+27 83 271 1808 | + 27 83 276 7922

Paper and Pulp

The global production of paper was 400 million tons in 2015. Production is expected to increase to attain a world production of 550 million tons in 2050. About 40–50 kg of sludge (dry) is generated in the production of 1 ton of paper at a paper mill. Various wastes are generated in pulp and paper mills, such as ash, dregs, grits, lime mud and pulp mill sludge. Over the years, these wastes have typically been sent to landfills or incinerated and this type of disposal can have a significant impact on the environment, damaging the water, soil and air.

We want to enable the paper and pulp industry to reduce specific landfilled solid waste, beneficiating it and ensure more water resource replenishment by creating a "fit for purpose" process using our innovative, energy efficient and environmentally friendly technologies.

The way we can assist  the industry is by using the Sinowatek Fundamental Process Template  to design a process where the sludge are treated and valorized in such a way that it can be used to create new value-added products.

PAPER AND PULP MILL SLUDGE WASTE

Pulp and paper mills generate various types of sludge: Primary sludge (fiber sludge), Biological sludge, Mixed sludge, De-Inking sludge, Hydroxide (chemical precipitation) sludge and Coatings sludge. The sludge results from wastewater treatment procedures used in the mills. The treatment procedures entail sedimentation, biological treatment, chemical precipitation, flotation and anaerobic treatment.

ANALYSIS AND RESEARCH

Samples of the sludge are tested to determine the composition of the sludge.

SEPERATION TECHNOLOGY

With the results of the analysis and research the sludge can be separated into a liquid and solid fraction by selecting innovative separation technologies explicitly tailored for paper and pulp sludge.

The Fournier Rotary Press technology is at the forefront of sludge dewatering. It is a high quality technology with superior performance and a small environmental footprint, making it the most desirable separation technology for this application.

For many years the belt press and the screw press have been the standard sludge dewatering devices in the paper industry. However the environmental legislation of recent years has forced many mills to install secondary or biological treatment for the wastewater in order to reduce trade effluent charges by reducing COD levels.

The addition of surplus biological sludge to the primary sludge for dewatering has been problematic for the belt press and the screw press. The Fournier Rotary Press is establishing itself as an ideal piece of equipment to process this mixture, and in other applications previously thought problematic.

The Fournier Rotary Press can better solids conditioning, thickening and dewatering, allowing higher dryness (the resulting solids content averages about 30%) at lower chemical dosages and therefore will improve the competitiveness of the mill using it. Primary solids become in such case in this part of the process already a value-added product.

The Fournier Rotary Press can better solids conditioning, thickening and dewatering, allowing higher dryness at lower chemical dosages and therefore will improve the competitiveness of the mill using it. Primary solids become in such case in this part of the process already a value-added product.

REJECT WATER TREATMENT

After the separation of the liquid and the solid fraction has taken place the liquid can be treated for storage, re-use or release. Flocculants and mechanical separation (Lamellae) are used to remove colloidal particles from the wastewater. Another treatment technology that is used by Sinowatek is Electro-coagulation.

DISINFECTION OF THE LIQUID

If the client wants to release the water, store the process water for long periods or use it as drinking water the treated water should be disinfected. Sinowatek can disinfect the water with the environmentally friendly Innowatech Anolyte® disinfectant - tradename Sulafect.

SOLID FRACTION

The solid fraction still in a viscous form can be dried by the progressive Pulse Combustion Drying (PCD) technology into a powder. This drying method is best suited, because the energy efficiency of the drying method is significantly (up to 50%) better than its nearest rival and it also ensure that no microbial activity will take place during storage and transportation on an industrial scale.

CIRCULAR ECONOMY OUTPUT

Pulp and paper mill sludge contain cellulose, calcium carbonate, lignin etc. and can be used in a dried state for low value applications such as deposition in agricultural fields and the production of energy. It can also be used in a dried state for high value applications such as the production of new materials like cellulose nanofibres.

We want to understand your challenges and problems therefore please contact us for an assessment or consultation.

FUNDAMENTAL PROCESS TEMPLATE

+27 83 271 1808 | + 27 83 276 7922