Minimization of Life Cycle Greenhouse Emissions and Cost in the Operation of Steam and Power Plants

The main objective of this work is to use environmental and economic objective functions to select the operating conditions of process plants. The operating conditions of a steam and power plant are selected to minimize greenhouse emissions and cost. The battery limits of the utility plant are extended to include the main greenhouse burdens of the imported electricity and its corresponding life cycle from raw material extraction, refining, transport, generation, transmission and waste disposal. Electricity generation by thermoelectric, hydroelectric and nuclear plants is considered. The reduction in CO2 equivalent emissions and its market price is included in the economic objective function. Significant reductions in greenhouse emissions and cost are achieved simultaneously, selecting the operating conditions such as temperature and pressure of high, medium and low pressure steam headers. The operating conditions include discrete decision for the selection of alternative drivers, between electrical motors and steam turbines, and equipment that are on or off, which are represented using binary variables in the mixed integer nonlinear programming problem. Significant reduction in greenhouse emissions and cost are achieved.