CO2 Recovery

CO2 Recovery

CO2 concentration and recovery (greenhouse cultivation, plant factories)

Carbon dioxide (CO2) has a greenhouse effect and is one of the greenhouse gases necessary to maintain global temperatures. However, it is considered a cause of global warming due to its rising concentration, and countries around the world have recently adopted policies to curb emissions.
Along with light and water, CO2 is indispensable for the growth of agricultural crops through photosynthesis. It has also been confirmed that a certain increase in CO2 concentration (above 1,000 ppm) has the effect of promoting the growth of crops.

In plastic greenhouse cultivation and plant factories, the flow of outside air is controlled to prevent pests and manage temperature and humidity, but compared to outdoor cultivation, the environment is more likely to be deficient in CO2. This is because even if the amount of oxygen exhaled from the crops through photosynthesis increases, the amount of CO2 taken in from the outside air cannot be increased rapidly due to the closed environment.

This tendency toward carbon dioxide deficiency is especially noticeable in winter, when greenhouses are often closed. If the amount of CO2 is insufficient, plants cannot grow sufficiently, resulting in low crop yields and affecting agricultural management.

Currently, the CO2 generators commonly used in plastic greenhouse cultivation and plant factories are mainly kerosene-burning, LPG (LP gas) burning, and liquefied carbon dioxide gas (gas cylinder) systems.

However, the combustion type generates a large amount of CO2, which is bad for the global environment, and the cost of fuel has skyrocketed in recent years. In addition, if cultivation is carried out at high altitudes, problems arise in transporting the fuel to the location.

Using NAGASEP to capture and concentrate CO2 in the air can solve these problems in an energy-saving and low-cost way.

Since NAGASEP has good CO2 permeability, air (O2: 21%, CO2: 450 ppm) is supplied to the module and the permeate side is depressurized by a vacuum pump, resulting in the permeated air being enriched to 30% oxygen and 2,000 ppm carbon dioxide.