Decarbonisation Technology - May 2023 Issue

and the MellaTech liquid distributors (see Figure 2 ) (Mellon & Duss, 2011). The first technology, which is installed in nearly all pump-arounds, is designed to maximise separation while reducing pressure drop by up to 60% compared to top-end, previous-generation structured packings for general applications. These features ultimately lead to considerable reductions in Capex and Opex. Given the 2021 cost of electricity at approximately EUR 0.2 kWh in Europe, even a limited pressure drop reduction of 5 mbar can lead to considerable cost savings in energy bills. For example, for an 800 MW coal power station, nearly €1 million can be saved yearly. In practice, In practice, SaskPower’s Boundary Dam Unit 3,115 MW coal-fired power unit in Saskatchewan, Canada, captures 800 kilo- tonnes of CO2 annually, in part thanks to Sulzer Chemtech’s solutions AYPlus DC, which is installed above the absorption section, enhances separation performance by limiting solvent emissions to sub-ppm levels thanks to remarkable wetting properties. MellaTech systems ensure a homogeneous liquid distribution from high to low liquid loads and support special requirements such as space, turndown ratio, flashing, fouling, and foaming. Finally, to support future-oriented decarbonisation strategies, Sulzer Chemtech is expanding its solvent portfolio to further enhance CCUS processes. CO 2 storage or utilisation? After capturing activities, carbon is stored or utilised to prevent its release into the atmosphere. In effect, the widespread adoption of CCUS can only occur if the infrastructure for CO 2 use or storage is developed at the same speed or faster than capturing facilities. Traditionally, CO2 has been sequestered in geological formations, such as depleted oil and gas reservoirs, coal beds, deep saline aquifers, and ocean sites. The first subsurface injections started in the 1970s and dedicated CO 2 storage from the late 1990s, with the first large-scale CCS project commissioned at the Norwegian Sleipner offshore gas field in 1996. The project has now stored more than 20 million tonnes of CO 2 in a deep saline formation (IEA, 2021). A risk associated with such practices is

leakage of the gas, which can migrate to the surface. This can hinder decarbonisation efforts while also having a negative impact on shallow potable aquifers, fauna, flora, and humans. An alternative to storage is the conversion and direct use of captured carbon. Moreover, utilisation is in line with the principles of the circular economy and can help meet the demand for greener chemicals, fuels, and materials. CO2 is largely being used in commercial-scale enhanced oil recovery (EOR) and the food and beverage industry (see Figure 1). It also finds some use in chemical manufacturing, biotechnology, and pharmaceutical manufacturing, such as for the production of urea, cyclic carbonates, salicylic acid, and poly(propylene) carbonate. For reference, approximately 70-80 million tonnes are used as feedstock for EOR every year. In addition, the fertiliser production industry uses around 215 million tonnes of CO2 annually (IEA, 2021), mostly to deliver blue urea and a growing volume of other, more circular, ammonium nitrate products. Widespread adoption of CCUS can only occur if the infrastructure for CO 2 use or storage is developed at the same speed or faster than capturing facilities In addition to these commercial applications, new uses for CO2 are being developed. For example, methanol, formic acid, and polycarbonate etherols processes are now at the pilot plant or demonstration scale. In addition, laboratory-scale systems are exploring the use of CO2 to produce alcohols, aldehydes, dimethyl ether (DME), organic acids, and carbamates. (Draxler, Schenk, Burgler, & Sormann, 2020). Most of these applications require hydrogen as a co-reactant, as well as high pressure and temperature. Mineralisation-based CCUS solutions More recently, new routes that solely rely on acid-base equilibria in the aqueous phase have emerged. These leverage mineralisation processes, particularly mineral carbonation, to react CO 2 with metal oxides, hydroxides, silicates, or other inorganic materials to form