Selection of Treatment Options for Sea Water Circulating Cooling Water
New methods of pulp bleaching have grown over the past decade as legislation grew around the use of chlorine. Sodium chlorate, which produces chlorine dioxide, has gained the most ground at the expense of chlorine, and now accounts for around 40% of pulp bleaching chemical volume. But other alternatives such as oxygen, hydrogen peroxide, and ozone pulp-bleaching processes hold the most potential for growth.
Oxygen's use in papermaking, for example, is projected to grow at double-digit rates to 41 billion cubic ft/yr by 2003, according to a study by The Freedonia Group. While oxygen is also used for oxygen delignification, oxygen alkali extraction, lime kiln enrichment, black liquor oxidation (where it converts sulfides to sulfates and thiosulfates to reduce the output of volatile organic compounds (VOCs), and wastewater treatment--it's increasingly being used for bleaching. The downside to oxygen is the high cost of switching from other forms of bleaching. But once the switch is made, oxygen itself is a relatively inexpensive and environmentally friendly alternative.
Specialty papermaking chemicals
Common chemicals used in papermaking include titanium dioxide, calcium carbonate, clays, starches, aluminum sulfate and talc. These and many other chemicals are used as fillers, coatings, strengtheners, and whiteners.
Fillers, for one, will increasingly be used as the inclusion of recycled materials in papermaking grows. Recycled fiber is weaker and shorter, requiring more fillers. Use of recycled fiber will also increase demand for pulping and deinking, because recycled materials need to have dyes, inks, and contaminants removed. Wet-strength resins and sizes, (which are used to improve paper strength and printability), as well as biocides and chelating agents, (which help remove contaminants) will also benefit.
Use of surfactants in papermaking will grow 2.2%/yr through 2002, according to Freedonia. Surfactants are used for deinking of recycled paper as well as in defoamer applications. Some growth for surfactant systems exists in the bleaching and process wastewater area as well.
Clays and titanium dioxide account for the largest share of papermaking chemicals--around one-half of total volume. But, cost benefits and performance advantages will boost calcium carbonate demand more quickly. Also, the shift from alkaline to acid papermaking will continue to benefit certain chemicals.
Paper chemicals prices set to fall
Prices for paper chemicals are set to fall, according to Purchasing's Index of paper chemicals prices. The index, which comprises transaction prices of industrial chemicals used in papermaking, including chlorine, soda ash, caustic soda, titanium dioxide, sodium sulfate, and sodium chlorate has fallen steadily all year long, from a high of 93 in January, all the way down to 76 in July. Buyers price forecasts show the index slipping further in the second half of '99--down as far as 74, then inching up to 76 by the second quarter of next yea
