Hydrogen – A fundamental component of the manufacturing process?
With the UK net-zero greenhouse gas emission 2050 target, there is a growing demand for sustainable methods of decarbonising industrial production. Many industries now find that Hydrogen will be a fundamental component of their manufacturing process.
Hydrogen has the potential to reduce emissions from most forms of industrial combustion. A report commissioned by the Committee on Climate Change published in 2019 showed that low-carbon Hydrogen also has a pivotal role in reducing carbon emissions in the UK.
Along with the significant benefits that Hydrogen offers to reduce carbon emissions, it also poses substantial safety hazards. Our own experiences in school science labs and memories of the Hindenburg disaster are all too clear on this. Nevertheless, users can safely manage Hydrogen in an industrial process context through robust hazard review and inherently safe design. The established methods of hazard identification, risk assessment, and application of the hierarchy of control can ensure that the overall risks are as low as is reasonably practicable (ALARP).
Understanding the critical differences between fossil fuel and hydrogen fuel sources and the inherent hazards associated with Hydrogen is vital to enable comprehensive risk assessment and ensure facilities are designed and operated to prevent, control, or mitigate Hydrogen hazards.
The primary regulations in the UK to regulate the storage, handling and usage of Hydrogen are the Dangerous Substances and Explosive Atmospheres Regulations (DSEAR) 2002 and the Control of Major Accident Hazards Regulations (COMAH) 2015; The regulator sets threshold levels to determine whether the COMAH regulations need to be applied. At the very least, the user must consider these regulations when exploring the prospect of a transition to Hydrogen fuel sources.
Hydrogen has a wide flammability range and low ignition energy – this means there can be a lot or a little in an air mixture, and only a small spark is needed for an explosion. Hydrogen’s low density and viscosity also increase release rates and dispersion distances compared to typical fossil fuels: these characteristics should all be factors in determining the hazardous area classification under DSEAR, especially when carrying out conversions on existing systems.
For example, using Hydrogen as a fuel in a furnace is not a new concept. It has been used in the steel industry for many years as part of the annealing process, where the gas’s highly reducing properties prevent oxidation and discolouration during the heating cycle while promoting surface cleaning. Therefore, the user should take extra care and do research to ensure that evolving knowledge gained in other industries and good practices are adopted when using Hydrogen in emerging technologies.
Designing systems with process safety in mind, for example, ensuring sufficient gas detection and monitoring in the workplace areas, effective atmospheric measurement systems, reducing the need for intrusive and frequent maintenance, and adopting condition monitoring technology, can all help for a safer adoption of Hydrogen and a more efficient system.