Modular thermal desalination plants?

[EBum]

Hello all,

I've been presented with an interesting problem at work. I have a client in an area of the world (at 4600m asl) who is drilling exploration wells for geothermal energy. The wells they have drilled are extremely deep and have uncovered several sources of water at very high pressures and temperatures. The wells themselves are dug using a high pressure solution that dissolves the rockbed. By the time the water from the source reaches the surface, it is at atmospheric pressure and 80 degree C. The water is high in salts and silicates.
Because water is extremely scarce to begin with in this area, and no grid electrical energy is available, the client wants to explore the possibility of reusing the water pumped out of these wells, filtering (UF) and desalinating it, and reusing it to drill other wells after it is made into drilling solution.
Reverse osmosis is a popular option, but I'd like to explore the possibility of using a thermal desalination technology to take advantage of the fact that the water is already coming out at 80 degree C (and thereby decreasing the delta T that a boiler would need to raise the temperature to) and because of the fact that RO is very energy-intensive due to high pressures needed in the membranes. The module would be producing ~50 GPM on average.
I see many many portable and containerized RO modules, but I don't see the same thing for any kind of thermal distillation (MSF: multi-stage flash, MED: multiple effect distillation, VCD: vapor compression distillation). Anyone have input into why this might be? I'm trying to find manufacturers (OEMs) that I could talk to about this and I am surprised at how little information I am finding.

Thanks in advance!

 

[bimr]

It is because the size of the MSF plants are very large capacity.

Onr would think that you should be looking into the use of mechanical evaporators.

http://www.gewater.com/zero-liquid-discharge-zld.html#featuredproductssection

http://www.publicpower.org/files/PDFs/GE ZLD Brochure.pdf

 

[MartinLe]

Or a manufacturer of large MSF plants has a pilot scale plant they are willing to sell, or license the plans for. Grasping for straws, probably.

 

[EBum]

Thanks for the responses. I've redirected my search toward mechanical vapor compression (MVC), but these things are really expensive. I was quoted $15 million USD for a new evaporator from one of the major manufacturers! As Martin has mentioned, I'll have to get creative in finding a used, modular plant.

 

[dicksewerrat]

Doesn't the US military have some type of portable plant?

Richard A. Cornelius, P.E.

http://WWW.amlinereast.com

 

[EBum]

In my research of military surplus, all I've found are mobile RO units, not thermal.

 

[dalcazar]

I'm just going to hazard a guess that you're talking about the altiplano area of the andes since you're that high and off the grid...

Have you thought about doing solar concentration for flash evaporation? There are a few companies out there that have good solar condenser and tracking systems. If you're in the area I think you're in then the sun is pretty much 100% reliable. You only have to raise the temperature about 4 degrees C plus the heat of vaporization to get the water to flash boil at that altitude and then it's just a matter of condensing it which you could do by injecting the steam into a tank of water. Night time temperatures at that altitude will take care of the increase in water temp in the tank.

I'm making assumptions here... but the idea should be pretty sound