2007 Recent Achievements and Advances

8/3/2019 2007 Recent Achievements and Advances

1/14

1

Recent Achievements and Advancesin Urea Technology

YASUHIKO KOJIMA,KENJI YOSHIMOTO

Toyo Engineering Corporation8-1, Akanehama 2-chome, Narashino-shi, Chiba 275-0024, Japan

INTRODUCTION

Since established in 1961, Toyo Engineering Corporation (TOYO), a global leadingengineering contractor and urea process licensor, has licensed its technologies for over100 urea plants including granulation units, sharing 1/4 of world urea production capacityas of January 2006. In 2000, TOYO and PT Pupuk Sriwidjaja (PUSRI) Indonesia,

completed the R & D of its latest urea synthesis technology named ACES21

[1].ACES21 is advantageous in low investment cost and low energy consumption for ureaproduction. A major feature of this technology is that it reduces the number of equipmentin the urea synthesis loop to simplify the system, which lessens construction costs withthe installation of the reactor on the ground in CO2 stripping process (resultantly existingurea reactor can be re-utilized in revamp case). In addition, the operation conditions ofsynthesis section have been optimized under the lower operation pressure than theprevious process. As a result, a remarkable reduction in energy consumption has beenachieved.

Another premium advantage of ACES21 is that it is flexible for various utilityenvironment. Although in middle to large scale urea plant CO2 compressor is usually

driven by steam turbine, it is sometimes required to be driven by electric motor dependingon availability and cost of steam (water) vs. electricity. If CO2 compressor is driven byelectric motor, excess low pressure steam usually utilized for admission to steam turbinemust be exported. If no low pressure steam user is found outside the urea plant, it mustbe vented or condensed. Needless to say, it is waste of steam and energy. Even in caseCO2 compressor is driven by electric motor, ACES21

enables the urea plant be operatedwithout exporting low pressure steam. This process variation is also advantageous incase CO2 compressor is driven by 110 barG steam turbine because 110 barG top steamconsumption can be minimized by limiting extraction steam consumption required forheating HP stripper.

ACES21 has been first selected for modernizing a 1,620 mtpd conventional urea plant ofSichuan Chemical Works (Group) Ltd. (SCW) to increase production capacity to 2,460mtpd and reduce energy consumption by 30%. The first ACES21 plant for SCW hasbeen smoothly operated since its successful commissioning in 2004 [2]. The second butthe first complete new urea plant based on ACES21 technology is for PT Pupuk KujangIndonesia (see Photo-1). The fertilizer complex named Kujang-1B consists of 1,000 mtpdammonia unit, 1,725 mtpd urea unit with ACES21 and associated service unit. The initialstart-up of the urea plant on October 24, 2005 was very smooth and urea prills wereproduced only several hours after ammonia was initially fed to the plant. The performancetest run conducted in January 2006 has demonstrated the important features of ACES21,i. e. low energy consumption, environment-friendliness and high operability [3].

In the same year 2006, TOYO was awarded two landmark contracts; one is an


2/14

2

engineering contract from MAN Ferrostaal AG (MFS) for the Chemical Fertilizer Complexplanned by Methanol Holdings (Trinidad) Limited (MHTL) to produce Urea AmmoniumNitrate and Melamine, at Point Lisas Industrial Estate in Trinidad and Tobago; and the

other is an license and PDP supply contract from PetroChina Tarim PetrochemicalCompany. The former contract is to license the ACES21 technology for a 2,100 mtpdUrea synthesis unit in Trinidad and the latter is to license TOYOs Spout-Fluid Bedgranulation technology for a 2,640 mtpd granulation unit to be built in Korla, XinjiangAutonomous Region, China.

Upon completion of the first ACES21 urea plant, TOYO has started licensingtechnologies for so-called Jumbo Urea Plant over 3,000 mtpd capacity. Design andengineering up to 4,500 mtpd have completed and a number of proposals of 3,000 3,500 mtpd single train plants have been carried out. In early 2007, TOYO was awardedan epoch-making contract to supply license and to perform basic engineering to build a3,250 mtpd Urea Plant in Iran. TOYOs ACES21 and Spout-Fluid Bed granulationtechnologies are being applied to the project.

