The SOSCO2 Project: Giving Carbon Dioxide a Second Chance

Alicia Monleón Ventura, PhD. Decarbonization Group Researcher, AIMPLAS, shares how the SOSCO2 Project is helping to develop a more environmentally sustainable economy.

Climate change, greenhouse gases and global warming are just some of the terms frequently mentioned in today’s news, interviews and essays. The causes and their effects on health, biodiversity and the environment are undeniable, as demonstrated by the urgent need to take action that helps decarbonise the economy by 2050.

Great efforts have been made in recent years to achieve this goal through the implementation of renewable energies, the electrification of sectors such as the auto industry, encouraging the use of hydrogen as an energy source and replacing fossil raw materials with biomass. These and other measures aim to reduce greenhouse gas emissions, mainly carbon dioxide (CO₂), in order to mitigate climate change. And yet, it is now a utopian idea to think that an industry can produce zero CO₂ emissions.

In fact, for some years now, research has focused on optimising industrial processes to reduce the CO₂ inevitably generated, capturing it and turning it into a useful compound, thus giving it a second life.

The SOSCO₂ Project, developed by AIMPLAS, the Plastics Technology Centre, was created to address the challenges faced by emerging CO₂ capture and use processes, and to provide a useful, profitable and sustainable solution that reduces the economy’s impact on the environment and also gives this molecule a new opportunity. The SOSCO₂ Project therefore focuses on two research areas: selective CO₂ separation using polymeric membranes and recovery of CO₂ using thermochemical and electrochemical methods to obtain compounds of commercial interest. The project is being carried out to find sustainable solutions applicable to different industrial sectors with the support of the companies Ercros, LafargeHolcim, Laurentia Technologies, Quimacova, Torrecid and UBE.

In an industrial process in which fossil fuels are burned to produce energy, the main emission is usually CO₂, along with other gases. To transform CO₂ into other compounds of industrial interest, we first need to separate it selectively from the other gases and impurities in the gas emission. This separation is carried out commercially by using liquid absorbents, particularly amines, which capture CO₂. In order to release pure CO₂, a great deal of energy must be applied to these absorbents, which is the main disadvantage of this kind of carbon capture technology.

The alternative proposed by the SOSCO₂ Project, in collaboration with EURECAT (Technology Centre of Catalonia), involves the use of polymeric membranes, which act like filters by allowing certain molecules to pass through while holding back others. This technology’s attractive advantages include its high selectivity, simplicity of design, high energy efficiency and environmental compatibility. In particular, the SOSCO₂ Project is focused on preparing membranes from different organic polymers and studying their stability and efficiency when selectively separating CO₂ under conditions similar to those found in industrial gas emissions.

Captured CO₂ can be recovered through chemical transformations that give rise to new compounds with higher value added. These transformations are not always easy, mainly due to the high level of stability of the carbon dioxide molecule, which makes it necessary to apply extreme pressure and temperature to alter this stability. Catalysis is a tool for activating the CO₂ molecule and facilitating its transformation. Catalysts make molecules less stable, thus reducing the need to use high temperatures and pressure, and therefore reducing energy needs and making processes more sustainable. The SOSCO₂ Project is doing research on different catalytic processes with the aim of recovering CO₂ in the form of compounds of high economic value for industry.

In a first approach, CO₂ is transformed into molecules called carbonates. They are precursors of polycarbonates, a kind of polymer that has different properties depending on its chemical structure. They are also highly versatile materials for different applications in sectors such as packaging, ceramics, foam formulation, the automotive industry, electronics and even construction. Polycarbonates are currently obtained mainly from phosgene, a highly toxic and corrosive compound, and bisphenol A, an endocrine disruptor, which explains the pressing need to find synthetic alternatives to this kind of polymer. The SOSCO₂ Project is therefore working on the development of synthetic routes to obtain polycarbonates from bio-based compounds and CO₂ in a more sustainable and innocuous way for human health.

Another target molecule in the SOSCO₂ Project is ethylene. This compound is the raw material of different chemical processes and the basic unit of a polymer known as polyethylene, one of the most widely produced and used plastics worldwide due to its many applications in packaging, bags, films, pipes, coatings, containers and much more. Ethylene is traditionally produced by ethane cracking at temperatures of 750-950°C. The SOSCO₂ Project is doing research on two alternative methods for obtaining ethylene from CO₂.

The first method is being applied in collaboration with the research groups led by Professor José María López Nieto at the Instituto de Tecnología Química - ITQ (UPV-CSIC) and Professor Benjamín E. Solsona Espriu at the Universitat de València. It involves using CO₂ as an oxidant and ethane to obtain ethylene through a process known as oxidative dehydrogenation of ethane. Thanks to the application of catalysts, less intense conditions of pressure and temperature can be achieved than those currently applied in industry, with the subsequent reduction in energy costs.

The project is also doing research in collaboration with the Institut de Recerca de l’Energia de Catalunya (IREC) on the transformation of CO₂ into ethylene by means of an electrochemical reaction. In this process, ethylene is formed from two CO₂ molecules by means of a catalyst and electrical energy without the need to use ethane. This transformation therefore has two main advantages: 1) It requires electrical energy, which can come from renewable energies such as solar and wind power, and 2) ethane, a petroleum product, does not need to be used to produce ethylene. Instead, the raw material is CO₂, a greenhouse gas.

In summary, the SOSCO₂ Project was created to satisfy the need to offer sustainable solutions to the climate emergency that make it possible to capture the carbon dioxide emitted as waste by industry and transform it into new compounds with high commercial demand in a sustainable and profitable way thanks to concepts such as polymeric membranes, catalysis and electrochemistry.

The SOSCO₂ Project is funded by the Regional Minister of Sustainable Economy, Production Sectors, Trade and Employment of the Valencian Community through IVACE and co-founded by EU ERDF funds within the ERDF Operational Programme of the Valencian Community 2014-2020. These funds were awarded to technology centres in the Valencian Community to develop non-economic R&D projects carried out in cooperation with companies in 2021.