With the increasing use of natural gas, Liquefied Natural Gas (LNG) is becoming more extensively used to ease the storage and transport of gas. The process of returning the natural gas to its gaseous state (regasification) prior to distribution to the gas pipeline absorbs large quantities of heat and therefore provides a readily available and inexpensive source of 'coldness' at low temperatures.
This available 'coldness' source can constitute a challenging opportunity to return to the technology of desalination by freezing, which was developed by IDE Technologies back in the 1960s, or to modify the commonly used multi-effect distillation (MED) process for operation at low temperatures. The vast experience accumulated by IDE over the last decades, in both MED and vacuum freezing vapor compression (VFVC) processes, will now serve as an effective tool for evaluating the feasibility of desalinating seawater by utilizing the 'coldness' resulted from the LNG regasification process.
In this article a case study was considered, in which an LNG regasification plant can supply 1750 ton/hr of water-glycol solution at -15°C to be utilized for seawater desalination. The main challenge in this evaluation is being able to provide a desalination solution able to compete with the commonly used RO plants.
Utilizing available `coldness` from Liquefied Natural Gas (LNG) regasification process for seawater desalination