18 May 2017

O.3.8.4 Valorization of industrial waste heat by heat pumps based on case studies of the project EnPro

Industrial processes have great relevance to contributions to the European Union’s climate targets of reducing greenhouse gas emissions by 40% and increasing energy efficiency and renewable energy by 27% by 2030. Reducing waste heat streams is an important measure to increase energy efficiency in industry. A number of processes, such as drying processes, generate humid exhaust gas streams that are currently vented without any further use. Those waste streams can be valorized by heat pumps. In this work, three case studies – a paper mill, a laundry and the production of expanded polystyrene foams – are analyzed in detail. Integration concepts to use humid gas streams as a heat source for heat pumps are developed. The concepts are evaluated by technical-economic assessment to quantify the effects in terms of energy, emissions, and cost savings. In all cases, the integration of a heat pump is an environmentally sound measure. Energy cost savings depend on the individual conditions of the case study and are often a limiting factor. Valorization of CO2 emission reductions as it is intended in the emission trading system will have a strong positive effect on heat recovery with heat pumps.