The iso-syn method you referred to is the patented refining process that is used by Chevron to produceits base oils. This process is a hydrocracking process that consists of the follwoing steps
The first step in this process is atmospheric and
vacuum distillation.
The second step in the process is severe
Hydrocracking to remove the majority of
sulfur, nitrogen and polar compounds and
saturate most of the aromatic and naphthenic
compounds that may be present.
The next step is Hydroisomerization which
is also known as Isodewaxing.
The Isodewaxing process which is patented by
Chevron takes n-paraffins and other molecules
with waxy side chains and converts them
into isomerized branched paraffinic
molecules (isoparaffins).
The Isodewaxing process can also use wax produced
by solvent dewaxing as one of its feedstocks.
The third step is severe hydrofinishing which is
used to remove any remaining sulfur,
nitrogen, polar compounds and unsaturated
molecules.
The final step is atmospheric and vacuum distillation to produce the desired viscosity grades.
This process produces Group III UCBO base oils
that have viscosity indexes ranging from 120 to
over 140.
The advantages and disadvatages of hydrocracked
base oils are as follows:
The careful selection of the proper base oil
remains the key to the formulation of a quality
finished lubricant. Contrary to much of the hype
taking place in the lubricants industry, hydrocracked base oils are not a panacea.
Very good to excellent oxidation stability due to
their high saturate content.
Very good low volatility characteristics due to
their high saturate content and the lack of lighter molecular ends.
Very good response to oxidation inhibitors and pour point depressant additive systems.
Light color and clear in appearance – Water White
in color.
High natural Viscosity Indexes ranging form
95 to 140
The hydrocracked base oil’s High Viscosity
indexes reduce the amount of viscosity index improver need when formulating a multi-grade oil. This improves shear stability.
Very good low temperature properties especially those Group III base oils that are produced by the Isodewaxing/Hydrocracking process.
Very good to excellent thermal stability due
to their high saturate content.
Low carbon residue forming tendencies.
Very good to excellent demulsibility characteristics due to their low polarity.
Low toxicity due to the absence of impurities.
Some hydrocracked base oils are pure enough
to be used in cosmetics, pharmaceuticals and
food grade oils.
Hydrocracked base oils can be used as correction
stocks to improve lower quality base oils.
Lube oil base stocks may be manufactured
from inferior (non-lube) crudes.
Hydrocracking produces highly sought after by
products such as naphtha and middle distillates.
Hydrocracked base oils do not contain any of the
natural sulfur antioxidants that are needed for
oxidation stability.
Hydrocracked base oils generally require the
use of additional oxidation inhibitors.
Once the oxidation inhibitor additive package is
depleted rapid oxidation will occur.
Uninhibited hydrocracked base oils will darken
and form sludge when exposed to air and light.
Hydrocracked base oils have a low ability to
solubilize the byproducts of oxidation.
This can result in the formation of sludge and
rapid depletion of the oxidation inhibitors that
are present in the lubricant formulation.]
Hydrocracked base oils exhibit low solvency
characteristics than other types of base oils.
Without formulation adjustments additive
solubility can be marginal and some additive
drop-out can occur
This lack of solvency characteristics also
inhibits hydrocracked base oils’ ability to
dissolve, disperse and hold sludge and
deposit forming materials in suspension.
Hydrocracked base oils due to lack of aromatic
compounds require the use of seal swell additives
in order to protect seal quality.
The hydrocracking refining process produces
predominately low viscosity base oils due to the
cracking of heavier molecules into smaller lighter
molecules.
The highest viscosity grade available from the
various producers of hydrocracked base oils is
equivalent to an ISO 100 or an SAE 30 grade.
Hydrocracked base stocks can not be used in
the formulation of many high viscosity industrial
and engine oil products without being blended
with other types of base stocks such as Group I
base oils or the use of viscosity index improvers.
Additional refining methods such as such as
severe hydrotreating is required to stabilize
hydrocracked base oils
Initial investment costs and operating costs
are higher for hydrocracking units.
Highly aromatic by products suitable for use
in carbon black or rubber extender oil manufacture
are not produced.
The Isodewaxing/Hydrocracking process
does not preserve wax volume or wax quality
because the wax is converted into lube oil
basestocks and fuels. This results in less wax
and wax-like products for resale.
