The process integration approach has been extended with a plant utility emphasis by the Department of Energy (DOE) Industrial Heat Pump (IHP) Program. In this approach, reject heat from a process is upgraded to plant utility conditions and fed into the plant distribution system. Therefore, the reject heat from any process can be used as input and the output can be used at any location within the plant. With this design philosophy, the unit can be easily integrated into existing industrial applications, and all reject heat streams become potential targets of opportunity.
The plant utility approach cannot be implemented without heat pumps with high-lift capabilities (on the order of 150°F or 83°C). Currently available heat pumps have only about half the lift capability required. Thus the current emphasis for the DOE IHP Program is the development of high-lift chemical heat pumps that can deliver heat more economically to higher heat delivery temperatures. This paper details the proof-of-principle of innovative process cooling (refrigeration) and process heating technologies that are based on advanced cycles and/or advanced working fluids. In addition, it discusses the current status of the program to develop economically competitive, environmentally acceptable heat pump technologies that are capable of providing the delivery temperature and lift required to supply industrial plant utility-grade process heating and/or cooling.