DESUL is about exposing old ideas and teaching new ideas.  The shoe-horned sulfate scale in many water installations is one of the contrived old ideas that deserve immediate attention.  

The upper image of the figure on the lead page (link to figure) shows the top part of a flashing stage (pre-heating/condensing tubes) of a MSF train for seawater desalination hampered with sulfate-based scale.  The lower image of the same figure shows extracted sulfate-based scale from a plugged injection well in an oil production facility.  The poetic solution in both cases is scale inhibitors; yet the figure forcibly emphasizes that they are neither an essential feature nor a miraculous solution of anything, but strictly useless. 

The precipitation of the three principal forms of calcium sulfate is the result of a physical process that occurs only when solubility limits of these forms exceeded, which can be reached by concentrating source water, raising the temperature, and/or mixing incompatible waters.  

In seawater thermal desalination, the use of scale inhibitors to overcome raising the temperature to a lower limit by limiting the top brine temperature palliates the productivity of a MSF seawater desalination train by 40-60%, and yet without solving sulfate scale (or any other scale form including carbonate for that matter).

In seawater injection for pressure support of oil-fields, the use of scale inhibitors to overcome mixing incompatible waters (sulfate-rich seawater with alkaline cations rich-formation water) at downhole elevated temperatures palliate the productivity of oil wells; as illustrated in the upper figure on the left-hand side, wherein a picture worth a thousand words. 

In some in-land water disposal, solutions for the sulfate scale problem vary from unsound application of scientific and economic principles to something approaching insanity.

The lower figure on the left-hand side captures the consequences (repeated workovers and eventually halting operations) of using scale inhibitors to overcome concentrating source water by RO or NF; mixing the sulfate-concentrate RO or NF reject with alkaline cation-rich regenerated stream from ion exchangers in processing the same source water; mixing the mixture with alkaline cation-rich hot produced water from thermally extracted oil, thereby generating readily saturated calcium sulfate mixed water; and then injecting the mixed water (after further steps including pre- or co-injection of buffer water and scale inhibitors) into disposal wells containing formation water that is also nearly naturally saturated with calcium sulfate.    

DESUL’s innovation matters when it comes not only to effectively navigating sulfate scale, but also to integrating power-seawater desalination plants with fluids injection in oil fields and to abating air pollution. 

DESUL’s innovation is, not about vanishingly small or negative returns on investments with so unfruitful technical results that practically no one is proud of them, but about the opposite of the maximum uselessness of fake notions and formats.  Preserving your reputation and funds in the short and long-runs is a further benefit of many benefits of DESUL’s innovation.