District Heating/Cogeneration Application Studies for the Minneapolis-St. Paul Area. Impact of a District Heating/Cogeneration System on Annual Average SO sub 2 Air Quality in the Twin Cities

摘要

A study was made to determine the potential impact of a district-heating/cogeneration system on the air quality in the Minneapolis-St. Paul metropolitan area. Annual average SO sub 2 concentrations in air at ground level were determined for a base year (1976) and for a future year (1987) with and without a 2600-MW(t) district-heating system. Without district heating, the SO sub 2 concentrations in the area are predicted to increase with time because of anticipated increased substitution of oil for curtailed natural gas. Implementation of the district-heating/cogeneration system is predicted to mitigate this increase of SO sub 2 concentrations significantly. Although the total emissions will be slightly higher with district heating/cogeneration because of the substitution of coal for natural gas and oil, use of tall stacks at the cogeneration plants will permit greater dispersion of the SO sub 2 emissions. Considerable overall energy savings, particularly in the form of natural gas and oil, will be realized with a district heating/cogeneration system. (ERA citation 06:014333)