I was researching and developing desiccant dehumidifiers and VOC removal and concentration technology at my company.

20 years ago, I had the idea of ​​applying this technology to create a revolutionary, energy-saving desiccant air conditioning system that would separate and remove carbon dioxide from conditioned air.

The desiccant dehumidifiers and VOC (organic solvent) concentration devices, which I was good at, use a separation technology called the TSA method (Thermal Swing Adsorption). Water vapor or gas is adsorbed onto a gas adsorbent (material) to dehumidify or purify the air. The adsorbed gas or water vapor is heated and desorbed to regenerate it for continuous use. This method has been in practical use for over 100 years, and in recent years, desiccant dehumidifiers and VOC separation and concentration devices using adsorptive honeycombs have become increasingly popular.

There are various methods for CO2 separation and concentration, but I have been trying to use the TSA method, which I am good at. However, I realized that it would be impossible to put this technology into practical use because it was incomplete, complicated, required a lot of energy for desorption, and was not competitive in terms of performance. It was a technological wall that I just couldn't break through. Many companies and research institutes have attempted to use the TSA method in the past, but none have been able to break through the barriers.

Liquefied CO2 is sold for welding, medical, and food products, and as a raw material for dry ice.

The raw material has traditionally been collected and distributed as a by-product from oil refineries. However, in recent years, there has been an accelerating movement to reduce the production and use of petroleum fuels such as gasoline, and plastics, as part of measures to combat global warming. In the future, there will likely be a shortage of liquid CO2 sources, even though there will be a lot of CO2 in the atmosphere.

For this reason, research, development, and demonstration tests are being conducted in various countries to capture CO2 from combustion exhaust gases from thermal power plants, etc., but there are many issues that need to be resolved in terms of initial costs, running costs, and the treatment of captured CO2.

In recent years, research, development, and demonstration tests are being conducted in various countries around the world on Direct Air Capture (DAC) technology, which directly captures CO2 from the atmosphere.

The CO2 concentration in the atmosphere is about 400 ppm (0.04%), which is much lower than the 10% concentration in exhaust gas from power plants, making it more difficult to capture at high concentrations.

　The reason DAC is being researched and developed is that it can be installed anywhere that captures CO2, not just in places where power plants or combustion furnaces that generate a lot of CO2 are installed, or where there are large-scale heat sources such as geothermal energy. In addition, combustion exhaust gas is a high-temperature, high-humidity gas that contains SOx, dust, and combustion by-product gases, so expensive pre-treatment equipment is required. However, DAC has the advantage of being able to use relatively clean air with almost the same components anywhere on the planet.

　When capturing CO2 that is scheduled to be emitted from conventional power plants, even if it is reused, it is ultimately emitted, and even if it is stored underground, it is zero, so the CO2 emissions required in the process are ultimately positive.

　G.V.Lab.'s DAC technology uses thermal energy from within the system and from exhaust heat from air conditioning to separate and concentrate CO2, recovering CO2 that was previously emitted, which has the potential to significantly reduce CO2 emissions from the entire system.