The gasification process is investigated using 2D Computational Fluid Dynamics (CFD) model. A 2D gasifier is presented in which biomass is fed from the side of the gasifier, while the gasifying medium is injected from nozzles at the bottom and top/downstream of the gasifier.The aim of the current research is to develop novel approach for maximizing H2 production, and CO2 reduction from biomass gasification. To this end, the effect of using different gasifying mediums (oxygen, steam, air, and CO2) on the gasifier performance are investigated. Additionally, the injection of such mediums from bottom (with the gasifying medium) and top of the gasifier (within reduction zone) is also studied. The results showed that higher heating values are achieved for steam, and oxy-gasification. Additionally, for the proposed design, at the gasifier bottom, the temperature reached ∼1500 K, which is favourable in reducing tar, ash, and residual amounts during the gasification process. Furthermore, the optimum results are achieved when injecting steam with (SB = 0.5), within the downstream of the gasifier. The novel idea results in higher H2 production, and lower CO2 emissions by (5–80) %, (12–40) % respectively, and correspondingly, higher heating values for the produced gas than air, and oxy-gasification for the same working conditions. As a result, the study presents significant outcomes for maximizing H2 yield, and the potential for CO2-free syngas, which demonstrates the promising technology and novelty that does not require any catalysts, absorbents, solvents, or additional CO2 removal. Such findings are applicable for different gasifier scales and fuel types.