Researchers at DOE’s National Energy Technology Laboratory have designed and constructed a high-pressure water tunnel that simulates deep-ocean temperature and pressure conditions, up to 3460 meters. The facility is being used to investigate the thermal, physical, and thermodynamic behavior of CO₂ under the conditions anticipated in deep-ocean sequestration scenarios. By manipulating water flow, the rig is capable of holding a buoyant drop of CO₂ stable for extended observation through its viewing port (photo), and will help scientists understand the formation mechanism of CO₂ hydrate – carbon dioxide trapped in ice – and the ultimate fate of sequestered CO₂ in deep-ocean conditions.