Simulation and Technological Analysis of Thermal Evaporation Methods for Produced Water Desalination

The development of cost effective shale gas produced water treatment technologies for water recovery (sometimes with the co-production of salt) has raised high interest among industries and academia.  Depending on the source and location, the components of produced water varies widely.  Currently, reverse Osmosis (RO) is not suitable to treat high-salinity water but some thermal methods are applicable. There are three dominant treatment technologies for produced water desalination on the market: multistage-stage flash (MSF), multi-effect distillation (MED) and mechanical vapor compression (MVC).  Recently the hybrid of MED with thermal vapor compression (TVC) is gaining strength due to reduced energy cost. Another emerging technology is membrane distillation (MD). For the effective deployment of technologies, a major challenge is how to evaluate their performance holistically.

In this work, representative processes of the aforementioned produced water treatment technologies were simulated and their performances were compared along multiple dimensions. In technology dimension, the indicators including salt removal ability, gain output ratio (GOR) and energy intensity are considered. In economic dimension, the annualized capital and operational costs (CAPEX & OPEX) of the treatment processes are compared.  The environmental impacts of the processes were evaluated using a life cycle analysis approach.