The Middle East Gets (Less) Salty

It’s commonly known that while the Middle East in abundant in fossil fuel deposits, it’s very deficient in supplies of fresh water. The search for ways to make do with the water they have, water from the Persian Gulf, has lead to concentrated waste brine from the desalinization process being pumped back into the Gulf.

This waste brine is typically twice as salty as normal sea water and is leading to the Gulf and surrounding areas turning saltier as a consequence of it’s disposal back into the source. This threat is not only short-term either, it also threatens future drinking water supplies and ground-water sources.

Recently, a chemical engineer at Qatar University by the name of Farid Benyahia has had a breakthrough of sorts and has come up with a new solution to deal with both excess CO₂ emissions, and waste brine at once. Benyahia has taken the 150-year-old Solvay seven-step process of producing sodium carbonate for industrial purposes, and reduced it to a two-step process to produce sodium bicarbonate, what we commonly refer to as baking soda.

The process involves those lovely chain reactions we all learned about in CHE102, whereby he reacts the pure CO₂ with waste brine in the presence of ammonia gas, producing ammonium chloride and baking soda. Then he reacts the ammonium chloride solution with calcium oxide to recover the ammonia gas to reuse.

What makes Benyahia’s method better than those people are currently using is that most systems currently in place don’t use pure CO₂, but flue gas from power plants which contains only small amounts of actual CO₂ and requires the separation of the gases to extract it. Qatar has multiple plants producing pure CO₂ gas, making this country ideal to try the new process out.

It’s estimated that Benyahia’s method can reduce brine waste by almost 100%, which makes it pretty ridiculous that they haven’t tried this already. He believes he can offset the hefty cost of implementing this process by selling the by-products, baking soda and calcium chloride, pointing out that this process will actually produce these products cheaper than current industrial processes.

Until a way of desalinating water without creating concentrated brine is thought up (maybe by someone from Waterloo, who knows!), I’ll be following these developments. This is an exciting proposal and it can be hoped that Qatar will pursue this option more thoroughly and start reducing their waste emissions significantly!