Steam methane reformers (SMR) are the most common large-scale hydrogen production technique in use today. Much of the installed base of SMRs is linked to refinery operations, with the balance being associated with syngas, methanol and ammonia production in the chemicals and fertiliser sectors.
Hydrogen consumption on refineries has increased significantly in recent decades to treat heavy feedstocks, produce clean burning low sulfur fuels and for the hydrogenation of biofuels. The most recent uptick in demand has been driven by the IMO2020 changes which have increased the demand for low sulfur marine fuels.
In this context, anything that could be done to squeeze a few percent more hydrogen out of an existing SMR has been desirable. Strategies that SMR operators can use to increase hydrogen output include:
- Maximising the catalyst performance with adequate replacement
- Use of reformer and shift reactor catalysts with high conversion yields
- Minimising hydrogen losses through optimising the PSA hydrogen purification system bed sizing and operation
- Preventative maintenance to ensure that the plant equipment remains functional to ensure maximum up-time of the SMR
- Turnaround maintenance for future operation at maximum capacity
- Installation of additional reformer tubes within the SMR to increase the catalyst volume and, consequently, the plant capacity
- Adding a pre-reformer or post reformer
- Adjusting the steam-to-carbon ratio in the feed to the SMR
- Process control improvements
- Implementation of SMR operating best practices.
Focus adds value
For many refiners, the 10-point SMR optimisation plan above might theoretically be achievable. However, it may represent a distraction from their core focus on processing crude oil to produce a marketable palette of refined products and maximise refinery margins.
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