This document is a summary of the deliverable DC3.1, which describes the pilot unit designed and constructed to capture CO2 in water.
The pilot unit consists in a system that put in contact the flue gases coming from a spray dryer with water for irrigation, leading to the dissolution in the water of the CO2 found in the flue gases.
The system selected to put in contact gases and water is a bubbling device, in which gases are forced to pass through a cylinder perforated in its whole surface. Once the system is immersed in water, the gases circulation through the cylinder creates a continuous curtain of bubbles.
Thus, a large contact surface is generated between gases and water.
As moving the water may facilitate the release to the atmosphere of the captured CO2, the system has been designed to capture the CO2 directly in the deposits of water that will be used later to irrigate the crop field. Therefore, the bubbling system is not static and can be moved from one deposit to another.
Because of the CO2 dissolution in water, pH is reduced until a minimum value is reached after a given working period which corresponds to the maximum CO2 dissolution in water, in the operational conditions of the pilot unit.
Once the CO2 is dissolved in the water, the bubbling system is removed and the deposit of water is sealed, as it is ready for irrigating the crop field.
The pilot unit has been designed to carbonate all the water needed to irrigate the selected crop field for 15 months, which is the planned period for this action of the project (Action C3).