The first step in this process is atmospheric and
vacuum distillation.
The second step in the process is severe
Hydrocracking to remove the majority of
sulfur, nitrogen and polar compounds and
saturate most of the aromatic and naphthenic
compounds that may be present.
The next step is Hydroisomerization which
is also known as Isodewaxing.
The Isodewaxing process which is patented by
Chevron takes n-paraffins and other molecules
with waxy side chains and converts them
into isomerized branched paraffinic
molecules (isoparaffins).
The Isodewaxing process can also use wax produced
by solvent dewaxing as one of its feedstocks.
The third step is severe hydrofinishing which is
used to remove any remaining sulfur,
nitrogen, polar compounds and unsaturated
molecules.
The final step is atmospheric and vacuum distillation to produce the desired viscosity grades.
This process produces Group III UCBO base oils
that have viscosity indexes ranging from 120 to
over 140.
The advantages and disadvatages of hydrocracked
base oils are as follows:
The careful selection of the proper base oil
remains the key to the formulation of a quality
finished lubricant. Contrary to much of the hype
taking place in the lubricants industry, hydrocracked base oils are not a panacea.
Very good to excellent oxidation stability due to
their high saturate content.
Very good low volatility characteristics due to
their high saturate content and the lack of lighter molecular ends.
Very good response to oxidation inhibitors and pour point depressant additive systems.
Light color and clear in appearance – Water White
in color.
High natural Viscosity Indexes ranging form
95 to 140
The hydrocracked base oil’s High Viscosity
indexes reduce the amount of viscosity index improver need when formulating a multi-grade oil. This improves shear stability.
Very good low temperature properties especially those Group III base oils that are produced by the Isodewaxing/Hydrocracking process.
Very good to excellent thermal stability due
to their high saturate content.
Low carbon residue forming tendencies.
Very good to excellent demulsibility characteristics due to their low polarity.
Low toxicity due to the absence of impurities.
Some hydrocracked base oils are pure enough
to be used in cosmetics, pharmaceuticals and
food grade oils.
Hydrocracked base oils can be used as correction
stocks to improve lower quality base oils.
Lube oil base stocks may be manufactured
from inferior (non-lube) crudes.
Hydrocracking produces highly sought after by
products such as naphtha and middle distillates.
Hydrocracked base oils do not contain any of the
natural sulfur antioxidants that are needed for
oxidation stability.
Hydrocracked base oils generally require the
use of additional oxidation inhibitors.
Once the oxidation inhibitor additive package is
depleted rapid oxidation will occur.
Uninhibited hydrocracked base oils will darken
and form sludge when exposed to air and light.
Hydrocracked base oils have a low ability to
solubilize the byproducts of oxidation.
This can result in the formation of sludge and
rapid depletion of the oxidation inhibitors that
are present in the lubricant formulation.]
Hydrocracked base oils exhibit low solvency
characteristics than other types of base oils.
Without formulation adjustments additive
solubility can be marginal and some additive
drop-out can occur
This lack of solvency characteristics also
inhibits hydrocracked base oils’ ability to
dissolve, disperse and hold sludge and
deposit forming materials in suspension.
Hydrocracked base oils due to lack of aromatic
compounds require the use of seal swell additives
in order to protect seal quality.
The hydrocracking refining process produces
predominately low viscosity base oils due to the
cracking of heavier molecules into smaller lighter
molecules.
The highest viscosity grade available from the
various producers of hydrocracked base oils is
equivalent to an ISO 100 or an SAE 30 grade.
Hydrocracked base stocks can not be used in
the formulation of many high viscosity industrial
and engine oil products without being blended
with other types of base stocks such as Group I
base oils or the use of viscosity index improvers.
Additional refining methods such as such as
severe hydrotreating is required to stabilize
hydrocracked base oils
Initial investment costs and operating costs
are higher for hydrocracking units.
Highly aromatic by products suitable for use
in carbon black or rubber extender oil manufacture
are not produced.
The Isodewaxing/Hydrocracking process
does not preserve wax volume or wax quality
because the wax is converted into lube oil
basestocks and fuels. This results in less wax
and wax-like products for resale.
