17_Solutions for Energy Efficiency Challenges Proceedings.pdf

7/28/2019 17_Solutions for Energy Efficiency Challenges Proceedings.pdf

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Solutions for Energy Efficiency Challenges

Ccile Plain


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Agenda

Energy and CO2 Challenge

Axens as a key partner

Equipment optimization

Case Studies

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Energy and GHG Challenge in Refining

Energy sector represents 66.5% of the total Greenhouse Gas(GHG) emissions:

GHG from Oil & Gas (O&G) industry: about 6% of the total GHG

Chemicals & petrochemicals: about 4% of the total GHG

Energy costs represents onaverage more than 50% oftotal operating cost

Product specificationdevelopments anddieselization lead to anincrease in energyconsumption

61.5%

59.0%

38.5%

41.0%

0% 20% 40% 60% 80% 100%

2008

2006Energy

Non-Energy

Operating Expenses Split

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Agenda




Case Studies

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Axens as a Key Partner

Axens has set up a structured knowledge

management process to capitalize on each project

Axens as a licensor:

Extensive know-how and

experience on whole refining &

petrochemical scheme.

Axens as catalyst &special equipmentprovider:

Innovative solutions for OPEX

reduction in existing assets

Western

Europe

19%

Middle East

14%Africa

4%

North

America

12%

Latin

America

8%

Asia

35%

Eastern Europe +

CIS 8%

Axens has been awarded a total

2205licensesas of 31st December 2012:

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Establish Referential

On-site Data collection:

- Utilities network

- Process units performance

- Large thermal & power equipment

performance

- Flare system

- Emissions assessment- Maintenance & Operational good

practices

Baseline setting:

- KPIs, EIITM, CO2- Energy consumption / cost

Energy Efficiency & GHG Mitigation

Cost Estimate &Financial Analysis

Detailed study of selected

projects (CAPEX, IRR, NPV)

Estimation of related saving

(including Solomon EIITM

Screen projects options

that could improve energy

efficiency:- Non-CAPEX options

- Low CAPEX options

- High CAPEX options

Evaluation compliance to

CDM criteria

Customer selection of

projects to be further

developed

over 80 options

screened

Case ranking

Validation of project

options to be developed

during the next phase

Unit energy consumption

2004 Solomon standard - Case study 2004 - Case study 2006

0

1000

2000

3000

4000

AD U1 AD U2 AD U3 VD U1 VD U2 HC K RE F 1 RE F 2 SMR PS A NHD T1

NHDT2

KHDS1

KHDS2

Others

98

16

19

7

7

C ur re nt E II O pe ra ti on

Optimisation

M ai nt en an ce L ow CA PE X H ig h C AP EX E II Po te nt ia l

RecycleGas

H2

QuenchGas

Fuel Oil

Sour OilFeed

Reactor Strip

PackinoxExchangers

Propose Options

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CO2&

Energy

SOURCING

IMPROVEMENT

ENERGY

CONSUMPTIONREDUCTION

ASSET

OPTIMISATION Combined Heat and Power

Load curve management

Supply / Demand Response

Renewables

Spot market access

Shipping/Transmission

Balancing

Renewables sourcing

CO2 Allowances

Energy equipement expertise

Heat integration

Processes optimization

Refining scheme integration

Emissions capture Peak shaving

Work organization

Energy performance

Management

Axens & Solvay Energy Services combine their expertise toprovide an integrated services to the refining industry

Axens / SES Combined Expertise for Refiners

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1st Quartile

2nd Quartile

UNITS BenchmarkMeasured energy consumption and EII

Use benchmark

But go beyond a first level analysis

Process expertise is required to assess energy performance

and identify improvements in any refinery process unit 8


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Example of High Severity CCR Reforming

ReactorFurnaces

56%

Others44%

Aromatics yields:

Heat of reaction

governed by

thermodynamics

Includes:

catalyst regeneration

recycle compressor

Stabilization section

H2

export compressor

80% of CCR reforming net energy consumption

is directly linked to production objectives

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Agenda




Case Studies

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High Efficiency Heat Exchangers

High efficiency HX gains

Heat Duty - 48%

Electrical power - 8%

RecycleGas

H2

QuenchGas

Fuel Oil

Sour OilFeed

Reactor Strip

PackinoxExchangers

RecycleGas

H2

QuenchGas

Fuel Oil

Sour OilFeed

Reactor Strip

S&TExchangers

Heater

RecycleGas

H2

QuenchGas

Fuel Oil

Sour OilFeed

Reactor Strip

S&TExchangers

Heater

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High Efficiency Furnace

Optimising heat recovery Efficiencies above 92%?

