Integrated Pulp Mill Targets Low-Emission Production

Wuzhou Special Paper (Jiangxi) Co. Ltd. has commissioned ANDRITZ to supply core technologies and equipment for a new greenfield pulp mill in Hukou County, Jiujiang City, Jiangxi Province, China. Scheduled for start-up in the first quarter of 2027, the mill is designed to strengthen pulp self-sufficiency while reducing environmental impact in large-scale paper production.

Integrated process design for pulp production
The project covers key process areas of a modern pulp mill, including fiber processing, chemical recovery, and energy generation. The fiberline incorporates continuous cooking using the LoSolids process, followed by brown stock washing, screening, two-stage oxygen delignification, and a four-stage elemental chlorine-free (ECF) bleaching sequence.

Washing stages are supported by drum displacer washers and press-based systems to reduce water and chemical consumption while maintaining pulp quality. These technologies are designed to optimize yield and minimize effluent load, aligning with environmental compliance requirements in China’s pulp and paper sector.

Chemical recovery and energy efficiency
The recovery cycle includes a recovery boiler operating at steam conditions of 515 °C and 105 bar(g), enabling efficient energy generation from black liquor combustion. The system integrates flue gas cooling, air preheating, and feedwater preheating to increase thermal efficiency and power output.

A complete white liquor plant is also part of the scope, including recausticizing and lime kiln operations. The integration of gasification technology allows fossil-free lime kiln operation, contributing to a reduced carbon footprint. The recausticizing process incorporates high-efficiency filtration to improve chemical recovery rates and process stability.

Biomass gasification and decarbonization
The mill includes a biomass gasification system based on circulating fluidized bed (CFB) technology. This system processes dried biomass to generate fuel gas for internal energy use, reducing reliance on fossil fuels and supporting decarbonization targets.

Additional environmental technologies include an ash re-crystallization system that removes chloride and potassium from electrostatic precipitator ash while recovering sodium and sulfate. The system uses evaporative crystallization with mechanical vapor recompression, enabling resource recovery and reducing waste streams.

Emissions control and process safety
A mill-wide non-condensable gas (NCG) handling system is designed to collect and safely incinerate odorous gases generated during pulping processes. Combustion in a dedicated low-NOx boiler minimizes emissions, while integrated sulfur dioxide recovery further enhances environmental performance.

These systems contribute to compliance with increasingly stringent emissions regulations and support stable mill operation under varying process conditions.

Strategic role in the digital supply chain
The new pulp mill is expected to enhance Wuzhou Special Paper’s position within the digital supply chain by integrating production, energy management, and environmental control systems. This allows improved traceability of raw materials, optimized resource utilization, and consistent pulp quality across downstream paper production.

Edited by Romila DSilva, Induportals Editor, with AI assistance.