FOULING MANAGEMENT IN CRUDE OIL PREHEAT …€¦ · · 2018-02-13FOULING MANAGEMENT IN CRUDE OIL PREHEAT TRAINS/DHP UNITS Presenter: Metin BECER Process Superintendent Turkish Petroleum

FOULING MANAGEMENT IN CRUDE OIL PREHEAT TRAINS/DHP UNITS

Presenter: Metin BECERProcess Superintendent

Turkish Petroleum Refineries Corporation15/11/16 Lisbon-Portugal ERTC

22

Kırıkkale Rafinerisi CCR Ünitesinin Modellenmesi

&Oktan Optimizasyonu

• Petroleum Refinery

• Total of 28,1 M ton refining capacity with 4 refineries

• Privatized in 2006 and owned by Koc Holding (%51)

Turkey’s LeadingIndustrial Enterprise

33



44

55

OUTLINE of the Presentation

The Fouling problem in the Refinery Units

1. The Crude Oil Units,

2. The DHP Units

TUPRAS solution for the FOULING MONITORING

Details about the HEXMON programme

FOULING MANAGEMENT INCRUDE OIL PREHEAT TRAINS

77

FOULING PROBLEM

Fouling in heat exchangers is one of the major problems in chemical process

industries.

In refineries, considered as the main source for energy loss, reaching up to

2% of the refinery’s total energy consumption.

Profound interest in minimizing the energy consumptions due to the

challenging refinery margins

Decrease in thermal and hydraulic performance of the heat exchangers

Higher heat load is required in the furnace which leads more fuel gas/ fuel oil

consumption in the furnace

Increase in greenhouse gas emissions

88

FOULING PROBLEM (cont’d)

E 7108 E 7109 E 7110

E 7115 E 7116 E 7117

E 7111

E 7119E 7118 E 7120

E 7113

Fouling in the crude oil preheat trains is considered as ~20% of all heat exchanger

fouling.

In the current process, the crude oil is being heated via products (and pump-around

streams in first and second pre-heat exchanger trains prior to furnace.

In order to reduce the energy consumption in the furnace, the efficiency of the heat

exchangers in the preheat trains is very crucial.

99

FOULING (cont’d)

Fouling is mainly defined as the formation of deposits on heat exchange surfaces due to sedimentation, crystallization, organic and biological growths, chemical reactions, corrosion products, or their combination ..

The deposit formation due to chemical reactions may be complex in nature, and will include several mechanisms such as autoxidation, polymerization, cracking or coke formation.

If there is ambient oxygen, it will catalyze the gum formation which is usually seen in hydro-processing units.

Gum-like material will also be observed in jet fuel, gas oil and similar products upon heating due to the precipitation of paraffinic hydrocarbon mixtures. Thus, temperature, pressure and flow rate are important operating parameters which affect the fouling formation.

Usually, the temperature increase will lead to an exponential increase in the chemical reaction rates; pressure increases the solubility of the oxygen thus will increase the gum formation rate. Flow rates, however, will have a reverse effect such that higher velocities make it difficult for deposits to attach to the surface.

1010

R&D in TUPRAŞ Refineries

R&D study has been started in the refinery in order to find a better way to monitor the fouling in HEAT EXCHANGERS (CRUDE OIL and DHP units)

The study has been continued both for CRUDE OIL and DIESEL HYDROPROCESSING UNITS and as well as the all prone to fouling heat exchangers throughout the refinery,

The study has been partially sponsored by the government

The main findings related with the CRUDE OIL/DHP plants will be shared in this presentation

The main aim is to monitor the fouling, (to find out the reasons behind the fouling, to make a fouling model for the units) and to estimate and to optimize the cleaning periods of the exchangers

1111

STUDIES ON CRUDE OIL UNIT SITE

1212

ANALYSIS ON SITE

All the exchangers are bypassed

Mechanically cleaned

Steam outed, and the thermocouples

are installed

1313

ANALYSIS ON SITE

1414

ANALYSIS ON LABORATORY

HPLC Total Aromatics ANTEK 9000 S Sulphur Content

ASTM D86- Atm. Distillation Crude Oil Acid/Base

Number

Oxygen Content

Anton Paar

Black Product Density

Anton Paar

White Product Density

In order to calculate the physical properties of the crude oil and product streams and

therefore to better evaluate the parameters effecting to the fouling mechanisms a R&D

laboratory has been established.

1515

SOFTWARE DEVELOPMENT

A Software has been developed by Tupras engineers

Sample screenshot is shown below

1616

SOFTWARE DEVELOPMENT

In the software,

Simple components, hydrocarbon mixtures and petroleum fractions have

been identified

All the physical properties (density, boiling point, condensation point,

viscosity, dew point, vapor pressure, thermal conductivity) of the

components with respect to different operational conditions can be

calculated in the software

All the relevant exchangers has been identified in terms of Data Sheet

specifications,

The algorithm has been adapted in order to calculate the fouling factor of the

heat exchangers in the real time operational conditions (temperature,

pressure, flow, distillation data) and by taking the heat exchangers design

specifications into consideration.