Consultation with equipment manufacturers

Temperature (C)

Flue Gas Temperature (C)

COMBUSTION

AIR

283

FDF

LP STEAM

HEATER

LP STEAM

HOT AIR DUCT

296

150

PROCESS FLUID

BFWBFW / HP STEAM

HP STEAM

BFWBFW

SUPERHEATED HPS

FLUE GAS

15.6

257

307

150

257

257

PROCESS

H-47102 H-47103

ATM

COMBUSTION

AIR

FLUE GAS

FLUE GAS

305 320

164

32?

FDF

IDF

PH-47103AIR PREHEATER

2.0 (est.)

COLD FLUE GAS DUCT

HOT AIR DUCT

197

Heat release Heat release

9.37 18.98

13027 kg/h 26390 kg/h

HOT FLUE GAS DUCT

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Optimum Heat Exchanger Networks: Pinch Technology

First: Adjust process parameters to improve heat integration

Then: use PINCH technology to

intensify process /process heat

exchanges and minimize wasted

heat (air coolers, trim coolers)

Last: Use Licensors experience to define schemes that provide

operability and flexibility

Stripper FeedStripper

TC

Reactor FeedFract. Feed

ReactorEffluent

Reactor

Fractionator

428 376 307 270 245 213 193 168 152 122

53

122

240

245

193

213

209

263

325

307

376407

12.35 16.63 8.70 5.83 7.87 4.60 6.00 3.76 7.16

5.38

9.81

134

168

10% bypass

90%152

To ReactorEffluent Air Cooler

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Application of Innovative Designs

Dividing Wall Columns

lower energy requirement for reboiling of the combined column

Plate heat exchangers reduce T approach and increase heat recovery

replace several heat exchangers in series

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Agenda




Case Studies

Aromatic Complex

Steam Generation

Process Heat Integration

Delayed Coker Unit

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Aromatics Complex Scheme Overview

Benzene

Paraxylene

Extractive

Distillation

Xylenes

Isom.

Transalkylation

Heavies

Reforming

(CCR)

Raffinate

B

C

Eluxyl

B

T

Hydrotreated

Naphtha

C7-

C8+

C9+

C9+C10

C8A

H

A

XC

R

S

C8+

Tol

FG + LPG

Conversion units

Separation units

Fractionation columns

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Aromatics Complex Scheme Overview

Benzene

Paraxylene

Extractive

Distillation

XC

Xylenes

Isom.

Transalkylation

Heavies

Reforming

(CCR)

Raffinate

B

C

Eluxyl

B

T

Hydro-

treated

Naphtha

C7-

C8+

C9+

C9+C10

C8A

H

A

RS

C8+

Tol

FG + LPG

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Energy Efficiency Study for Aromatic Complex Project

Detailed study to reviewpotential energy efficiencyimprovements: Project specific (based on client

requirements) Technical and economical

optimisation (CAPEX & OPEX)

Example of modification toAromatics Complex design:

Maximize heat conservation Minimize air coolers

Produce steam and electricitywhen possible

0

100

200

300

400

500

0 1 0 2 0 3 0 4 0 50 6 0 7 0 8 0 9 0 1 00 1 10 1 20 1 30 1 40 1 50 1 60 1 70 1 80 1 90 2 00 2 10 2 20 2 30 2 40 2 50

Duty (Gcal/h)

Temperature (C)

Cold Composite

Hot Composite

PinchTemp (256C)

Minimum Hot utilities : 86 Gcal/h

Minimum Coldutilities : 43.9 Gcal/h

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Agenda




Case Studies

Aromatic Complex

Steam Generation


Delayed Coker Unit

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Steam Generation Study: Basis of design

Several levels of steam considered from LLP to MP steam

Reviewed opportunities for:

Steam recompression from LLP to LP and LP to MP

Pre-heating BFW

Pre-heating furnace air20


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Steam Generation Study: Suggestions

Scheme modifications proposed

Increase column pressure

To generate required steam level

For heat integration with other process streams

Replacement of columns condensers by steam

generators

Installation ofadditional process exchanger on reaction

sections (higher heat recovery on reactor effluentstreams)

Increase heat efficiency of fired heater

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Agenda




Case Studies

Aromatic Complex

Steam Generation


Delayed Coker Unit

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Example of Process Heat Integration

Feed 1

Feedheater

Reactor

Feed /

Effluent

exch.

Effluent

air coolerRecycle

comp-

ressorCold

separator

HPpurge

HPst

Distillate

to stab.

