Page 1 of 7 M ME EA AS S U UR RE EM ME EN NT TA AT TI I O ON N,I I N NC C.1 16 6 7 73 30 0 H Hed dg gecr r of ft t ,S Sui it t e e3 30 0 0 0Ho oust ton, Te exa as 7 7 7060 02 2 8 81 -4 44 5 5-7 7228FTNIR Application Note Pulp and Paper Applications On- line measurements in the pulp and paper industry are among the most difficult challenges of process analytica l chemistry. Pulp and paper prod uction streams are typica lly very high in both d issolv ed and suspended solid material. The samples are often optically opaque or nearly so. Sample con ditioning syst ems are pr one to plu gging and corrosion. On-line titrators tend to be very troublesome due to the problems with handling the streams, disp ensi ng measured amounts of sample, reagent consumption and disposal of the titrated wastes. Here we report on the application of the InfraSpec NR800 FT -NI R analyzer to the determination of alkali salts in various Kraft process streams. The Kraft Process Alth ough there are a number of different processes for making pulp and paper from wood, the Kraft or “sulfate” pr ocess of chemical pulpin g is the most common. Wood chips are fed into a solution of Sodium Hydroxide and Sodium Sulfide at high temperature in a d igester which breaks the lignin chemic al bonds which bind the cellulose fibers toge ther. After cooking, the fiber or “pulp” is then separated by screening and/or filtering from the undigested wood chips and was hed. Additional steps to remo ve residual lignin are often employed in modern plants. The pulp is then bleac hed to whiten the fiber s, formed into a sheet, drie d and rolled. Figure 1: Simplified schematic of pulp and paper mill
