About High Activity Clay Catalyst
High activity clay catalyst is an intensively acid-activated montmorillonite for refinery and petrochemical duties. Its main use is the removal of trace olefins and dienes from aromatic streams, such as reformate, benzene, toluene and xylenes, to bring bromine index within product specification before downstream processing or sale.
In clay treaters, the hydrocarbon passes through a fixed bed of granular clay at elevated temperature and enough pressure to keep it in the liquid phase. The strong acid sites alkylate olefins onto aromatic rings and polymerise dienes into heavier compounds that are removed later by fractionation. Higher acidity and surface area than standard grades mean more olefin conversion per tonne of clay, which supports longer cycle lengths between change-outs. Bed life depends on feed olefin content, operating temperature and flow rate, and spent clay is usually replaced when bromine index breakthrough occurs. The grade is also available as powder for slurry-phase alkylation and other reactions requiring strong solid acidity.
Obsidian Minerals produces granular and powder forms of this grade, screened to agreed mesh ranges for fixed beds. Each batch is tested in our NABL-accredited laboratory, with surface area, pH, moisture and particle size reported on the Certificate of Analysis. A Technical Data Sheet and MSDS/SDS accompany every shipment, and samples are available on request for laboratory activity testing.
Typical specifications
| Parameter | Typical Value | Test Method |
|---|---|---|
| Specific surface area | 200–300 m²/g | BET, nitrogen adsorption |
| pH (10 % slurry) | 2.5–4.0 | Internal method |
| Free moisture (105 °C) | ≤ 10 % | Internal method |
| Particle size (granular) | Typically 30/60 or 20/60 mesh; other ranges on request | Sieve analysis, internal method |
| Loose bulk density (granular) | 0.60–0.80 g/cm³ | Internal method |
| Thermal stability | Up to approx. 400 °C | — |
Typical values for guidance. Guaranteed limits are stated on the Technical Data Sheet and batch CoA. Cycle length and olefin removal depend on feed composition and operating conditions.
Key features & benefits
Strong solid acidity
Intensive activation gives the high activity clay catalyst more and stronger acid sites than standard grades, increasing olefin and diene conversion per tonne of clay in treating service.
Bromine index control
Designed to reduce bromine index in reformate and BTX streams by converting olefins and dienes, helping aromatics plants meet product specifications for downstream units and customers.
Granules sized for fixed beds
Screened granules support even flow distribution and an acceptable pressure drop through clay treater vessels, while limiting fines that can migrate downstream and foul equipment.
High surface area
Specific surface area typically between 200 and 300 m²/g provides the accessible acid site population needed for high throughput and longer cycles between clay change-outs.
Applications
Aromatics clay treating
Removes trace olefins and dienes from reformate, benzene, toluene and mixed xylenes in fixed-bed clay treaters, typically ahead of extraction, fractionation or para-xylene recovery units.
Hydrocarbon purification
Used to treat kerosene, hydrocarbon solvents and other refinery streams, removing unsaturated compounds and polar trace impurities that can affect colour, storage stability or the life of downstream catalysts.
Alkylation with strong acid demand
Powder form serves slurry-phase alkylation of aromatics and phenols where higher acid strength is needed than the standard activity grade provides, subject to customer trials.
Usage & handling
- Load granules into the treater with even distribution and dense loading where practical, to avoid channelling.
- Dry the bed with inert gas or hot hydrocarbon before introducing feed, following the plant's start-up procedure.
- Monitor bromine index at the outlet and plan change-out when breakthrough occurs.
- Handle granules gently and store in sealed bags in a dry area to limit fines and moisture pick-up.
Packaging & supply
- 25 kg or 50 kg HDPE or paper bags
- 1 MT or 1.2 MT FIBC jumbo bags for treater loading
- Custom packaging on request
Frequently asked questions
What is a high activity clay catalyst used for in refineries?
Its main refinery and petrochemical use is olefin removal from aromatic streams in fixed-bed clay treaters. The acid sites convert olefins and dienes into heavier compounds that are separated by fractionation, reducing bromine index. It is also used to purify other hydrocarbon streams and, in powder form, for alkylation reactions needing strong acidity.
How long does a high activity clay bed last?
Cycle length varies widely with feed olefin content, temperature, space velocity and the bromine index target. Higher activity clays generally convert more olefins per tonne before breakthrough. We do not quote a fixed cycle length; instead, we recommend a laboratory activity comparison with your current clay using a sample, so expected bed life can be estimated for your conditions.
Which mesh size of high activity clay granules is used in treaters?
Granular clays for treaters are commonly supplied in ranges such as 30/60 or 20/60 mesh, which balance pressure drop against contact efficiency. The right range depends on vessel design, flow rate and allowable pressure drop. Other ranges can be produced on request to match your current loading specification.
Can the high activity grade be compared with my existing treating clay?
Yes. We can supply samples for side-by-side laboratory testing against your current clay, typically measuring olefin removal or bromine index reduction on your own feed under agreed conditions. Share your current specification, including surface area, particle size and bulk density, so we can propose the closest match.