How many possibilities are there for carbon dioxide, from starch to fuel?

From synthesizing starch to "converting it into fuel" to generating electricity, carbon dioxide has recently caught on fire.

202 1 12 13, Elon? Musk announced on social media that in the future he will focus on how to extract carbon dioxide from the atmosphere and convert it into rocket fuel.

Musk, who crossed the border from the technology circle to the energy circle, is ambitious. A seemingly simple declaration reveals the cutting-edge research between "extraction" and "transformation" of carbon dioxide.

Let's look at "extraction" first.

At present, the global carbon capture technology is relatively mature, but it has not been commercialized on a large scale because of the high investment cost.

The Asian Development Bank has done a study, taking a 600 MW conventional pulverized coal power plant as an example. Without installing CCS equipment, the investment cost of the power plant is 2.78 billion yuan (4.6 million yuan per megawatt). After installing CCS equipment, the investment cost of power plant rose to 3.42 billion yuan (5.7 million yuan per MW), and the investment in power plant equipment increased by 24%.

Wei Jianguo, vice chairman of China International Economic Exchange Center, also revealed that in order to achieve carbon neutrality, China needs to invest 2.2 trillion yuan annually in carbon capture, storage and utilization by 2030, and 3.9 trillion yuan annually by 2030 and 2060.

It can be seen that Musk's public reward of $654.38 billion to find the "best carbon capture technology" is not a joke.

According to the global CCS Institute, as of June, 2020 165438+ 10, there are only 26 commercial facilities in operation in the world, with an annual handling capacity of about 40 million tons.

Ordinary CCS is not easy, but the technology of "extracting" carbon dioxide from the atmosphere, that is, direct air capture and storage (DACS) mentioned by Musk, is more difficult and costly.

To put it simply, the principle of DACS is to let air pass through the chemical solution of DACS system to form new compounds, and then heat to separate carbon dioxide. The remaining compounds are separated from the chemical substances, turned into gases without carbon dioxide, and released back into the atmosphere.

Because DAC captures carbon dioxide from the air, the advantage is that the factory can be built anywhere, but the problem also stems from this. Because the concentration of carbon dioxide in the earth's atmosphere is very thin, only 0.04%, which means that the cost of DAC is obviously higher than other carbon dioxide capture technologies.

However, if this technology is applied to Mars with carbon dioxide content as high as 95%, it is another matter.

Let's look at "transformation".

The conversion of carbon dioxide into rocket fuel mentioned by Musk is not a fantasy.

The day after Musk tweeted, on 202114, China University of Science and Technology, University of Electronic Science and Technology of China and Dalian Institute of Chemical Physics of Chinese Academy of Sciences jointly developed a new electrolytic reactor based on solid electrolyte.

It is understood that the reactor can efficiently convert carbon dioxide into high-value and high-purity liquid fuel formic acid by using clean energy and cooperating with the developed copper-based monoatomic catalyst without further product separation. At present, this achievement has been published in the top international academic journal Nature Nanotechnology on February 14.

In fact, in recent years, there have been many international studies on reducing or decomposing carbon dioxide. There are more than 10 articles on carbon dioxide reduction in top international journals such as Science and Nature, and its principles involve electrocatalytic reduction, thermal catalytic reduction and photocatalytic reduction.

However, some experts pointed out that the above technologies or research results are not a "panacea" to solve climate change. First of all, the cost is a big problem, and it is unknown whether it can be commercialized on a large scale in the future.

Therefore, it seems more important to focus on how to reduce emissions than to study how to recycle carbon dioxide. After all, the cost of reducing one ton of carbon dioxide is much lower than the cost of recycling one ton of carbon dioxide.