Density grading

Density grading is used for separation of similar-sized catalyst particles based on their density difference. Effective separations have been accomplished on catalysts containing particles with a density difference as small as I0%.

Porocel's proprietary density grading technology will maximize the yield of reusable catalyst, resulting in substantial cost savings to the refiner.

Examples of density grading applications include:

  • Separation of mixtures of different types of catalysts, for example, the separation of dewaxing and hydrotreating catalyst (High Purity Density Grading)
  • The removal of heavy-metal contaminated catalyst from uncontaminated catalyst
  • The separation of high carbon heel catalyst from reusable CCR Platforming catalyst

Density Grading of high-carbon contaminated CCR catalyst

Process description and benefits

When heel contaminated CCR reformer catalyst is density graded, three fractions are produced: light, medium and heavy.

The light fraction, having a low average and peak carbon content, is fully re-usable and is returned to the refiner. The heavy fraction containing the highest carbon levels is not reusable and is sent to noble metal reclaim for platinum recovery. The medium fraction is typically density graded again to maximize the recovery of re-usable catalyst.

The refiner sets the specification for the light fraction carbon. The higher the acceptable carbon level, the higher the yield of reusable catalyst. Typically, the average carbon spec is less than 7 wt%, with a peak carbon spec of no more than 12 wt%. The yield of reusable CCR catalyst can be as high as 80% or even 90% when low amounts of heel catalyst are present. Average yields range from 50% to 80%.

Cost savings from density grading depend on:

  • the amount of catalyst to be graded
  • the yield of reusable catalyst
  • the catalyst replacement cost
  • the metals recovery cost

The company will sample the spent CCR catalyst conditioned in drums or flow-bins upon arrival at its facility.

Spent catalyst samples will be used to do a so called pre-job analysis. The objective of the pre-job is to determine if the spent CCR catalyst is suitable for density grading or not. The spent CCR catalyst will be analyzed for average carbon content and for the presence of volatile hydrocarbons.

Based on this analysis it can be decided whether or not a stripping and light burn are necessary. The stripping and light burn are only performed if necessary or if requested by the customer.

A material balance and analytical report will be issued at the completion of the job.

If necessary an additional screening can be requested by the customer in order to remove broken CCR catalyst particles (dust and fines, and chips) to produce a better quality CCR catalyst.

The waste products, which are separated during the density gradporoce ing, stripping and light burn and screening, remains the property of the refinery and will either be returned together with the light fraction of CCR catalyst for reuse, or they will be forwarded to a noble metal reclaim company on behalf of the catalyst owner for ultimate noble metal recovery . The waste products will be packed in clearly identified drums.

All the formalities related to packaging, transportation and customs clearance of the catalyst the company OptimLine Technologies shall settle on its own.

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OptimLine Technologies is ready to offer to its customers innovative solutions for catalyst packaging.


April 2017 saw fulfillment of another project  for recovery of hydroprocessing catalysts for LUKOIL Nizhegorodnefteorgsintez.


The significance of the quality of catalysts for oil refinery can’t be emphasized too strongly. Having a price incomparably smaller than total cost of final refinery product, low quality catalyst may lead to long term production shutdown and consequently to multimillion losses.