RFCC LPG TREATER
DUTY SPECIFICATION
A

FOSTER WHEELER ENERGY LTD
PROCESS DOCUMENT
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4.7.15 Flare Loads and Flare Design 11
4.7.16 Effluents and Emissions 11
4.7.17 Start-up and Shutdown 11
4.7.18 Process Control, Safety and Shutdown Systems 11
4.7.19 Purging, Flushing and Blanketing Requirements 11
4.8 Utilities 12
4.8.1 Make-up Water 12
4.8.2 Process Air 12
4.8.3 Fuel Gas 12
4.8.4 Other Requirements 12
5. BATTERY LIMIT CONDITIONS 12
6. PROCESS GUARANTEES 13

RFCC LPG TREATER
DUTY SPECIFICATION
A

FOSTER WHEELER ENERGY LTD
PROCESS DOCUMENT

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1. INTRODUCTION
1.1 Unit Processing Objectives
The primary objective of the RFCC LPG Treater Unit is to reduce the Mercaptans,
total sulphur content, and remove H
2
S from the LPG obtained from the Residue
Fluid Catalytic Cracker Unit (RFCC). The product specifications need to meet the
processing requirements of downstream processing (Alkylation and Polypropylene
Units) and LPG sales.
The product will meet the quality requirement to produce treated LPG with
maximum total mercaptans content of 3 ppmw with maximum total sulphur of 10
ppmw.
1.2 Use of Document
This document shall be used as the design basis for the process design of the
RFCC LPG Treater Unit only.
The design requirements specified in this document are considered to be the
minimum required. Where Licensor has more onerous requirements than those
specified in this document, these shall be notified to Employer prior to
implementation.
2. UNIT DEPENDENCE
The RFCC LPG Treater Unit shall be capable of operating as an independent
block subject to the availability of:
• Feed stocks.
• Utilities and Process Chemicals.
The Unit draws RFCC LPG directly from the Unsaturated Gas Plant at the RFCC

Unit.
RFCC LPG TREATER
DUTY SPECIFICATION
A

FOSTER WHEELER ENERGY LTD
PROCESS DOCUMENT
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3. SYSTEM SKETCH
Residue
Fluidized
Catalytic
Cracker
Reactor
Unsat Gas Plant
Propane
Polypropylene Unit
Mixed butanes Alkylation
Treated
LPG
Untreated
LPG
Propylene
LPG
RFCC LPG
Treater

Licensor scope
Fresh Caustic
Spent caustic
Chemicals
Storage
Foul Air
CDU Heater (or)
RFCC CO Boiler (or)
Sulphur Recovery Unit (or)
HC Flare
Disulphide Oil
Naphtha
Hydrotreating Unit
(or) Slop Tank
Fresh Solvent
Waste Water
Storage
Effluent Treatment
Plant
LP BFW
Utility
Effluent Treatment
Plant

4. BASIS OF DESIGN
4.1 Design Objective
The Unit is designed to process LPG feedstock from the RFCC Unit after amine
scrubbing. The Unit shall process the feed to produce treated LPG with a
maximum total mercaptans content of 3 ppmw with maximum total sulphur of 10
ppmw. Spent caustic treatment design shall be part of the scope of work and shall

include the spent caustic from RFCC Light Gasoline Treater Unit for treatment.
Regenerated caustic shall be recycled back to the extraction section.
4.2 Design Capacity
The RFCC LPG Treater Unit shall be designed to process 43,000 BPSD of LPG
from the RFCC Unit.
The Unit shall be design to meet a turndown of 40% of product design capacity
whilst meeting all product specification requirements.
Licensor is requested to provide a qualitative analysis regarding the flexibility of
the proposed configuration in terms of changes in feedstock.
RFCC LPG TREATER
DUTY SPECIFICATION
A

FOSTER WHEELER ENERGY LTD
PROCESS DOCUMENT
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4.3 Design Feed Cases
The Unit shall be designed for the design feedstock defined in Section 4.4.
Material balance shall be provided for design case.
4.4 Design Feedstock Properties
4.4.1 RFCC LPG Treater Unit feed
The RFCC LPG Treater Unit feed has the following properties:
Parameter Unit Design Case
Specific Gravity 0.5634
Water wt% 0.08
Ethane wt% 0.04

Ethylene wt% 0.0
Propane wt% 5.58
Propylene wt% 36.55
n-Butane wt% 3.37
Iso-Butane wt% 8.79
1-Butene wt% 8.91
Isobutylene wt% 14.50
Trans-2-butene wt% 12.84
Cis-2-buene wt% 8.69
butadiene wt% 0.34
C
5
+ wt% 0.29
Arsine ppmw 0.5 max
Amine ppmw 5 max
Mercaptans Sulphur, as Sulphur ppmw 120 max
H
2
S

ppmw 50 max
COS ppmw 6 max
CO
2
ppmmol 0.5
CO ppmw Negligible
SO
2
as S ppmw Negligible
Total Sulphur ppmw 176 max

