Potential of two-stage oxygen delignification for Eucalyptus camaldulensis pulp | |
| Author | Zhang, Xian |
| Call Number | AIT RSPR no. PP-03-03 |
| Subject(s) | Eucalyptus camaldulensis Pulping |
| Note | A research study submitted in partial fulfillment of the requirements for the degree of Master of Engineering. |
| Publisher | Asian Institute of Technology |
| Abstract | Oxygen delignification has been rapidly developed since the early 1980's, when serious concern about energy consumption, pollution control and bleaching plant effluent discharges came to the surface. Today effective oxygen delignification is of great imp01iance for both ECF and TCF bleaching processes for both technical and economical reasons. Two-stage oxygen delignification makes it possible to achieve a kappa number low enough especially for TCF bleaching, still remaining an acceptable selectivity, high yield and viscosity. The aim of the study is to find out the difference between one and two-stage oxygen delignification and to optimize the reaction conditions in two-stage oxygen delignification for E. camaldulensis pulp. The optimal alkali charge in one-stage oxygen delignification was found to be 2%. The viscosity and kappa reduction in this case were 613ml/g and 31.4% respectively. In two-stage oxygen delignifcation, 01 stage was optimized regarding reaction time, alkali charge and temperature. The viscosity was preserved much better by increasing alkali charge than prolonging reaction time and the higher brightness was obtained by increasing alkali charge than increasing temperature. The optimal reaction conditions in 01 stage were found to be: NaOH 3%, 85°C, 35 min. The kappa reduction of 28.5% and the viscosity of 622 ml/g were achieved in this case. The second oxygen stage was optimized regarding alkali charge and temperature. Significant kappa reduction, brightness and viscosity preservation were achieved at 105°C with the alkali charge of 2%. Comparison between one-stage and two-stage oxygen delignification showed that approximately 10% units more kappa reduction was achieved in the two-stage of oxygen delignification compared to that in one-stage. |
| Year | 2003 |
| Type | Research Study Project Report (RSPR) |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Pulp and Paper Technology (PP) |
| Chairperson(s) | Malinen, Raimo |
| Examination Committee(s) | Kolehmainen, Heikki;Viljakainen, Esa |
| Scholarship Donor(s) | Government of Finland I AIT Fellowship |
| Degree | Research Studies Project Report (M.Eng.) - Asian Institute of Technology, 2003 |