2. 01
02
03
04
05
What is reforming and
its purpose?
Chemical reactions
and its types
Desirable
reactions
Adverse
reactions
Catalysts used
in reforming
Table of content
3. Introduction
Reforming takes straight chain hydrocarbons in
the C6 to C8 range from the gasoline or
naphtha fractions and rearranges them into
compounds containing benzene rings.
This process converts low octane linear
hydrocarbons (paraffins) into branched alkanes
(isoparaffins) and cyclic naphthenes, which
arethen partially dehydrogenation.
The gasoline quantity present in petroleum is
generally not of good quality.
When it burns in a automobile engline ,
combustion can be initiated before the spark
plug fire.
This produces a sharp metallic sound
KNOCKING which greatly reduces the
efficiency of engine.
Quanlity of fuel is indicated by its octane
number.
4. 1
2
To improve the
octane number of
feedstock,
especially of the
heavy napthas.
.
To reduce
antiknock
quality, of
gasoline
PURPOSE OF
REFORMING
5. Use or disclosure of data contained on this sheet is subject to the restriction on the title page of this proposal or quotation.
Desirable reactions Adverse reactions
These reactions lead to a
higher octane number and to
produce high purity
hydrogen .
These reactions lead to a
decrease of octane number
and a decrease in
hydrogen purity.
Chemical reactions
7. • Naphthenic
compounds
dehydrogenated into
unsaturated
(aromatics) with
production of 3 moles
of H2 per mole of
naphthene
• Promoted by the
metallic function
• Highly endothermic
• Thermodynamically
favored by high
temperature, low pressure
and high number of
carbons
• At the selected operating
conditions, reaction is very
fast and leads to
completion
Dehydrogenation
8. A
B
C
A
.
B
.
At the selected operating
conditions, much lower rate
than that of
dehydrogenation
Multiple step reaction.
Increases octane number
from 0 to 110
Promoted by both acidic
and metallic functions
Kinetically favored by
high temperature,
and low pressure
Dehydrogenation step become
easier as paraffin molecular
weight increases, but is competed
by hydro cracking
Paraffin's dehydrocyclization
10. Slightly endothermic
Desirable reaction because of
subsequent dehydrogenation of the
alklycyclohexane into an aromatic
Difficulty of ring rearrangement
and high risk of ring opening
(paraffin formation)
Easier reaction for
higher carbon number
Naphthene's
isomerization
12. Consumes hydrogen
And decrease he
yield of reformate by
Production Of
Gaseous
hydrocarbons
Hydrocracking is the
conversion of
paraffins to smaller
molecules.
Promoted by
Both acidic and
Metallic
functions
Favored by high
temperature and
High pressure
Exothermic(risk of
runaway
reactions)
HYDROCRACKING
MAJORADVERSE REACTIONS
13. • Promoted by metallic function
• Favored by high temperature and high
pressure
• Exothermic (risk of runaway reactions)
• Breakage of the branched radical of an
aromatic ring
• Promoted by metallic function
• Favored by high temperature and high
pressure
• Consumes hydrogen and produces methane
Hydrogenolysis
Hydrodealkylation
15. The catalyst used
for the processes
are of bifunctional
type. Bifunctional
means there are
two functions
incorporated into
the same catalyst.
In reforming catalyst, metal
function is performed by
metals like platinum or
platinum-rhenium. Metal
function derived from the
active metal present on the
surface of the catalyst mostly
performs hydrogenation and
dehydrogenation reactions.
Acid function derived from
the catalyst supports like
alumina, zeolites and
other catalyst supports
having strong acid sites
mostly performs acid
related reactions like
dehydrocyclization,
dehydroisomerization,
hydrocracking etc.
These strong acid sites present
in the catalyst support produces
positively charged protons in
the presence of moisture. These
protons on migration to the
carbon portion of the organic
molecule will produce positively
charged carbonium ions. This
imbalance of charge helps in
conducting various acid
controlled reactions.
SITES OF CATALYST
16. Cracked products
n-paraffns
Isoparaffns
Cyclopentanes
M or A
M or A
M/A
M/A
Cyclohexanes Aromatics
Naphthene
isomerizaton
Naphthene
dehydrogenation
1. Hydrocracking and demethylation
2. Paraffin isomerzation
3. Paraffin and naphthene dehydrogenaton and dehydrocyclizaton
1 2 3
1 2 3