Product 1

Feed 2

LP purge

to

Process

stab.Comp.

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Product 1

LPpurge

Off gas fromTP stab

Feed 1

Feed

heater

Reactor

Feed /

Effluent

exch.

Effluent

air coolerRecycle

comp-

ressorCold

separator

HP

purge

HPst

Distillate

to stab.

Feed 2

Example of Process Heat Integration

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Energy efficiency versus CapEx

Gains in performances, an additional20%

Impacts on Capital Expenditure

Adjusting columns operating pressure: Higher pressure to improve heat integration

Lower pressure to reduce reboiler duty (offgas compressor)

More equipment: large heat exchangers and steam

generators Risk mitigation of water leakages (Special HX design,

equipment test & inspection, S/D S/U procedures)

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Agenda




Case Studies

Aromatic Complex

Steam Generation


Delayed Coker Unit

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Energy Efficiency Results: Delayed Coker Unit

Savings: 6.8 M US$/y

Close the gap versus DCU top energy performers by 57%

Focused delivery:

Short list of Energy Projects

Less than 1 year pay out time

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The Right Start: Strategic Energy Review

Exhaustive energy balance 78% of total energy is fuel gas

Benchmark with top

performers / best design 2.5 times more than top

performers

Identify and check top energy

consumers

Energy GJ/d Percent

Fuel gas 4 600 78%

Steam (MP) 700 12%

Electricity 600 10%

Total 5 900

Questionnaire

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C1C

3

C

2

F2

/A

F2

/B

V

2

V

1

V

3

V

4E1

E3

E5E4

V5

E6 E7

LCGO

HCGO

Unstabilized

Naphtha

Coker HeaterEfficiencyFeed Heater

Coker

Drums

Water

cooler

Air

cooler

Water

cooler

Air

cooler

Air

cooler

UnstabilizedNaphtha

Heat

Exchanger

Upper feed

Lower feedF1

E2

C4

Reboiler

The Right Start: Identify Energy Losses

LOST

ENERGY

Legend

Cold Feed

Site Visit

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Identify most valuable energy projects

Long list of energy saving projects Select with customer most attractive projects

Providing highest efficiency improvements

Strong Pay Out Time

Delayed Coker Unit:

Focus on fuel gas savings projects (78% of total energyconsumed)

Project Short List

1. Shutdown Feed Heater

Most DCU do not have one!

2. Improve coker heater efficiency

Interim Meeting

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Shutdown Feed Heater: 1000 kg/h of fuel gas saved

Cold Feed

Hot Feed

New Line from

Vacuum Distillation Unit

New Cold Feed

Pre-Heat Exchangers

New Mixed Feed

Heat Exchanger

Recover hot feed duty: Blend hot and cold feed Recover process duty to pre-heat cold feed

Recover coker heater duty to heat mixed feed

To C1

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TC

Pre-heated

F2A/B

Fuel gas

Flue gas

To HeatMixed Feed

Air Damper

02

QC

CO

New

Burners

Improved Coker Heater Efficiency 770 kg/h of Fuel Gas Saved

Feed from

C1 bottomTC

To

C1

6 projects New Burners

Control Inlet & Outlet

heater Temperature

Measure and ControlOxygen

Measure CO

Pre-Heat Combustion Air

Combustion Air

Heater Efficiency improved by 20%(calculation with heater simulation software)

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Projects Economic Summary

Projects Fuel GasSavingskg/H

GapClosure

SavingsM$/year

CostsM$

POTYears

F2 shutdown 1,000 32% 3.8 3.7 1,0

Coker HeaterEfficiency 770 25% 3.0 2.4 0,7

Total 1,770 57% 6.8 6.1 0,9

Feed heater is bypassed and shutdown

= Extra savings on maintenance !

Other projects on Coker heaters= Beyond Energy Efficiency, improved heaters and yield stability !

Gap to top performers normalized at 10033


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Delayed Coker Study Key Lessons

Major step towards high performance

Study was performed in 2 months time

Quality of collected data

Good relationship between staff

Energy savings are not obtained at the expense of

the process

The implementation remains simple: Short list of items easier to manage

Focused on feed and Coker heaters

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Conclusion

Energy efficiency practices can be applied to new process unit

design as well as existing units

However, expected gains for existing assets will be more

limited than for new built

Energy efficiency improvements have to be economically viable

and sustainable

Axens is actively working on energy efficiency improvements:

Technologies & products even beyond Axens technology

portfolio (process integration, equipment)

Consulting services

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Documents

17_Solutions for Energy Efficiency Challenges Proceedings.pdf