Spanish pulp mill uses ozone generation system for bleaching operation
SNIACE S.A. is a pulp mill located in Torrelavegas, Spain (near Santander), with an annual production capacity of 66,000 tons of dissolving pulp from Eucalyptus. Forty percent of the pulp is used in its own viscose plant, and the remaining 60% is sold to the market.
SNIACE’s cellulose is used to make various products, such as viscose fibers for the textile industry; acetate for the chemical industry; sanitary towels, insulators and cellulose film for industrial applications; and cloths and sponges for household use.
SNIACE is the only factory producing short fiber soluble cellulose in Europe. It chose the WEDECO ozone technology from Xylem to meet the high environmental targets from the European Union and received European subsidies as a result.
Xylem supplied a containerized WEDECO ozone generator to SNIACE. The system was installed in February 2007 and successfully handed over in March 2007.
Xylem’s WEDECO ozone technology solution and expertise in process design are the perfect match for the pulp and paper industry, in which the high uptime requirements are crucial for the successful operation of the bleaching line.
The ozone plant is designed for an ozone production capacity of more than 3,000 ppd at 12 weight percent (wt%) and 28°C.
An ozone dosage of up to 7 kg/ton of pulp will result in a final brightness of greater than 93% ISO, a pulp viscosity of 500 cu dm/kg and a final kappa of less than 0.4.
The Xylem scope of supply included:
• One containerized WEDECO PDO 6000 ozone system,
• Two catalytic ozone destructors type WEDECO COD 810, skid-mounted, including water separator and gas/steam heat exchanger, and
• Skid-mounted cooling water pumping and heat exchanger
Containerized systems are ideal solutions for the outdoor installation needs of the site and offer the following advantages:
• The entire ozone system is completely preassembled and tested at Xylem’s factory in Herford, Germany.
• No expensive building or ventilation system is required, since all containers are insulated and air-conditioned.
• The on-site installation and commissioning time is minimized with a “plug and play” concept.
• Foundation work is considerably reduced due to small footprint.
• Modular design makes future system expansions easy.