Provided herein are methods of optimizing energy recovery from oilseeds. The methods disclosed provide at least the ability to swell oilseeds and disrupt the cell walls (hulls) without changing the functionality and quality of oil; the process integration of removing the impurities from oilseeds, oil extraction, protein hydrolysis, and green coal production to maximize the energy recovery in the form of crude oil, polypeptides, oligopeptides, amino acids, and/or green coal from oilseeds; and heat integration during processing stages including subcritical water pretreatment, oil extraction, subcritical water post-treatment, and subcritical water carbonization to minimize the process heat requirement.