1717

FOULING MANAGEMENT ALGORITHM

ALGORITHM calculates the Uc (clean

heat transfer coefficient) for the heat

exchangers at the operational

conditions by using Kern (tube side)

and Bell-Delaware (shell side)

approaches

THEN, the fouling factor (Rf) for the

heat exchangers are calculated by

using the Ud (calculated from the

operational data)

A METHOD for MONITORING Rf is

developed.. Needs an exact

knowledge of the overall thermal

resistance of the exchangers in the

same flow and operational conditions,

but not fouled

1818

SIMULATION RESULTS, a Comparison

The output of the programme has been compared with the commercial

software when the exchangers are clean, Rf = 0 (just after maintanence),

Both for 1st and 2nd preheat trains, the simulated tube-shell outlet temperatures

are in well coincidence with the real data and as well as the commercial

outputs.

1919

SIMULATION RESULTS (cont’d)

Operational tube outlet temperatures of the clean heat exchangers were

found to be consistent with the calculated outlet temperature

Software is capable of simulating the clean case.

Also observed that the results of the software were closer to the operational

data in comparison to the commercial software in SOR conditions

2020

CRUDE OIL UNIT 1ST PREHEAT TRAIN

2121

SIMULATION RESULTS, CRUDE OIL

1st PREHEAT TRAIN SIMULATION RESULTS

Simulation result of crude oil-mid pumparound heat exchanger after

the cleaning time to 1 year period

-0,008

-0,006

-0,004

-0,002

0

0,002

0,004

0,006

0

20

40

60

80

100

120

140

160

26.2.11 17.4.11 6.6.11 26.7.11 14.9.11 3.11.11 23.12.11 11.2.12 1.4.12 21.5.12 10.7.12

Sıca

klık

( C

)

E 7107

Tube Outlet Temp Tube Outlet Temperature Simulation Result Rf

-0,008

-0,006

-0,004

-0,002

0

0,002

0,004

0,006

0

20

40

60

80

100

120

140

160

26.2.11 17.4.11 6.6.11 26.7.11 14.9.11 3.11.11 23.12.11 11.2.12 1.4.12 21.5.12 10.7.12

Sıca

klık

( C

)

E 7107

Shell Outlet Temp Shell Outlet Temperature Simulation Result Rf

2222


1st PREHEAT TRAIN SIMULATION RESULTS for Rf values

-0,001

0

0,001

0,002

0,003

0,004

0,005

0,006

11.2.2012 1.4.2012 21.5.2012 10.7.2012 29.8.2012 18.10.2012 7.12.2012 26.1.2013 17.3.2013 6.5.2013 25.6.2013

Rf-7107

Simulation result of crude oil-mid pumparound heat exchanger after

the cleaning time for 1 year period.

2323

Rf values (2013-2016)

2424


1st PREHEAT TRAIN SIMULATION RESULTS

IMPACT of INORGANICS, METAL, API ETC..

Subject of Phase II study of this project

20

25

30

35

40

45

6.6.11 26.7.11 14.9.11 3.11.11 23.12.11 11.2.12 1.4.12 21.5.12 10.7.12

Tuz

( m

g/L)

SALT

25

27

29

31

33

35

37

39

6.6.2011 26.7.2011 14.9.2011 3.11.2011 23.12.2011 11.2.2012 1.4.2012 21.5.2012 10.7.2012

API

2525

2nd PREHEAT TRAIN

Atm resid is 360 C, crude oil is around 200 C

2626

SIMULATION RESULTS

2nd PREHEAT TRAIN SIMULATION RESULTS

0

0,001

0,002

0,003

0,004

0,005

0,006

0,007

0,008

Rf E-7113

Simulation result of crude oil-atm resid. Heat exchanger after the

cleaning time to the mid 2012

-0,002

-0,0015

-0,001

-0,0005

0

0,0005

0,001

0,0015

0,002

0,0025

0

50

100

150

200

250

0.1.00 19.2.00 9.4.00 29.5.00 18.7.00 6.9.00 26.10.00 15.12.00 3.2.01 25.3.01

Sıca

klık

( C

)

E 7119


Simulation result of crude oil-Mid PA. Heat exchanger after the


0

0,0005

0,001

0,0015

0,002

0,0025

0,003

0,0035

0,004

0

50

100

150

200

250

26.2.11 17.4.11 6.6.11 26.7.11 14.9.11 3.11.11 23.12.11 11.2.12 1.4.12 21.5.12 10.7.12

Sıca

klık

( C

)

E7118


Simulation result of crude oil-heavy diesel Heat exchanger after the


0

0,0005

0,001

0,0015

0,002

0,0025

0,003

0,0035

0

20

40

60

80

100

120

140

160

180

200

26.2.11 17.4.11 6.6.11 26.7.11 14.9.11 3.11.11 23.12.11 11.2.12 1.4.12 21.5.12 10.7.12

Sıca

klık

( C

)

E 7117


Simulation result of crude oil-bottom PA. Heat exchanger after the


-0,001

0

0,001

0,002

0,003

0,004

0,005

0

20

40

60

80

100

120

140

160

180

26.2.11 17.4.11 6.6.11 26.7.11 14.9.11 3.11.11 23.12.11 11.2.12 1.4.12 21.5.12 10.7.12

