Monday, January 17

R & D Strategy Launch Out-88th “Technology for Atmospheric CO2 Recovery to Realize the Paris Agreement”

Mr. Koji Oyama Mr. Koji Oyama

The Paris Agreement agreement (* 1) at COP21 held in 2015 was widely reported in the news. The essence of this agreement is to keep the temperature rise due to global warming well below 2 ° C compared to before the Industrial Revolution (2 ° C target). “1.5 ℃” was set as an effort target. To achieve this, carbon dioxide (CO) is based on the contributions (NDCs) submitted by the participating countries and determined by their own countries.2) Is being reduced.

However, it is expected that the “2 ° C target” cannot be achieved by reducing emissions by accumulating these NDCs (* 2). Therefore, further measures are required.

Atmospheric CO by recovery and reuse2Make the balance of

Technologies that have not been so familiar to the general public are also attracting attention. For example, as one of the climate engineering (geoengineering) that artificially manipulates the climate, a method of spraying fine particles (aerosol) in the atmosphere and reflecting sunlight to prevent global warming has been proposed. However, this method may have some adverse effects on the global environment, and it is difficult for current science to accurately predict its effects and adverse effects. Therefore, it is considered difficult to be accepted by society and it is difficult to reach an international agreement for implementation.

Under such circumstances, CO in the atmosphere2There are also movements to collect and bury it underground for storage, or to use it as a raw material for fuels and chemicals. This CO called DAC (Direct Air Capture)2The recovery technology of the plant is to artificially do what the plant is doing naturally, and it is considered that it is easy for society to accept.

Large amount of CO in DAC2And CO in underground storage etc.2CO in the atmosphere if it can be prevented from coming out to the atmosphere again2You can reduce the concentration. This is called negative emission technology. Also, the CO recovered by the DAC2If hydrocarbons can be produced using renewable energy as a raw material, CO recovered in advance during combustion, similar to biomass fuel.2It is a “carbon neutral” non-fossil fuel that emits. By using this fuel, carbon can be recycled, and the net CO can be used without significantly changing the existing energy system.2You will be able to achieve zero emissions.

It is necessary to collect a huge amount of air to realize it

If you just listen to this, it feels like you should do it right away, but the problem is the scale. Annual CO emitted by the use of energy2The amount is more than 30 billion tons in the world. As a measure against global warming, even trying to recover about 1% of it is 300 million tons. CO in the atmosphere2The concentration is about 400ppm, and 1 ton of CO2At least 1.4 million cubic meters of air is required to collect air from the atmosphere. Considering that the volume of Tokyo Dome is 1.24 million cubic meters, 300 million tons of CO2It turns out that a huge amount of air needs to be collected to recover.

CO that is contained only in the atmosphere like this2At a feasible cost (and CO2Collecting large quantities (without emissions) is considered a high technical hurdle. Of course, there is also the idea that it is more realistic to expand the use of biomass by planting trees and reforesting, but that requires vast land and a large amount of water. Therefore, expectations for DACs that do not have many such restrictions are increasing. Recently, it was announced as a roadmap draft (* 3) at ICEF (Innovation for Cool Earth Forum) held in Japan.

In recent literature, CO by DAC2It has been reported that the recovery cost will be 94 to 232 dollars per ton in the future, but in the past trial calculation example, there is a figure of 1000 dollars, and in order to realize it, efficiency improvement by research and development, Improving durability and reducing costs are very important. Also, as a feature of DAC, CO2CO2CO when recovering2It is necessary to install it in a place where renewable energy such as solar power, wind power, and geothermal energy can be used as an energy source for recovery so as not to generate energy.

In Europe and the United States, several start-up companies are already developing DAC technology. Mainly atmospheric CO2Is once adsorbed and absorbed by chemical substances, and then heat is applied to release it to recover it. In the future, in addition to engineering research and development for large-scale and significant cost reduction, development of chemical substances used for adsorption and absorption, their optimization, control technology will be evolved, and while trying to demonstrate, it will be more institutional. It is necessary to review the financial framework and connect it to large-scale introduction in the future.

Scenery of a pilot plant of Climeworks (Switzerland), which develops DAC technology Pilot plant of Climeworks (Switzerland), which develops photographic DAC technology (900 tons / year) (* 3)

DAC and CO2If hydrocarbon synthesis from, etc. becomes a reality, future energy systems and CO2It can be an option with great potential when considering mitigation measures. In order for Japan and the world to transform into a sustainable society in the long term, energy efficiency and CO2In addition to reduction technology and biomass utilization, we believe it is important to promote such research and development in the future.

  • (* 1) http://www.env.go.jp/earth/cop/cop21/ etc.
  • (* 2) https://www.nies.go.jp/ica-rus/15workshop/pdf/2-4_Kato.pdf PDF
  • (* 3) https://www.icef-forum.org/pdf2018/roadmap/ICEF2018_Roadmap_Draft_for_Comment_20181012.pdf PDF