Automated KMnO₄ Feeding with the LAMBDA POWDER DOSER into the Reactor
When a laboratory process moves toward continuous operation, controlled feeding of solid reagents becomes an important part of the process. Automated powder dosing can provide a defined feed rate while reducing the need for manual addition.
The LAMBDA POWDER DOSER is a programmable powder feeder designed for automatic, continuous or intermittent dosing of free-flowing powders and crystalline substances. It can be configured for different feeding rates and vessel sizes to suit laboratory and process-development applications.
LAMBDA POWDER DOSER in Continuous Graphene Oxide Production
A 2025 study by Wang, Xue and Züttel demonstrated a continuous production prototype for graphene oxide/multi-walled carbon nanotube (GO/MWCNT) composites. The process included an automatic feeding and mixing stage in which KMnO₄ and graphite were separately introduced into concentrated H₂SO₄ before the oxidation process.
The published study specifically identifies the LAMBDA POWDER DOSER as part of the automatic feeding system.
Research reference: Wang, Y.; Xue, Y.; Züttel, A. Continuous production prototype for scaling up of graphene oxide/carbon nanotube composite synthesis towards efficient hydrogen storage. Green Chemistry, 2025, 27, 756–769. DOI: 10.1039/D4GC04753B.
Controlled 5 g/min KMnO₄ Feeding
In the reported experiment, 150 g of potassium permanganate (KMnO₄) was introduced at 5 g/min into 656 mL of concentrated H₂SO₄, with the temperature maintained below 5 °C. The LAMBDA POWDER DOSER was integrated with two double-walled, jacketed bottles and continuous stirring.
The controlled feed was then integrated with the rest of the continuous process. The cooled KMnO₄/H₂SO₄ solution and a graphite/H₂SO₄ suspension were simultaneously transferred through a T-joint into a PTFE tube reactor.
Managing an Exothermic Process
The addition of KMnO₄ to concentrated H₂SO₄ is exothermic, making heat generation an important consideration in the continuous process. In the study, the LAMBDA POWDER DOSER was incorporated into an automatic feeding and mixing system together with continuously stirred, jacketed vessels.
Cooling was used to maintain the temperature below 5 °C during the KMnO₄ addition stage. The overall process design combined controlled feeding, mixing, cooling and continuous-flow reactors to help prevent uncontrolled reactions during the oxidation process.
From Controlled Feeding to Continuous Production
The automated feeding stage was integrated into a larger continuous process involving mixing, oxidation and subsequent composite formation. The researchers ultimately produced 100 g of GO/MWCNT composite, while noting that maintaining continuous feeding at the LAMBDA POWDER DOSER feeding point could enable production at kilogram scale.
This study provides a practical example of how controlled powder feeding can become part of a continuous chemical production workflow, rather than simply being a standalone dosing operation.
Why Consider the LAMBDA POWDER DOSER?
For researchers developing continuous synthesis or automated reagent addition, the LAMBDA POWDER DOSER offers:
- Programmable powder feeding
- Continuous or intermittent dosing
- Adjustable dosing speed and pauses
- Different vessel capacities
- Remote-control options for process integration
- Controlled-atmosphere operation with suitable configurations
- Compact integration with laboratory reactors and process equipment
The actual feed rate depends on the properties of the powder and the selected DOSER configuration, so calibration with the specific material is recommended.
A Practical Powder-Feeding Application
The Wang et al. study demonstrates a practical application of the LAMBDA POWDER DOSER in a continuous graphene oxide production process: 150 g of KMnO₄ was automatically introduced at 5 g/min as part of a cooled, continuously stirred feeding system.
For laboratories moving from manual reagent addition toward controlled, programmable and continuous powder feeding, the LAMBDA POWDER DOSER provides a practical way to integrate solid dosing into the process.
Explore the LAMBDA POWDER DOSER
If you need to feed powders or crystalline solids at a controlled rate, LAMBDA can help you select the appropriate POWDER DOSER configuration based on your powder, required feed rate and process setup.
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