Process integration of a steam turbine

Abstract

Cogeneration consists of combined production of electricity and heat using fuel which allows remarkable energy savings in comparison with a system producing electricity and heat separately. The possibilities for integrating a cogeneration system with chemical processes has been studied in this paper. Improvement in the systems where high temperature process streams exist can be achieved by direct integration of steam turbine with them. A hot reactor stream was used instead of fuel to produce electricity and steam for further process heat requirements. A thermodynamics oriented approach to identify a cogeneration plant that completely satisfies process heat and power demand is highlighted. Pinch analysis with extended grand composite curve enables rational choice of utilities. The acrylic acid process was used to illustrate the procedure proposed. Economic attractiveness based on payback time and net present worth indicated that the steam turbine based cogeneration system would yield a return period of less than 3 months, showing that the investment in cogeneration could be of interest for this plant.