Advanced Search
MyIDEAS: Login

Optimized on-line process control of bleaching operations with OptCab

Contents:

Author Info

  • Flisberg, Patrik

    ()
    (Department of Mathematics, Linköping University)

  • Nilsson, Stefan

    ()
    (Billerud Skärblacka AB, Sweden)

  • Rönnqvist, Mikael

    ()
    (Dept. of Finance and Management Science, Norwegian School of Economics and Business Administration)

Registered author(s):

    Abstract

    To produce pulp for paper production or as market pulp is a complicated on-line process with many integrated stages that impact the final quality. In the bleaching plant which is at the end of pulp production, the main objective is to increase pulp brightness within specified limits. Here chemical treatments are applied in sequential stages to achieve the right brightness while striving to maintain the pulp strength as unaffected as possible. The raw material, i.e. pulp logs and wood chips from saw mills, differ in quality and properties. Due to this, it is important to continuously update the amount of chemicals added to the pulp in real-time. This is typically done by experienced operators. In this paper, we describe an on-line optimization based decision support system called OptCab that controls the bleaching process at Billerud AB's paper mill in Skärblacka. The solution approach is based on two phases. In phase one, we establish approximations of each of the processes based on process data collected on-line. These approximations are found by solving a set of constrained least square problems and are updated every 15 minutes. In phase two, we formulate an overall nonlinear control problem that links all stages together and aims to minimize the cost of chemicals. This is solved on-line every five minutes. The system has been in operation during the last three years providing a 10% reduction in the use of chemicals. Additional benefits include a more stable brightness quality.

    Download Info

    If you experience problems downloading a file, check if you have the proper application to view it first. In case of further problems read the IDEAS help page. Note that these files are not on the IDEAS site. Please be patient as the files may be large.
    File URL: http://www.nhh.no/for/dp/2007/0907.pdf
    Our checks indicate that this address may not be valid because: 404 Not Found. If this is indeed the case, please notify (Stein Fossen)
    Download Restriction: no

    Bibliographic Info

    Paper provided by Department of Business and Management Science, Norwegian School of Economics in its series Discussion Papers with number 2007/9.

    as in new window
    Length: 19 pages
    Date of creation: 27 Mar 2007
    Date of revision:
    Handle: RePEc:hhs:nhhfms:2007_009

    Contact details of provider:
    Postal: NHH, Department of Business and Management Science, Helleveien 30, N-5045 Bergen, Norway
    Phone: +47 55 95 92 93
    Fax: +47 55 95 96 50
    Email:
    Web page: http://www.nhh.no/en/research-faculty/department-of-business-and-management-science.aspx
    More information through EDIRC

    Related research

    Keywords: Pulp production; on-line optimization based decision support system; nonlinear control problem;

    Find related papers by JEL classification:

    This paper has been announced in the following NEP Reports:

    References

    No references listed on IDEAS
    You can help add them by filling out this form.

    Citations

    Lists

    This item is not listed on Wikipedia, on a reading list or among the top items on IDEAS.

    Statistics

    Access and download statistics

    Corrections

    When requesting a correction, please mention this item's handle: RePEc:hhs:nhhfms:2007_009. See general information about how to correct material in RePEc.

    For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: (Stein Fossen).

    If you have authored this item and are not yet registered with RePEc, we encourage you to do it here. This allows to link your profile to this item. It also allows you to accept potential citations to this item that we are uncertain about.

    If references are entirely missing, you can add them using this form.

    If the full references list an item that is present in RePEc, but the system did not link to it, you can help with this form.

    If you know of missing items citing this one, you can help us creating those links by adding the relevant references in the same way as above, for each refering item. If you are a registered author of this item, you may also want to check the "citations" tab in your profile, as there may be some citations waiting for confirmation.

    Please note that corrections may take a couple of weeks to filter through the various RePEc services.