The potential of crematoria as a recoverable waste heat resource for district heating in the UK

Cremation is an energy-intensive process that represents the most popular funeral rite in the United Kingdom. Typically, a cremation lasts for 80 min and furnaces reach temperatures of up to 1000 °C. In order to remove pollutants such as mercury, cremation flue gas must be cooled down to temperatures below 160 °C, offering an opportunity for waste heat to be recovered and reused. Recent case studies have estimated that from 200 to 400 kW of waste heat is released during a typical cremation. Firstly, these reported values are used to determine the heat recovery potential from 314 crematoria across the UK, which varies from 141 to 281 GWh per annum. Secondly, a case study for integrating cremation waste heat into district heating (DH) in England is presented, and heat demand data for an existing network are used to evaluate the carbon and cost implications of exploiting cremation waste heat. Findings suggest that, although a small heat source, cremation heat can be an efficient resource for displacing peak gas usage in larger DH networks. This paper sits within the broader field of heat recovery, and the methods and concepts presented can also be applied to a wider range of heat sources and localities.