A method and an apparatus for producing a chemical compound from biomass based raw material. The bio-mass based raw material is gasified in a gasification device for forming a gasification gas, the gasification gas is treated in the reactor which includes at least one catalyst layer including Fe-based catalyst for forming a hydrocarbon composition, at least one hydrocarbon fraction including olefins is recovered from the hydrocarbon composition, and a chemical compound is formed from the hydrocarbon fraction. Further, the invention relates to the produced chemical compound.