The use of residual biomass streams for production of liquid fuels will help in achieving the goal of renewable transportation fuels and sustainable society. Hence, efficient, and reliable processes offering a flexible product distribution proven at commercial scale are required. This study explores the technical feasibility of producing gasoline and diesel range hydrocarbons from thermochemical processing of biomass via the production of light olefins (C2-C4) and their subsequent oligomerization through mathematical modelling and simulation using MATLAB software. Different biomass processing scenarios were considered, including a standalone biomass gasification plant and integrated biomass pyrolysis- char gasification (O2- or air-blown) process. Process analysis indicated that the integrated plant offers 10-11% higher carbon efficiency. The processing step with the highest carbon penalty for all the cases is the syngas composition tailoring via water-gas shift reaction.