Hydrocarbon Processing - June 2021 - 38

Process Optimization
this target value incurs further costs to the refiner. For example,
in the U.S., this cost calculates to approximately $1 MM per 0.1
octane giveaway per 100,000-bpd crude capacity. The RVP is
slightly different, as refiners aim to blend as much low-value
normal-butane (component RVP of 52 psi) into the final blend
without exceeding the specification. For example, the cost of nbutane
is $7/bbl that can be sold as gasoline at $25/bbl just by
blending. The $18/bbl profit is significant to the refiner, making
RVP economics important.
Distillate fuel blending has other specifications that must be
ascertained. Distillate blending includes jet fuels, diesel fuels,
kerosene and No. 1 and No. 2 fuel oils. Diesel fuels properties
that are measured include:
* Cetane number (analogous to octane number for the
gasoline engine)
* Flash points (relates to fire hazard in storage)
* Low-temperature properties (including cloud point)
* Pour point and sulfur content.
In blending some products, such as residual fuel oils or asphalt,
viscosity is one of the specifications that must be met.
Previously, blending was performed in batch operations.
However, with on-line equipment, computerization and improved
techniques, blending is readily performed with greater
efficiency and accuracy. Keeping inventories of the blending
stocks along with cost and physical data have increased the flexibility
and profits from on-line blending through optimization
programs. In most cases, the components blend nonlinearly for a
given property (vapor pressure, octane number, cetane number,
viscosity, pour point, etc.), and correlations and programming
techniques are required for reliable predictions of the specified
properties in the blend.
Blends of petroleum-based gasoline with 10% ethanol (referred
to as E10) account for more than 95% of the fuel consumed
in motor vehicles with gasoline engines in the U.S. Ethanol-blended
fuels are a pathway to compliance with elements of
the federal Renewable Fuel Standard (FRS). The total volume of
ethanol blended into motor fuels used in the U.S. has increased
since 2010, although at a declining rate of growth; meanwhile, the
use of ethanol-free gasoline (E0) by fuel consumers has declined.
FIG. 1 shows a refinery in-line blending facility.
Blending processes. Two types of blending exist: batch
and continuous. Batch blending begins with mixing known
amounts of components in a tank mixer using an agitator and
other accessories, such as pressure gauge, liquid level indicators,
etc. Agitation can also involve air where toxic materials like lead
and biocides are blended. Mixing in tanks is also accompanied
by heating or cooling coils.
Most refiners employ computer-controlled on-line blending
for blending gasoline and distillates. All components to be
blended are pumped simultaneously into a common header
at rates specified as per the formulations in FIG. 2. The rate of
flow is controlled by a valve operated by a pneumatic or electric
relay system. The received signals correspond to the flowrates,
and these can accurately modulate the flowrates by adjusting
the valve. The long pipeline through which these proportioned
components travel acts as a mixer to produce the blend. Additives
can also be injected into the system.
Inventories of blending stocks, together with cost and physiFIG.
1. Refinery in-line blending.
cal property data, are maintained in a database. Many of the
properties of the blending components, such as the octane
number, are non-linear; therefore, estimating final blend properties
from the components can be quite complex. When a certain
volume of a given quality product is specified, LP models
are employed, permitting the rapid selection of an optimal solution
from multiple feasible alternative solutions. The LP can be
used to optimize blending operations to select blending compoFIG.
2. Schematic diagram of a blending process.
FIG. 3. Screenshot of the blending of linear straight run (LSR) naphtha
and mid-cut reformate using the Ethyl model.
38 JUNE 2021 | HydrocarbonProcessing.com
http://www.HydrocarbonProcessing.com

