LowCarbDry – Electricity-Based, Energy-Efficient and Intelligent Drying Using Superheated Steam as a Contribution to Industrial Decarbonization

Challenges

The decarbonization of industrial processes is crucial for achieving climate targets and maintaining competitiveness; in Germany, the industrial sector is the second-largest greenhouse-gas emitter after energy generation. Drying processes account for a significant share of industrial energy demand (around 20–25 percent); about 85 percent of these processes use fossil-fired, convective exhaust-air dryers. In roughly 99 percent of these plants, water vapor is discharged with the exhaust air and not used for energy recovery—meaning a large amount of latent heat of evaporation is lost.

Objectives and project plan

The project’s goal is a substantial reduction in energy consumption and sector coupling by shifting from fossil energy carriers to renewable electricity. This is to achieved by combining superheated steam drying with mechanical vapor recompression as a heat-pump principle, using water as the working fluid.

Technical focus areas:

• Further development and optimization of superheated-steam technology for spray drying of silica
• Development of an innovative compression system with novel turbo-compressors and a multi-stage setup for large temperature lifts, including efficient intercooling
• Use of model predictive control to improve energy efficiency and increase the share of “green” electricity by integrating real-time electricity price/availability forecasts
• Construction and demonstration of a pilot plant and development of a scale-up concept for industrial deployment

Impact

LowCarbDry contributes to policy and funding objectives such as tightened emissions-reduction targets by 2030 and greenhouse-gas neutrality by 2045 by electrifying process heat and drying while improving efficiency. There is significant savings potential: if a relevant share of industrial drying processes is replaced by the combination of superheated-steam drying and a high-temperature heat pump, a noticeable portion of the final energy demand for drying can be reduced. In addition, reductions in primary energy use and CO₂ emissions are expected. Faster transfer into industrial practice is intended to be supported through a demonstrator plant and an accompanying scale-up concept.