Question
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What are some of the optimal strategies for processing (or co-processing) second- and third-generation renewable feedstocks?
Mar-2023
Answers
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Steve DeLude, Becht, sdelude@becht.com
The optimal strategy is dependent on each site’s specific configuration, level of exposure to GHG emission-related costs (penalties) and/or biofuel production incentives, the logistical considerations related to the available biomass feedstocks, the cost of the feedstock, and corporate capital availability/investment hurdle rates.
The mandates of the Paris accord established requirements for carbon intensity and GHG emission reductions that impact energy firms, regional/national governments, and investors. As part of the transition to lower emissions, traditional fossil fuel-based transportation fuels will be substituted by a combination of electric vehicles and bio-derived and renewable fuel sources. Existing refining and petrochemical assets are seen as key infrastructure in the energy transition equation, as much of the existing processing and distribution infrastructure can be repurposed for this new reality.
This change in the marketplace will drive traditional refiners to examine processing and configuration options to align with the new feedstock and product profile, as well as energy input options. Those entities that are able to meet the changes in this dynamic market while remaining profitable will continue as long-term viable enterprises. Biofuel- related strategies seen in the industry range from:
• Full biofuel integration with dedicated biofuel units providing fully fungible final product blend components
• Partial integration and co-processing approach with biofeeds brought on-site and pretreated adequately to match with the site’s existing units.
• Third-party pretreatment arrangement or an owned, dedicated facility with feed specifications strictly monitored to ensure meeting co-processing/blending requirements
• Purchase of biofuel blend components via open market
• Purchase of GHG offsets from other entities.Finding an optimal strategy requires fully analysing each specific situation and identifying the range of options that could achieve the desired business goals.
The progression of biofuel processing technologies from the current level to those in development is more catalyst-related than process-related. The steady progression of catalyst advancements has improved hydrogen selectivity and isomerisation to final products. As catalyst technologies further improve, opportunities exist for processing more challenging feedstocks and moving from biofeeds in competition with food sources to those which are non-edible.
Europe’s Annex IX describes some of these bespoke biofeeds, with consideration given to the use of non-edible cover crops using non-food-producing lands. The changing feedstock quality imposes increasing levels of contaminants and lower carbon contents. Processing these feeds requires consideration of how to remove the contaminants (including water) and capture the maximum amount of hydrocarbon products.The future transition to these new feeds requires consideration of thermal pretreatment processes linked with refinery post-treatment to make fungible fuels. (For additional details, see Sayles and Ohmes, Conversion to a green refinery, Decarbonisation Technology, Nov 2022). Refinery configuration and biofeed considerations determine the ease of integration. In general, more complex refineries offer greater opportunities for biofeed integration.
In conclusion, the consideration of co-processing is dependent on the refinery configuration, feedstock selection, catalyst application, and location.
Optimised process designs are just one aspect of the overall solution, with biofeed supply logistics very often being the overall controlling factor determining the most attractive co-processing opportunity.
Mar-2023
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