The Environment-Enhancing Energy research aims at converting biowaste such as food waste, animal manure, algae bloom and wastewater sludge into biocrude oil via hydrothermal liquefaction (HTL). The HTL biocrude is then upgraded into transportation drop-in fuels. Nutrients in the original biowaste are separated into post-HTL wastewater (PHW), recovered and reused for crop and energy biomass production, thus achieving net-zero-carbon energy, and enhance the environmental quality.