Aïcha El Khamlichi
Aïcha El Khamlichi works for ADEME (the French Agency for Environment and Energy) as an engineer specialised in capture, use and storage of CO2. In particular, she leads several studies on CO2 conversion by chemical or biological transformation. Aïcha received a PhD in chemistry from the University of Rennes in 2010 after graduating from ENSCR Rennes as a chemical engineer in 2007.
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Why is CCU an important technology option for Europe?
A range of technical solutions is required to fight climate change. Among these, the capture and storage of CO2 (CCS) emissions from fixed sources such as power plants or manufacturing industries could help to achieve emission reduction targets. In addition to CCS, CO2 can be used as raw material for the synthesis of products with high added value or energy content, or materials. So, carbon capture and utilisation (CCU) technologies make it possible to transform CO2 into value as new raw materials that could substitute oil in the long term. In Europe, there are many available sources of carbon dioxide: CO2 capture at industrial emission sources (cement- or oil-based chemical processes, but also at any kind of combustion facility), or emissions coming from power plants, or recovery of CO2 from the purification process of biogas (from biomass methanisation) or syngas (from biomass gasification). Another important point, CCU could have a positive impact on industrial activity. The deployment of CCU technologies will prevent the shutdown of industrial plants (e.g. through carbon leakage) in France and in Europe by emerging new sectors. In conclusion, CCU will allow us to create value and decrease CO2 emissions by focusing on CO2 applications with environmental benefits (using less fossil energy, emitting less CO2…).
Many see CCU as an enabler to CCS, others as a pathway to new industrial opportunities. What is your opinion?
In my opinion, CCU is a pathway to new industrial opportunities. CO2 can be used as a carbon source for the synthesis of products such as chemicals, fuels or materials. There are several differences between CCS and CCU. The main differences are the capture technologies and CO2 volume involved. To use CO2 as a raw material, we need to improve CO2 capture technologies for small CO2 emitters with two main constrains: the small space available for the capture equipment and the low cost. This is why there is the development of CO2 applications with flue gases or a low level of CO2 concentration - to decrease the cost of CCU. At the opposite end, CCS requires specific capture technologies for high purity of CO2 for injection underground. Moreover, the volume of CO2 is not the same for CCS and CCU. In most of the cases, CCU projects address a diversity of products for different markets, and they cover both niche and mass applications with volumes of CO2 from thousands to tens or hundreds of thousands of tonnes. So the volume of CO2 use will always be less than the volume of CO2 stored where the amount, in most cases, is around 1 million tonnes of CO2 per plant per year. One proposition is to develop a CCU project with CCS when it is possible. This synergy could make it possible to decrease costs if some of the CO2 captured is used in CO2 conversion to produce a high value product.
What are the most promising CCU pathways? What are the main technological barriers to their commercialization?
It is difficult to give an answer to this question. Seen from a climate change point of view, mineral carbonation is a priority target application because the CO2 is immobilised for a long period just like CO2 storage. But it is difficult to find profitability; the production price is higher than the market price.
CO2-based fuels and chemicals are interesting pathways; these could enable the substitution of petroleum based products. But they provide short term CO2 storage and they emit CO2 when they are used. The CO2 avoided is limited. But even for CO2-based fuels and chemicals, it is difficult for CCU technologies to compete with conventional oil technologies. The economic barrier is the main hurdle for the deployment of CCU technologies. In a recent ADEME study, the main objective was to identify the most promising CCU pathways. Three processes were selected because they were promising: methanol synthesis by direct hydrogenation of CO2, formic acid synthesis by electro-reduction of CO2 and sodium carbonate synthesis by aqueous mineralisation. Finally, an environmental assessment showed that, although the CO2 avoided was limited, each tonne of CO2-based product produced makes it possible to not emit CO2. Furthermore, a techno-economic assessment showed that only formic acid could be competitive with petroleum-based products. However, formic acid is a niche application so the market volume is low with a risk of saturation if CO2 conversion to formic acid is developed. In conclusion, the study confirmed the potential of these three CO2 chemical conversions.
The main technological barrier is the capture of CO2. At the moment, it is extremely expensive. The deployment of CCU technologies implies a portfolio of breakthrough capture technologies. Also, another challenge is to work with the flue gas stream directly to transform CO2 into products. The direct use of the CO2 from flue gas, with minimal treatment, to be used locally where emitted, will make it possible to improve the energy efficiency of the process and limit utilisation costs.
How is research and innovation in CCU supported in France?
