A method and apparatus for synthesizing ethanol using synthetic routes via synthesis gas are disclosed. A method and apparatus for gasifying biomass, such as biomass, in a steam gasifier that employs a fluidized bed and heating using hot flue gases from the combustion of synthesis gas is described. Methods and apparatus for converting synthesis gas into ethanol are also disclosed, using stepwise catalytic reactions to convert the carbon monoxide and hydrogen into ethanol using catalysts including iridium acetate.