Sorb-Zero: Sub-Zero Cooling @ Zero Emission, Waste-Heat-Driven Adsorption Chiller Below 0°C


Henninger, Matthias © Copyright: Lehrstuhl fuer Technische Thermodynamik der RWTH Aachen


Matthias Henninger

Sorption Systems Engineering


+49 241 80 95384



The goal of the project is the development of a demonstrator of a waste heat driven, high performance adsorption chiller with an environmentally friendly refrigerant, which can meet cooling demand between -3 and 7°C. One of the innovative objectives of this project is to replace the common refrigerant water with alternative refrigerants in order to eliminate the temperature restriction of water due to the freezing point at 0°C. Since existing adsorbents (silica gel, zeolite) are characterized by a low adsorption capacity of alternative refrigerants, novel adsorbents with a high adsorption capacity will be used instead. The material properties of these new adsorbents are to be measured in particular with the new working fluids and optimized for operation in the adsorption chiller.

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Thus, further parts of the cooling energy demand below 0°C, which could not previously be replaced by water-based adsorption processes, can be served by adsorption chillers. In sorption processes, the use of waste heat as driving energy instead of electricity results in a reduction of emissions, e.g. CO2 from electricity generation. The planned development thus offers an environmentally friendly and sustainable alternative to the compression chillers primarily used in this temperature range, which are exclusively electricity-operated and thus cost-intensive in terms of electricity.


Project Details

Project Duration

June 1, 2019 to May 31, 2022

Project Partner

InvenSor GmbH