Pulper 7: How Alier Is Scaling Up Recycling Capacity and Cutting Energy Consumption

On March 23, a special transport, 33 meters long and 4.7 meters wide, arrived at Alier’s plant in Rosselló carrying the screen piece of Pulper 7. Moving it required cutting the railway line, dismantling road signs and traffic lights, and a night-time journey with police escort.

The logistics alone tell you something about the scale of this investment.

What Is a Pulper and What Role Does It Play?

A pulper is one of the most fundamental pieces of equipment in paper manufacturing. Its function is to shred paper and cardboard used as raw material, mixing it with water to form paper pulp, the base from which all paper production begins.

Pulper 7 is a drum pulper, which sets it apart from the conventional vertical pulpers Alier currently operates. Unlike vertical pulpers, which work in batches, a drum pulper feeds and operates continuously. This alone represents a significant efficiency gain. Additionally, in the final section of the drum, the pulp goes through a screening stage that separates and rejects the largest impurities from the process, making the overall output cleaner and the process more efficient, with less pasta loss in the rejects.

The Technical Specifications

Pulper 7 has been designed for high-volume, continuous operation:

• Drum diameter: 4,250 mm.
• Drum length: 31,490 mm.
• Pulping consistency: 20–30%.
• Main motor nominal power: 1,100 kW.
• Energy consumption per tonne fed: 30 kWh/t.

It will be located in the raw materials yard, parallel to the feed belt of the existing drum pulper (Pulper 6).

The Energy Efficiency Case

At first glance, 1,100 kW of installed power sounds like a significant increase. But the comparison with the existing pulpers tells a different story.

Alier currently operates two high-consistency pulpers for this workload: Pulper 3 (450 kW) and Pulper 5 (450 kW), with an energy consumption of 50 kWh per tonne fed. Pulper 7 brings that down to 30 kWh per tonne. The higher installed power is required only at startup. In continuous use, Pulper 7 consumes far less than the combined consumption of the two conventional pulpers it replaces.

The result is approximately a 40% reduction in energy consumption. Pulpers 3 and 5 will be kept as backup.

A Milestone for Tetra Pak Processing

The incorporation of Pulper 7 is a strategic milestone in Alier’s path toward increasing the use of Tetra Pak cartons, also known as UBC (Used Beverage Cartons), as raw material. With this new equipment, Alier will be able to process up to 200,000 tonnes per year of Tetra Pak.

This has a direct impact on raw material costs, reducing dependency on other inputs and improving alignment with Alier’s recycling policy. It also contributes to a meaningful reduction in the company’s carbon footprint.

What This Means in Practice

The combined effect of Pulper 7 is what Alier describes as creating sustainable value: lower costs, better operational efficiency, reduced energy consumption, and a smaller environmental footprint, all from a single investment.

It also prepares Alier for growth. The capacity unlocked by Pulper 7 opens the door to processing volumes that were simply not viable before. In a market where raw material costs and environmental performance are increasingly decisive, that positions Alier well for what comes next.

The screen piece arrived on March 23. The shredding piece will follow in the coming days. Full operation is expected shortly after both pieces are installed and commissioned.