The novelty of this work represents in three main points. First, improved the quality of diesel fuel using bio-waste of coconut to produce modified ash activated carbon. The modified ash activated carbon is applied as an adsorbent to remove sulfur contain from diesel fuel to develop high quality diesel. The experimental depends on three hybrid treatments, namely; physical, chemical and mechanical. Among the noticeable achievements is that the rate of Sulphur adsorption is raised to about 37% without using any chemical reaction. The fixed bottom technology that is utilized in this work is adopted and tuned to deliver an environmentally friendly process, where the absorption of toxic gases is reduced leading to safer fuel utilization and therefore less pollution. Second, estimated physical properties of diesel are changing with the treatment time of diesel fuel to make active interaction with sulfur content. Third, employing the modified mathematical model to estimate and optimize the effect of the rate constants of adsorption and desorption of modified ash activated carbon on the concentration of solute for four treatments of physical and mechanical, water, solvent and carbonate potassium treatments are 4.128, 11.905, 2.061 and 2.06 respectively. Outcomes that obtained from mathematical model are compared with experimental results and a high degree of accuracy obtained for four treatments of physical and mechanical, water, solvent and carbonate potassium treatments are 89.69%, 91.998%, 90.979% and 91.15% respectively. Newton Raphson is optimizing technique applied to determine the optimal values of rate constants adsorption of the modified ash activated carbon for sulfur to increase the accuracy of the mathematical model for physical and mechanical, water, solvent and carbonate potassium treatments are 95.698%, 98.944%, 96.955% and 98.898% respectively. Still, further studies are required to accentuate with the results of this study using this new technique.