Pulp & Paper

With increasing regulatory pressure and growing market demand, the pulp and paper industry must find new ways to reduce the environmental impact and to improve product quality and competiveness. By choosing OZONE, as one of the strongest oxidants, many mills in various parts of the world, have already obtained these benefits.

OZONE is considered today as one of the Best Available Technologies for several applications in the P&P industry. Beside pulp bleaching where OZONE is already implemented as a very economical and environmental friendly technology, it is also used to improve the process- and wastewater quality of mills.

OZONE for pulp bleaching

OZONE bleaching marks a clear milestone in the development of pulp bleaching methods by combining high brightness and pulp strength with lowest specific pulp production costs - a smart technology where ecofriendliness is compatible with quality and production goals. With more than 30 pulp mills in operation worldwide, OZONE can be considered as one of the safest technologies to meet market demand for:

Better pulp quality
Low specific pulp production costs
High reliability
Easy and safe operation
Compliance with strict environmental regulations

OZONE can be applied as a bleaching agent on both softwood and hard wood pulps. As “Z-stage” it is considered today as an integral part of bleaching sequences in totally chlorine-free (TCF), and in elemental chlorine-free (ECF) processes. Keeping the same delignification efficiency, ozone is very efficient in terms of operating cost since each kg of ozone can replace between 2 to 4 kg of pure chlorine dioxide.

OZONE for waste- and process water treatment

OZONE dissolved in process and/or waste water can eliminate pollutants like i.e. organic compounds (COD) as well as colorants until their levels are below the legal limits. The well known applications for OZONE in the P&P industry are elimination of inert organic material (COD), colour removal, reduction of AOX concentration, disinfection, odour elimination, improvement of SVI, etc.. Considering the demand for stricter discharge limits and the requirement to enable process water recycling, OZONATION ensures the following advantage:

OZONE but especially the combination of OZONE and Biofilter as a tertiary treatment step represents the most reliable process to eliminate inert COD
No overdosing with adopted control philosophy
No additional sludge production
No discharge of concentrates
Easy to operate compared to other technologies
Extensive decolouration
makes recycling of water possible (even for white paper production)
Very low operating costs

Products

OZONE production mainly requires electricity and oxygen generally produced locally. Compared to other bleaching chemicals, ozone is a real on-site technology since not any cost for chemical delivery, logistics and storage facility is involved. It makes the pulp mill more independent from the chemical market where the evolution of costs and availability is difficult to forecast. For applications in the P&P industry, Xylem provides mainly the WEDECO PDO-series. WEDECO ozone generators for the P&P industry are usually installed in special engineered container houses called Z-Compact Systems. The Z-compact system perfectly meets the demands by providing ozone production capacities in the range of 15- 250 kg/h per generator.

Next tab...