Decarbonisation Technology August 2022 issue

Engineering challenges of processing biofeeds

and achieve a world of net-zero emissions, oil demand stagnates, coal use declines, and use of natural gas and solar both grow. Government policies begin to crystallise and, as energy companies develop their energy-transition- related ambitions, technologies such as blue hydrogen, HVO, and carbon capture are adopted. Adapting to the new energy landscape In the short term, it will be critical for energy companies to begin to adapt or reposition their businesses while concurrently maintaining their competitiveness. Flexibility will be key, so there will be a need for incrementally moving molecules to the most profitable paths. For example, many refiners’ profitability will depend on their ability to find ways to shift increasingly heavy, low-value, bottom-of-the- barrel molecules into lighter aromatics and olefins to make intermediates for the growing manufacturing and chemicals industries. To maximise margins, it will also be important for them to supply the increasing global demand for kerosene molecules, which has almost recovered to pre-pandemic levels, while diesel and gasoline may start to decline in certain geographical markets. As the market changes, there will likely also be a need for repurposing existing assets through revamps. Important technology solutions may be revamping a hydrocracker to capture new In 2020, Shell Catalysts & Technologies commercialised the Shell Renewable Refining Process, an HVO technology for converting 100% biofeeds into renewable diesel and jet fuel. Its rapid development owes much to lessons learned from other technologies, as Roy Henket of Shell Catalysts & Technologies explains. “There are many technical challenges to overcome when processing renewable feedstocks: the high levels of contaminants, high heat release and high hydrogen consumption, to name a few. Much of our technology de-risking is built on lessons learned from other technologies, such as

business opportunities in petrochemicals or lubricant base oils, revamping a fluidised catalytic cracker to maximise propylene for polypropylene production, or revamping newly built HVO units to increase the yield of sustainable aviation fuel (SAF) or extend the catalyst cycle life. Decarbonisation pathways Energy companies will likely need to act in each of the three classic decarbonisation pathways: they will need to increase energy efficiency, make lower-carbon energy products, and store the remaining emissions. Many will probably begin with energy efficiency studies, as these are low-cost solutions. In addition, carbon pricing, which may be adopted by governments globally during this period, would lead to a meaningful cost for carbon being embedded into consumer goods and services and help justify more developments. Essentially, this would change the evaluation criteria for energy efficiency improvements. In the past, the main criterion was the cost of energy, but the economic case is likely to be strongly enhanced when the cost of carbon is factored in. Although it is imperative for energy companies to ensure that their own operations use energy as efficiently as possible, the reality is that most the Shell gas-to-liquids process and our dewaxing hydroprocessing technology, which, like the Shell Renewable Refining Process, has a first-stage conversion reactor and a second-stage isomerisation reactor. Shell’s experience in fouling abatement and reactor design was also crucial. “As you might expect, though, this is not the end of the story. Research and development continue. Key focus areas include increasing the feedstock processing window, which will be important as new regulations mandate the use of even more challenging feeds, and optimising the design for increased SAF yields.”