Optimization of CO2 Removal Process in Ammonia unitsgpcafertilizers.com/wp-content/uploads/2017/10/14-Shomit-Haldar-OG...2 Removal Process in Ammonia units ... Formulated AmineFormulated

Optimization of CO2 Removal Process in Ammonia units

Presenters: Shomit Haldar & Praveen Dadhwal.

Co Authored By: Rich Ackman, Fanil Abdullin, Armin Hassanzadeh.

Dow Chemical

Optimization of CO2 Removal Units

• Introduction

• The Haber-Bosch Process

• CO2 Removal Solvents

• CO2 Removal Processes

• AMINE MANAGEMENTSM Program

• Solvent Analytical

• Process Simulation

• Process Optimization Results

• Case Studies

• Global References

Agenda

New Beginnings: Return to Growth

The Haber-Bosch Process


CO2 Removal Solvents

Hot Potassium Carbonate and variations.

Monoethanolamine (MEA) Commodity

Solvent.

Some designers used a physical solvent

Formulated solvents – First Generation

1980’s – 1990’s

Formulated solvents – Next Generation

2000’s to now

Process Name Solvent

Purisol N methyl pyrrolidone

Rectisol Methanol

FluorSolvent Propylene carbonate

Selexol Polyglycol ether

Generic Amine MEA 20% solution

Amine Guard Inhibited MEA >30% solution

Benfield Formulated Potassium Carbonate

Vetrocoke Formulated Potassium Carbonate

Catacarb Formulated Potassium Carbonate

Carsol Formulated Potassium Carbonate

Alkazid Formulated Potassium Carbonate

Amine Aminoethoxyethanol solution

Formulated Amine Formulated MDEA solution

Physical Solvents

Chemical Solvents

MEA : Monoethanolamine

MDEA: N-Methyldiethanolamine


Ammonia Plant CO2 Removal Unit Designs

Single-Stage Design

• Single solvent circulation loop, relatively high energy consumption

(28,000 to 32,000 Kcal/kgmol-CO2)

Two-Stage Design (AM-70)

• Lean & semi-lean streams from regenerator to the absorber, significant energy reduction vs. single stage design

(19,500 to 22,000 Kcal/kgmol-of-CO2)

Two-Stage Design with Regenerator Internal HX (AM-76)

• Lean & semi-lean/Rich streams exchanging heat inside the regenerator tower, excellent heat integration

(15,000 to 17,500 Kcal/kgmol-of-CO2)

Two-Stage Design with LP/HP Flash Configuration

• Rich stream flashed at low and high pressures (LP/HP) for partial regeneration, fully strip CO2 from a portion of the solvent

(7500 to 9500 Kcal/kgmol-of-CO2)


AMINE MANAGEMENTSM ProgramTechnical Support UCARSOL™ Solvents

Technical Support from Initial Design Studies to full Plant Life Cycle

Process Material

& Energy Balance

UCARSOLTM Technology

Evaluation & Selection

Design guidance

UCARSOL Manufacture

& Delivery (Initial Fill)

On-Site Start-up

Assistance

On-Site Assistance by

Dow TS&D Engineers

Plant Optimization &

Troubleshooting

UCARSOL Laboratory

Analysis

UCARSOL Make-up

Plant Design &

Pre-commissioningPlant Start-Up Long-Term Support

Equipment Evaluation

(solvent upgrade)

Training – Operator,

Analytical, Safety

In-house Simulation


Simulations vs. Plant Data (AM-70 Design)

SIMULATIONS

MATCH

PLANT DATA.


Two-Stage AM-76 Design


Two-Stage with LP/HP Flash Configuration


Process Optimization (AM-76 Configuration)


Conclusions

CO2 Specification Achieved in two-stage AM-76 configuration

• utilizing UCARSOL™NH 605 solvent

• solvent showed optimum performance at lowest energy consumption rate

Experience with Successful Conversions of Ammonia Plants from MEA to the UCARSOL™ NH

series

Conversion Benefits - Significant energy saving, reduction in solvent circulation rate, a lower

treated gas CO2 concentration and no detectable corrosion.

