Preliminary Economics of Black Liquor Gasifier/Gas Turbine Cogeneration at Pulp and Paper Mills

Black liquor, the lignin-rich byproduct of kraft pulp production, is burned in boiler/steam turbine cogeneration systems at pulp mills today to provide heat and power for onsite use. Black liquor gasification technologies under development would enable this fuel to be used in gas turbines. This paper reports preliminary economics of 100-MWe scale integrated black-liquor gasifier/combined cycles using alternative commercially-proposed gasifier designs. The economics are based on detailed full-load performance modeling and on capital and operating and maintenance costs developed in collaboration with engineers at Bechtel Corporation and Stone and Webster Engineering. Comparisons with conventional boiler/steam turbine systems are included.Copyright © 1998 by ASME