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BENZENE SATURATION: TWO OPTIONS

Increased regulatory pressure to reduce benzene in the

gasoline pool requires a comprehensive solution.

Controlling reformer feed or severity as a means oflimiting benzene production is a costly option and

may be inadequate for some refiners. Benzene

hydrogenation downstream of the reformer offers a

reliable solution for positive benzene control without

constraining the reformer.

As the world leader in the field of hydrogenation, in

the refining and petrochemical industry, and with

more than 500 commercial references, Axens offers

the cost effective Benfree technology to saturate

benzene without compromising reformer severity.

Benfree addresses operator requirements in terms ofperformance, flexibility, reliability, safety and cost

with two configuration options:

BenfreeC: The Conventional option employs a

hydrogenation unit downstream of a reformate

splitter to saturate the benzene contained in the light

reformate stream.

BenfreeC is generally the best option for very high

benzene reduction requirements (above 97% overall

benzene conversion).

BenfreeRD:The alternative option utilizes ReactiveDistillation and integrates a hydrogenation reactor

with the reformate splitter column.

For 95% benzene conversion and below, Benfree RD

is the winner while the optimum scheme for a

conversion between 95% and 97% is case specific.

With the two Benfree options, Axens offers an

optimized solution for each specific case based on the

benzene conversion requirement (from 80% to 99+ %),

existing equipment availability including revamping

options, refinery configuration and cost constraints.

BENFREEC

BenfreeC features independent splitter and reaction

sections for maximum benzene removal.

Full range reformate from a catalytic reformer is fed to

a low pressure naphtha splitter column. The splitter

operates as a dehexanizer lifting the C5 and C6overhead, including benzene. This benzene-rich light

reformate stream is sent to the hydrogenation section.

The C7+ components are recovered in the splitter

bottoms as the heavy reformate product.

Off Gas

Light

Reformate

H2

HeavyReformate

Splitter

Hydrogenation

Section

Full Range

Reformate

Stabilizer

Off Gas

Light

Reformate

H2

HeavyReformate

Splitter

Hydrogenation

Section

Full Range

Reformate

Stabilizer

Typical BenfreeCprocess flow scheme

The reformate splitter is designed to:

Minimize toluene carry-over in the light reformate

sent to the hydrogenation reactor to maximize

octane retention

Maximize overall benzene conversion by limiting

the benzene content in the heavy reformate stream.

The hydrogenation section achieves total conversion of

the benzene into cyclohexane from the light reformate

stream. The reaction takes place in a fixed catalyst bed

reactor under mild operating conditions with no

cracking and very little hydrogen excess. Hence, no

make-up or recycle compressor is required. Most of the

hydrogen excess can be recovered from the

hydrogenation section and sent back to the hydrogen

network.

Benfree

DELIVERING LOW BENZENE GASOLINE WHILE MEETING TODAYS DEMANDOF BALANCING COST AND PERFORMANCE

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A stabilizer is provided to vent light ends entering with

the hydrogen; and in some instances, it is also designed

to meet a specific RVP target in the light reformate

stream for additional flexibility.

BENFREERD

The more recently developed BenfreeRD technology

integrates the reformate splitter with the hydrogenation

section thus, reducing equipment andassociated costswhile still providing excellent benzene conversion

levels.

H2

Splitter

Light

Reformate

Off Gas

Full Range

Reformate

Heavy

Reformate

H2

Splitter

Light

Reformate

Off Gas

Full Range

Reformate

Heavy

Reformate

Typical BenfreeRDprocess flow scheme

Similarly to BenfreeC, a full range reformate stream is

fed to the reformate splitter. The Benfree RDsplitter is

designed to take a benzene rich stream as a side-draw

from the column. This C6-rich heart cut stream is

routed after mixing hydrogen make-up to a fixed bed

hydrogenation reactor located outside the column.

The benzene depleted reactor effluent is then returned

to the column where a light reformate product is taken

as a side-cut withdrawn below a pasteurization zone

aimed at controlling RVP while the heavy reformate

product is recovered in the splitter bottoms. Design andoperating conditions are adjusted to minimize toluene

carry-over into the reaction section and maximize

octane retention.

The BenfreeRDprovides a number of benefits:

Simple integrated reactive distillation concept which

ensures a high level of benzene saturation with great

operation flexibility

Easy catalyst loading and change-out in a

conventional fixed bed instead of proprietary

catalytic structured packing

Continuous splitter operation, even if the reactor isshutdown to meet market demand or fluctuations

Lower capital cost and plot area

Enhanced separation to deliver superior light naphtha

to an isomerization unit which is practically free of

benzene and C7s.

CATALYST SELECTION

Either non-noble metal (i.e. Nickel) or noble metal (i.e.

Platinum) catalysts can be employed. We manufacture

and have commercial experience with both catalysts.

BENFREE HIGHLIGHTS

Benfree technology offers:

Customized solution: BenfreeCor BenfreeRD

Lower cost with integrated BenfreeRDscheme:

90-95% conversion Benfree C BenfreeRD

Capital cost Base Base 30%

Plot area Base Base 35%

Mild operating conditions to minimize operating and

capital cost as no hydrogen make-up or recyclecompressor is required

Superior flexibility to handle potential variations in

the feed throughput and benzene content

Easy unit operation with limited maintenance

Ability to co-process other streams such as Light

Straight Run Naphtha, Light Hydrocrackate Naphtha

Extremely robust design where great consideration

for safety has been taken each step of the way.

COMMERCIAL EXPERIENCE

Axens has been awarded more than 40 Benfree

licenses using both Nickel and Platinum catalysts.

17 units are currently in operation, and another 10 units

will be started-up by 2010.

This extensive commercial experience coupled with

our complete portfolio of gasoline technologies,

including Catalytic Reforming and Isomerization,

provides an unparalleled expertise to help you comply

with the most stringent gasoline pool benzene

specifications.

Oct10-Benfree