Capabilities of Dow In-house Simulator• provides good match to plant data for complex cases like AM-76 configuration


МAXAM-Chirchik (AM-76) – MEA → UCARSOL™ NH 608UCARKLEAN™ cleaning procedure

Key incentive:Energy savings to meet state requirements

Obstacles/Challenges:o MEA unit operated for many years without proper cleaning

o Equipment limitations for proper cleaning (drainage vessels,

pumps, no vessel for foam collection, no vent line hose, etc.)

o UCARKLEAN™ treatment uses foaming for maximum

cleaning effectiveness, must be adequately rinsed before

loading amine

Solution from Dow Oil & Gas: UCARKLEAN™ cleaning of the amine system

Conversion from MEA to UCARSOLTM NH-608

Service support through Dow’s AMPSM to ensure

smooth transition, no operational disruptions


Chirchik – UСARKLEAN™ cleaning results (steam reboiler 307)

BEFORE AFTER


Chirchik – UСARKLEAN™ cleaning results(dead tray of regenerator 303A)

BEFORE AFTER


Chirchiq – UСARKLEAN™ cleaning results(heat exchanger bundle)

BEFORE AFTER


MAXAM-Chirchiklean amine rate reduced at 31% after conversion

350

400

450

500

550

600

650

700

750

800

07.11.2014 26.05.2015 12.12.2015 29.06.2016 15.01.2017 03.08.2017

Lean

am

ine

circ

ulat

ion

rate

, m3/

hr

Run days

Lean amine circulation ratelean amine rate, m3/hr Solvent conversion to UCARSOL NH-608

average solvent rate is 705 m3/hr

average solvent rate is 495 m3/hr


MAXAM-Chirchiksteam rate reduction >90% after solvent conversion

0

2

4

6

8

10

12

14

16

18

20

22

24

07.11.2014 26.05.2015 12.12.2015 29.06.2016 15.01.2017 03.08.2017

Stea

m ra

te, t

ons/

hr

Run days

Steam rate Steam rate to reboiler Solvent conversion to UCARSOL

average steam rate is 18 tons/hr

average steam rate is <1 tons/hr

Plant shutdownin July 2017


MAXAM-Chirchikdeep CO2 removal <30ppmv after solvent conversion

0

20

40

60

80

100

120

140

07.11.2014 26.05.2015 12.12.2015 29.06.2016 15.01.2017 03.08.2017

CO2

con

tent

in t

reat

ed g

as, p

pm

v

Run days

CO2 content in treated gasCO2 in treated gas Solvent conversion to UCARSOL

average CO2 content is 90 ppmv

average CO2 content is 25 ppmv


МAXAM-Chirchik (AM-76) – MEA → UCARSOL NH 608

Achieved results:

Smooth start-up and stable operation without any foaming issues

31% decrease in lean amine circulation rate and

13% decrease in semi-lean amine circulation rate

>90% reduction in steam consumption

MEA reclaimer pulled out of operation, 3 tons/hr reduction in steam usage

30 ppmv CO2 specification achieved and maintained


МAXAM-Chirchik (AM-76)Current UCARSOL™ condition (after 1.5 years of operation)

171

5

95

55 5

5 10

Anions distribution, ppmw

Acetate Glycolate Formate Chloride

Sulfate Oxalate Thiosulfate Thiocyanate

No foaming

No suspended solids

No degradation

No HSS

No corrosion

No losses

21

2

13

6

0.05Cations distrubution, ppmw

Calcium Chromium Copper Iron Magnesium

Manganese Nickel Sodium Silicon Vanadium

Thank youwww.gpca.org.ae

Documents

Optimization of CO2 Removal Process in Ammonia unitsgpcafertilizers.com/wp-content/uploads/2017/10/14-Shomit-Haldar-OG...2 Removal Process in Ammonia units ... Formulated AmineFormulated