A process for producing synthesis gas (S) from biomass, includes drying the biomass and gasifying the biomass. An equipment to carry out the process is also disclosed. The process further includes: subjecting the outgoing gases (CO2, N2 and H2O) from the gasifying step to a first heat exchange, where the outgoing gases (CO2, N2 and H2O) are cooled, purifying the outgoing gases (CO2, N2 and H2O) to achieve a process gas (P), the purification being effected by eliminating nitrogen (N2) from the outgoing gases (CO2, N2 and H2O), subjecting the process gas (P) to heat exchange, where the process gas (P) is heated, reducing the process gas (P) to synthesis gas (S), subjecting the synthesis gas (S) to heat exchange, where the synthesis gas (S) is cooled and supply air to the gasification is heated.