I would agree that if your ambition is to be employed as a chemical engineer and you have the academics to be admitted to Harvard, there is a very good chance that you would earn a full merit scholarship to any number of universities with accredited ChemE departments.
If, however, you feel that you may eventually want to work in a management or consulting capacity, I would think long and hard before turning down H, especially if you are from a lower to moderate income background (the FA at HYP is top notch)