KIRA
Adaptive water treatment with any energy source.
Introduction
Desalination & water treatment equipment historically operate with constant operating power, limiting the environments and applications in which they can be applied. We have developed energy management and control strategies that allow desalination & water treatment to operate with any variable power source — including renewable sources such as solar and wind as well as accommodating for grid intermittencies and price fluctuations. We use electrochemical systems and leverage novel modeling, optimization, and control theory to build desalination systems for previously unreached environments: concentrating produced water at decentralized oil & gas sites, desalinating brackish water for agriculture, treating remote community drinking water, and decarbonizing large scale municipal & industrial plants.
Problem
In oil & gas extraction, there's a significant amount of wastewater ("produced water") - for every 1 barrel of oil, up to 10 or more barrels of highly saline water is generated. The current way of dealing with this water is to truck or pipe it from remote sites to centralized salt water disposal wells, and inject it deep underground. However, the pore space in the ground is rapidly filling up, causing earthquakes, and even breaching nearby wells causing surface contamination. There is an exponentially growing problem of where to put this waste.
One solution is desalinating this highly saline water. This reduces the amount of wastewater being injected (minimal to zero liquid discharge) and creates clean water that can be beneficially reused in industrial processes (O&G, power plants, semiconductor fab., hydrogen production), in local agriculture (non-edible crops like cotton), and discharged to recharge aquifers and surface water bodies (the Pecos river in TX).
However, these sites are located in remote regions with unreliable power, and the water is highly saline - making it extremely challenging for conventional desalination technologies to work (e.g., reverse osmosis). Currently, thermal methods are the standard for desalinating this highly saline water, but these methods are often an order of magnitude higher in energy consumption than membrane based methods.
Opportunity
We are proposing utilizing our technology: adaptive electrodialysis reversal (AER). We are utilizing a membrane-based electrochemical technology called electrodialysis to desalinate these highly saline wastewater streams, and we are coupling this technology with solar energy to treat water with near zero operating cost. Our innovations in control, power electronics, and hydraulic architectural design enable us to flexibly operate our system. We can operate with variable input feedwaters, variable target streams, and fluctuating input power. A recent field pilot published in Nature Water and featured in MIT News demonstrated our ability to couple solar energy with desalination without the need for energy storage in the form of batteries, which can be CapEx and OpEx intensive.