Copper strip corrosion (1 hr 38°C) 1 max
RFCC LPG TREATER
DUTY SPECIFICATION
A

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4.4.2 Fresh Caustic Make-up
Make-up caustic will be available from the chemical storage unit at 20
°Be.
4.4.3 Fresh Solvent
Desulphurised Heavy Naphtha from storage will be available as fresh solvent.
Licensor is requested to confirm the solvent specification and provide required
flow rate.
The Desulphurised Heavy Naphtha has the following properties
Parameter Unit Value
° API 59.78
ASTM D-86 Distillation, °C
IBP
10%

30%
50%

70%

90%

FBP


89.7
99.3
108.3
116.5
139.2
164.0
183.6
RSH-S ppmw <0.5
H
2
S ppmw Nil
Total Sulphur ppmw <0.5
Flow rate kg/hr Report (1)
(1) Licensor to define.
4.5 Design Product Specifications
For the design feedstock and flow rate, the RFCC LPG Treater Unit shall be
designed to maximise treated LPG product with the specifications outlined below:

Property Unit Value Test Method
Density (@15°C) kg/l 0.5 min
ASTM D-1657 or
ASTM D-2598
Composition
Ethane
Ethylene

Propane
Propylene
n-Butane
Iso-Butane
1-Butene
Isobutylene
Trans-2-butene
Cis-2-buene
C
5
+
wt%
Report
Report
Report
Report
Report
Report
Report
Report
Report
Report
Report

ASTM D-2163
ASTM D-2163
ASTM D-2163
ASTM D-2163
ASTM D-2163
ASTM D-2163

ASTM D-2163
ASTM D-2163
ASTM D-2163
ASTM D-2163
ASTM D-2163
Olefin content vol % Report ASTM D-2163
RFCC LPG TREATER
DUTY SPECIFICATION
A

FOSTER WHEELER ENERGY LTD
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Property Unit Value Test Method
Composition of 100 ml
vaporized residue
ml 0.05 max ASTM D-2158
Copper strip corrosion
(1 hr 38°C)
1 max ASTM D-1838
Total Sulphur ppmw 10
ASTM D-2784/
ASTM D-6667
Hydrogen Sulphide ppmw 0.5 max ASTM D-2420
Sulphur dioxide ppmw Report
Total Mercaptans S ppmw 3 max ASTM D-3227

COS ppm mol 6 max
Sodium as Na
+
ppmw 0.5 max
CO
2
ppmw Report ASTM D-3416
CO ppmmol Report ASTM D-3416
Amine ppmw Report
Free Water Content None Visual
Oxygen ppmw 0.25 max ASTM D-2233
Oxygenated Organic ppmmol Report
Basic Nitrogen ppmw Report
4.6 By-product Specification
The following by-products are expected to be produced in the RFCC LPG Treater
Unit:
• Foul Air to the CDU Heaters or RFCC CO Boiler or Incinerators located at
the Sulphur Recovery Unit (SRU) or HC Flare.
• Disulphide Oil (DSO) to Naphtha Hydrotreting Unit (NHT) or Slop Tank.
• Spent Caustic & Waste water to the Effluent Treatment Plant.
Licensor is requested to provide the process conditions and composition of the
below streams in addition to any further by-product streams not stated below.
Licensor shall provide below specifications as minimum.
4.6.1 Foul Air
Paramete
r
Unit
V
alue
Hydrogen mol% Report

Methane mol% Report
Ethane mol% Report
=C2 mol% Report
Propane mol% Report
=C3 mol% Report
Iso-Butane mol% Report
n-Butane mol% Report
1-Butene mol% Report
Isobutylene mol% Report
Trans-2-butene mol% Report
RFCC LPG TREATER
DUTY SPECIFICATION
A

FOSTER WHEELER ENERGY LTD
PROCESS DOCUMENT
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Paramete
r
Unit
V
alue
Cis-2-buene mol% Report
butadiene mol% Report
n-Pentane mol% Report
C

5
+ mol% Report
A
romatics mol% Report
COS mol% Report
N
2
mol% Report
O
2
mol% Report
Water @ operating conditions mol% Report
RSSR’ wt% Report
Total Mercaptans (S) ppmw Report
Total S ppmw Report
Flow rate m
3
/
h
r
Report
Paramete
r
Unit
V
alue

