Potential of Elephant Grass for Pulp Production

Abstract

Elephant grass (Pennisetum purpureum) (EG) is a fast-growing plant with high biomass productivity in the range of 30-45 bone dry t/ha/yr. This high productivity qualifies EG as a potential raw material for bleached pulp production. This study evaluated elephant grass as a raw material for paper pulp production. This was accomplished through determining its full chemical and morphological characterization, pulpability at kappa numbers 15 and 20 via the kraft and soda-AQ processes, and its pulp bleachability to 90% ISO brightness. The results were compared with those of a commercial hybrid eucalyptus wood clone (Eucalyptus urophylla x Eucalyptus grandis) (EUCA) that is widely planted in Brazil. Concerning its chemical composition, the elephant grass presented a high ash (60,100 mg/kg) and total extractives content (14.8%). However, the elephant grass showed good potential for pulp production. The kraft process was the ideal cooking process at kappa number 20, producing the highest screened yield (47.9%), bleachability (0.163 Δkappa/TAC), and good viscosity (812 dm3/kg). For EUCA, the ideal cooking process was the kraft process at kappa number 20, resulting in a screened yield of 52%, bleachability of 0.217 Δkappa/TAC, and final viscosity of 886 dm3/kg. This high productivity qualifies EG as a potential raw material for bleached pulp production.