Comparative techno-economic analysis of hydrate-based desalination using propane and CO2

• A propane-based hydrate desalination process using propane was modelled in Aspen Plus. • Two cold utilities were evaluated: ammonia cycles and LNG regasification cold utility. • The ammonia-cycle hydrate process achieved a SEC ∼9.1 kWh·m −3 . • Using LNG cold utility reduced the SEC to 2.7 kWh·m −3 . • The proposed desalination technology shows competitiveness with leading technologies. This work assesses the use of propane as a hydrate-forming gas for seawater desalination. The process is modelled in Aspen Plus, simulating a continuous hydrate formation reactor that employs NETmix technology through a user-defined function. A parametric study was conducted to evaluate the solubility of propane in water under conditions where hydrate formation begins, allowing for the selection of an appropriate property method for the simulation. An energy analysis was performed to quantify heat sources and sinks, aiming to minimise utility consumption throughout the process. The heat duties required in both the reactor and the dissociator were integrated with heat pump and refrigeration cycle technology, using ammonia as refrigerant. The energy requirements for this process are lower than those using CO 2 as a hydrate-forming gas, owing to the lower operating pressures at the same temperature and a higher hydration number. When compared to leading desalination technology using liquefied natural gas to replace ammonia cycles results in a specific energy consumption that falls within the lower range typically associated with Reverse Osmosis (RO) systems.