Penentuan Nilai Alkali Aktif (Aa Charge) dalam Proses Pemasakan Serpih Akasia di Unit Digester Fibre Line 2 PT Riau Andalan Pulp And Paper

Abstract

White liquor has a function as the cooking liquor in the Kraft (Sulfate) pulping. The active chemical substances in the white liquor are NaOH and Na2S called as active alcali. Active Alcali Charge (AA Charge) is the mix concentrations of NaOH and Na2S defined as Na2O needed for one cooking stage. AA Charge is used to determine the amount of white liquor added into digester in the cooking process based on the amount of chip into digester. The active alcali in the white liquor has the functions to degread lignin and extractive and keep remain cellulose and hemicelluose in the chip. In the chip cooking process, the using of more white liquor will make the active alcali is not selective anymore to dissolve lignin but it is start to attack cellulose. And if the using of less white liquor will make the uncook chip or it does not reach kappa number target. Therefore, it is important to count the correct AA Charge so that the cooking process goes well.