A reduced environmental load while maintaining pulp quality
The use of oxygen-based systems to remove lignin from pulp significantly reduces the biological load (AOX, COD, and BOD) in a pulp mill compared to systems utilizing chlorine. The trade-off in using oxygen delignification in the past has been an increase in fiber damage, and a resulting loss in fiber strength. ANDRITZ has developed and enhanced its oxygen delignification technology to not only efficiently reduce the environmental load, but also maintain pulp quality.
Single- or two-stage reactor systems
ANDRITZ technology provides highly efficient oxygen delignification using one or two reactors, depending upon process requirements. The reactors are pressurized and operate in the medium consistency range.
The ANDRITZ process ensures a significant reduction in kappa with low variation (uniform pulp quality). In the ANDRITZ oxygen delignification process, screening is performed after the oxygen stage, prior to washing and bleaching, to increase the wood yield since a considerable fraction of shives is converted into good pulp.