GBHE C2PT Catalyst Process Technology

VULCAN VGP Series Purification Catalyst and Absorbents

Gerard B. Hawkins Managing Director, C.E.O.

High Temperature Sulfur Removal in the Presence of Chlorides In Magnaforming Units

Catalytic reforming is a chemical process used to convert petroleum refinery naphthas, typically having low octane ratings, into high-octane liquid products called reformates which are components of high-octane gasoline.

Basically, the process re-arranges or re-structures the hydrocarbon

molecules in the naphtha feedstocks as well as breaking some of the molecules into smaller molecules. The overall effect is that the product reformate contains hydrocarbons with more complex molecular shapes having higher octane values than the hydrocarbons in the naphtha feedstock.

◦ Note: all of which utilize a platinum and/or a rhenium catalyst.

Rheniforming: Developed by Chevron Oil Company. Powerforming: Developed by Esso Oil Company, now known as

ExxonMobil. Magnaforming; Developed by Engelhard Catalyst Company and

Atlantic Richfield Oil Company. Ultraforming: Developed by Standard Oil of Indiana, now a part of

the British Petroleum Company. Houdriforming: Developed by the Houdry Process Corporation. CCR Platforming: A Platforming version, designed for continuous

catalyst regeneration, developed by UOP. Octanizing: A catalytic reforming version developed by Axens, a

subsidiary of Institut Francais du petrole (IFP), designed for continuous catalyst regeneration.

Catalytic Reforming Processes and Licensors

Licenser Process Name Commercial Installations

Process Type

Universal Oil Products (UOP) Process Division

Platforming Over 700 units ò Semi-regenerative ò Continuous catalyst

regeneration

Institut Franτais du PΘtrole Catalytic Reforming

90 unit licensed (30 units continuous regeneration

ò Semi-regenerative ò Continuous catalyst

regeneration

Chevron Research Co. Rheniforming 73 units ò Semi-regenerative

Engelhard Corp. Magnaforming 150 units ò Semi-regenerative ò Semi-cyclic

Exxon Research and Engineering Co.

Powerforming 1.4 million BPSD

ò Semi-regenerative or cyclic

Amoco Oil Co. Ultraforming 150 units ò Cyclic or semi- regenerative

Houdry Division of Air Products and Chemicals, Inc.

Houdriforming 0.25 million BPSD

ò Semi-regenerative

Typical Process Flow Diagram Semi-Regenerative Unit

Sulfur Removal

Catalyst commonly used in catalytic reforming contain noble metals such as platinum and/or rhenium, which are very susceptible to poisoning by sulfur and nitrogen compounds. Therefore, the naphtha feedstock to a catalytic reformer is always pre-processed in a hydrodesulfurization unit which removes both the sulfur and the nitrogen compounds.

Sulfur is primarily a platinum function poison and its effect is similar to an over

chlorided catalyst. For operation at a constant octane the effect of sulfur poisoning is to decrease the reformate yield, hydrogen make and reactor temperatures, and increase the coking and hydrocracking rates.

Catalyst regeneration is also more difficult if the catalyst has been

contaminated with sulfur. Sulfur on the catalyst and vessel surfaces is oxidized during catalyst regeneration. The result is a regenerated catalyst with low activity.

This upstream hydrodesulfurization unit will remove most of the organic

sulfur in the naphtha feed, feed. However, there will still be ingress of small amounts of sulfur to the reforming unit because. H2S will be dissolved in the liquid naphtha because of inadequate stripping at the hydrotreating stripper.

Olefins and H2 S exit the hydrotreating reactor will recombine to form mercaptans, especially

at higher reactor temperatures towards the end of cycle. Feed/effluent exchanger leaks on the hydrotreating unit. Or as in some cases, recycle gas system has also been used as an alternative location by a

number of operators. Typically this location has been chosen when the operator has vessels already available say for a recycle gas dryer.

Sulfur Removal

Application: High Temperature Sulfur Removal in the Presence of Chlorides

In Magnaforming Units, the high temperature recycle gas stream is the location of choice for sulfur guards.

This location offers a greater degree of sulfur removal because of its multi-pass nature and hence quicker recovery from large sulfur upsets.

HIGH SEVERITY OPERATION

0 0.2 0.4 0.6 0.8 1 1.2 1.4-3.5

-3

-2.5

-2

-1.5

-1

-0.5

0

Feed sulphur ppm

C5+ yield vol% change

Pt only

Balanced

Skewed

LOW SEVERITY OPERATION

0 0.2 0.4 0.6 0.8 1 1.2 1.4-3.5

-3

-2.5

-2

-1.5

-1

-0.5

0

Feed sulphur ppm

C5+ yield vol % change

Pt only

Balanced

Skewed

REFORMATE

LPG

Key : Vulcan Series S guard

RECYCLE GAS

MAKE GAS OFF GAS

NAPHTHA FEED

Magnaforming - Reaction Section with Heaters

- Semi-Regenerative - Semi-Cyclic

William C. Pfefferle Invented Magnaforming, whilst Section head of Engelhard Industries, Iselin, NJ, 1956–1969 Section Head. In charge of research on petrochemical processes. Pioneered field of permeation mediated catalysis. Patent # 3,3392,107 Issue Date: July 9, 1968 By 1988 150 Units were operating worldwide, with HRI having installed units in Argentina, Algeria and the USSR.