Sıca

klık

( C

)

E 7116


Simulation result of crude oil-heavy diesel Heat exchanger after the


-0,03

-0,025

-0,02

-0,015

-0,01

-0,005

0

0

50

100

150

200

250

26.2.11 17.4.11 6.6.11 26.7.11 14.9.11 3.11.11 23.12.11 11.2.12 1.4.12 21.5.12 10.7.12

Sıca

klık

( C

)

E 7110


Simulation result of crude oil-light diesel Heat exchanger after the


-0,02

-0,01

0

0,01

0,02

0,03

0

50

100

150

200

250

26.2.11 17.4.11 6.6.11 26.7.11 14.9.11 3.11.11 23.12.11 11.2.12 1.4.12 21.5.12 10.7.12

Sıca

klık

( C

)

E 7109


Simulation result of crude oil-atm. resid Heat exchanger after the


-0,004

-0,0035

-0,003

-0,0025

-0,002

-0,0015

-0,001

-0,0005

0

0

20

40

60

80

100

120

140

160

180

26.2.11 17.4.11 6.6.11 26.7.11 14.9.11 3.11.11 23.12.11 11.2.12 1.4.12 21.5.12 10.7.12

Sıca

klık

( C

)

E 7108


Simulation result of crude oil-top PA. Heat exchanger after the

cleaning time to the mid 2012 (totally 1 year)

2727

SIMULATION Rf results (2nd train)

2828


2nd PREHEAT TRAIN SIMULATION RESULTS

IMPACT of ASPHALTENES, SULPHUR, API, SURFACE TEMPERATURE,

ATM. RESID ETC..

Subject of Phase II study of this project

0

0,5

1

1,5

2

2,5

6.6.11 26.7.11 14.9.11 3.11.11 23.12.11 11.2.12 1.4.12 21.5.12 10.7.12

Asf

alte

n (

% M

/M)

ASPHALTENE

0,000

0,500

1,000

1,500

2,000

2,500

3,000

3,500

6.6.11 26.7.11 14.9.11 3.11.11 23.12.11 11.2.12 1.4.12 21.5.12 10.7.12

Kü

kürt

( %

M/M

)

SULPHUR

25

27

29

31

33

35

37

39

6.6.2011 26.7.2011 14.9.2011 3.11.2011 23.12.2011 11.2.2012 1.4.2012 21.5.2012 10.7.2012

API

FOULING MANAGEMENT INDHP Unit PREHEAT TRAINS

3030

ANOTHER STUDY

TUPRAS has also completed another study in DIESEL

HYDROPROCESSING UNIT HEAT EXCHANGERS FOULING

Dealing with the FOULING mostly due to oxygen in the imported diesel feed

and also refinery cracked diesel streams

3131

DHP Unit preheat exchangers

3232


Subject to FOULING (due to autoxidation and free radical polymerization

reactions) especially when having feed from storage or cracked feed stocks

Have a huge impact on furnace duty/unit cycle time

Careful MONITORING is a MUST

3333

DHP PREHEAT EXCH. Rf values (2006-2016)

FINALLY UNDER CONTROL

Chemical treatment programme/O2

stripper column/H2 sweeping

3434

DHP PREHEAT EXCH. FOULING (2010-2016)

3535


Hexmon monitoring is an important tool for both the unit engineers and the

control operators and is widely used in TUPRAS refineries

The changes in feed rate/feed quality/reactor temperatures/import-storage

tank ratio/cracked feed ratio are all have impacts on the FOULING

mechanisms

The fouling trends are daily monitored and any change is noted. Thus the

furnace duty is aimed to be under control together with the catalyst

deactivation rates.

3636

RESULTS and DISCUSSION

TUPRAS owns a simulation program that has the capability of simulating the

clean overall heat transfer coefficient at the current operating conditions and

by gathering data from the real time values, calculates the FOULING

FACTOR

FUTURE STUDY: As the fouling starts to occur in the exchangers, the

parameters effecting to the fouling will be determined by laboratory analysis

program, then the fouling models will be derived, and OPTIMIZATION of

cleaning (by-passing) will be decided with a optimizer tool adapted to the

program

In the network simulation, the impact of any exchanger’s fouling and extra

duty to the furnace will be determined

A better CLEANING time schedule by REAL TIME MONITORING will mean

LESS LOSS due to FOULING

3737

SUMMARY

FOULING monitoring is a highly critical parameter for the refineries.

THEN, one may decide on the excellent time about the unit or heat

exchanger shut down/bypass by taking in to account of furnace duty.

With the help of the HEXMON programme, TUPRAS engineers are easily

adapting their critical and prone to fouling heat exchangers to the system

and routinely monitoring the fouling trends.

Widely used in all of the 4 refineries in nearly all units.

3838



Thank you for your time and consideration.

Documents

FOULING MANAGEMENT IN CRUDE OIL PREHEAT …€¦ · · 2018-02-13FOULING MANAGEMENT IN CRUDE OIL PREHEAT TRAINS/DHP UNITS Presenter: Metin BECER Process Superintendent Turkish Petroleum