Decarbonisation Technology - February 2023

Decarbonisation with CO 2 utilisation: review of the GtL route

A re-examination of the synthetic fuels path with CO 2 used as a feedstock in the context of decarbonisation

Haralambos Panagopoulos Hellenic Petroleum, Part of HelleniQ Energy Holdings S.A.

C limate change has triggered a rapid turn to the development, scaling-up, and implementation of decarbonisation technologies in the industrial sector. Among the proposed technologies, carbon capture is considered one of the first necessary steps. It is expected to play a significant role in the EU industrial sector, especially for cement production facilities and oil refineries with a dedicated hydrogen production unit – a steam methane reformer (SMR) – as they both need to cut their costly Scope 1 CO₂ emissions. Options for the safe and cheap transportation expansion of renewable power generation in the electricity sector and a massive and storage of CO₂ are being examined and appear to make sense on an industrial cluster level. In the meantime, the same CO 2 emitters (oil majors and mid-sized oil companies in the EU) have played and continue to play a significant role in the development of large-scale wind farms and solar parks, along with other traditional and non-traditional players (such as power utilities, funds). This leads to an excess of renewable power generation, which stimulates initiatives to re-examine the utilisation of CO 2, especially as refineries are committed to reducing CO 2 emissions and providing alternative fuels for road, maritime, and aviation sectors. This re-examination may provide useful insights and feasible alternatives that supplement the primary option of developing CO 2 sinks, either through land use, land use change, and forestry or underground storage in depleted oil field formations.

Brief look at history of GtL technology One of these utilisation routes is the well– established gas to liquids (GtL) process. The origin of GtL technology dates back to the 1910s in Germany, where scientists discovered that mixtures of hydrocarbons, oxygenated compounds, and water could be produced, under certain conditions, from the catalytic reaction of syngas (carbon monoxide with hydrogen). In 1913, Friedrich Bergius patented a process for hydrogenating brown coal to synthetic fuels. Later, in the 1920s, two other chemists – Franz Fischer and Hans Tropsch – developed the Fischer-Tropsch (FT) process to convert syngas to synthetic fuels. After extensive research on different catalysts, pressures, temperatures, and reactor designs, the process was commercialised by Ruhrchemie in 1932 and nine industrial-scale plants were commissioned in Germany. These plants were essential for producing synthetic fuels in the 1933-1945 WWII period, with an estimated peak of ~600 ktpa (~14.0 kbpd). The partnership with several German technology companies, including Lurgi, constituted a key enabler for this development. Later on, Sasol acquired the rights to the FT process for the exploitation of coal reserves in South Africa to produce synthetic liquid fuels via the development of the 5.0 kbpd Sasol-1 plant in Sasolburg in 1955. The impact of sanctions on oil imports in South Africa during the Apartheid era and then the world oil crisis in the early 1970s acted as catalysts for existing and new players to further develop, improve, and optimise the