Project AdsoWaL - Adsorbent bodies for solar-powered water extraction from the air

01/11/2024

• Challenge
• Objective
• Methods
• Partners

3D adsorbent bodies are the core part of the solar collector and are responsible for the separation of the humidity from the ambient air. The design of a 3D body allows finding an optimized compromise between the amount of adsorbed water, the adsorption and desorption kinetics and the pressure drop. In the project, the Robocasting additive manufacturing technology will be used to take advantage of the geometrical freedom that it enables. In close collaboration with BAM, project partner Adsorbus develops and characterizes the collectors to create a proof-of-concept prototype.

The aim of project „AdsoWaL” is the development and proof-of-concept of a new type of solar collector, able to produce up to 5 liters drinkable water per day. The collector will be designed to be modular and adaptable to different formats.

A water-based ceramic paste will be formulated according to its adsorption and rheological properties. With this paste, different 3D-printed adsorbent bodies will be shaped and heat treated. The heat treatments must be optimized in a way to have a minimal impact on the adsorption properties of the material. After the optimization phase, the 3D adsorbent bodies will be loaded in the pipes of the collector. Project partner Adsorbus will test the adsorption kinetics and the pressure drop in the collector to compare the 3D bodies with a reference packed bed.

Project partners: Adsorbus GmbH, Berlin

Funding: Zentrales Innovationsprogramm Mittelstand (ZIM), Bundesministerium für Wirtschaft und Klimaschutz (BMWK)

Access to clean drinking, utility, and process water is a growing problem worldwide. In most parts of the world, decentralized, environmentally friendly, and high-quality water services are virtually non-existent.

Specially developed solar collectors use a solar-thermal adsorption process to convert humidity in the air into usable water—even in areas with low humidity.

The goal of this development is to demonstrate a prototype of a new type of solar collector that supplies approximately 5 litres of drinking water per day, can be modularly expanded, and is adaptable to various climatic conditions.

The adsorption material is integrated into the collector so that solar heat can be transferred directly to the adsorbent. This direct utilisation of solar heat makes the system more efficient, simpler, and more durable. Optimizing the airflow and adsorption kinetics in the adsorber are important steps in achieving the collector’s efficiency goals.

At the same time, this type of water collection can also be used in hyper-arid to semi-arid climate zones where relative humidity is well below 50%. Two approaches to optimizing the air flow are being investigated: one involves loose fill through access structures, while the other uses parts created by directly 3D printing the active adsorption material.

Partners

Adsorbus GmbH