The needs to replace petroleum-based polyol by bio-source polyol in polyurethane industry were increased dramatically in the last few decades. The main obstacles associating with using bio-based polyol where the change in foam density and foam shrinkage. The reacting monomer was preheated to achieve a higher maximum reaction temperature that allows more setting of the cell structure and more stable foam matrix to overcome the vacuum forces and prevent density change and foam shrinkage. A simulation code for polyurethane reaction was used to find the optimum recipes with low catalyst loading to achieve a polyurethane foam with good properties.