This paper reviews the latest advances in urea process technology; updated status ofACES21 process, and TOYOs approach to Jumbo Urea Plant.

PHOTO-1:1,725 MTPD ACES21UREA PLANT,PTPUPUK KUJANG,INDONESIA


3/14

3

PROCESSDESCRIPTIONFig.1 shows a typical process flow sheet for ACES21 urea plant and Fig. 2 shows aschematic flow sheet of ACES21 synthesis section consisting of a reactor, a stripper anda carbamate condenser. Liquid ammonia is fed to the reactor via HP Carbamate Ejectorwhich provides the driving force for circulation in the synthesis loop instead of gravity forthe original ACES Process. Most of the carbon dioxide with small amount of passivationair is fed to the stripper as a stripping medium and a raw material for urea synthesis, andthe rest is fed to the reactor as a raw material and to passivate the reactor. The reactor isoperated at N/C ratio of 3.7, 182 - 184C and 152 barG. The CO2 conversion to urea is ashigh as 63 - 64% at the exit of the reactor. Carbamate solution from the carbamatecondenser is fed to the reactor after being pumped by the HP ejector that is motivated byhigh pressure liquid ammonia. Urea synthesis solution leaving the reactor is fed to thestripper where unconverted carbamate is thermally decomposed and excess ammonia

and CO2 are efficiently separated by CO2 stripping. Stripped urea solution is sent to MPdecomposition stage to be purified further. The stripped off gas from the stripper is fed toVertical Submerged Carbamate Condenser (VSCC), operated at N/C ratio of 2.8 - 3.0,180 - 182C and 152 barG. Ammonia and CO2 gas condenses to form ammoniumcarbamate and subsequently urea is formed by dehydration of the carbamate in the shellside. Reaction heat of carbamate formation is recovered to generate 5 barG steam in thetube side. Packed bed is provided at the top of VSCC to absorb uncondensed ammoniaand CO2 gas into recycle carbamate solution from MP absorption stage. Inert gas fromthe top of the packed bed is sent to MP absorption stage.

FIG 1: FLOW SHEET OF ACES21UREA PROCESS


4/14

4

TO MP ABSOPTION

FROM CARB. PUMP

TO MP DECOMPOSITION

BFW LPSTEAM

FROMFROM CO2-COMP

EJECTOREJECTOR

FROMFROM NH3-PUMP

CONDENSERCONDENSER((VSCCVSCC))

STRIPPERSTRIPPER

REACTORREACTOR MP STEAM

COND

FIG.2: ACES21SYNTHESIS SECTION

PROCESSFEATURES

Low Elevation and Compact Layout

In CO2 stripping technology, the reactor, the largest and the heaviest vessel in ureaplant, is normally installed at 20-22 meter level so as to feed urea synthesis solution tothe stripper by gravity. If the reactor is installed on the ground level, civil and erectioncost can be greatly reduced. TOYO and PUSRI have jointly developed ACES21

process aiming at installing the reactor on the ground level, maintaining advantages ofCO2 stripping technology. The two stage synthesis concept in combination of VSCC andthe reactor is employed to enable the reactor be installed on the ground level and tosimplify the synthesis loop. The forced circulation of the synthesis loop driven by HPcarbamate ejector also makes the VSCC be installed on fairly low elevation. As shownin Photo-1, HP equipment in the synthesis section is laid-out quite compactly in lowelevation. The highest level in the synthesis section, that is VSCC top, is only 30 to 35m.

Vertical Submerged Carbamate Condenser (VSCC)

Fig. 3 illustrates a configuration of the Vertical Submerged Carbamate Condenser

(VSCC)which functions to:(1) condense NH3 and CO2 gas mixture from the stripper to form ammonium carbamatein the shell side; (2) synthesize urea by dehydration of ammonium carbamate in theshell side; (3) remove the reaction heat of ammonium carbamate formation bygenerating 5 barG steam in boiler tubes.

