Comparative assessment of the pulping potentials of soda and mea processes for the development of paper-pulp from sugarcane bagasse

Abstract

Pulping trials were carried out using MEA and the soda process comparing their pulping potentials. The operating conditions such as the concentration of the cooking liquor (50%, 75%, 100%) for MEA and (10%, 15%, 20%) for NaOH, the maximum cooking temperature (150oC, 160oC, 170oC) and cooking time (60, 90, 120minutes) for both processes were investigated systematically to establish optimal pulping conditions. The agro-biomass used in this investigation is Sugarcane Bagasse viewed as alternative raw material for pulp and paper production. The lignin content of Bagasse (19.5%) was low; indicating that Bagasse should be easier to pulp. The optimum cooking conditions (independent variables) for MEA pulping were 75% MEA concentration, 150oC cooking temperature and 90 minutes cooking time. Excel 2013 was used to analyze the effect of independent variables on yield of bagasse pulp and properties of furnished paper from MEA process in comparison with the Soda process which include tear index, tensile index, burst index and folding endurance with errors less than 15% in all cases. The Kappa number range (12.7-16.9), viscosity (270-870 ml/g) and brightness (62.1-93.2%) of bagasse pulp are appropriate for high-brightness printing and writing papers. The physical properties of furnished paper, tear index (13.4 mN.m2/g), tensile index (71Nm/g), Burst index (4.8 KN/g) and folding endurance (82) recommend the cellulosic pulp from Sugarcane Bagasse obtained from the MEA process for strengthening the virgin fiber in recycled papers and also for developing certain types of printing and packaging papers. Due to the awareness towards the negative impact of kraft mill’s effluent to the environment recently, soda pulping started to regain its popularity among the pulp mills especially non-wood based pulp mills. MEA process is more economically attractive given its high pulp yield, despite the significant increase in chemical demand for bleaching. MEA pulping is a good alternative to soda pulping furnishing high pulp yield with less cooking temperature, i.e. 150oC, thereby saving a considerable amount of energy with less odoriferous pollutants and pollution load associated with the soda process.