A process is provided to make ethylene and propylene from a carbonaceous feedstock. The process comprises preparing a gaseous mixture of carbon monoxide and hydrogen from a feedstock. A Fischer Tropsch synthesis is then performed on the gaseous mixture to obtain a Fischer Tropsch product along with unconverted carbon monoxide and hydrogen. The Fischer Tropsch product in admixture with the unconverted carbon monoxide and hydrogen from the previous step is then subjected to terminal cracking to form ethylene and propylene.