A state-of-the-art review of heat recovery steam generators and waste heat boilers

Industrial processes are often accompanied by energy losses. These energy losses can be in the form of exhaust gas or effluents occurring at different temperature levels. All these losses are being curbed, but with an economic disadvantage. However, with the application of various waste heat recovery technologies such as heat recovery steam generator (HRSG) and waste heat boiler (WHB), this lost energy, mainly associated with the exhaust gas, can be recaptured and reused, thus resulting in better energy efficiency. This is also a firm step towards the protection of the environment and other associated gains like small plant size, less power consumption, less water consumption, etc. In this regard, the present paper revisits and reviews the current technology and practices in the context of HRSG and WHB. The future technological needs in this field have also been highlighted.