Waste heat recovery and its integration with district heating systems: Case study for ceramic industry

Abstract

Industrial waste heat available from ceramic plants is investigated to understand economic benefits gained from the heat integration of waste heat with the district heating systems. One of the scenarios for the case study is to consider the combined use of waste heat for generating electricity via the ORC (Organic Rankine Cycle), as well as for supplying heat as a heating source to the district heating systems, while the other is to maximize the utilization of waste heat as heating only. A process simulation framework using AspenHYSYS (R) is built to estimate the amount of waste heat available from the kiln exhaust gas. The integration of ORC and district heating systems is also modeled by an established framework. Two profiles for characterizing changes in heating demand are considered on a daily basis and annual basis, while three levels of insulation efficiency for the heat storage facility are considered. Case study clearly illustrates that heat recovery with only using district heating systems can provide more benefits than using ORC about 64 similar to 86% of cost savings. Technical issues related to over-the-fence heat recovery in practice are discussed.