ENHANCED LIGNIN REMOVAL IN BROWNSTOCK WASHING

Concerns about the effects that chlorine bleaching effluent may have o n the environment have made the paper industry more interested in lowe ring pulp lignin levels before bleaching. Current industry alternative s include oxygen delignification and extended cooking, but both proces ses require a significant capital investment. This project was designe d to study lignin removal during kraft brownstock washing and screenin g and to assess the feasibility of modifying the brownstock washing un it operation to maximize the leaching of freeable lignin.