This document discusses catalytic reforming and hydrocracking processes. It provides details on:
- Catalytic reforming converts low octane naphtha into high octane reformates through reactions like dehydrogenation and dehydrocyclization.
- Hydrocracking breaks down heavier hydrocarbon molecules into simpler molecules like gasoline and kerosene using hydrogen and catalysts at high pressures.
- Both processes upgrade petroleum fractions through chemical reactions like cracking, isomerization and hydrogenation to produce more valuable products like gasoline and jet fuel.
2. Catalytic reforming is a chemical process used to
convert petroleum refinery naphtha distilled from crude
oil(typically having low octane ratings) into high-octane
liquid products called reformates, which are premium
blending stocks for high-octane gasoline
To produce high yields of aromatics , to make high
quality aviation gasoline and to produce LPG.
3. Catalytic conversion can be done by changing the no. of carbon
changing the C/H ratio or by isomerization.
C no. is changed by catalytic cracking, hydrocracking and
polymerization.
C/H ratio is changed by hydrogenation and dehydrogenation.
Isomerization neither changes the C no. nor C/H ratio but it
changes the shape of the molecule and it’s quality.
Catalytic processes removes impurities and convert certain
hydrocarbons into the products by breaking it into simpler
molecules.
4. The main reactions involved in the catalytic
reforming are given below-
• Dehydrogenation of naphthenes to aromatics.
• Dehydrocyclization of paraffins to aromatics.
• Hydrocracking
• Isomerization
• Demethylation and dealkylation
5. Dehydrogenation of naphthenes to aromatics.
Dehydrocyclization of paraffins to aromatics.
9. REACTION TEMP PRESS
Dehydrogenation of
naphthenes to aromatic
High Low
Isomerisation of
naphthenes
Intermediate Intermedia
te
Dehydrocylistion of
paraffins to
aromatics
High Low
Hydrocracking High High
13. Increase in temp increase aromatization and,
therefore reaction inlet temperature should be
high
By simply raising or lowering reactor inlet
temperature, operators can raise or lower the
octane number of the product
Since all the reactor inlet temperatures are not
necessarily identical, it is commonly accepted to
consider the Weighted Average Inlet Temperature
14. Increase in pressure desirable for the hydrocracking
reaction .
Low pressure is desirable for the aromatization
reaction.
But we do not operate the reactor at very low pressure
because at very low pressure it results in fast coking of
the catalyst .
15. Space velocity is a measure of contact time .A sufficent
contact time is needed for rxn to be complete .
In the process of catalytic reforming two types of velocity
generally defined
liquid hourly space velocity (LHSV)
Weight hourly space velocity (WHSV)
LHSV ranges 1 to 3 /hr
WHSV ranges 1.5 to 3 /hr
16.
17. It is a process by which the hydrocarbon molecules of
petroleum are broken into simpler molecules as of gasoline
of kerosene by the addition of the hydrogen under high
pressure and in presence of catalyst.
Amorphous silica alumina or zeolite catalysts are used.
18. There are two types,depending upon the feedstock used.
1 - Distillate hydrocracking
2- Residual hydrocracking
If the feedstock is heavy distillate obtained from straight-run
refinery or cracking operation then it is called as distillate
hydrocracking.
If the feedstock is residue of the straight-run refinery it will
be called as residual hydrocracking.
22. Sulphur,nitrogen and oxygen are almost completely removed
and olefins are saturated thereby giving a stable product.
Hydrocracking of vacuum gas oil and propane deasphalted oil
to produce high quality lube oil.
It hydrocracks compound of low viscosity index into high
quality naptha and distillates.
Wide range od distillate products can be obtained in the
hydrocracker namely either gasoline or jet fuel or diesel fuel.
23.
24. Hydrocracking unit is generally more costlier of the order of 1.6
times that of fluid catalytic cracking unit.
Operating cost is also high as compared to a catalytic cracker.
The metallurgy of unit needs special care,is costly and also
more difficult from maitainance point of view.