CHP in the pulp industry using black liquor gasification: thermodynamic analysis

Black liquor supplies the major share of the energy used in the production of chemical kraft pulp, the dominant pulping process worldwide. Traditionally, black liquor, which contains dissolved organic and inorganic substances from pulping, is recycled to a recovery boiler that performs the dual function of recovering chemicals and energy. Gasification of the black liquor as an alternative to the conventional recovery system is under intense development, because it offers potential advantages in both functions. The realization of the energy recovery potential of black liquor gasification is strongly connected to changes in the pulp mill's system for cogeneration of heat and electric power. In this work, pinch analysis of the integrated gasification cogeneration system, is used to identify systems which maximize power and heat yield under given process constraints and before considering integration with the mill. (C) 1998 Elsevier Science Ltd. All rights reserved.