We plan to purchase regenerated catalyst for our kero and LGO hydrotreater. We did regenerate our own catalyst, but never purchased one from an external company. What parameters should I pay attention to, what are the recommended limits for poisons and other parameters to guarantee a near-fresh activity and lifetime?
Robert Stults, Eurecat US, email@example.com
Eurecat sells regenerated catalyst and REACTTM Albemarle rejuvenated catalysts. REACTTM is a licensed secondary rejuvenation for Albemarle’s STARS catalysts. Axens, Criterion, and Haldor-Topsoe regenerated catalysts can also be rejuvenated by the manufacturer if the activity rejuvenation is required.
In order to address the key question of “how will this regenerated catalyst perform in my unit”, Eurecat goes beyond the contaminant and physical testing to include pilot activity testing for HDS (hydrodesulfurization) and RDP (relative delta pressure). The Eurecat HDS activity testing is reported as RVA (relative volume activity) and RWA (relative weight activity) versus the fresh version of the catalyst. RDP testing addresses the question of pressure drop with regenerated catalyst by testing the regenerated catalyst against its fresh version with sock or dense loading. The objective is to provide a full picture of the regenerated catalyst characteristics as well as expected activity and pressure drop.
Pilot Plant Activity: >90% RVA (relative volume activity) after regeneration (Type 1) or after rejuvenation (Type 2).
Relative Delta Pressure Drop (RDP) versus the same size fresh catalyst version (sock or dense loading)
Eurecat Typical Resale Contaminant Metals Specification
Contaminant Metal Maximum, wt%
Ni + V 1
Eurecat Typical Resale Physical/Chemical Specifications for Regenerated Catalyst
Carbon <1 wt%
Sulfur <1 wt%
Crush >4 lbs/mm for extrudates
Fresh 1.2-1.6 mm catalysts >2 L/D
Fresh 2.5-3.0 mm catalysts >1.5 L/D
Length Distribution Graphical representation of regenerated catalyst length distribution
Attrition <3 wt%
Fines <1 wt%
Loading Density Sock, Dense and Compacted Bulk for each resale lot
David Berman, Amlon Resources Group LLC, firstname.lastname@example.org
Below are specifications for acceptable spent catalyst for the purpose of regeneration and subsequent use. However, most of these specifications equally apply for the regenerated product itself. I suggest that you pay careful attention to L/D and attrition as well as contaminant fouling.
SURFACE AREA (RETAINED FOLLOWING LABORATORY REGENERATION):
>90% OF FRESH CATALYST SURFACE AREA RETAINED
>75% SURFACE RETENTION FOR 1/10" OR LARGER SIZED CATALYST
>80% OF FRESH CATALYST SURFACE AREA RETAINED
>70% SURFACE RETENTION FOR 1/10" OR LARGER SIZED CATALYST
LENGTH / DIAMETER (L/D) MEASUREMENTS:
1/20" AND 1/16" DIAMETER CATALYST: >2.0 L/D
1/10" AND LARGER: >1.5 L/D
ATTRITION: <2.0 WEIGHT %
CRUSH STRENGTH: COMPARABLE TO TYPICAL FRESH CATALYST
CARBON AND SULFUR: <1.0 WEIGHT % EACH (FOLLOWING LABORATORY SIMULATED REGENERATION)
CONTAMINANT METALS (AS, PB, FE, V, NA, AND SI):
<0.15 WEIGHT % FOR AS OR PB
<0.30 WEIGHT % FOR NA
<1.0 WEIGHT % FOR FE, V, OR SI (EXCLUDING INTRINSIC SILICON)
<2.0 WEIGHT % FOR COMBINED CONTAMINANT METALS
MINIMAL OR NO FREE LIQUIDS (AS HYDROCARBON OR WATER)
SPENT MATERIALS ARE FREE-FLOWING
Hope that helps. If you would care for an objective opinion on any given specific material, please feel free to write. I am involved in spent catalyst recycle, so I believe I could offer an objective opinion.
Sridhar Balakrishnan, Bharat Oman Refineries Limited , email@example.com
For a hydro treating catalyst attention shall be paid to metals and nitrogen content in the hydrocarbon feed.