Advantages of the vertical submerged configuration of carbamate condenser are:

(1) High gas velocity, appropriate gas hold up and sufficient liquid depth in the bubblecolumn promote mass and heat transfer; (2) An appropriate number of baffle platesdistributes gas bubbles in the column effectively without pressure loss; (3) A verticaldesign inevitably requires smaller plot area.


5/14

5

VSCC is categorized into a kind of bubble column reactor with boiler tubes. VSCCconsists of the condensation-reaction section in the main cylindrical shell and thescrubbing section with packed bed in the top. The condensation-reaction section is

equipped with a U-tube bundle and baffle plates. A down flow pipe connects thescrubbing section and the condensation-reaction section so as to feed carbamatesolution from the scrubbing section to the bottom chamber of the VSCC by gravity.Mixed gas from the stripper is introduced and distributed into the bottom compartmentas small bubbles via a gas sparger. Carbamate solution is introduced to the bottomcompartment of the condensation-reaction section from the scrubbing section via thedown-pipe as absorbent. From the bottom to the top of the condensation-reactionsection, the mixed gas bubbles rise through the bundle of boiler tubes and partiallycondense, contacting with urea-carbamate solution. The condensation (carbamateformation) heat is removed by the boiler tubes in which saturated boiler water iscirculated by a circulation pump. The shell side volume is sufficient to promotedehydration of ammonium carbamate to form urea at the conversion rate of 40 to 50%.

Fig. 4 shows a result of a computationalfluid dynamic (CFD) analysis for gasbubbles and solution in a compartmentof VSCC. The rising bubbles in thecentral tube bundle area agitates theurea-carbamate solution to circulatebetween the space among bristledboiler tubes and the surrounding openannular space near the interior wall,giving high mass transfer between thegas bubbles and the absorbent

urea-carbamate solution and high heattransfer between the carbamatesolution and the boiler tubes.

The bubbles enter the compartmentthrough holes provided among the tubeholes on the lower baffle plate, then risein the space among the tubes and

finally gather beneath the upper baffleplate to be re-distributed evenly as the

form of small bubbles while passingthrough the holes on the baffle plate.

Urea-carbamate solution enters acompartment from an opening providedon each baffle plate, then circulates,being agitated by the rising bubbles andexits to the next compartment throughthe next opening provided on the nextbaffle plate. Such carbamate formation -heat removal - urea formation processcycle taking place in a compartmentbetween two baffle plates repeatscompartment-by-compartment frombottom to top, achieving high CO2

conversion to urea at the exit of VSCC

tube bundle area open annular space

upper baffle plate

lower baffle plate

FIG.3:CONFIGURATION OF VSCC

FIG.4:CFDANALYSIS RESULT IN VSCC


6/14

6

and efficient heat recovery in VSCC. The urea-carbamate solution leaving the topcompartment on the top baffle plate is extracted through a down-pipe to be fed to the HPejector.

Mixed gas containing uncondensed ammonia and CO2 entrained by inert is introducedto the scrubbing part where the most of NH3 and CO2 is absorbed adiabatically intocarbamate solution recycled from the downstream middle pressure stage whilecontacting counter-currently in a packed bed. The mixed gas which is rich with inert afterscrubbing is sent to middle pressure stage for further treatment.

Sufficient annular space is available between the U-tube bundle and the interior wall ofthe shell so that inspection and maintenance personnel can work and walk through.Tube thickness is precisely measured for full length of all the U-tubes from channel sideby eddy current technique.

Optimized Synthesis ConditionsFig. 5 shows CO2 conversion and equilibrium pressure vs. N/C. In ACES21

