capacity increase of urea plants...capacity increase of urea plants 24th afa int’l. technical...

Capacity Increase of Urea Plants

Thomas Krawczyk, Uhde Dortmund

24th AFA Int’l. Technical Fertilizers Conference & Exhibition

22 – 24 November 2011, Amman, Jordan

Capacity Increase of Urea Plants24th AFA Int’l. Technical Fertilizers Conference & Exhibition

22 – 24 November 2011, Amman, JordanT. Krawczyk

2

Outline

o Targets and requirements of a revamp

o Revamp concept for a capacity increase of 17% (1925-2250 MTPD)

o Contractor‘s input

o CO2 generation



3

Targets and requirements of a revamp

� Capacity increase

– By using existing margins to get maximum possible additional product with the lowest effort

necessary

– Elemination of bottlenecks

� Reduction of energy consumption (e.g. heat integration)

� Environmental improvements

– Reduction of emissions (to comply with new laws and international standards)

� Increase of reliability and availability

� Utilization of a well proven and reliable technical concept

� Short as possible implementation downtime for modifications and new equipment



4

Revamp targets

STAC

1925 mtpd

STAC

1925 mtpd

UFT

2000 mtpd

STAC

2000 mtpd

Melt Plant Granulation

+ ~17%

2250MTPD

Plant II

Plant I

+ ~17%

2250

MTPD

+ 12.5%

2250MTPD

+ 12.5%

2250

MTPD

actual design revampactual designrevamp



5

The basis before the revamp for both plantsConventional Stamicarbon CO2 Stripping Process

H2 RemovalH2 Removal

NH3

CO2

Air

S

C

From recirculation

Condensate

LPabsorber

LPabsorber

StripperStripper

ReactorReactor

HPCCHPCC

HP ScrubberHP Scrubber

WC

WC

To recirculation

S

C

To atmospheric absorber



6

MP SectionMP Section

Block Diagram Plant I & II (MP Section)

SynthesisSynthesis

EvaporationEvaporation

GranulationGranulation

DesorptionDesorption

1925 MTPD

CO2NH3

+17% �� 2250 MTPD

carbamate

20wt% water

urea solution

CO2

waste heat

carbamate 30wt% waterLP RecirculationLP RecirculationPur. Process Cond.

Carbamate

Parallel

LP Recirculation

Parallel

LP Recirculation

Parallel

Desorption

Parallel

Desorption



7

Revamp concept 1925 � 2250 MTPD

NH3

CO2

Air

S

C

StripperStripper

ReactorReactor

WC

WC

To recirculation

S

C

HPCCHPCC

MP Section

HP ScrubberHP Scrubber

carbamate 20wt% water

To LP absorber

CO2

After reactorAfter reactor

new equipment



8

MP Section (operating at ~20bar)

MP Rectifying

Column

MP Rectifying

Column

MP StripperMP Stripper

MP Pre-EvaporatorMP Pre-Evaporator

MPCCMPCC

HP Carbamate PumpHP Carbamate Pump

Level Tank f. MPCCLevel Tank f. MPCC

MP CO2 CompressorMP CO2 Compressor

To recirculation

To 2bar Absorber

To synthesisCO2

From synthesis

new equipment



9

Granulation Revamp 2000 � 2250 MTPD

Fluidising air

Urea solutionfrom evaporation

Atomising air

SC

Air

First Cooler

ScreenScreen

CrusherCrusher

Bucketelevator

Bucketelevator

Granulator

Air

To storage

Process

condensate

to US

tank

Coolerscrubber

Granulatorscrubber

Final Cooler

Start-upbin

Safetyscreen

NH3

NH3

NH3

Water injection

Air cooler

Air coolernew equipment



10

Overview of the revamp measures for plant I & II



11

Overview of the revamp measures for plant I & II



12

Uhde‘s input to optimise the concept

Case 1: before revamp

� One pump in operation

� One pump stand-by

HP NH3 / Carbamate Pumps

A B

in operation stand-by

1925 MTPD



13

Uhde‘s input to optimise the concept

Case 2a : after revamp

� Two pumps in operation

� Fall back to capacity before revamp in case

of malfunction or maintenance

Case 2b : after revamp

� Two pumps in operation

� One pump stand-by

� Production remains at revamp capacity A B C

HP NH3 / Carbamate Pumps

in operation stand-byin operation

2250 MTPD



14

Uhde’s modifications of closed cooling water loops

Lower water temperature in order to reduce fouling on CW side.

TIC

Circ. Cooler f. 225E003

229E006

Circ. Cooler f. 225E003

229E006

MP Carbamate Condenser

225E003

MP Carbamate Condenser

225E003

225P010 Circ. Water Pump f. 225E003

229P006

Circ. Water Pump f. 225E003

229P006

65°C

55°C

90°C

90°C

80°C

new

CW



15

CO2 and NH3 for Urea Production

�Production of ammonia plant is typically with lower ratio CO2 / NH3

(1.14 t/t for ideal process with no loss and pure CH4 as feedstock)

�Demand of urea plant per ton of urea: 0.566 t NH3 + 0.733 t CO2

⇒Ratio CO2 / NH3 needed: 1.29 t/t

Ammonia

plant

Urea

plant

CO2

ureaNH3

Ammonia

plant

Urea

plant

CO2

ureaNH3



16

Ways of CO2 Production

o Standard Ammonia Process

Reforming CO shift CO2 removal Purification Synthesis

NH3

NG feed

NG fuel

CO2 flue gas

CO2 to urea

Syngas return as reformer fuel

o Increased CO2 production by recovery of CO2 from flue gas

CO2 to ureaCO2 recovery

o Increased CO2 production by increased throughput of CO2 removal and return of

excess synthesis gas to reformer fuel



17

Conclusion

�Changes in one place always lead to changes in another place

– Overall knowledge

�Many constraints in an existing plant and set by the existing periphery

– Collaboration between all involved parties

� Input to optimize the revamp concept for a tailor-made solution

– Expierenced contractor

Thank you for your [email protected]

www.uhde.eu

capacity increase of urea plants...capacity increase of urea plants 24th afa int’l. technical...

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