Hydrocarbon Processing - September 2021 - 22

Refining Technology
yields. The unique flow scheme and the
tailored catalyst system offered high middle
distillate yields, while reducing energy,
hydrogen consumption and other costs
compared with competing technologies.
A high-level flow scheme of the integrated
hydroprocessing units is shown in FIG. 5.
The RUP complex comprised the folFIG.
4. (Left) Location of TÜPRAŞ' refineries, Turkey; (right) Aerial view of the RUP complex,
Izmit refinery.
lowing main units: vacuum unit, delayed
coker, integrated hydrocracker and hydrotreating
units, hydrogen generation unit,
two trains of sulfur recovery units, an amine
regeneration and a sour water stripper unit
as well as a new cogeneration unit (120
MW). The project was completed in ~4
yr at an estimated cost of $3.2 B, including
utilities and tank farm area. All units were
successfully commissioned by 3Q 2015.
The 50,000-bpd (8,000-m3
/d) unitk
FIG. 5. Integrated RUP hydroprocessing units flow schematic.
to increase the flexibility of the Izmit refinery
(one of four TÜPRAŞ refineries) to
process heavier and high-sulfur crude oils,
together with the capability to convert 4.2
MMtpy of high-sulfur fuel oil to 3.5 MMtpy
of valuable high-quality white products,
such as diesel, jet fuel, gasoline and LPG
conforming to Euro-5 specifications.
Based on its internal evaluation,
TÜPRAŞ had clear aspirations to reduce
its fuel oil production and chose one of
the most common and proven refinery
configurations for residue conversion: a
delayed coking unit (DCU) with downstream
hydrocracking and hydrotreating
units for upgrading all coker products.
This widely used option offers a reliable
configuration with minimal risk at the
lowest capital cost. However, the biggest
challenge was to create an integrated hydroprocessing
complex design that offered
the desired degree of flexibility between
the hydrocracking and hydrotreating units
at optimum CAPEX and OPEX costs to
keep the project economically viable.
Tailored integrated design. The authors'
company developed several potential
configurations and analyzed the
pros and cons to help TÜPRAŞ choose
the most optimum solution. Each poten22
SEPTEMBER 2021 | HydrocarbonProcessing.com
tial configuration included an analysis of
resources requirements for both people
and equipment, high-level performance
projections, cost estimates and constructability
rankings. This iterative process
enabled the TÜPRAŞ team to refine objectives,
understand the numbers in detail
and provide feed definitions to optimize
the cut point between straight-run VGO
and coker feed to optimize unit sizes. The
collaboration ultimately resulted in an
ideal configuration to meet the project objectives.
FIG. 4 shows the refinery location
(left) and an aerial view (right) of the site.
The selected design comprised of an
integrated coker naphtha and distillate
process unitj
, with all product rundowns
routed to a process unit fractionation sectionk
.
Key common high-pressure equipment,
such as washwater pumps, make-up
gas compressors and amine pumps, helped
improve the integration and reduce costs
without compromising the degree of flexibility.
Extensive heat recovery between
the units and common PSA for recovery of
CLPS off-gases from the complex helped
minimize the carbon footprint.
For the hydrocracking unit configuration,
TÜPRAŞ chose a proprietary enhanced
two-stage processl
to minimize the
impact of difficult feeds on the product
was designed to process a 60:40 feed blend
of HVGO/HCGO at 98 wt% conversion.
An integrated hydroprocessing complex
checkout was begun in July 2014 and the
units were successfully commissioned in
May 2015. A demonstration test run confirmed
that the units are meeting or exceeding
performance guarantees.
Technical support. The original unit design
solely relied on the UCO purge and a
customized catalyst system to prevent the
HPNA buildup. It worked well with feeds
similar to the design feed case. Encouraging
test run results coupled with spare
margin in unit hydraulics and hydrogen
availability offered further potential to increase
ROI. Within 4 mos of commissioning,
capacity was gradually increased to
110% of design in continuous collaboration
with the authors' company's technology
services to harness the full potential
of the unit. Catalyst performance, key unit
variables and the health of key equipment
were closely monitored to stay within
the design limits. Changes to feed blend,
both in terms of cracked to straight-run
ratio and increase in HVGO/HCGO end
points, were necessary to allow TÜPRAŞ
to push the feed rate further and reduce
the reliance on imported HVGO. Sustained
operation at high capacity coupled
with the processing of relatively heavier
feed blends eventually increased the operating
severity to a point where the design
UCO bleed rate was no longer enough to
purge the HPNAs from the system. UCO
color turned from off-white to orange in
a matter of days following the increase in
HCGO end point by ~45°C.

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Hydrocarbon Processing - September 2021

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