Process,the N/C ratio in VSCC differs from that in the reactor. VSCC is operated at N/C ratio of2.8 3.0 where the equilibrium vapor pressure of urea-carbamate solution gives thelowest. This optimum N/C selection allows VSCC be operated at relatively hightemperature (180 182 C) and low pressure (152 barG), rendering efficient heattransfer between the shell and the tube and higher reaction rate of ammoniumcarbamate dehydration to form urea as high as 45% conversion from CO2. The reactorN/C ratio is selected at 3.7 to maximize CO2 conversion with appropriate excesspressure to that of equilibrium. As inert gas fed to the reactor is only 1/5 of that ofconventional CO2 stripping process, vapor fraction in the reactor decreases drastically

and the reactor volume is fully utilized for urea synthesis reaction which takes place onlyin the liquid phase. Resultantly, high CO2 conversion of 63 - 64% is achieved in thereactor at relatively low temperature and pressure, i.e. 182 - 184 C and 152 barG. Thehigher CO2 conversion at lower synthesis pressure requires less decomposition heat inHP stripper and less energy for CO2 compression and liquid ammonia and carbamatesolution pumping.

40

50

60

70

80

2 2.5 3 3.5 4

100

120

140

160

180

200

EQUILIBRIUMC

ONVERSION

EQUILIBRIUM

PRESS.

REACTORREACTORN/CN/C

CONDENSERCONDENSERN/CN/C

EXCESS PRESSURE

OPERATING PRESSURE

EQUIL

IBRIUM

EQUIL

IBRIUM

CONV

ERSIO

N

CONV

ERSIO

N

EQUILIBRIUM

EQUILIBRIUM

PRESSURE

PRESSURE

N/C

FIG.5: EQUILIBRIUM CONVERSION AND EQUILIBRIUM PRESSURE VS.N/C


7/14

7

Unique Heat Integration Concept

The unique heat integration between the HP stage and MP/LP stages further reducesenergy requirement (see Fig. 6). MP steam is supplied to HP stripper in synthesissection to decompose and separate excess NH3 and carbamate. The stripped NH3 andCO2 gas mixture is sent to the VSCC to form ammonium carbamate solution. Thereaction heat (condensation heat) in VSCC is recovered by generating LP steam. Thegenerated LP steam is utilized in medium pressure decomposition stage, in the lowpressure decomposition stage and evaporation stage. The heat of ammoniumcarbamate formation in MP stage is also utilized to evaporate water in evaporationsection. This multiple heat integration concept, originally invented and developed byTOYO, realizes the most energy efficient urea process.

C.W.

C.W.

C.W.

UREA

NH3 +CO2 +H2OMEDIUM PRESSURE

SECTION

LOW PRESSURE

SECTION

EVAPORATION

SECTION

HEAT RECOVERY

SECTION

SYNTHESIS

NH3 CO2

UREA

MELT

NH3 + CO2 + H2O

H2O

UREA

NH3 + CO2 + H2O

UREAH2O

WATER

(BY-PRODUCT)

L.P. STEAM(GENERATED)

M.P. STEAM

FIG.6:UNIQUE MULTIPLE HEAT INTEGRATION CONCEPT

Flexibility in Various Utility Environment

ACES21 is quite flexible for various utility environment. Although in middle to largescale urea plant CO2 compressor is usually driven by steam turbine, it is sometimesrequired to be driven by electric motor depending on availability and cost of steam(water) vs. electricity. If CO2 compressor is required to be driven by electric motor,excess low pressure steam usually utilized for admission to steam turbine must beexported. In such situation, if no low pressure steam user is found outside the urea plant,it must be vented or condensed. Needless to say, it is waste of steam and energy. Evenin case CO2 compressor is driven by electric motor, ACES21

enables the urea plant beoperated without exporting low pressure steam. High CO2 conversion in urea synthesisreactor, moderate stripping in HP stripper by adjusting steam pressure and efficientintegration with 16.5 barG stage into the process minimize middle pressure (lower than20 barG) steam consumption in HP stripper without sacrificing overall process efficiency.In such case, middle pressure steam consumption decreases to 0.58 metric ton per tonof urea product.

This process flexibility is also advantageous in case CO2 compressor is driven by 110

barG steam turbine. Top steam flow for steam turbine for CO2 compressor must be more


8/14

8

than extraction steam required by the urea plant, mainly by HP stripper. In other words,if extraction steam quantity required for maximizing stripping efficiency in HP stripper ismore than 0.7 mt/mt, top steam consumption may increase unnecessarily to 0.75 mt/mt

or more so as to supply sufficient steam to HP stripper. In ACES21

, as aforementioned,moderate stripping in HP stripper integrated with MP decomposition stage reduces MPsteam consumption to 0.58 mt/mt, enabling full utilization of 110 bar steam energy andsignificant reduction of overall steam consumption including CO2 compressor to0.69 mt/mt.

