin equation and estimate the carbon dioxide diffusing capacity under various conditions. https://www.biotech-asia.org/vol22no2/numerical-modelling-of-alveolar-gas-exchange-to-calculate-the-fractional-pressure-of-carbon-monoxide/ Carbon monoxide; Concertation; Fractional Pressure; Gas Exchange; Mathematical Model;  Volume