Kemtrak photometers are ideally suited to the needs of the pulp and paper industry. From environmental monitoring of raw water and discharge to controlling chemical consumption and optimizing product quality. Efficient chemical use through process photometry can reduce costs, increase quality and insure environmental compliance.

Pulp & Paper applications include:

• Alkali
• Chlorine dioxide
• Effluent water color monitoring
• Ozone
• White water color monitoring

Sodium hydroxide is a key chemical used in the delignification of wood fibres in the kraft pulping process in addition to being used in a number of stages in the bleaching process.

On-line continuous measurement of sodium hydroxide can be made using near infrared (NIR) spectroscopy as sodium hydroxide absorbs selectively at ca 1300 nm. A second wavelength can be used to correct for both turbidity and sensor fouling.

The Kemtrak DCP007NIR photometer is suited for the monitoring of sodium hydroxide. Please contact a Kemtrak sales representative for additional information.

Chlorine dioxide (ClO2) is used primarily as a bleaching agent in the pulp and paper industry for elemental chlorine free (ECF) bleaching.

Chlorine dioxide has a strong absorption between 350 and 500nm that the Kemtrak DCP007 can measure – from ultra low parts per million concentrations when used for gas detection or disinfection, to high concentration solutions used for the bleaching of pulp (>20 g/L).

The Kemtrak DCP007 can be used to optimize the reaction efficiency of ClO2 generation, improve the control of vent-gas scrubbers to reduce emissions into the atmosphere and for monitoring the final concentration of chlorine dioxide product sent to the bleaching plant.

Chlorine dioxide is an aggressive chemical substance – all wetted parts of the Kemtrak DCP007 flow cell are manufactured from corrosion resistant materials, such as PCTFE, PVC, titanium and sapphire.

Chlorine dioxide information sheet

Ozone is a powerful oxidizing agent used to bleach chemical and mechanical pulp. Ozone is used as an alternative to chlorine or chlorine dioxide to remove lignin from wood pulp . It is often used in conjunction with oxygen and hydrogen peroxide to completely eliminate the need for chlorine-containing compounds in the manufacture of high-quality, white paper.

Ozone strongly absorbs at wavelenghts below 400nm (UV) that the Kemtrak DCP007 can easily measure. The Kemtrak DCP007 uses a reference wavelength to compensate for turbidity and/or fouling of the optical windows providing accurate measurements with low drift and long-term calibration stability.