Table I summarizes utilities consumption for the following four cases: (1) all rotatingmachines are driven by electric motor, LP steam is exported; (2) all rotating machinesare driven by electric motor, steam system is self-balanced (no export); (3) CO2compressor is driven by 42 barG steam turbine; (4) CO2 compressor is driven by 110barG steam turbine.

Table I

Typical Consumption Figures of ACES21Urea Plant

Unit Electric Motor Driven Steam Turbine Driven

- Steam Export Self Balance 42 bar Steam 110 bar Steam

Steam Import

22 bar x 300 C ton 0.67 0.58

42 bar x 380 C ton 0.80

110 bar x 510 C ton 0.69

Steam Export

5 bar, Saturated ton 0.24

Cooling Water

(T=10C) m3

52 52 81 75

Electricity

Process kWh 105 105 21 21

Granulation kWh 24 24 24 24

Notes:

1) unit: per metric ton of final granular urea product2) including CO2 compression

THE KUJANG-1B PROJECT

At 21:15 on October 24, 2005, a brand-new urea plant located in Cikampek, West Jawa,Indonesia has produced urea prills only several hours after receiving liquid ammonia toits synthesis loop for the first time. The 1,725 mtpd urea plant has been designed andconstructed by TOYO based on ACES21 technology as its second application in theworld, following the urea plant revamp project for Sichuan Chemical Works China. On


9/14

9

January 17, 2006, as soon as conditions became ready, the fourteen days performancetest run commenced together with ammonia plant. The performance test has beensuccessfully completed and the ammonia-urea complex has been handed over to PT

Pupuk Kujang, an Indonesian state-owned fertilizer company. Table II outlines theprofile of the second ACES21 urea project called Kujang-1B.

Table II

Kujang-1B Project Profile

Plant Capacity: ammonia 1,000 mtpd / urea 1,725 mtpd

Location: Cikampek, West Java, Indonesia

Ammonia Process: KBR conventional

Urea Process: TOYOs ACES21 with prilled product

Project Scope: turn-key lump sum in cooperation with Rekayasaand IKPT as J/V partner

Technological Features of Kujang-1B

TOYO considers the latest urea plant should be designed to meet recent increasing

demand for safety, health and environment. The Kujang-1B urea plant embodies the

latest technological advances, enhancing reliability, safety and environment protection

feature in addition to its high energy efficiency originally given by ACES21. Table IIIshows technological features of the Kujang-1B urea plant.

Table III

Technological Features of Kujang-1B Urea Plant

CO2 Compression centrifugal compressor driven byextraction-admission-condensing steam turbine

Liqiud Ammonia Feed centrifugal pump driven by condensing steam turbine

Carbamate Solution Feed Ditto

Urea Reactor operating conditions: N/C = 3.7 mol/mol, 152 barGtype : bubble column with baffle plates

HP Stripper Type : falling film with CO2 stripping

material : swirler = DP28W, tube = DP12

HP Condenser operating conditions: N/C = 2.9 mol/mol, 152 barG

type : vertical submerged (VSCC)

material : tube = 25Cr22Ni2Mo

Finishing vacuum evaporation + prilling (acoustic nozzle)

Waste Water Treatment hydrolyzer & stripper for BFW use

Liner Leak Detection continuous monitoring with nitrogen gas purge circuit

BFW Quality Monitoring continuous urea analysis by TOYO-MCI proprietary analyzer


10/14

10

Leak Detection System for HP Equipment Liner Plates

In urea plant, anti-corrosive liner plates are usually applied to high pressure static

equipment exposed to urea-carbamate solution. It could be told even correct materialselection, elaborate fabrication and careful maintenance do not eliminate risks of liner

leakage which might damage the pressure holding shell made of carbon steel as learned

from past experiences. Therefore it is essential to prevent the equipment damage and to

minimize shut-down period once leakage happens. Conventionally, weep holes

connecting the space between the liner and the pressure holding shell to outside of the

shell (atmosphere) are usually provided to detect leakage from liner plates. The vent

holes are sometimes connected to bottles containing ammonia-sensitive reagent by

tubing so as to detect leakage more easily and quickly. However the system may take

longer time to detect very minute leakage and the tubing is susceptible to plugging due to

crystallization of urea or ammonium carbamate.

