The present work aims to investigate the cumulative effect of hydrogen enrichment with the fuels of diesel, Neat chlorella vulgaris oil (NCVO), and Chlorella vulgaris methyl ester (CVME) in a mono-cylinder CI engine. The performance, combustion, and emission parameters of diesel, NCVO, and CVME are analyzed and compared to the findings obtained with hydrogen induction in the intake manifold under dual fuel configuration. With the effect of hydrogen infusion, the metrics of performance, combustion and emission parameters are improved. Under maximum load condition, the induction of hydrogen escalates the BTE from 32.74%, 28.01%, and 23.02%–35.39%, 31.40%, and 28.12% with diesel, CVME, and NCVO at maximal hydrogen share energy of 14.38%, 11.50% and 9.61% respectively. Alongside, the enrichment of hydrogen declines the carbon monoxide (CO) from 4.13, 10.38, and 19.24 g/kWh to 3.16, 8.02, and 15.26 g/kWh, unburned hydrocarbons (UHC) from 0.51, 0.71, and 2.02 g/kWh to 0.36, 0.50, and 1.64 g/kWh, smoke opacity from 55%, 75%, and 85%–43%, 67%, and 71% with diesel, CVME, and NCVO respectively. However, the hydrogen's significant flame velocity and immense calorific value confect to an elevated combustion temperature and subsequent rise in heat release rate (HRR) to, cylinder pressure, and emission of nitrogen oxide (NO). Among the tested fuels, diesel posses maximum HRR and cylinder pressure of 80.46 J/0CA and 88.67 bar respectively. Maximum specific NO emission was observed with CVME having 10.80 g/kWh, whereas diesel and NCVO has 9.49 g/kWh and 4.93 g/kWh respectively.