Preliminary investigations on the feasibility of co-production of cane pulp and raw sugar

Abstract

Laboratory-scale mechanical refiners were used to prepare four varieties of sugar cane for depithing, and for the production of refiner mechanical pulp (RMP) and chemi-mechanical pulp (CMP) from depithed canes and from cane rind. Pulp quality was assessed and the amount of raw sugar recovered was measured to determine if co-production of cane pulp and raw sugar might be feasible on an industrial scale. The tests showed that simple RMP pulps with strength properties adequate for commercial purposes cannot be prepare~ from sugar cane, but CMP pulps with strength properties equivalent to hardwood CMP are feasible, at least at brightness levels below 60% ISO. The yield and quality of CMP pulps prepared from depithed canes and cane rind were .: ...... influenced by the sugar cane variety. The use of brightening agents such as hydrogen peroxide, sodium metabisulphite and sodium hydrosulphite improved overall pulp brightness but did not remove dark coloured plant fragments. CMP pulps prepared from sugar cane rind had slightly poorer pulp strength properties and lower brightnesses than pulps made from depithed whole cane. Raw sugar recovery from the mechanical pulping processes was c.22% lower disruption was reduced and the washing method was crude.