Although some urea plants have already applied liner leak detection system with

continuous gas circulation or purging between liner and pressure holding shell to improve

the reliability and response time, such urea plants are still minority.

The Kujang-1B urea plant applies continuous nitrogen gas purge circuit to detect liner

leakage for urea reactor, HP stripper and HP condenser (VSCC). The continuous

nitrogen gas purge circuit is featured by:

Accurate and reliable in detecting liner leakage.

Quick response

Easy identification of leakage location

Nitrogen gas is circulated in the loop by a gas circulator. Flow meter is provided to the

gas inlet tubing to each segment of liner plate or group of liner plates so as to control and

distribute the purge gas flow rate appropriately. Nitrogen gas is made up to the circuit to

maintain the system pressure. A water sealed breather protects the liner plates from

overpressure. Ammonia detector detects ammonia in nitrogen gas circuit at as low as

ppm levels. The signal from the ammonia detector is connected to central control room so

that plant operators find occurrence of liner leakage quickly. The on-line leak detection

system for HP Equipment liner has been successfully operated in Kujang-1B urea plant

since October 2005.

Continuous On-line Analysis of Urea in Treated Process

Condensate

Water (process condensate) is the largest byproduct of urea production process, which

amounts stoichiometrically 0.3 mt/mt-urea and industrially as high as 0.5 mt/mt-urea, and

the treatment of process condensate containing ammonia and urea has been the

challenges since urea production process was industrialized. In former times, the process

condensate was treated by steam stripping and hydrolysis to the level of 50 100 ppm

for being utilized as cooling tower make-up or disposed outside of urea battery limit.

Recently, deep urea hydrolysis and steam stripping technology reducing urea and


11/14

11

ammonia content to lower than 1 ppm in treated process condensate has been

developed, enabling its use for make-up for boiler feed water (BFW). In case the treated

process condensate is utilized for BFW make-up, urea content must be strictly controlled

because urea can not be removed in ion-exchange resin bed. In case urea is containedexcessively in BFW, it is hydrolyzed in boiler to form carbon dioxide which lowers pH and

resultantly excessive corrosion in boiler may happen. As conductivity meter does not

show the level of urea content (urea does not become electrolytes in aqueous solution),

urea in treated process condensate must be periodically analyzed in laboratory where a

few hours are required to obtain urea analysis result. To eliminate the risk of corrosion in

boiler due to low pH by excessive urea in BFW, urea in treated condensate should be

analyzed continuously and real-time. TOYO and Mitsui Chemicals Inc. (MCI) have

developed proprietary on-line urea analyzer for process condensate, which analyzes

urea continuously and real-time in the range from 1 ppm to 300 ppm. As the TOYO-MCI

on-line urea analyzer is simply configured and does not require any chemicals and

reagents, its initial and running cost is rather low. Figs. 7 and 8 show an example of its

application and schematics of the analyzer. The TOYO-MCI on-line urea analyzers have

been running in MCI Osaka Factory (Japan) and Kujang-1B since 2001 and 2005

respectively.

PerformanceTest Result

Table IV shows the results of performance test of Kuajng-1B urea plant conducted

January 2006. As shown in Table IV, the plant has shown excellent performances. It

should be noted that the steam consumption in urea plant including steam turbine for CO 2

compressor, steam turbines for ammonia feed pump and carbamate feed pump is only

1.035 mt/mt. If ammonia and carbamate pumps were driven by electric motor, the steam

consumption could have been reduced to 0.92 mt/mt.

