Cashew nut extract developed as alternative water softener

A recent study done by the Forest Products Research and Development Institute (FPRDI) found cashew nut extract as an alternative water softener.

Researchers from the FPRDI, an attached agency of the Department of Science and Technology, found that liquid from cashew nut shell or CNSL can be converted into a biopolymer resin to soften the water fed into boilers in different industries.

“CNSL is a viscous dark liquid found in the thin honeycomb structure between the softer outer skin of the nut and the harder inner shell. The biopolymer resin developed from this liquid can be an affordable substitute to imported chemical water softeners,” the DOST said.

Water softening is an important process because the hardness of water in different applications is reduced during this process.

When water is hard, it can clog pipes, damage boilers, heat exchangers and many other devices.  It has also damaging effects on household machinery such as laundry machines.

“Results of the FPRDI study showed that CNSL biopolymer resin is as effective as commercial synthetic resin,” the DOST said.

Moreover, the biopolymer resin can be washed with a slightly acidic solution and reused for boiler water treatment, it said.

“It is a natural resource that could help industries reduce their energy and maintenance cost. The material is environment-friendly, as it helps reduce the accumulation of cashew nut shells normally regarded as waste,” the DOST said.

Water has many impurities in the form of minerals or salts, acids, organic matter, oil, grease, and others. These cause sludge or deposits, scales, corrosion, priming, foaming, and make boiler metal brittle.

Removing these impurities is necessary especially to manufacturing industries. When impurities precipitate on hot boiler tubes, scales and deposits form and these insulate boiler tubes requiring more fuel to generate the same amount of steam.

Lime-scale deposits build up and block pipes and thus lower the efficiency of boilers and tanks. They reduce the efficiency of heat exchangers and other equipment and raise energy use.