I think a better design would be to construct a reinforced holding tank underground (either underneath the basement or adjacent to the house) that would hold the NaOH solution, then lay piping and use a pump to circulate small amounts of it to a heat exchanger in a central ventilation system.
Wikipedia notes that it reacts with aluminum but not with iron. Iron is relatively plentiful as well and we know how to build holding tanks with that material.
It's probably not a good idea for earthquake-prone areas, but this method might work ok in places like Minnesota to replace burning LNG in a furnace or coal-plant-powered electric heating as the primary source of heat in the winter. I guess it depends on the reaction rate and efficiency of the system - how many tons of NaOH would be required to heat the house throughout the entire winter?
"how many tons of NaOH would be required to heat the house throughout the entire winter?"
This is one of those cases where the fact that it wasn't mentioned leads me to believe "embarrassingly large amounts".
(That said, the technique may not be useless, and they may have a valuable machine. It's just that this particular application is setting off my energy-scale alarms. Press releases tend to get pretty breathless.)
I have worked with NaOH before, and I think the amount required would probably be more than a (US tank-style) water heater and less than a typical above-ground swimming pool.
I think you would need some of the tables typically found in chemical engineering manuals to work out the exact amount.
You would need the heat capacities for 50% and 30% (wt%) aqueous NaOH, mass fractions, enthalpy of dilution, and maybe activity coefficients. It sounds like a homework problem for a ChemE student.
Yeah, I never took enough chemistry to be confident I could get that correct or I would have done it myself. I've done Physics 101 BotE work on HN before but I'm pretty sure I'd have screwed this up. :)
I agree. One would hope that when this research-level technology reaches the market, they can effectively isolate and contain the NaOH, and have some solid safeguards against malfunctions.
On the optimistic side, we've mostly succeeded in doing that for other volatile things like gas tanks in cars and lithium batteries in electronics.
On the pessimistic side, the failure modes can be very catastrophic! I'd definitely want to know what failsafe mechanisms are in place to prevent my house from blowing up before I'd consider using it.
Personally I would have no problem to have that stuff in the basement, whilst having it circulating in pipes just under the floor (you know, the heated kind, where likely you go around barefooted) might be an issue. Also, consider how on multi-storey houses the ceiling is nothing but the underside of the upper floor. ;)
Sure, I do hope that those scientists are not totally irresponsible.
Still another heat exchanger will further lower the efficiency of the system. In my experience (maybe a tad bit dated) common heat exchangers (water/water) are difficult to maintain as - generally speaking - the most efficient ones have smaller passages for the liquid and they tend to become clogged and it is "normal" to clean them periodically.
I have no idea how large must be a heat exchanger (where one of the fluids is lye) to be efficient enough, considering also that the temperature is relatively low, but most probably it won't be exactly "compact".
Ammonia is already a product that is stored and used by lots of people. It is a common fertilizer. There are guidelines for safety equipment and tank maintenance, but I'm not convinced that everyone follows those.
I think ammonia's next big application will be as an easier-to-use form of hydrogen for fueling ICEs with renewable energy.
So it might be relatively cheap to acquire the working material.