Hydrocarbon Processing - June 2021

Table of Contents for the Digital Edition of Hydrocarbon Processing - June 2021

Contents
Hydrocarbon Processing - June 2021 - Cover1
Hydrocarbon Processing - June 2021 - Cover2
Hydrocarbon Processing - June 2021 - Contents
Hydrocarbon Processing - June 2021 - 4
Hydrocarbon Processing - June 2021 - 5
Hydrocarbon Processing - June 2021 - 6
Hydrocarbon Processing - June 2021 - 7
Hydrocarbon Processing - June 2021 - 8
Hydrocarbon Processing - June 2021 - 9
Hydrocarbon Processing - June 2021 - 10
Hydrocarbon Processing - June 2021 - 11
Hydrocarbon Processing - June 2021 - 12
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Hydrocarbon Processing - June 2021 - 20
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Hydrocarbon Processing - June 2021 - 27
Hydrocarbon Processing - June 2021 - 28
Hydrocarbon Processing - June 2021 - 29
Hydrocarbon Processing - June 2021 - 30
Hydrocarbon Processing - June 2021 - 31
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Hydrocarbon Processing - June 2021 - 33
Hydrocarbon Processing - June 2021 - 34
Hydrocarbon Processing - June 2021 - 35
Hydrocarbon Processing - June 2021 - 36
Hydrocarbon Processing - June 2021 - 37
Hydrocarbon Processing - June 2021 - 38
Hydrocarbon Processing - June 2021 - 39
Hydrocarbon Processing - June 2021 - 40
Hydrocarbon Processing - June 2021 - 41
Hydrocarbon Processing - June 2021 - 42
Hydrocarbon Processing - June 2021 - 43
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Hydrocarbon Processing - June 2021 - 45
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Hydrocarbon Processing - June 2021 - 88
Hydrocarbon Processing - June 2021 - 89
Hydrocarbon Processing - June 2021 - 90
Hydrocarbon Processing - June 2021 - Cover3
Hydrocarbon Processing - June 2021 - Cover4
Hydrocarbon Processing - June 2021 - GP-1
Hydrocarbon Processing - June 2021 - GP-2
Hydrocarbon Processing - June 2021 - GP-3
Hydrocarbon Processing - June 2021 - GP-4
Hydrocarbon Processing - June 2021 - GP-5
Hydrocarbon Processing - June 2021 - GP-6
Hydrocarbon Processing - June 2021 - GP-7
Hydrocarbon Processing - June 2021 - GP-8
Hydrocarbon Processing - June 2021 - GP-9
Hydrocarbon Processing - June 2021 - GP-10
Hydrocarbon Processing - June 2021 - GP-11
Hydrocarbon Processing - June 2021 - GP-12
Hydrocarbon Processing - June 2021 - GP-13
Hydrocarbon Processing - June 2021 - GP-14
Hydrocarbon Processing - June 2021 - GP-15
Hydrocarbon Processing - June 2021 - GP-16
Hydrocarbon Processing - June 2021 - GP-17
Hydrocarbon Processing - June 2021 - GP-18
Hydrocarbon Processing - June 2021 - GP-19
Hydrocarbon Processing - June 2021 - GP-20
Hydrocarbon Processing - June 2021 - GP-21
Hydrocarbon Processing - June 2021 - GP-22
Hydrocarbon Processing - June 2021 - GP-23
Hydrocarbon Processing - June 2021 - GP-24
Hydrocarbon Processing - June 2021 - GP-25
Hydrocarbon Processing - June 2021 - GP-26
Hydrocarbon Processing - June 2021 - GP-27
Hydrocarbon Processing - June 2021 - GP-28
Hydrocarbon Processing - June 2021 - GP-29
Hydrocarbon Processing - June 2021 - GP-30
Hydrocarbon Processing - June 2021 - GP-31
Hydrocarbon Processing - June 2021 - GP-32
Hydrocarbon Processing - June 2021 - GP-33
Hydrocarbon Processing - June 2021 - GP-34
Hydrocarbon Processing - June 2021 - GP-35
Hydrocarbon Processing - June 2021 - GP-36
Hydrocarbon Processing - June 2021 - GP-37
Hydrocarbon Processing - June 2021 - GP-38
Hydrocarbon Processing - June 2021 - GP-39
Hydrocarbon Processing - June 2021 - GP-40
Hydrocarbon Processing - June 2021 - GP-41
Hydrocarbon Processing - June 2021 - GP-42
Hydrocarbon Processing - June 2021 - GP-43
Hydrocarbon Processing - June 2021 - GP-44
https://www.nxtbook.com/gulfenergyinfo/gulfpub/hpi-market-data-2024-v2
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https://www.nxtbook.com/nxtbooks/gulfpub/refining_processes_handbook_2020
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https://www.nxtbook.com/nxtbooks/gulfpub/hp_202007
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202006
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https://www.nxtbook.com/nxtbooks/gulfpub/petrochemical_2018_v2
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https://www.nxtbook.com/nxtbooks/gulfpub/hp_201812
https://www.nxtbook.com/nxtbooks/gulfpub/hpimarket_2019_v2
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