The Value of Condensate
Water treatment consultants should always be looking for ways to provide a return on investment (ROI) for their customers. Harvesting used steam, which is in the form of condensate, is one of those projects that can offer an excellent ROI. Let’s dig into the facts about this valuable resource.
Because it is condensed steam and the dissolved solids are almost non-existent, condensate should be very pure, and when added to the boiler feedwater, this will allow for a higher number of cycles of concentration in the boiler water. Higher cycles of course mean lower blowdown rates. It should come as no surprise that the greatest expense in a boiler house is the fuel needed to heat up the boiler water, but now that the blowdown rates have been reduced, the fuel consumption has been reduced as well.
While we are on the topic of fuel efficiencies, let’s talk about the heat in the condensate. Certainly the condensate is warmer than the make-up water which it replaces, so those higher Btu’s coming back to the boiler house will also help reduce the amount of fuel consumed.
As the returned condensate offsets the amount of make-up water just discussed, the customer is saving money by not having to purchase make-up water for the boiler that would also require conditioning (softening, reverse osmosis, demineralization …). I think you can see how this is starting to add up to some significant savings.
Not only does the condensate contain heat, but it usually helps us recover treatment chemical in the form of volatile amines. The steam treatment amines are generally the most expensive and most hazardous chemicals in the boiler house. Reducing their usage rate saves even more dollars.
The other chemicals fed are the oxygen scavenger and the internal treatment chemicals. Since the condensate is very low in oxygen and contaminants like hardness, iron, and copper, the treatment chemicals can also be reduced. You certainly will notice a reduction in the oxygen scavenger usage rates required to achieve your desired residual levels.
To support your ideas for ROI, I recommend visiting the Department of Energy’s website http://energy.gov/eere/amo/steam-systems and checking out their Steam Systems Assessment Tool (SSAT). The “Steam System Modeler” is particularly useful. This program can give you the calculations you need to explain to your customers how they can save money with condensate. They may need to invest in equipment to return the condensate, keeping in mind that all of that piping should be insulated to conserve the heat. Knowing the expected savings upfront will make the difference in the project’s acceptance.
After implementation, you most definitely will want to meter the returned condensate to prove the savings. Your make-up water should already be metered, so be sure to collect before and after the project data. You may also want to report reduced blowdown and chemical savings.
Condensate — which I like to refer to as “gold” — should be the focus in any boiler house, for when it is pure/free of any contaminants, it is a very valuable resource!
