Nov-2019

Meeting increased hydrogen demand (TIA)

Hydrogen is a simple molecule, yet around 70 million t/y are produced today mostly for oil refining and chemical production; and the demand is growing.

Susan Simpson, Josh Siegel, Matthew Wilson, and Ken Chlapik
Johnson Matthey

Article Summary

Currently, the global hydrogen market exceeds 5% growth annually. In the refining industry, the popularity of petroleum products in emerging economies and the strengthening of environmental regulations are some of the driving forces behind this growth. Hydrogen is vital to hydrocracking which is widely used to produce these consumer petroleum products. The tightening of environmental regulations to reduce sulphur oxide emissions also supports the strong projected growth as hydrogen is utilised by refiners to remove sulphur from finished products. These restrictions are broadening to reduce sulphur oxide emissions in the marine, aircraft and rail industries as well. Further, the usage of heavier, lower quality ‘opportunity’ crudes is increasing the need for desulphurisation and hydrogen to meet the final product specifications. Outside of oil refining, hydrogen is a strong business for the industrial gas industry. New distribution channels are being developed to more efficiently deliver their product and expand the marketplace. In the chemical industry, hydrogen is used for methanol and ammonia production. The rising demand for ammonia in fertilizers is expected to boost this industry’s growth. According to Global Market Insights, Inc: “Hydrogen generation industry size is projected to surpass $180 billion by 2024.”

Throughout industry, the bulk of this hydrogen is produced by steam reforming. It is the most economical process due to the low cost and availability of the natural gas that is used as feedstock to the steam reformer. In addition, the use of alternative feedstocks has the attention of the industry, as feedstocks derived from plant crops, biomass and other agricultural wastes turn low value material into desirable hydrogen. These factors ensure hydrogen produced by steam reforming will continue to grow.

It is possible that current demand for hydrogen exceeds refiners’ capacity to produce this essential intermediate. To meet this increasing need, refiners with low capital availability are looking for cost-effective options to increase their supply. Due to the low capital availability and longer unit life cycles, new hydrogen plant projects are diminishing. In addition, costs can be $1-1.4 million/ mmscfd of hydrogen. Revamps including heat exchange reformers and pre-reformers also require significant capital investment.

Johnson Matthey’s Catacel SSR technology allows increased production with minimal capital expense. In fact, increases of 15-20% have been observed in plant rates. Catacel SSR is a structured catalyst coated metal foil that is precisely engineered to provide a very large reactive surface, resulting in improved activity and a controlled process gas flow to improve heat transfer properties. The SSR is designed to address the bottlenecks of an individual plant to maximise production and can be installed in the existing tubes of the steam methane reformer.

The ‘fan’ structure, created by the manipulation of the foil, directs the process gas onto the tube wall, destroying any stagnant gas layer that limits heat transfer. This gas flow repeats itself down the tube, lifting heat transfer to levels never observed by pelleted catalysts. In addition, this directed gas flow ensures contact with all the active surface of the Catacel SSR. Randomly loaded pellets do not interfere with the stagnant gas layer on the tube interior wall to this degree, and rely on diffusion and randomness of flow to reach the active surface (see Figure 1).

The improvements in heat transfer and activity allow increased production rates. This increased production is achieved while maintaining a similar pressure drop to conventional pellets. With production rates maintained at current levels, 10-20% lower pressure drop has been observed compared to pelleted catalyst. The high void space and stability of the SSR structure means no increase in pressure drop is observed over time as the foil stacks expand and contract with the tubes, unlike pellets.

Furthermore, the operating benefits of using Catacel SSR have been documented and proven in commercial units. Some of the benefits are:
•    Substantial trim fuel savings at the same tube wall temperatures
•    Removal of pressure drop limitations
•    Lower tube wall temperatures at similar feed rate
•    Increased hydrogen production by higher throughput
•    Shorter reduction times.

In addition to all the operating benefits of Catacel SSR, it can be loaded within a normal changeout schedule; there is no need to extend the turnaround period to accommodate the increase in plant capacity which is normal for other revamp options.

Combing the operating benefits with the ability to be loaded within a normal changeout schedule allows hydrogen producers to see very short payback times, typically 9-12 months. The additional hydrogen produced by higher throughput or the removal of current production barriers adds value to the bottom line.

This short case study originally appeared in PTQ's Technology In Action feature - Q4 2019 issue.

For more information: Susan.simpson@matthey.com