4.6.2 Disulphide Oil (DSO)
Parameter Unit Design Case
SG Report

RSSR

mol% Report
Wash Oil mol% Report
Flow rate kg/hr Report

4.6.4 Waste Water
Waste water from wash water section will be sent to the Effluent Treatment Plant.
Flow rate, composition, operating condition and pH of waste water should be
defined by Licensor.
4.6.5 Spent Caustic
Spent Caustic shall be sent to Effluent Treatment Plant. Flow rate, composition
and operating condition of spent caustic should be defined by Licensor.
4.7 Specific Design Requirements

4.7.1 Feedstock Specification
Licensor shall specify the RFCC LPG Treater Unit design to process the feedstock
as determined in Section 4.4 above.
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DUTY SPECIFICATION
A

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4.7.2 On-Stream Factor

The on stream time for the Unit shall be 8320 hours per calendar year, equivalent
to an on-stream factor 0.95 where:
On stream Factor = (1)

(1) + (2)

(1) = total duration of productive operation.
(2) = total duration for repairs and maintenance including turnaround and
typical trip outage.
4.7.3 Turndown
The Unit is designed to meet a turndown of 40% design feed for the design cases
specified, whilst meeting all product specification requirements. Any additional
facilities or deviation from standard operation required to achieve this shall be
clearly identified and incorporated.
4.7.4 Cycle Length
The Unit cycle length will be 4 years between scheduled turnarounds. All fixed
bed catalysts systems shall be designed to operate for a minimum of 4 years
without regeneration or catalyst change out being required.
4.7.5 Energy Efficiency
• Licensor’s design shall optimise the consumption of energy and utilities. It is
expected that Licensor’s proposed process will incorporate a high level of
heat integration in order to provide optimum refinery efficiency.
• Licensor shall investigate the potential for recovery of low grade heat from
the process unit and utilities systems.
• Licensor shall base the inclusion of energy integration processes against a
payback time of 8 years.
• Licensor shall comment on opportunities to improve process and energy
efficiency by use of Advanced Process Control.
• Steam is expected to be used for reboiler duties, Licensor to specify any
reboilers where an alternative heating medium is proposed.

4.7.6 Design Guidelines for Process and Equipment
Guidelines for the design of process and equipment are contained in the Process
Engineering Design Guidelines, Document No.: 3550-8110-PD-0007. The
guidelines are used to achieve a consistent design approach across the project.
These are not intended to supersede the Licensor design requirements, or any
criteria which may impact the Licensor guarantees.
RFCC LPG TREATER
DUTY SPECIFICATION
A

FOSTER WHEELER ENERGY LTD
PROCESS DOCUMENT
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4.7.7 Caustic Treatment
The Unit design shall incorporate spent caustic treatment for removal of sulphur
from caustic, in order to reduce caustic consumption. The caustic treatment
system shall be common for RFCC LPG Treater Unit and RFCC Light Gasoline
Treater Unit. Regenerated caustic shall be recycled back to the extraction section.
Licensor to consider sending the Foul Air to the CDU Heaters or RFCC CO Boiler
or Incinerator located in the SRU. A connection to the HC Flare shall be provided.
Disulphide Oil will be normally routed to Naphtha Hydrotreating Unit (NHT). A
connection to Slop tank is to be provided.
4.7.8 Spent Caustic Drum
Licensor shall design spent caustic drum for bleed stream from caustic treatment
section.
4.7.9 Water Wash Drum

Licensor shall provide a wash water system for reducing of caustic content in the
treated RFCC LPG.
4.7.10 Material Selection and Corrosion Inhibition
Licensor shall specify any particular metallurgical, corrosion inhibition monitoring
or injection requirements.
4.7.11 Catalyst Type and Regeneration (if applicable)
Licensor is request to advise all applicable catalyst type for LPG treatment
process including the advantage and the disadvantage of each type of catalyst.

The Unit shall not be designed for in-situ catalyst regeneration. If required,
Licensor shall provide details and costs of suitable regeneration facilities for this
project.
4.7.12 Catalyst Handling
Licensor shall specify all permanent facilities required to load and unload
catalysts. Licensor shall provide guidance as to any special conditions relating to
these operations and any effluent problems that might be expected.
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DUTY SPECIFICATION
A

