CHP IN THE PULP INDUSTRY USING BLACK LIQUOR GASIFICATION - THERMODYNAMIC ANALYSIS

Black liquor supplies the major share of the energy used in the produc tion of chemical kraft pulp, the dominant pulping process worldwide. T raditionally, black liquor, which contains dissolved organic and inorg anic substances from pulping, is recycled to a recovery boiler that pe rforms the dual function of recovering chemicals and energy. Gasificat ion of the black liquor as an alternative to the conventional recovery system is under intense development, because it offers potential adva ntages in both functions. The realization of the energy recovery poten tial 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 yie ld under given process constraints and before considering integration with the mill. (C) 1998 Elsevier Science Ltd. All rights reserved.