CRACKING LARGER MOLECULES MORE SELECTIVELY
RIVE™ FCC catalysts powered by Molecular Highway™ Y-zeolite (also branded as MHY™) technology enhances feed molecules' access to and from active catalytic sites in the zeolite. As a result, MHY™ zeolites crack larger FCC feed molecules more selectively than conventional active matrix materials. This allows refiners to make more of what they want and less of what they don't.
Typical signatures of RIVE™ FCC catalysts powered by MHY™ zeolite technology include:
- Improved bottoms upgrading
- Increased LPG olefinicity and octane
- Decreased delta coke
- Increased operational flexibility for the refiner
The RIVE™ FCC catalyst represents the first and only use of ordered mesoporosity in FCC zeolites or catalysts capable of providing a step change in value for many FCC operations. The result: enhanced diffusion of hydrocarbons both into and out of the catalyst particle. This adds options to process heavier feeds, reduce costs, circulate more catalyst, and preserve valuable products increasing operating flexibility for the refiner
As refiners around the world face new challenges every day, MHY™ zeolite technology offers a proven, novel approach to the design of FCC catalysts to address many of these issues.
Ordered mesopores are Integral to the
MHY™ Zeolite Crystal
Conventional USY with network of channels connected by small, tortuous pathways||
Molecular Highway™ Y-zeolite (MHY™) with vast network of ordered mesopores|
THE MOLECULAR HIGHWAY™ ADVANTAGE
With conventional Y zeolites, molecules with kinetic diameters up to roughly 1 nm (10 Å) can directly enter the Y zeolite structure. This corresponds to hydrocarbons that boil up to around 950°F (510ºC). Larger hydrocarbons boiling above this temperature are traditionally cracked in the FCC by mesoporous aluminas. These materials have somewhat less selective acid sites, and the goal is to cleave off hydrogen-rich side chains, which can subsequently enter the zeolite cage. With the vast network of ordered mesopores (3-5 nm; 30-50 Å) in the MHY™ zeolites, larger feed molecules which boil at temperatures in the 950-1100ºF (510-593ºC) range are now able to directly access the strong acid sites in the zeolite. MHY™ zeolites can crack these larger feed molecules more selectively than conventional active matrix materials. This translates commercially into coke-selective bottoms cracking. Additionally, MHY™ zeolite technology rapidly channels the valuable cracked products out of the zeolite before they succumb to potentially undesirable reactions such as over-cracking, hydrogen transfer, or condensation reactions to form coke within the catalyst pores.
Among the primary and secondary "cracked products", LPG olefins such as propylene and butylene are very reactive, particularly at the high temperatures, such as those present within the FCC Riser and Reactor. If these valuable, reactive molecules spend too much time inside the catalyst, they can become saturated through hydrogen transfer reactions into less-valuable LPG paraffins. MHY zeolite's ordered mesopores allow rapid transport of valuable LPG olefins out of the zeolite. Preservation of primary products in conjunction with reduced hydrogen transfer also leads to a boost in Research Octane Number (RON), with more efficient bottoms upgrading.
Refiners have used these trademark benefits to increase FCC feed throughput by alleviating existing unit constraints such as maximum Air Blower rate, Wet Gas Compressor rate, and Regenerator temperature. Improved operating flexibility allows for increased catalyst circulation via lower delta coke, or the introduction of heavier opportunistic feeds, if increased circulation is not possible.
An Overview of Molecular Highway™ Y-Zeolite (MHY™) Technology
Small pore in conventional Y zeolites work well with molecules that boil up to 950ºF (510ºC).
MHY™ Zeolite technology creates larger pores, allowing zeolites to crack significantly larger molecules that boil at temperatures in the 950-1100ºF (510-593ºC) range.