How renewable fuel producers can unlock lower emissions and stronger economics

Topsoe’s integrated hydroprocessing and hydrogen technologies HydroFlex® and H2bridge™ offer fuel producers a pathway to lower emissions, reduced costs and greater feedstock flexibility

By Milica Folić, Director for Clean Fuels and Chemicals, Topsoe
Special to the Digest

Securing bankability and strong economics in renewable fuel production projects are of primary importance. Producers must manage production costs and hydrogen use efficiently, while also navigating feedstock security, securing market demand and keeping emissions low. For many refineries and biorefineries, the path forward needs technologies capable of delivering genuine carbon intensity reductions without sacrificing operational control or commercial viability.

One solution, combining two Topsoe technology platforms, addresses these challenges directly. HydroFlex® is a proven hydroprocessing solution designed for renewable feedstocks. H2bridge™ represents Topsoe’s portfolio of hydrogen production technologies, enabling the optimal hydrogen solution to be matched to each HydroFlex configuration.

For most renewable fuel plants, the H2bridge solution is HTCR, while larger facilities benefit from SMR‑B, and very large‑scale projects can be served by SynCOR™. Together, HydroFlex and H2bridge form an integrated system that delivers competitive economics and a significantly improved emissions profile across a wide range of plant sizes. This scalability is exemplified by the NXT Clean Fuels project, where a SynCOR hydrogen unit is designed to supply hydrogen to three HydroFlex trains when constructed.

HydroFlex® provides proven flexibility in renewable feedstock processing

HydroFlex is a hydrotreating technology that converts a wide range of renewable feedstocks into drop-in fuels, including renewable diesel, sustainable aviation fuel (SAF) and naphtha. The technology is designed to accommodate feedstock variability, a critical capability given the inconsistent quality and availability of inputs such as used cooking oil, animal fats and other lipid- and waste-based materials.

Since its initial industrial implementation in 2004, HydroFlex has accumulated a reliable commercial track record, with more than 25 licensed units operating globally. The technology can be deployed in new-build facilities or retrofitted into existing hydrotreaters, making it suitable for both greenfield projects and asset conversions.

Each HydroFlex unit is configured to the specific requirements of the refinery or fuel producer, taking into account factors such as capacity, feedstock slate and target product mix. Additionally, Topsoe’s proprietary catalysts are selected to handle the particular contaminants present in renewable feedstocks, which differ significantly from those encountered in conventional fossil processing. Guard catalysts, for instance, protect the bulk catalyst bed from irreversible contamination, helping to maintain yield, extend cycle lengths and reduce unplanned downtime.

The fuels produced meet international standards and are fully compatible with existing distribution infrastructure and combustion engines. If feedstock availability shifts or regulatory requirements change, HydroFlex can adapt without compromising product quality. This flexibility is a core design attribute.

Rethinking hydrogen supply with H2bridge™

Hydrogen consumption is one of the larger challenges of renewable fuel production. Hydrotreating renewable feedstocks requires substantially more hydrogen than processing conventional crude, primarily because of the need to remove oxygen and saturate carbon bonds. Traditionally, this hydrogen has been sourced from natural gas reforming, which can carry a significant carbon impact and exposes producers to commodity market fluctuations and potentially higher cost.

H2bridge offers an alternative. Rather than importing hydrogen, the H2bridge produces it on site using the light hydrocarbons and off-gases generated during the HydroFlex process. These byproducts are reformed into high-purity hydrogen and fed back into the hydrotreating unit. With H2bridge, refineries and biorefineries can integrate a circular solution that helps replace external fossil feedstocks with LPG or naphtha to produce hydrogen.

Depending on the plant’s requirements, it is possible to create a circular system that either reduces or eliminates the need for external natural gas.

This has the knock-on benefit of insulating producers from hydrogen price fluctuations, and simplifies supply logistics and dependencies. The environmental benefit is equally significant: by producing hydrogen from on-site, renewable sources rather than virgin fossil feedstocks, H2bridge materially lowers the carbon intensity of the fuel produced.

H2bridge is not designed as a standalone technology. Its value comes specifically from its integration with HydroFlex, where it can take advantage of process heat and optimise energy use across the combined system.

The combined HydroFlex and H2bridge advantage

Renewable feedstocks enter the HydroFlex unit, where they are converted into finished fuels. The off-gases from this process are captured and routed to H2bridge, which reforms them into hydrogen that is returned to HydroFlex. The result is a near-closed system with minimal waste and significantly reduced external inputs.

This integration delivers measurable advantages across several dimensions.

Reduced operating costs. Cutting natural gas requirements removes a major variable cost. The coupling of the two units also enables advanced heat integration, reducing energy consumption. For some H2bridge sizes, water usage can be lower than in conventional hydrogen production from natural gas.

Capital efficiency. The integrated design simplifies the overall plant layout, particularly for new-build projects. For revamps, the modular nature of both technologies allows staged implementation. It also allows for the generation of the extra hydrogen needed for renewables (in the case of revamps).

Operational resilience. Producing hydrogen on site removes dependency on external suppliers and insulates the facility from market disruptions. Feedstock flexibility in the HydroFlex unit provides further protection against supply chain volatility.

Lower carbon intensity. By replacing fossil-derived hydrogen with renewable hydrogen produced on site, the combined system achieves substantial reductions in lifecycle greenhouse gas (GHG) emissions. In many regulatory frameworks, lower carbon intensity translates directly into tax credits and improved product margins.

Regulatory alignment. The system supports compliance with evolving renewable fuel standards many jurisdictions. As emissions thresholds tighten, having a production process with inherently low carbon intensity provides a long-term, durable competitive position.

Key benefits of combined HydroFlex® and H2bridge™ operation

• • On-site hydrogen production from renewable off-gases
  • Elimination or significant reduction of natural gas consumption
  • Lower lifecycle GHG emissions and improved carbon intensity scores
  • Reduced OPEX through better heat integration and lower water use
  • Feedstock flexibility across a wide range of renewable inputs
  • Compatibility with both new-build and retrofit projects
  • Alignment with current and anticipated regulatory requirements 

A strategic pathway forward for fuel producers

The shift toward renewable fuels like HVO and SAF is accelerating, driven by regulatory mandates and growing demand for lower-carbon energy. For fuel producers, the challenge is to enter the market and to do so in a way that is economically sustainable and operationally sound.

The combination of HydroFlex and H2bridge represents a considered response to this challenge. The two technologies address the core obstacles facing renewable fuel production: feedstock variability, hydrogen cost and carbon intensity. It does so in an integrated solution that is proven in commercial operation, adaptable to different facility configurations and designed to meet tightening emissions standards.

In the context of renewable fuel production, hydrogen units are central to both the emissions profile and the profitability of the operation. The ability to produce hydrogen from process byproducts, rather than importing it from fossil sources, changes the fundamental economics of the business – for the better.

For refineries and biorefineries evaluating their options, the question is how to address hydrogen supply in a way that supports long-term competitiveness. An integrated approach, built around technologies with a long, strong commercial track record, offers a clear pathway. The details of implementation will vary by facility, but the strategic logic is evident: lower emissions, lower costs and greater control over the production process. These are the solid foundations for production in the renewable fuels market.

 

 

Category: Thought Leadership