The hydrogen plant of CPIngredientes, Guadalajara, Mexico, has a typical reformer configuration consisting of tubes of varying ages. The plant recharged several of these tubes with traditional ceramic catalyst as recently as January 2012.
"With an operational goal to reduce natural gas consumption in our burner and increase plant efficiency, we decided to replace all of the ceramic pellet catalyst media in the reformer with Catacel Corp.'s Stackable Structural Reactor (SSR), a foil-supported steam reforming catalyst," notes Javier Fortuna, principal of Total Energy, plant operations consultant to CPIngredientes.
SSR media offer significantly better heat transfer coefficients than ceramic media, reducing the furnace and tube temperatures needed to achieve the required reaction temperature. Ceramic media typically operate with a 90–100°C temperature differential between media and tube — SSR media decrease that differential by 35°C or more. This allows the tubes to operate cooler, extending their life. In addition, each SSR fan (Figure 1) is engineered to provide a reactive surface area about 2.5 times greater than typical of ceramic media. The higher surface area exposes more active ingredient to the reaction and provides a longer catalyst life.
"After a very thorough study and analysis we were convinced that the Catacel approach to improving plant efficiency and performance would yield significant results for us. SSR involves coating proprietary high-performance catalyst onto engineered foil supports ('fans') specifically designed to deliver superior heat transfer at the same or lower pressure drop than the traditional ceramic pellet catalyst we had been using. With the increased heat transfer coefficient, we are able to maintain our hydrogen production rates at reduced furnace temperatures and natural gas consumption," Fortuna adds.
The plant's staff, with Catacel supervision, completed the catalyst changeout to SSR in two days in May 2012. The installation involved 72 3-ft-long sections of structured foil catalyst, comprising a total of nearly 2,000 SSR fans. Each section was inserted into the reformer tubes with a special Catacel-designed tool and, once in place, was expanded to conform to the specific geometry of each tube (Figure 2).
"Our data log for the first three months of operation with the new SSR catalyst indicated burner fuel consumption decreases of up to 30% compared to the consumption data logged for the same plant rates when our plant was charged with traditional ceramic pellet supported catalyst," notes Fontana. Table 1 provides details.
"The initial reporting at 100% plant rate indicated a 13.5% reduction in natural gas consumption by the reformer burners over the nominal values of previous months and years of operation. Continued readings, however, taken in the following months and at various plant rates, clearly indicate burner fuel reductions of up to 30%, and reductions to furnace temperatures of 35–70° Celsius."
Based on current natural gas pricing in Mexico, the estimated payback period for the entire SSR catalyst charge changeover is 2.1 years.
An additional benefit to the SSR catalyst system is that it will not fracture, clump together, create space voids or increase tube pressure drop over time, as is typical with ceramic catalyst pellets. The SSR technology is expected to allow the catalyst to extend the life of the reformer tubes and remain active over the extended tube life.
WILLIAM WHITTENBERGER is president and chief technology officer of Catacel Corp., Garrettsville, Ohio. E-mail him at email@example.com.