RO Plant Feed Water Temperature High 42 C

Please define RO and the type of fibers you are referring to in you post.

If you are referring to reverse osmosis,here is a related link that may be of benefit:

https://www.purewaterproducts.com/articles/ro-membrane-production

And here is another link:

https://www.watertreatmentguide.com/factors_affecting_membrane_performance.htm#Figure_4

Looks like you are good 'till 50 degrees C,depending on type of membrane is used.

These are excellent links, thanks for sharing.

Temperature till 55 we had operated RO's with good recovery ratio. Its normal in KSA

KSA what is temperature and membranes types?

https://www.acronymfinder.com/KSA.html

I'm making the assumption that the feed water is not at the required pressure for the RO plant.

As the water is further pressurised, the temperature will rise further. What is the temperature before the membranes?

As you cannot change the borehole temperature,adding a heat exchanger online or around the feed pipe could draw energy from the water.

This does not necessarily mean that there will be increased cost, as the heat removed might be useable elsewhere. Either directly or using a refrigerant circuit to upgrade to a more useful temperature.

Where else can you use this heat? Space heating? Hand washing? Preheat for ?? Lots of ways to use this issue to reduce the cost elsewhere.

<...almost 33000 ppm...> is akin to seawater. One might switch to this source instead, which rarely reaches <...42 degree celcius...>.

The answer to the question <...why...invest money and let it run on 42 degree celsius.?...> is a commercial one on the grounds of the risk and the return on the investment to avoid the risk. Commercially sensitive matters are best dealt with away from this forum, which deals with technical ones.

The membrane manufacturer is merely indicating that the membranes are running above the warranty maximum temperature, so, if they fail as a result, the facility will be buying new ones and not having them replaced under warranty.

There is nothing more the undefined <...we...> needs to discuss.

There is insufficient information in this posting to make an accurate assessment however I suspect I am going to be with PWS here

You say that the borehole water is hot at 42°C which is certainly warm. That membranes operate at 55°C in KSA is to a point irrelevant.

What the OP needs to know is the specification against which the membranes that they are using were purchased.

If the original specification was for say 35°C then the vendor is completely within their rights to say that you cannot operate above 42°C. It would not be a total surprise to discover that 55°C membranes are substantially more expensive then 42°C membranes and so a cost decision would have been made at the time of the purchase order.

If 42°C is the limit of the performance spec in the purchase order and in the supply agreement with the vendor then operation beyond that point will be at your risk and any replacement will be at your cost.

If the vendor originally specified the membranes at 45°C and is now trying to reverse ferret back to 42°C then the boot is on the other foot. They have supplied equipment that does not meet the agreed spec and so replacement would be at their cost (IMHO depending on the wording of the contract)

There are a huge variety of materials and treatment available for membranes in RO and similar usages with an equally wide range of operating ranges. It is a universal truth that as you push the limits of performance the cost goes up.

If the borehole temperature has gone up since you started extraction then my guess is that this is your problem the vendor can only produce kit to meet specified conditions. They cannot be expected to guess how conditions might change in the future.

If your purchasing department purchased these items knowing that their operating limit was below the 42°C borehole temp then the fault is with the corner cutter in purchasing.

Which of these is relevant to you I do not know

As to the problems with exceeding 42°C again I do not know but a few guesses

The mechanical integrity of the fibres or coatings is degraded above this temperature

Whatever method they use to create the holes / tubes in the membrane has a differential temperature effect and so the holes open or close either allowing a lower purity of water through the membrane or reducing the clean water capacity

there are probably others it is not my field

I will just say again even if other membranes (or even this one) can be used at higher temps if the supplier in their specific agreement with you has specified a max temp of 42°C then if you exceed that temp they will absolve themselves from all fault and in my opinion rightly so

good luck