Online double spectroscopic measurement of washing losses
| Reference number | |
| Coordinator | Sveriges Lantbruksuniversitet - Institutionen för skogens biomaterial och teknologi |
| Funding from Vinnova | SEK 500 000 |
| Project duration | December 2014 - April 2015 |
| Status | Completed |
| Venture | Strategic innovation programme for process industrial IT and automation – PiiA |
Purpose and goal
The objective was to evaluate UV/NIR for monitoring the chemical content in the pulp wash. The method will replace conventional manual analysis and will give continuous and detailed information which will improve the possibilities for regulating the process which would result in less consumption of chemicals and costs. Two probes, UV/NIR (PulpEye AB) were installed in the flow and spectra were correlated to manual analysis of POC, DOC and minerals measured in laboratory. The results show that UV/NIR can monitor DOC and Na and that NIR gives additional process related information.
Results and expected effects
We have shown that UV can be used for measuring DOC, the amount of Na and conductivity (relates to the amount of Na). NIR proved useful for measuring DOC and also to process related information. On-line monitoring with UV/NIR has a great potential and several paper mills have expressed an interest for using the technology for monitoring other important chemicals such as fatty acids, triglycerides, CH, lignin, in the pulp wash and other flows in the process.
Approach and implementation
The installation of the device, (UV/NIR-probes) was made in the final stage of a pulp wash. Spectra were taken 10/min during a period of instability on the process to ensure a good variation on the data. Manual samples, n= 48, were taken and analyzed for POC, DOC and minerals at an external laboratory. The NIR and UV spectra were analyzed using multivariate data analysis.