INNOVATIONS: PRESENT&FUTURE
SPECIAL ON PROTECTIVE TECHNOLOGIES FOR THE ENERGY INDUSTRY
Efficiency Increases in Catalytic Reformers Marina Silva IGS Integrated Global Services, Inc., Richmond – United States
marina.silva@integratedglobal.com
Process Overview
increased temperature promotes the development of further scale. As
Catalytic reforming converts low-octane, straight-run naphtha fractions,
oxidation continues, tube metal is consumed leading to a decrease in
particularly heavy naphtha, into a high-octane, low-sulfur reformate,
tube wall thickness, which shortens the tube life (Figs. 1 and 2).
which is a major blending product for gasoline/petrol. The process is endothermic and is carried out by feeding a naphtha and hydrogen
Ceramic coatings
mixture to a furnace, where it is heated in a series of fired heaters to
Ceramic coatings for process tubes prevent oxidation and scale
the desired temperature, 450° to 520°C (840° to 965°F), before passing
formation for approximately two turnarounds. This thin-film coating
through a series of reactors.
maintains the process tube in a like-new condition, maximizing conductive heat transfer to the process and increasing radiant section
Thermal inefficiencies
efficiency. Likewise, by stopping oxidation, tube metal loss is prevented
In a high temperature environment, steel alloy process tubes will
(Fig. 3).
immediately oxidize, and scale will develop. This oxidation scale layer acts as an insulator and will lead to a decrease in heat transfer as the
Coating refractory lining
scale increases in thickness. To compensate for the insulating effect of
The emissivity of typical refractory linings in fired heaters ranges from
the scale, the heater is subjected to excessive fuel firing. The resulting
0.45-0.65. When radiant energy encounters these refractory linings,
Process tubes of catalytic reformers in oil refineries are subject to oxidation caused by high temperatures. The resulting thermal inefficiency can be avoided by applying ceramic coatings.
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N.31 - 2019 OCTOBER - ipcm® Protective Coatings