Pulp & Paper processing

Hydrogen peroxide is rapidly replacing chlorine as the bleaching agent of choice for increasing brightness of paper pulp. In the absence of a stabilizer, a significant portion of peroxide is wasted as a result of decomposition, catalyzed by heavy metals present both in the wood pulp and in the process equipment. Dequest phosphonates effectively sequester transition metal ions such as iron, copper and manganese, allowing the peroxide to do its work as a brightening agent. Dequest can also be used as a pretreatment chemical for wood pulp for extraction of transition metals prior to actual bleaching.

Phosphonates also offer scale inhibition in the bleaching bath, a function not provided by more typically used stabilizers, such as sodium silicate and DTPA.