Basics Carbon Capture & Utilisation T h is article is an edited excerpt from the nova-Paper #12 on renewable carbon: “Renewable Carbon – Key to a Sustainable and Future-Oriented Chemical and Plastic Industry”. The full report can be downloaded for free from [1]. One almost endlessly available source of renewable carbon is the carbon dioxide (CO 2 ) and other carbon oxides (e.g. CO) contained in exhaust gases, waste air, and the atmosphere, which may be utilised as a raw material for the chemical industry by means of a number of technologies. Nowadays, fossil CO 2 and CO is mainly obtained from fossil point sources such as power plants, steel and cement/lime plants as well as chemical industry factories. For some of these industries, owing to the specific technologies used there, the generation of CO 2 will remain unavoidable in the decades to come. Biogenic CO 2 is typically generated during the fermentation process of the food and animal feed industries but also in biogas plants, when combusting biomass or in the paper industry. The largest reserve of CO 2 exists in the atmosphere, from which CO 2 may be retrieved using specialised facilities in a process called direct air capture [2]. In order to make the carbon contained in CO 2 usable once more, it must be chemically reduced, which requires large amounts of energy. From an ecological viewpoint, this means that only renewable energies or existing process energy qualify as options. And this in turn means that, in order to be able to use the CO 2 itself as a source for raw materials, there must be massive, worldwide growth in renewable energies such as solar and wind energy, hydropower and geothermal energy. Provided there is sufficient renewable energy available, direct CO 2 utilisation is an inexhaustible and sustainable source of carbon for the chemical industry. nova Institute’s own calculations demonstrate that just 1–2 % of the Sahara area would be sufficient to cover the chemical industry’s entire carbon demand in 2050, which will continue to grow from today with a CAGR of 3–4 %, by means of photovoltaics and CO 2 utilisation. It only takes a simple chemical reaction to turn CO 2 and hydrogen (H2), the latter of which may be obtained from renewable energies, into methane, methanol, formic acid, ethylene, and alcohols, which in turn may be used to produce the bulk of today’s chemicals. The Fischer-Tropsch process adds naphtha, diesel, kerosene, and long-chained waxes, permitting even today’s refinery structures for the production of platform chemicals to be maintained and, at the same time, decoupled from fossil raw materials. New chemical catalysts allow for the development of novel CO 2 -based chemicals and polymers, and even complex organic molecules may be directly obtained from CO 2 thanks to biotechnological, electrochemical, and hybrid solutions. If the chemical industry switches to renewable carbon, society would not have to relinquish anything it has become used to over time. “Almost all chemical products currently manufactured from fossil raw materials can be produced from carbon dioxide”. (Lehtonen et al. 2019) In the medium to long term, considerable progress is also expected in the development of artificial photosynthesis and photocatalysis, with the aid of which sunlight is to be used directly for the production of chemicals. The foundation are developments based on novel nanomaterials and polymer systems, through which efficient use of solar radiation, water splitting, and CO 2 reduction can be directly coupled with the synthesis of the desired products. Commercial systems with artificial photosynthesis are expected to be on the market by 2050. Compared to the utilisation of biomass, direct CO 2 utilisation has some considerable advantages: The requirement for space and water is significantly below the one incurred by the utilisation of biomass. In 2017, Searchinger et al. calculated that on world average, the area required for the production of ethanol from wood is 85 times higher than the one for ethanol production from photovoltaics and direct CO 2 utilisation [3]. The reason for this discrepancy is the significantly better yield of modern solar cells (20–25 %; experts even believe 72 bioplastics MAGAZINE [03/21] Vol. 16
By: Basics Michael Carus, Lara Dammer, Achim Raschka, Pia Skoczinski Christopher vom Berg nova-Institute, Hürth (Germany) efficiency rates of 40 % to be possible by 2050) compared to natural photosynthesis, where – considering the entire process chain including agriculture and down-stream processes – only 0.1–0.3 % of solar exposure ends up in the final product. Economic and employment effects of CCU Under current conditions, renewable carbon from CCU is generally more expensive than fossil carbon from crude oil or natural gas. It will never again be as easy and cheap to access carbon as it has been in the fossil age. How much more expensive CCU fuels or chemicals are exactly, depends on a number of factors but mostly on the price at which renewable energy can be obtained. As a rule of thumb, price parity with fossil fuels could be achieved at electricity prices of 1.5–2 Eurocents per kWh [2]. In terms of employment, it is expected that a switch to renewable carbon will have positive effects. According to Eurostat, more than 65,000 employees (EU-28) (4,000 in Germany) worked in oil and gas production in Europe in 2016. If the raw material base were to be converted to renewable carbon, this figure would increase considerably – decentrally produced renewable carbon would certainly require 5–10 times the number of employees. In addition, there are already hundreds of start-ups developing new technologies for the production and use of renewable carbon. “A third important driver for CCU is the potential for new business cases based on the sustainable supply of carbon for value-added products. Economic feasibility is a long-term prerequisite for the viability and large-scale realisation of CCU concepts. In addition, there are CCU business cases, such as high-value speciality chemicals and materials that can be justified solely on an economic basis” [4]. For more details on the economic aspects of CCU, please see nova-Paper #11 on Carbon Capture and Utilisation [2]. References [1] Carus, M. et al. 2020: Renewable Carbon is Key to a Sustainable and Future-Oriented Chemical Industry, Hürth 2020-09; Download at https://tinyurl.com/nova-paper-12 [2] Carus, M., Skoczinski, P., Dammer, L., vom Berg, C., Raschka, A. and Breitmayer, E. 2019. Hitchhiker’s Guide to Carbon Capture and Utilisation. nova paper #11 on bio – and CO 2 -based economy. nova- Institut (Ed.), Hürth, Germany, 2019-02. Download at https://tinyurl.com/nova-paper-11 [3] Searchinger, T. D., Beringer, T. and Strong, A. 2017. Does the world have low-carbon bioenergy potential from the dedicated use of land? Energy Policy, Vol. 110 434-446. doi: 10.1016/j.enpol.2017.08.016 [4] Lehtonen, J., Järnefelt, V., Alakurtti, S., Arasto, A., Hannula, I., Harlin, A., Koljonen, T., Lantto, R., Lienemann, M. and Onarheim, K. 2019. The Carbon Reuse Economy: Transforming CO 2 from a pollutant into a resource. VTT Technical Research Centre of Finland (Ed.), www.renewable-carbon-initiative.com newsletter: http://bio-based.eu/email Direct CO 2 utilisation: Pros in a nutshell • Very high potential in volume (almost unlimited) • Low demand for land and water, low carbon footprint • High TRL (Technology Readiness Level) technologies available Direct CO 2 utilisation: Cons in a nutshell • Potential lock in effects using fossil point sources • Competition on limited renewable electricity • High investment necessary • Almost all chemicals and plastics can be produced from CO 2 • High employment potential • Inexhaustible source of carbon for the next millennia bioplastics MAGAZINE [03/21] Vol. 16 73