There are several programs to support CCU technologies from research to development and demonstration. Since 2010, several research and innovation programs have supported CCU projects with wide applications: chemical conversion to produce chemical products such as methanol, formic acid or calcium carbonate, or capture and purification of CO2 for direct commercialisation, or methanisation in Power to Gas projects.
At the research programs level, CCU is included in the decarbonised energy program of ANR (French National Research Agency). For example, there was the Vitesse2 project on the production of methanol from CO2 and hydrogen (produced by electrolysis of water and decarbonised electricity). Also, in the innovation programs of ADEME (French Agency of Environment and Management of Energy), CCU appears in several programmes dealing with different themes. For example, the utilisation of captured CO2 for algae growth is included in the biomass technologies program. In 2015, two projects on the production of algae from flue gases were supported. For one project, the aim is to develop a system of algae production by directly injecting flue gases from the cement production process. Then the algae biomass will be transformed into a high-value product. For the other project, the aim is to try different flue gases from industrial processes. There are also several projects at demonstration scale on Power to Gas or chemical conversion of CO2 supported by the French government through its Investments for the Future programme.
What have been the most significant achievements of CCU research to date?
CCU could be used to achieve several goals. One of them is to substitute chemical products based on petroleum. CCU technologies could also bring other benefits. In electricity systems for example, an increase in the supply of fluctuating renewable energy sources (wind and photovoltaics principally) implies more and more time periods during which production will exceed consumption. Research on technological solutions is in progress (curtailment, storage of electricity, etc.). One of these is Power to Gas: the conversion of electrical energy into chemical energy in the form of hydrogen gas (H2) or methane (CH4). This technology is a solution that gives value to these surpluses. The gas produced can be used in different ways, for example by manufacturers for their own process needs or it can be injected into gas distribution or transmission networks or stored locally for later conversion back into power. Power to Gas provides a new way to create added-value from power surpluses. The production of liquids from CO2, electricity and hydrogen is currently being developed and it is known as Power to Liquids or Power to X. For example, CRI (Carbon Recycling International) produces methanol from carbon dioxide (from a geothermal power plant), hydrogen, and electricity.
In France, also, several Power to Gas and power-to-liquid projects are under development. Currently, there is a call for projects, in Investment for the Future, on Power to Gas and Power to X at demonstrator scale.
How can policy and regulation support CCU?
CO2-based products produced with captured CO2 are much more expensive than traditional chemical synthesis routes so it is difficult to compete with conventional oil technologies. CCU technologies need support through a regulatory framework and a long-term policy (>20 years). There is the emissions trading system (ETS) market, but CCU is not part of this market, so this mechanism could be an obstacle to development for CCU technologies. For example, an industry with CO2 emissions that wants to decrease GHG emissions by using a CO2 conversion solution would not be eligible. So, it is necessary to effectively implement a mechanism for setting the price of CO2 (carbon market, tax, etc.) and for which the CO2 conversion solutions would be eligible. Since CO2 is not stored permanently in most cases, the mechanism would require further study to take this into account. For CCU, it is necessary to calculate the CO2 avoided rather than the CO2 used in the process. A life cycle analysis could help to develop CO2 technologies with environmental benefits. So the creation of a label certifying that the CO2-based products are produced with better environmental benefits than the traditional routes would support the development of CCU.
How does progress with the development of CCU in Europe compare with the rest of the world?
In Europe, several countries are working on CCU technologies, such as Germany, the UK, France, Italy… but they are not all at the same stage of development. Germany set up a dedicated program on Chemical Processes and Use of CO2 included in its Technologies for Sustainability and Climate Protection Programme. This programme supported projects on chemical conversion (production of CO2-based polymers). Also, a program on Sustainable Energy supported several Power to Gas projects. So Germany has made a lot of progress with the development of CCU. In spite of these advances, when compared with the rest of the world Europe is behind the United States, Japan and China. China and the United States are the first countries in terms of articles published on CO2 utilisation technologies followed by Germany and Italy. In the ADEME study mentioned above, a review of international projects on CCU showed that the most advanced CCU technologies (at demonstrator scale or commercial units) were in the United States. This can be explained by the strong support from the US Department of Energy for CCU technologies. There are exceptions in Europe, when conditions are in place for the emergence of a particular CCU technology. For example, in Iceland CRI produces methanol from carbon dioxide (from a geothermal power plant), hydrogen, and electricity and it is profitable because the methanol is recognised as renewable.