Author | Yuan Yilin
Produced by | Tiger Sniff Technology Group
Caption | IC photo
Carbon dioxide is the number one nuisance of the climate crisis. Now, a more imaginative challenge is: use it to generate electricity, store energy, or do something else?
Musk, who was just named Time's "Person of the Year" for his environmental protection and space exploration, has always missed any brain-opening opportunity - announcing that SpaceX has launched a plan to remove carbon dioxide from the atmosphere, which is made into rocket fuel, adding that "this is also important for Mars", after all, carbon dioxide accounts for 95% of the Martian atmosphere.
According to Bloomberg, the idea would involve a new technology that is still in the early stages of development , direct air capture (DAC), which uses chemical materials to filter carbon dioxide. According to the World Bank's 2019 statistics, every ton of carbon obtained using DAC technology costs $100 to $1,000. Similar "black technology", technical difficulty, high cost can not rely on the market digestion, if you want to really land to promote, you must first survive the long "valley of death".
Without the ability to banknotes, how to execute?
In February, Musk launched the $100 million XPrize Carbon Removal award to encourage research teams to develop carbon removal technologies. Not long ago, the $5 million prize money in the project was awarded to 23 student teams , including northeastern university from China — and the winning program focused on two problems: removal, and measurement and inspection of carbon dioxide.
The Martians were not the first to recognize the importance of "carbon removal."
Carbon capture, is it a prospect or a chicken rib?
As early as the 1920s, carbon capture technology emerged during the development of natural gas reservoirs.
In the early 1970s, the oilfield in Texas in the United States began to inject carbon dioxide into the oilfield, because the carbon dioxide was mixed in crude oil, that is, the solubility was high, which made the crude oil viscosity decrease and the volume expanded, which could effectively improve the oil recovery of the oilfield (Enhanced Oil Recovery, referred to as EOR), and gradually developed into a mature oil recovery method. The carbon dioxide brought out of the crude oil extraction process can be recovered and reinjected, and the carbon dioxide can be sealed in the reservoir and reduce the entry of greenhouse gases into the atmospheric environment. CO2 oil flooding, fire extinguishing, and chemical products are the most important application scenarios for carbon dioxide currently captured.
Carbon capture, utilization and storage equipment captures, compresses, transports high concentrations of carbon dioxide emitted from industrial activities to storage sites and into rock formations. In its 2014 report, the United Nations Intergovernmental Panel on Climate Change (IPCC) mentioned the importance of CCS technology to temperature control targets. According to the Statistics of the International Energy Agency, since 2017, more than 30 new comprehensive CCUS deployments have been added around the world, mainly in Europe and the United States, as well as China, South Korea, New Zealand and other countries.
On 18 May 2021, the International Energy Agency's Net Zero Emissions 2050: A Roadmap for the Global Energy Sector report states:
In the 2050 net zero emissions scenario, CCUS emission reductions will increase from the current 40 million tons/year to 1.6 billion tons in 2030 and 7.6 billion tons/year by 2050. By 2050, 40% of carbon emissions from energy-related industrial processes can be eliminated through CCUS technology.
Since the country put forward the carbon peak carbon neutrality target in September last year, the development of domestic carbon capture, utilization and storage technology (CCUS) has also gone from behind the scenes to the front of the stage.
China Petroleum News Center december 14 news, the national energy group Jiangsu Taizhou power plant carbon dioxide capture project is about to start, as the largest (500,000 tons) demonstration construction device in China, the total project budget of up to 386 million yuan, the captured carbon dioxide will be mainly applied to oilfield flooding.
Ma Jinfeng, a professor at the Department of Geology at Northwest University and executive director of the National and Local Joint Engineering Research Center for Carbon Dioxide Capture and Storage Technology, told Tiger Sniff that many energy and industrial companies have recognized that CCS is the only means of emission reduction and are prepared to be active.
Among the energy companies that have already carried out CCS, there are: Shaanxi Guohua Jinjie Power Plant of National Energy Group, Shidongkou Second Power Plant of Huaneng Group, PetroChina, Sinopec, CNOOC, and Yanchang Petroleum. CcS is used in the cement and steel industry, including Conch Group Anhui Baima Mountain Cement Factory and Baowu Iron and Steel Group.
Specific to key provinces, such as Shaanxi, there are two major oilfield companies in Changqing Oilfield and Yanchang Petroleum to carry out CO2 flooding demonstrations. In June this year, the Jinjie Power Plant of Guoneng Group successfully completed the installation of 150,000 tons/year post-combustion capture facility, which is the largest in China. Among the many test fields, Shaanxi, as a major province of resources - the largest province in the country's oil and gas, the third largest coal energy province, is the region with the most CCUS demonstration projects in China, the MOST COMPLETE CCUS industrial chain and supply chain - more than 80% of the materials and equipment can be manufactured independently.
CCS is difficult to meet expectations, who is at fault?
