Techno-economic analysis of steam generating heat pumps for integration into distillation processes

To decarbonize process heat in industry, there is an urgent need to promote more energy-efficient and environmentally friendly technologies. In this context, electrically driven steam generating heat pumps (SGHPs) attract great attention for upgrading waste heat to low-pressure steam with high efficiency. This study analyses different integration concepts of SGHPs into distillation processes with heat source temperatures ranging from 20 to 45 degrees C providing low-pressure steam at about 110 to 120 degrees C and about 0.5 to 2.5 MW heating capacity. The technical and economic feasibility of the integration is investigated based on case studies in the Swiss chemical industry. Furthermore, a heat pump and cost model was developed based on fit curves to evaluate the economic feasibility considering the investment, operating, maintenance costs, potential subsidies, and CO2 taxes. The analysis shows that the integration of SGHPs is technically feasible and economical. Furthermore, payback periods of 3 to 5 years are reached.