Process Research Tools for Pitch and Stickies
Deposition of pitch and stickies continues to plague pulp and paper makers,mainly in form of deposits on the equipment,and as spots and specks in the pulp and paper products.Analytical tools for process research on pitch and stickles are described.Appropriate fractionation methods for components in fiber suspensions are centrifugation and filtration in DDJ-type devices to separate dissolved,colloidal and larger pitch particles.Chemical analysis by GC and GC-MS can give the amounts and composition of wood pitch,AKD and other sizes,and soaps added in flotation of recycled pulps.HP-SEC followed by pyrolysis-GC-MS is a convenient methodology for chemical characterisation of wood pitch and polymers in white pitch and RP stickles.Flow Cytometry(FCM)is an established technique for automated analysis and separation of different particles in water suspensions.The technique enables determination of the number and size of different types of dispersed particles in papermaking process waters.By selective labeling with fluorescent markers it is possible to distinguish between different pitch particles and microbes.Especially useful is the ability to detect aggregates of pitch and stickles that in many cases have been found to trigger deposition on paper machines.The described analytical tools have been used successfully both in scientific laboratory studies,and in process research and monitoring in pulp and paper mills.Chemical analysis of pitch by GC-MS,HP-SEC and pyrolysis-GC-MS,together with characterization of dispersed pitch particles by FCM,are valuable,complementing tools for assessing the character and state of pitch components and particles in pulp and paper mills.
wood pitch white pitch stickles extractives coated broke, recycled pulp, flow cytometry pitch deposits chemical analysis GC-MS Pyrolysis-GC HPLC SEC
BJARNE HOLMBOM LARI VAHASALO
Process Chemistry Centre,Abo Akademi University,FI-20500 Turku/Abo,Finland
国际会议
第二届国际造纸与环境学术会议(The Second International Papermaking & Environment Conference)
天津
英文
41-48
2008-05-14（万方平台首次上网日期，不代表论文的发表时间）