Sustainable Thermal Hydrolysis Treatment

Thermal hydrolysis is a common treatment used at wastewater plants to improve methane production from anerobic digestion step of sewage sludge. However, conventional systems require significant energy and can be expensive to install. This project explored using natural geothermal heat as an alternative energy source. In the proposed system, sludge would flow through a sealed loop in a deep geothermal well, where it would be heated by the surrounding rocks and exposed to high pressure created by the deep column of sludge. The concept was tested in the laboratory using a pressurized batch reactor to simulate the high-temperature and high-pressure conditions expected underground.