This work presents a critical assessment of the main principles, technologies, and constraints of the gasification process. Finding adequate solutions to address the major limitations of the process could boost the application of gasification as a mean to fulfil the waste-to-energy agenda. This work focused mainly on the gasification of lignocellulosic residues, namely residual forest biomass. Fluidized bed gasifiers were identified as the most promising gasification technology, owing to their good mixing capacities and high heat and mass transfer. Major limitations regarding the application of this process were pointed out, related to the presence of contaminants in the producer gas, such as tar and particulate matter, alongside its low calorific value, and reduced hydrogen concentration and H2:CO molar ratio. These limitations hinder the producer gas application for advanced processes, including biofuel production or chemicals synthesis. Therefore, increasing research efforts are being directed towards unlocking the full potential of this energy carrier.