Case Study 2: Pulp & Paper

Operator: ESSITY

Modules combined: Module 1 combined with Module 3, Module 4, Module 5, and Module 6

Focus: energy, water, acid, and sulphate-compounds recovery

 

ESSITY – P&P Industry - recycles waste paper and food cartons into toilet paper, hand towels, kitchen towels, and napkins. Although over 98% water reuse is common in paper mills, excessive recycling can lead to issues like increased temperature, organic load, and various concentrations, resulting in liquid waste. CORNERSTONE aims to research and demonstrate modern technologies for integrated treatment of P&P effluents to recover water, energy, and materials sustainably.

 

The CORNERSTONE systems integration plan for typical recycled fibre (RCF) industrial effluents includes four key technologies:

• (a) Non-clogging heat exchangers (Module 1),
• (b) Hollow fiber nanofiltration (HF-NF) for selective removal of ions and organic matter (Module 3),
• (c) Bipolar electrodialysis (BMED) for converting permeate to acid and base (Module 5), and
• (d) Membrane crystallization (MCr) for removing inorganic substances as a solid by-product (Module 6).

The integrated process involves pre-treatment, pH control, and filtration through an HF-NF membrane unit, followed by BMED and MCr stages. Recovered thermal energy is utilized in MCr by preheating the NF concentrate. The goal is to optimize conditions for efficient continuous operation while promoting sustainable water, energy, and material recovery.

 

Added value for society

• Minimization of freshwater consumption though the drastic reduction of the industry’s water footprint.
• Recovery of valuable materials to produce new products (NaOH, HCl, CaSO₄) for industrial use in the spirit of the circular economy.
• Zero liquid discharge and protection of the environment.
• Sustainable development of the P&P industry and creation of new green jobs.