Future Steam Generation Pressures in the Pulp and Paper Industry, 1996 Engineering Conference Proceedings

It is common to compare incremental capital and operating costs to determine the most cost effective steam generating pressures for new or expanding pulp and paper mills The objective of this paper is to develop simple payback periods for typical capacities at steam pressure levels of 4.14, 6.21, 8.96, and 10.34 MPa (600, 900, 1300 and 1500 psig). The sizes chosen were a recovery boiler of 1500 kg/day ( 3,300,000 lb/day) of solids and a second case with the recovery boiler and a power boiler at 113 tonne/hr (250,000 lb/hr) of steam capacity The results show that the expected simple payback periods are best at 1.9 and 3.0 years with electricity costs at 6 and 4 cents per kilowatt - hour respectively. It is concluded that for expansions or new kraft pulp and paper mills in the 700-1100 tonne per day range the optimum steam generation pressures are 8.96 or 10.34 MPa (1250 or 1500 psig). The 8.96 and 10.34 MPa are for 4 and 6 cents power cost respectively.