- Complete pulp mills
- Chemical pulping
- Wood handling
-
Cooking and fiber line
- Cooking
- Screening
- Washing
- Oxygen delignification
- Bleaching
- Services for cooking and fiberline
- Pulp drying
-
Chemical recovery
- Evaporators
- Recovery boilers
- White liquor plant
- Process support and optimization
- Rebuilds and upgrades
- Heat and power production
- Services for chemical recovery
- Air emission control
- Other value-adding processes
- Dissolving pulping
-
Mechanical pulping
- Chip washing
- Chip treatment
- Refining and grinding
- Steam separation
- Washing
- Bleaching
- Screening and cleaning
- Services for Mechanical pulping
- Recycled fiber
-
Automation for pulp
- Analyzers and measurements
-
APC Advanced Process Controls
- Valmet WinGEMS
- Valmet Debarking Optimizer
- Valmet Batch Cooking Optimizer
- Valmet Continuous Cooking Optimizer
- Valmet Washing Line Optimizer
- Valmet Oxygen Stage Optimizer
- Valmet Bleaching Optimizer
- Valmet Evaporation Optimizer
- Valmet Recovery Boiler Optimizer
- Valmet Recovery Boiler Leak Detector
- Valmet Recovery Boiler Sootblowing Optimizer
- Valmet Causticizing Optimizer
- Valmet Lime Kiln Optimizer
- Valmet Recovery Line Management
-
AQC Advanced Quality Controls
- TMP Predictive Quality Controller
- TMP Specific Energy Optimizer
- Paper Machine Blend Controller
- Paper Brightness Optimizer
- Power Contract Optimization
- Paper Quality Software Sensors
- Paper Quality Real Time Optimizer
- Sensor Validation
- IMonitor Performance Monitor
- Ponderosa Pulp Quality Software Sensors
- IMAS Process Control Data Server
- Mill information management
- Distributed control systems
- Quality management systems
- Boiler Diagnostics Systems
- Services for pulp
- Fiber Technology Center
- Pulp news and stories
- Pulp
- Cooking and fiber line
- Oxygen delignification
- White liquor oxidation
White liquor oxidation system
The purpose of white liquor oxidation is to improve the Na/S balance of the Kraft process by replacing make-up caustic with internally generated alkali.
Valmet offers two well proven and efficient alternatives, an air based oxidation system for production of partially oxidized white liquor for oxygen delignification and an oxygen based system for production of fully oxidized white liquor for bleaching and oxygen delignification. Oxidized white liquor can also be applied for many gas scrubbing applications.
Air based system
With the air-based system, oxidation takes place in a multi-stage reactor. The air is fed to the reactors from a rotary air blower. Primarily, partial oxidation takes place and the sulfide is converted into thiosulfate. The cost of operation is low as atmospheric air is used to supply the required oxygen. This process is highly suitable if the main target is the elimination of sulfide.
Sulfide conversion to thiosulfate: 97-98 %.
Oxygen based system
In the oxygen based process oxidation is carried out in pressurized loop reactors. High efficiency jet mixers secure that the liquid phase is saturated with oxygen at all times.
This technology provides good environment for high reaction rate for the conversion of sulfide to sulfate – an inert compound that will not be further oxidized in downstream processes.
Sulfide conversion into thiosulfate: 98–99 %
Sulfide conversion into sulfate: up tp 60 %