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4.7.13 Catalyst Solvent Handling
Licensor shall specify all permanent facilities required to load solvent from drums.
Licensor shall provide guidance as to any special conditions relating to these

operations and any effluent problems that might be expected.
4.7.14 Chemicals
Licensor shall specify consumption and facilities for the storage and preparation of
chemicals (if any) required for the normal operation of the Unit, or required to
facilitate Unit start-up, shutdown and maintenance. Licensor shall identify
estimated consumption rates for all chemicals and make recommendations for the
treatment of all waste effluent streams arising from the use of such chemical.
4.7.15 Flare Loads and Flare Design
Licensor shall specify all safety/pressure relief valves required to protect plant and
equipment within the Unit. Licensor shall also quantify the relief loads arising from
controlling and significant relief scenarios for each safety/pressure relief valve
(e.g. utility failure, blocked-in, external fire, etc).
4.7.16 Effluents and Emissions
Licensor shall identify all effluent streams (gaseous, liquid and solid) arising from
the process during normal operation and significant abnormal operations.
Estimated rates and compositions shall be provided for each stream, together with
recommendations for safe treatment and disposal. This should include all
transient and intermittent operations such as start-up and shutdown, catalyst
loading/unloading etc.
4.7.17 Start-up and Shutdown
Licensor shall specify any special facilities and operating guidelines required to
facilitate smooth and safe start-up of the Unit, and Unit shutdown
4.7.18 Process Control, Safety and Shutdown Systems
The Unit design shall incorporate the use of modern state-of-the-art process
control systems and shutdown logic systems. Licensor shall specify all necessary
process control systems and safety shutdown logic systems required to support
the safe operation and maintenance of the Unit.
4.7.19 Purging, Flushing and Blanketing Requirements
Licensor shall specify any special facilities required for the purging and flushing of
equipment and instruments. Licensor shall identify purging and flushing mediums

and estimated rates of consumption.
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DUTY SPECIFICATION
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4.8 Utilities
Design data for available utility supplies are given in the Basic Engineering Design
Data (BEDD), Document No.:3550-8820-SP-0001.
Licensor shall identify all utility consumption requirements and provide estimated
rates of consumption for normal operation and for significant abnormal operations.
4.8.1 Make-up Water
LP Boiler Feed Water will be available as make up water in the RFCC LPG Treater
Unit in accordance with recommendations established by the Licensor.
4.8.2 Process Air
Licensor shall include an Air Compressor Package for supply of air to caustic
treatment section. Plant air will be available as a back-up.
4.8.3 Fuel Gas
Fuel gas should be considered for purge foul air from caustic treatment section.
4.8.4 Other Requirements
Licensor shall specify all other raw materials required for the RFCC LPG Treater
Unit in addition to the feedstock, catalysts, chemicals and utilities discussed in this
document. This specification shall include materials, hazard data, method of use,
frequency of use and consumption. The design shall include all specialised

equipment required for their use.
5. BATTERY LIMIT CONDITIONS
When the Unit is operating at design throughput the temperature and pressure of
the feeds and products at the battery limits of the block are specified as follows:

Process Streams From To Pressure,
kPa (g)
Temperature
, °C
Untreated LPG
RFCC Unsat.
Gas Plant
RFCC LPG
Treater Unit
1850 42
Treated LPG
RFCC LPG
Treater Unit
RFCC Unsat.
Gas Plant
1400
(1)
42
(1)

Disulphide Oil
RFCC LPG
Treater Unit
NHT (1) (1)
Disulphide Oil

RFCC LPG
Treater Unit
Storage (1) (1)
Heavy Naphtha
(Wash Oil)
Storage
RFCC LPG
Treater Unit
600 42
Fresh Caustic Utility Plant
RFCC LPG
Treater Unit
295 40
Waste Water
RFCC LPG
Treater Unit
Effluent
Treatment
Plant
400
(1)
42
(1)

RFCC LPG TREATER
DUTY SPECIFICATION
A

FOSTER WHEELER ENERGY LTD
PROCESS DOCUMENT

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Process Streams From To Pressure,
kPa (g)
Temperature
, °C
Foul Air
RFCC LPG
Treater Unit
CDU / RFCC /
SRU / Flare
50
(1)
46
(1)

Spent Caustic
RFCC LPG
Treater Unit
Effluent
Treatment
Plant
400
(1)
42
(1)


(1) To be advised / confirmed by Licensor.
6. PROCESS GUARANTEES
Complete definitive guarantee statements for the RFCC LPG Treatre Unit shall be
specified by the Licensor in the Guarantee Agreement between Licensor and
Employer to which reference shall be made in respect of contractual obligations.
Nevertheless, for the benefit of users of this document, Licensor shall provide a list
of guarantees which shall apply to design case.
The minimum scope shall include:
• Unit design capacity as per section 4.2.
• Product specifications as per section 4.5.
• Unit Turndown capability (40%).
• Consumption of Catalyst, Solvent and Caustic.
• Cycle length.
• Catalyst life.
• Utility consumption based on the utility summary at completion of design.