Optimization of pulp yield for catalyzed-mea conversion of agro-wastes to paper-pulp

This paper investigates the suitability of Catalyzed-MEA pulping of agro-biomass (empty fruit bunches), viewed as alternative raw material for pulp and paper production. In this research work, the effect of three (3) pulping additives (anthraquinone, polysulfide and surfactant) used in the monoethanolamine pulping of agro-biomass, their possible interactions and the influence of operational variables on pulp yield were investigated. The agro-fibers were cut in bits and pulped using a biomass digester. For the pulping process, a 15litre capacity rotating type wood digester was used to pulp 1000 o.d. g of biomass considering the best pulping conditions investigated in previous research study (cooking temperature =125±2oC, cooking time =77.783minutes, liquor concentration=87.493%, and liquor/biomass ratio=4.832/1) that furnished the best pulp yield. The lid of the digester is attached at the top with measuring devices of temperature and pressure with careful consideration of other factors to ensure the cooking conditions are strictly adhered to. The cooking operation of the digester was designed so that the experimental conditions considered the following factors and levels: Factor 1: 0, 0.25 and 0.5% Surfactant charge, Factor 2: 0, 2 and 4% polysulfide charge, Factor 3: 0, 0.25 and 0.5% anthraquinone. The experimental design had 27 treatments (3×3×3) and 2 replicates. In this research, a non-ionic commercial surfactant was used; the polysulfide was generated by the addition of sulfure to the hot white liquor (80oC) under agitation until complete dissolution. By using a central composite factorial design, equations relating the dependent variable (pulp yield) to the different independent variables (surfactant, polysulfide and anthraquinone concentration) were derived; reproducing the experimental result for the dependent variable with errors less than 15%. The pulp yield range (42.12-53.17%), Kappa number (10.8-34.3), viscosity (382-849 ml/g) and brightness (65.7-90.6%). This is an indicative of the fact that the cellulosic pulp materials are averagely appropriate for high-brightness printing papers. It is also recommended that the cellulosic pulp obtained from the MEA process as virgin fiber is suitable for strengthening secondary fibers in recycled papers and also for developing certain types of writing, printing and packaging paper materials.