PropyleneMAX™ Catalytic Cracking (PMcc™)

Grace and Technip Stone & Webster Process Technology, Inc. (TechnipFMC) are jointly developing an improved catalyst and process designed to provide pathways to convert crude oil to petrochemical feedstocks.

PropyleneMAX™ catalytic cracking technology (PMcc™) is a high-severity fluid catalytic cracking process licensed by TechnipFMC and designed to produce high yields of propylene and other petrochemical feedstocks such as ethylene and butylenes. With this new collaboration, refiners will benefit from the combination of Grace's knowledge as the leading supplier of FCC catalysts and light-olefins additives, and TechnipFMC's expertise in high propylene catalytic cracking process technology, resid processing, and mechanical know-how as we design a high propylene cracking process with a specialized catalyst system to produce world class propylene yields.


While the PMcc flow scheme and operation are like conventional Fluid Catalytic Cracking (FCC) or Residue Fluid Catalytic Cracking (RFCC) units, there are key design features that help to produce higher yields of petrochemicals:

  • Higher severity operation

    • Higher reactor temperature

    • Higher catalyst to oil ratio

  • Lower hydrocarbon partial pressure

    • Higher steam rates

    • Lower reactor pressure

  • Higher residence time to convert naphtha to propylene

  • Potential to recycle C4's, LCN and Oligomer recycle to maximize propylene

  • Leading light olefin catalyst

    • Optimized activity

    • Dual zeolite functionality from USY and pentasil zeolites

    • Integral metals traps as required

    • Low slurry yield via high diffusivity alumina

    • Industry-leading coke selectivity

  • Single or two-stage regeneration depending on feedstock

  • Reliable proprietary components


The PMcc produces significantly more light olefins and increases octane level of naphtha. The increased yields are accompanied by reductions in the naphtha, Light Cycle Oil and Decant Oil production, thereby providing deeper level of conversion of feedstock through the PMcc process.

The typical product yields (wt% fresh feed) are:

  • Fuel gas: 7.6 - 11.5

    • Ethylene: 3.5 - 5.9

  • LPG (C3's - C4's): 35 - 45

    • Propylene: 16 - 20

  • LCO: 8 - 14

  • DO: 0 - 5

  • Coke: 6 - 8


  • Our proven Feed Injection Technology to provide effective atomization and vaporization

  • Riser Termination Device to maximize light olefins yields

  • High efficiency packed stripping technology to maximize product recovery at high catalyst circulation rates

  • Specially designed combustion air and catalyst distributors

  • Reliable catalyst cooler, if required

Using key design features, proprietary components described above and our experience in design of RFCC units, PMcc offers the following advantages in operation, maintenance and installed cost:

  • Excellent feedstock conversion efficiency to propylene, ethylene and other valuable petrochemicals

  • Low delta coke design to maximize conversion and minimize coke make

  • Robust, proven mechanical design with high reliability and low maintenance costs

  • Flexibility of performance over a wide range of feedstocks and operating modes

  • Inherent process safety design

  • Ease of normal operation, startup and shutdown

  • Stable and maintainable operation

  • High energy efficiency


Including a PMcc in a refinery integrated with a petrochemicals complex offers several advantages. PMcc or high propylene FCC can be designed to be a bridge between the refinery and a petrochemical complex. The integrated complex consisting of a steam cracker for ethylene production and PMcc for propylene production can provide the maximum yields of premium value petrochemicals utilizing the lowest cost feedstocks at reduced capital and operating costs. Integration provides streamlined handling of both FCC dry gas, C3/C4 streams and naphtha.  As a leading licensor of the steam cracking process, TechnipFCM has leveraged this know-how to offer an integrated refinery and petrochemical complex design that meets flexibility and operating requirements.