Economic evaluation of energy efficient hydrate based desalination utilizing cold energy from liquefied natural gas (LNG)

Abstract

Water scarcity is viewed as the top global risk for the next decade. One way to resolve water shortage is desalination which expends energy to derive fresh water from the vast amount of saline water. While the current desalination technologies are matured and reliable, desalinating seawater is still an energy intensive process, necessitating research for new generation desalination technology with lower energy consumption. Previously, our group proposed an innovative hydrate based desalination utilizing LNG cold energy (ColdEn-HyDesal) which reported a low specific energy consumption of 0.84 kWh/m3. In this work, we further evaluate the economic feasibility of ColdEn-HyDesal in Singapore. With a regasification rate of 200 t/h, the ColdEn-HyDesal facility simulated in this study produces 260 m3 water per hour. Through a comprehensive evaluation of the capital and operating costs, we observed significant reduction in the levelized cost of water (LCOW) from $9.31/m3 to $1.11/m3 with cold energy integration. The effect of water recovery rate, plant capacity and geological locations were analysed. Finally, the costs of water via the ColdEn-HyDesal process at various scales were benchmarked with matured desalination technologies, revealing that ColdEn-HyDesal technology is economically favourable at larger scale.