Fired heaters & emissions reduction: Fuel switching and hydrogen integration strategies

Global energy use and the demand for oil and polymer-based products continue to increase year on year. However, the need to reduce the environmental impact of the industry and move toward a circular economy is accelerating at a similar pace.

Fired heaters are among the largest sources of greenhouse gas (GHG) emissions in refineries and petrochemical facilities. Accordingly, we see incredible potential for meaningful emission reduction. Wood’s future-ready heater solutions consist of innovative products, technologies, and services to optimise existing or new fired heaters. These solutions allow our clients to remain compliant, competitive, and relevant while achieving positive GHG reductions and avoiding the need for wholesale process changes.

Future fuels

Fuel switching in fired heaters is not a new concept. Historically, oil was commonly used as fuel, however, the industry transitioned to a cleaner more efficient gas firing, such as natural gas (NG) or refinery fuel gas (RFG).  In today’s market, with the increased availability of hydrogen, many refineries and petrochemical facilities are injecting this clean energy vector into their existing fuel gas networks and exploring options to replace hydrocarbon fuels with hydrogen to reduce their emissions further. Hydrogen has the highest heating value of commonly used combustible gases meaning burning less gas achieves the same heating output. In contrast to carbon-based fuels such as NG or RFG, burning hydrogen produces no carbon emissions.

While existing heaters can accommodate a 30 ‐ 35% hydrogen blend without major modifications, the GHG emissions may only show a decrease of up to 20%. To achieve greater GHG emission reductions, a higher ratio of hydrogen blend should be considered which may require a more significant heater modification.

Future emissions

Where hydrogen firing is a solution to reducing carbon emissions, one concern is the generation of Nitrogen oxides (NOx) emissions. Hydrogen burns hotter than typical fuel gases and increases NOx formation. Integrating emission control technology such as modern process burner upgrades or selective catalytic reduction (SCR) systems into existing heaters can mitigate NOx emissions.

Minimising sources of tramp air can have a significant impact on fugitive emissions by ensuring that heater tube seals or observation doors are intact and sealing any other seams or sources of air infiltration. For instance, one client reduced their annual CO₂ emissions by 22,000 metric tons by reducing the tramp air into the furnace by 10%.  Although performing a comprehensive thermal and mechanical heater evaluation might seem trivial, it can offer solutions that have a big impact.

Interest in emission reduction through carbon capture has accelerated in recent years among end users. Implementation of carbon capture will affect the operations of the existing heater, which is why Wood is working with key technology partners offering a packaged solution to retrofit carbon capture economically within the tight constraints of existing facilities without impacting the performance of the heater.

Future performance

Improving the heater efficiency can mean less fuel is required to achieve the same heat input to the process. Simply put, less fuel means lower operating costs and lower emissions.

Many heaters in use today were built decades ago, meaning dated design codes and common wear-and-tear from operation. A proper evaluation can identify a wide variety of operational and mechanical solutions. For example, updating these heaters with energy efficiency improvements can recover significant amounts of wasted energy, improve performance, and increase the longevity of the units.

Future controls

While many of the changes can reduce emissions, significant improvements can only be achieved when controls are integrated. Carbon emission monitoring technology, such as Wood’s ENVision solution, automates environmental reporting and unlocks the value of data for an asset or portfolio of assets, whilst digital twin solutions allow accurate operations and maintenance forecasting in heaters. With these technologies, clients can have a fully integrated holistic solution for safer operations, higher reliability and optimised efficiency.

Future integration

New feedstocks, new products, circular economy, hydrogen fuel, and carbon capture, among many other changes just beyond the horizon, will drive fundamental change to the future integration of chemical processes. This in turn will change the mass, heat, fuel, carbon, steam and electrical balances across refineries and industrial clusters, meaning the fired heaters will need to be integrated differently.

Heat integration with energy from green sources, for example, the development of electrical heaters to offset fuel duty through renewable sources and the integration of bio feedstock processes with carbon capture to generate carbon-negative solutions are currently under development by Wood.

Need support to be future-ready?

Whether the solution will be hydrogen, biofuels, sustainable aviation fuels or plastic circularity process technologies depends on the end-user’s specific needs and circumstances which Wood is prepared to cater to. At Wood, we believe that to become future-ready, it is necessary to understand what the future of the industry looks like, and how to embrace it.  None of these challenges are new to us as we have over a century of experience in revamping and installing fired heater units – over 3000 globally.

Our team continues to innovate and improve the efficiency and overall performance of our technologies – old and new. Our proprietary heater designs and analytical modelling software can accurately deliver solutions to convert and upgrade heaters with all these challenges at the forefront – and these solutions are future-ready, now.

Learn more about improving the efficiency and reducing the emissions of fired heaters.

If you want to discuss your challenges with one of our experts, contact our fired heater specialists.