Comparative study of percentage yield of pulp from various Nigerian wood species using the kraft process

Twenty Nigerian wood species namely, Akomu (Pycnanthus angolensis), Ofun (Avicennia germinans), Akun (Uapaca guineensis), Oporoporo (Pterygota macrocarpa), Abura (Hallea ciliata), Masonia (Masonia altissima), Afara (Terminalia superba), Agba (Entada gigas), Mahogany (Khaya ivorensis), Obeche (Triplochiton scleroxylon), Itako (Strombosia pustulata), Odoko (Ipomoea asarifolia), Itara (Sacoglottis gabonensis), Eki-Eki (Lophira alata), Iroko (Milicia exelsa), Araba (Ceiba pentadra), Erimado (Ricindendron heudelotii), Erun (Erythropleum suaveolens), Opepe (Nauclea diderrichii) and Okilolo (Symphona globulifera) were subjected to kraft pulping process in order to obtain pulp. The mean percentage yield of pulp obtained from the twenty hardwood species were found to be significantly different when the data were subjected to Duncan’s multiple range test at p = 0.05. Abura (H. ciliata), Afara (T. superba) and Okilolo (S. globulifera) gave the highest mean pulp yield of 50% each while Iroko (M. exelsa) gave the lowest pulp yield of 35%. The difference in pulp yields is typically attributed to lignin content and lignin type present in these wood species. The infra red analysis of the pulp obtained from the various wood species confirmed the chemical integrity of the pulps obtained from all the hard wood species surveyed.Key words: Kraft pulp, Nigerian wood species, pulp yield, cellulose