CO2 is an essential component of the atmosphere for plant growth. In most greenhouses, additional CO2 is dosed to enhance plant growth and productivity. Currently, this additional CO2 mainly comes from sources with a fossil origin. However, it is also possible to extract and concentrate CO2 from the air. The Business Unit Greenhouse Horticulture and Flower Bulbs of Wageningen University & Research, commissioned by Kas als Energiebron, will be researching the quality and feasibility of such 'Direct Air Capture' machines in the coming years.

For CO2 in greenhouses, growers currently have several options. A commonly used method is utilizing CO2 released during the combustion of natural gas in a combined heat and power plant (CHP). These installations not only produce heat and electricity but also generate CO2 that can benefit plant growth.

Additionally, growers have the option to obtain CO2 through the OCAP pipeline network. This network transports CO2 directly from companies that emit it as a byproduct to the greenhouses. This is an efficient way to reuse industrial emissions for agricultural purposes. A third, often more expensive option, is the use of liquid CO2, delivered in tanks by trucks. However, with the shift to sustainable energy sources and plans to store CO2 under the North Sea, the availability of CO2 for horticulture may decrease in the future.

Therefore, efforts are underway to identify alternative, sustainable sources. One of these alternatives is capturing CO2 from the air using 'Direct Air Capture' technology (DAC). Several companies have developed DAC installations in recent years, and WUR will be studying these installations over the next three years. The research looks at CO2 quality, considering the purity of the CO2 and its potential effects on crops. Additionally, the applicability of these technologies is assessed, including factors such as the energy demand of the process, economic feasibility, and how these technologies can be integrated into the operational practices of greenhouse cultivation. The research takes place in WUR's greenhouses located in Bleiswijk, with each DAC installation being studied for six months.

Source: WUR