Alkaline pulping of some eucalypts from Sudan

Area of Science:

• Forestry and Wood Science
• Pulp and Paper Technology
• Sustainable Materials

Background:

• Eucalyptus species are vital for pulp and paper industries globally.
• Sudan possesses significant Eucalyptus plantations with underutilized potential for papermaking.
• Evaluating diverse Eucalyptus species and pulping methods is crucial for sustainable resource utilization.

Purpose of the Study:

• To assess the pulping and papermaking potential of four Eucalyptus species from Sudan.
• To compare the efficacy of various alkaline pulping methods, including kraft, soda-AQ, ASA, and ASAM.
• To determine the suitability of the resulting pulps for writing and printing paper grades.

Main Methods:

• Four Eucalyptus species (E. camaldulensis, E. microtheca, E. tereticornis, E. citriodora) were characterized.
• Pulping trials were conducted using kraft-AQ, soda-AQ, ASA, ASAM, and kraft methods.
• Pulp properties (yield, delignification, mechanical, optical) were evaluated.
• Selected pulps underwent totally chlorine-free bleaching (OQ1O/PQ2P).

Main Results:

• ASAM pulping yielded the best results across all evaluated Eucalyptus species.
• E. citriodora and E. tereticornis pulps showed promising characteristics with various methods.
• Bleached E. citriodora pulps achieved 88% ISO brightness using a TCF sequence.
• ASAM pulps exhibited superior mechanical and optical properties compared to other methods.

Conclusions:

• ASAM pulping is highly effective for Sudanese Eucalyptus species, offering excellent yield and pulp quality.
• Eucalyptus pulps, particularly from E. citriodora via ASAM pulping, are suitable for manufacturing writing and printing paper.
• These findings support the sustainable use of Sudanese Eucalyptus resources for the pulp and paper industry.