Chemist Uses CO2 to Convert Seawater into Drinking Water

Yes, this is very close to my area of expertise, my previous job title was director of chemical process development but I've got my degrees in materials science and physics so I think I mostly understand what they're doing in a broad sense if not the details at small scale. But yes, a 5% energy efficiency gain would be an enormous deal for some chemicals like ammonia. A 1% efficiency gain there is last I checked 2 power plants per year that could be taken offline in response to the lost demand.

But for most chemicals the energy efficiency is important while material efficiency is more important. Usually there are tradeoffs. For instance I have made a chemical to 99.8% purity without a ton of purification. If it were to 99% then I'd have to spend a lot more energy to reach 99.8% purity (which happened to be required to be useful as a product). But the process to reach 99% is simpler and uses less energy than the process to reach 99.8%. So really it's just an optimization problem where you definitely cannot assume that improving the yield or efficiency of one part of the system will result in an overall efficiency improvement unless you model it all.

The problem is that it is premature to talk about energy efficiency in any remotely meaningful way here because the "big box" you need to draw around your system is vastly bigger when you're talking about a complicated plant doing by my count at least a dozen (including heating, cooling, separations, etc) processes simultaneously.

I'm not saying that their idea wouldn't work in that context, I am simply saying that at TRL 2-3, if this were me doing the work, we would have noted the amine issue and deferred it until a later TRL level because it's theoretically a non-core technology to remove it. It doesn't tell you much about your throughput of your membrane or what salt gradients it works with or how to power it -- that's what I would expect them to be focusing on.

Removing the amine would be like TRL 3-4 maybe, if they're on the ball, but they have to attack the problems most likely to result in failure first. Amine contamination is way lower on a priority list than, say, the membrane rupturing every seventeen days. That's literally just more where I would guess they are at development-wise, regardless of whatever claims they make.

I just cannot trust claims made at that TRL level, at best they're extremely optimistic guesses extrapolated from a 1L benchtop apparatus they are trying to model a whole plant using data from. It's a good thing to do. It won't give a correct answer, but it will give you an idea of what's important at least.