ISABEL RUBIO ARROYO | Tungsteno
The concentration of carbon dioxide in the atmosphere is the highest in three million years, according to the World Meteorological Organization. Industry is responsible for a large part of these emissions. Curbing them and thereby combating climate change is one of the greatest challenges of the 21st century. This is what Valencian engineer Rubén Mocholí Montañés (Valencia, 1990), scientist and project manager at SINTEF Energy Research, one of the largest independent research organizations in Europe, located in Norway, wants to achieve.
In 2019 he received a Green Talent award for the development of mathematical models to reduce industrial CO2 emissions. Among the alternatives that different companies are considering is the implementation of new industrial models that trap and even make use of carbon dioxide instead of emitting it into the atmosphere. Mocholí is part of the Norwegian Carbon Capture and Storage Centre (NCCS), which is the world's largest centre of excellence for CO2 capture and storage.
Which industries have the largest carbon footprint?
Globally, fossil fuel power plants generate more carbon dioxide emissions than other industries. But there are also industrial processes that result in significant emissions, such as the steel production sector, cement plants, the paper industry, petrochemicals and natural gas production. These industries generate globally 25% of energy-related CO2 emissions. Cement plants, for example, produce about 7% of anthropogenic CO2 emissions.
Why is it important to curb these emissions?
We need large amounts of cement and steel to build houses, bridges, roads, hydroelectric power plants, wind turbines... But at the same time, we need to significantly reduce the CO2 emissions associated with these processes to meet the targets for reducing greenhouse gas emissions that contribute to climate change in the medium and long term.
What is the key to achieving this?
In the European Union, CO2 emissions have been reduced in recent years through energy efficiency measures and the implementation of renewables in the electricity system. But the capture and storage of CO2 is the only way to significantly reduce emissions in some industrial processes in the near future. If the carbon dioxide that is captured and stored comes from non-fossil sources, such as cogeneration plants that use biomass as fuel, this could result in negative CO2 emissions. In other words, a net reduction of CO2 in the atmosphere, which would have a positive effect on the climate.
Are there currently alternatives for trapping or harnessing carbon dioxide instead of emitting it into the atmosphere?
There are currently more than 50 large-scale CO2 capture and storage facilities in the world. Of these, four are under construction, 28 are at various stages of development and 19 are operational—17 in industrial processes and two in coal-fired power plants.
At the Lixhe (Belgium) pilot plant, the LEILAC project tests the direct separation technique to capture the CO2 emitted during the production of concrete. Credit: HeidelbergCement Group.
In Europe there are different research projects such as CEMCAP, LEILAC or ELEGANCY. In Sweden, the company Stockholm Exergy AB opened the first pilot plant for CO2 capture in a cogeneration plant using biomass as a renewable fuel in December 2019. In principle, this concept would succeed in removing CO2 from the atmosphere. In Norway there is the Norwegian Full-Scale project, which proposes an infrastructure network for the capture of industrial CO2 with the intention and capacity to store emissions from industries in the rest of Europe. If the Norwegian government gives the green light to the project soon, the infrastructure is planned to be operational by 2023.
How is carbon dioxide capture done?
There are a wide range of technologies to capture carbon dioxide that are in various stages of technological development. Currently, the one with the highest level of maturity is post-combustion absorption technology. CO2 is captured by a liquid that has the capacity to absorb it through a chemical process. This technology has been tested and installed on a commercial scale in multiple industries around the world.
What methods are there to transport it?
Large-scale CO2 emitting industries are rarely located near geological formations where CO2 can be stored, and therefore it needs to be transported. There are three main ways to do this: pipelines, ships and low-emission trucks. Trucking is the most expensive option and the one that allows for the transport of smaller volumes of CO2. Nevertheless, it is a flexible option that could be worthwhile for small emission points. The cheapest and most effective way of transporting it is through a network of pipes, although it requires a large investment in infrastructure. The use of ships would be a flexible option in the short term, useful when CO2 is transported over long distances, but access to a port is needed.
Existing structures such as gas pipelines are being used to transport carbon dioxide separately, as in the Snøhvit project in Norway. Credit: Equinor.
After capture, how is the CO2 stored?
Captured CO2 can be stored underground at great depths, in principle, permanently and safely. Carbon dioxide is injected, for example, into porous rock formations. These can be saline aquifers or oil and gas pockets that have already been exploited. When injected at great depth, it behaves like a liquid. Storage technologies have been tested in several projects, such as the Snøhvit project in Norway, which has been storing CO2 for more than 20 years.
What are the limitations for these projects to succeed massively?
The main barriers are the costs of capture and the need to both reduce the risks of implementing these projects and to get them deployed on a large scale. In other words, we need many industrial processes to commit to these technologies in order to achieve zero net emissions. The technology is available. What is necessary is to apply it in several projects on a commercial scale in Europe in order to continue reducing costs.
Does the future lie in completely eliminating carbon dioxide emissions or in learning how to reuse CO2?
If applied on the necessary scale and quickly enough, CO2 capture and storage can be an effective tool in the transition to a decarbonized society. Reusing CO2 can help in certain cases to generate business models in the initial designs and to develop an ecosystem around CO2 management, but only permanent CO2 storage would really be effective in the fight against global warming and climate change. A carbon-free world in the future is possible, but CO2 capture and storage would allow us to gain time in the transition to a sustainable energy system, where renewables and other climate-neutral or climate-positive technologies can meet the needs of our lifestyle.
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Tungsteno is a journalism laboratory to scan the essence of innovation. Devised by Materia Publicaciones Científicas for Sacyr’s blog.