PTQ Q3 2023 Issue

Technologies (now part of Lummus), Sulzer Chemtech GTC Technology, Grillo AG, and Sinopec. Another prospective light olefins process is via non-oxidative coupling of meth- ane (NOCM). Examples include SABIC/Dalian Institute of Chemical Physics (DICP)/China National Petroleum Corporation (CNPC). OCM is considered one of the most promising routes to convert methane into ethylene directly. OCM suffers from the conversion-selectivity challenge typical for many selec- tive oxidation processes due to oxidation of the C₂ products in secondary reactions, high methane conversions corre - spond to poor C₂ selectivities and a high yield of undesired COx products. This trade-off between conversion and C₂ selectivity is the main reason why OCM is currently unable to achieve the 30-35% C₂ yields suggested to make the process industrially relevant.⁵ A second important challenge for OCM is the extreme exothermicity of the process. Commercially viable OCM will depend on process intensification, like innovative reac- tor and process design, such as the vortex reactor.6 While OCM may never reach the scale necessary to compete with steam cracking, smaller scale or modular reactors, using renewable feedstocks like biomethane, could offer a decar- bonised solution to producing olefins. Biogas, mainly CH₄ and CO₂ typically produced via anaerobic digestion of organic waste material, is envisioned to be key in achieving the EU’s 2030 decarbonisation targets Electrification and novel reactor concepts The Cracker of the Future is a consortium of chemical majors based in Flanders, Belgium, North Rhine-Westphalia, Germany, and the Netherlands. The consortium came together in 2019, chaired by the Brightlands Chemelot Campus, to investigate the operation of naphtha and gas steam crackers using renewable electricity instead of fossil fuels. Two consortium members, BASF and SABIC, plan to develop an electrically heated cracker supported by Linde Engineering. The project partners have made a funding application to the EU Innovation Fund and the funding programme ‘Decarbonization in Industry’ run by the German Federal Ministry for the Environment. The project would see a multi-megawatt demonstration plant sited at BASF’s Ludwigshafen site with an on-site date of 2023 if the funding application is successful. The electrically heated steam cracker is stated in theory to be able to save up to 90% of the emissions from conventional fossil fuel steam crackers. Dow and Shell are working on improving steam crack- ers and developing an electric cracker. In 2021, they were awarded €3.5 million from the Dutch government, and the Institute for Sustainable Process Technology (ISPT; Amersfoort, the Netherlands) were added as project

partner. A wide range of technological improvements are being studied, including computational fluid dynamics, electrical design, hydrocarbon technology, and metallurgy. The concepts are being evaluated and validated against their emissions benefits. Patent filings are being made with respect to the inventions, and suppliers for equipment are being identified. A larger demonstration at the multi-MW scale is slated for 2025. The Coolbrook Rotor Dynamic Reactor (RDR) technology is an electrically powered naph- tha cracking concept originating from science developed for the Russian space program. Total olefin yields achieved as of 2018 were over 55%, outperforming conventional naphtha cracking technologies by 9-11%. The technology has received more than €12 million in funding from government and private investors for a new pilot plant to scale up the technology. With the very high- speed moving parts, the mechanical robustness of the system will need to be proven, and an estimate of plant maintenance and lifetime provided with more certainty. The technology will have to compete with other electrically heated crackers, which are much further ahead in the mar- ketplace, such as the Dow/Shell system. CO₂ to olefins The discovery and development of efficient technologies enabling the use of CO₂ as a starting material for chemi- cal synthesis (at scale) is probably one of the biggest sci- entific challenges of our time. Two approaches to convert CO₂ to olefins (and other valuable chemicals) being taken by Avantium (via its VOLTA technology) and the Stanford spin-out Twelve are noteworthy. While each has expressed goals to convert CO₂ directly to ethylene, both seem to have shifted focus to other routes – oxalic acid for Avantium and CO for Twelve. Other notable examples of CO₂ conversion to olefins include The University of Toronto, The University of Illinois/ Braskem, and Tokyo-based IHI Corporation/Singapore’s Agency for Science, Technology, and Research (A*STAR). While significant progress has been made over the last few years, the performance of state-of-the-art technologies seems to not yet at the level required for an economically viable large-scale process. Aside from activity and selectiv- ity issues, rapid deactivation of the catalysts, which leads to a shift in the product distribution favouring the hydro- gen evolution reaction (in the case of electrochemical CO₂ reduction), is also one of the main challenges. In most cases, catalyst lifetime is under 100 hours.⁸ Other methods of CO₂ conversion include dry reforming of meth- ane (DRM) and super dry reforming of methane (SDR). Conventional DRM, typically involving a Ni-based cata- lyst, has gained much attention recently. It reduces GHGs, applies CO 2 as a carbon source, and provides the oppor- tunity to utilise biogas and natural gas with a significant amount of CO₂.⁹ ,10 Biogas, a mixture of mainly CH₄ (40 to 75 vol%) and CO₂ (25 to 60 vol%) typically produced via anaerobic digestion of organic waste material, is envisioned to be one of the key resources in achieving, for example, the EU’s 2030 decar- bonisation and renewable energy targets.

PTQ Q3 2023