Effects of Operational Variables on the Pulp Yield and Lignin Dissolution of Cyperus Ar-ticulatus

Abstract

The influence of operational variables on the pulp yield and lignin dissolution of Cyperus articu-latus was studied. The study was aimed at optimizing pulping variables and selecting suitable delignification conditions for the production of pulp and paper from the plant. Cyperus articula-tus chips were delignified in a laboratory pulpwood digester under the soda pulping process us-ing the following pulping conditions: time (30 – 150 minutes), temperature (120 – 150oC), liquor to solid ratio (10:1 – 20:1) and concentration of cooking liquor (4 – 6% caustic soda). Experi-mental data were fitted into a central composite design and the polynomial equation derived re-produced the pulp yields and the residual lignin contents with errors less than 6%. Optimum pulp yields were obtained using low values of the process variables while the reverse was the case for the residual lignin. Pulping at high temperatures for a short cooking time with low to medium concentration of pulping liquor gives the best compromise for both pulp yield and resid-ual lignin content.