Not only China, but also governments and businesses in Asian countries are increasingly dependent on CCS, but despite this, an analysis by the Asian investor group Climate Change Commission (AIGCC) warns that CCS deployments in Asia may be economically and operationally difficult to meet expectations in the coming decades. Previous research statistics, as of 2020, the total annual carbon sequestration of the world is less than 40Mt, compared with the annual carbon emission (about 34000Mt), it is a drop in the bucket, which shows that the application of CCS is still limited.
High cost is an unavoidable factor, it is difficult for general enterprises and capital to invest high in CCS, and it is enough to see from the opening chapter of this article That Musk's "banknote ability" is enough. The AIGCC report points out that CCS will continue to face a cost-decompetitiveness by 2040 compared with alternatives such as renewable energy and energy storage technologies that continue to decline in cost.
In contrast, the reason why photovoltaic and wind power can develop today's scale is that on the one hand, the technical threshold is relatively low, and on the other hand, it is inseparable from the policy subsidies in the past decade.
Professor Ma Jinfeng believes that each kilowatt-hour of electricity incentive for wind and photovoltaic power generation is basically equivalent to a subsidy of hundreds of yuan per ton of CO2, and if such subsidies can be obtained, CCS is also completely profitable. In contrast, the United States has the support of the 45Q tax exemption bill to incentivize co2 geological storage, Norway has a carbon tax to force companies to carry out CCS, and Canada also has incentives in different provinces. Therefore, we still need incentives overall to increase R&D investment.
In addition, the AIGCC believes that large-scale deployment of CCS also needs to face multiple challenges such as "environmental risks, technical challenges, lack of funding, social opposition, and policy uncertainty."
Some personnel from international environmental agencies also revealed to Tiger Sniff that their attitude towards CCS is relatively conservative, lest it promote the path dependence of "after-the-fact remediation", in contrast, they will give priority to promoting renewable energy, and do not emit carbon from the source of power generation and industrial production.
However, in view of the fact that renewable energy sources such as wind power and photovoltaics are difficult to replace the energy "ballast stone" status of coal power for a period of time, and can only replace part of fossil energy, reducing emissions cannot reduce the CO2 accumulated in the atmosphere.
Professor Ma Jinfeng is more optimistic about the application of CCS. "As long as there is 'carbon neutrality', there must be a need for CCS technology to offset emissions," he said, "CCS is not only the only means of reducing emissions from coal power and coal chemical industry, but also the only means of dealing with carbon emissions from cement, steel, smelting and waste incineration." Even if we reach carbon neutrality in these areas, we still need cement, steel, smelting, garbage emissions, etc., and we will inevitably use CCS. ”
In addition, after achieving carbon neutrality, the global mission is to remove historical human emissions, which requires negative emission technologies – BECCS and forest carbon sinks , paired with direct air capture and CO2 sequestration from renewable sources.
CO2, more useful than you would expect
When it comes to the final hurdle of CCS applications, storage, geological conditions are also a natural limitation. Countries with relatively good geological conditions and CCS development are the United States, Canada, Norway and so on. According to Professor Ma Jinfeng, the geological structure of the Ordos Basin is stable and has the potential for carbon dioxide storage in the amount of 100 billion tons.
So in addition to making the captured carbon dioxide "never see the light of day", can this unwelcome greenhouse gas have more commercial potential? Although at present, carbon dioxide can create higher output value mainly in the oil flooding and beverage industries, there is still no more imagination.
A direct line of thinking is to let the carbon dioxide that is born of electricity be used for electricity.
Supercritical carbon dioxide can be used as a working substance for thermal and active conversion to generate electricity. Recently, Huaneng Xi'an Thermal Engineering Institute successfully commissioned a supercritical carbon dioxide cycle generator set with a power generation power of 5 MW. That is, to replace the role of water vapor in the traditional thermal power generation process by supercritical carbon dioxide. Studies have found that compared with water vapor-driven turbines, supercritical carbon dioxide cycle system power stations have more advantages: for example, high thermoelectric conversion efficiency, high energy density of the device, can be equipped with small size, small series of turbines, the volume can be 1/30 of the traditional steam system.
Image source: Energy Dome
In terms of using carbon dioxide for energy storage batteries, Italian startup Energy Dome has also put its brain hole into practice.
The system developed by Energy Dome first compresses carbon dioxide, then heats the gas into a liquid at 300°C, extracts and stores heat, and the gas is condensed into a liquid form for storage. The volume of air is reduced by compression or condensation, and then it is allowed to expand rapidly to its natural state, driving a power generation turbine to generate electricity.
For the cost issues that investors and users are most concerned about, Energy Dome claims that the levelized storage cost (LCOS) of the carbon dioxide battery system they developed has been lower than $100 per megawatt-hour, which has a great advantage over the cost of lithium battery energy storage.
According to the Lazard Investment Bank in France, the LCOS for large lithium-ion batteries is about $132-245 per megawatt-hour. Energy Dome hopes to continue to reduce LCOS to nearly $50 per megawatt-hour in the coming years.
Obviously, for the capture and application of carbon dioxide, there is no hesitation in the footsteps of technology at home and abroad, and as for how to cross the "Valley of Death", we must take it step by step.