FIG.7: APPLICATION OF ON-LINE UREA ANALYZER


12/14

12

FIG.8: SCHEMATICS OF ON-LINE UREA ANALYZER

Table IV

Performance Test Result of Kujang-1B ACES21Urea Plant

Production: 1747.2 mt/d

Consumption

- Ammonia: 0.568 mt/mt- Carbon Dioxide: 0.738 mt/mt

- Steam(1)

: 1.035 mt/mt

- Cooling Water(1) (2)

: 85.1 m3/mt

- Electric Power(3)

: 18.7 kWh/mt

Treated Effluent

- Ammonia: 0.36 ppm

- Urea: 0.15 ppm

Emission

- Urea from Prilling Tower: 41.7 mg/Nm3

Notes:(1) 41.2 barG, 380 C steam including steam turbines for CO2 compressor,ammonia pump and carbamate pump.

(2) at temperature rise 10.1 C(3) including power for urea dust scrubber of Prilling Tower

APPROACH TO JUMBO UREA PLANT

Nowadays urea plant capacity has been enlarging to 3,200 - 3,500 mtpd in single train.As urea plant capacity gets larger, ACES21 becomes more advantageous becausefewer and smaller HP equipment are laid out in low elevation, greatly improvingequipment manufacturability, transportability, constructability, operability and

maintainability for the Jumbo Urea Plant. TOYO has already completed the design up to


13/14

13

4,500 mtpd urea plant based on ACES21 and Spout-fluid Bed Granulation; and MajorHP equipment and machinery manufacturers have committed HP equipment andmachinery for 4,500 mtpd ACES21 urea plant can be manufactured. Fig. 9 shows a

3-D model view of a 3,250 mtpd ACES21

Urea Synthesis Unit combined withSpout-fluid Bed Granulation Unit. As shown in Fig. 9, the HP equipment are laid outquite compactly in low elevation with the highest level of 35 m (VSCC top).

In January 2007, TOYO has been awarded a contract to supply license and basicengineering to build a 3,250 mtpd urea plant in Iran based on ACES21 and Spout-FluidBed Granulation Technology. This project is epoch-making regarding the followingaspects:

the first ACES21 + Spout-Fluid Bed urea granulation plant in Middle East

the largest single train Jumbo Urea Plant ever engineered by TOYO, wherestate-of-the-art urea technologies will be incorporated and demonstrated

FIG.9: 3D-MODEL OF 3,250 MTPD ACES21UREA UNIT

COMBINED WITH SPOUT-FLUID BED GRANULATION UNIT

CONCLUSIONThe second ACES21 urea project has completed successfully in close collaborationamong TOYO, PT Pupuk Kujang, PT Rekayasa Industri, PT IKPT and PT PupukSriwidjaja (PUSRI, the co-licensor of ACES21), proving its advantages in energyefficiency, operability and environmental conservation. Those achievements in ureatechnology would lead to economical and safe urea production with minimumenvironmental impact, i.e. the high energy efficiency contributes to global warmingprevention; on-line leak detection system for HP equipment liner enhances reliability

and safety; and on-line urea analyzer for treated process condensate enhances total


14/14

14

utilization of process condensate for BFW without discharge.

The first ACES21 urea project of 2,460 mtpd in China was indeed a challenge forTOYO. Its success has laid the technological foundation for the significant 3,250 mtpd

Jumbo Urea Project in Iran. The Jumbo Plant is expected to be on stream in 2010.

TOYO, as urea technology provider, continues improving its urea technology for thesustainable growth of fertilizer industry with cleaner environment.

REFERENCES

1. Y. Kojima, H. Morikawa, E. Sakata, Development of ACES21 Urea Process,Nitrogen 2000, Vienna, Austria

2. Y. Kojima, T. Yanagawa, ACES21 demonstrated in a world scale urea plant inChina, Nitrogen 2005, Bucharest, Romania

3. Y. Kojima, The Latest Advances in Urea Process Technology (ACES 21TM), 19thAFA International Technical Conference, Doha, Qatar

ACES21

is a registered trademark of Toyo Engineering Corporation in Japan (RegisteredNumber 4309123)

Documents

2007 Recent Achievements and Advances