Side-fired tubular reforming features

With its ability to control the temperature profile along the tube length the side-fired tubular reformer is the only reformer which can run at a low steam to carbon ration as well as at a high outlet temperature.

The development of improved tube materials and reforming catalysts combined with a solid understanding of heat transfer and the influence of temperature levels and temperature gradients have made it possible to design and operate tubular reformers for tube wall temperatures up to 1050ºC/1920ºF.

Topsoe designs steam reformers with average heat fluxes close to 100,000 kcal/m3h in plants producing more than 200,000 Nm3 hydrogen equivalent in a single steam reformer.

Side-fired tubular reforming advantages

The side-fired tubular reformer offers the following advantages:

• uniform and higher heat flux
• fewer tubes and longer tube life
• no risk of flame impingement
• safer and more reliable operation

Application

Depending on plant capacity one or two radiant chambers are installed with tubes placed in a single row along the centerline of the furnace chamber.

Radiant wall burners are typically placed in the furnace walls, and flames are directed backwards to the furnace wall, eliminating the risk of flame impingement. Also, the short flames in the side wall fired furnace ensure very low NOx levels in the flue gas - typically below 50 ppm for reformers without combustion air preheat.

Hot flue gas leaves at the top of the radiant chambers through a refractory-lined duct, and the heat is used in the convection section. In modern plants with a large combustion air preheater the convection section is normally placed at ground level.

Focal points

Topsoe's range of catalysts for the reforming process may be combined to ensure optimal performance.

For reforming of light feedstocks such as natural gas Topsoe's R-67-7H catalyst meets all the requirements of today's demanding processes.
 
The R-67-7H catalyst provides a combination of high mechanical stability of the carrier and a large surface area, which results in a high catalytic stability and activity for the reforming reaction. High activity ensures that the reforming reaction is close to equilibrium at the outlet from the reformer. Furthermore, the high activity of R-67-7H results in lower tube wall temperatures, which prolongs life expectancy of reformer tubes, or alternatively allows operation at higher rates.

When operating in high-flux top-fired steam reformers and on feedstocks ranging from heavy natural gas to naphtha, R-67-7H is combined with Topsoe's series of RK-200 alkali-promoted catalysts. The RK-200 catalyst installed in the top part of the tubes offers protection against carbon lay-down.