Successful Startup of the First World Scale Ammonia Plant .../fileserver/... · Contracts for the ammonia plant license, basic engineering design packages, and supply of li-censer’s

Successful Startup of the First World Scale Ammonia Plant in Bolivia

The Yacimientos Petroliferos Fiscales Bolivianos (YPFB) fertilizer project is the first fertilizer project executed and first fertilizer plant built in Bolivia. The plant is located in a remote area near Bulo

Bulo of Cochabamba Department, Bolivia. In May of 2017, the complex was successfully commis-sioned and passed the performance test. The 1200 MTPD ammonia plant was constructed by Korea S Company, and is based on the KBR PurifierTM technology with the process air compressor driven by a

gas turbine.

This paper shares the commissioning and startup experience, describes the salient process and design features of the ammonia plant, as well as discusses challenges and issues encountered, and key les-

sons learned during the plant commissioning and startup.

Annie Jing, George Colman KBR, Houston, USA

Gwanghoon Lee, Mikyung Lee, Youngdae Kim

Korea S Company, Seoul, South Korea

12018 AMMONIA TECHNICAL MANUAL

Introduction olivia has been fully reliant on imports for the country’s fertilizer demand. To eliminate the dependency on importing fertilizer, monetize the country’s abun-

dant natural gas resource, and promote the devel-opment of the country’s industrialization, the Bo-livia government initiated their Bicentenary Strategy. These projects will commemorate the country’s independence from Spain as part of the bicentenary celebration in 2025. The Yacimientos Petroliferos Fiscales Bolivia-nos (YPFB) fertilizer project was one of the pro-jects in the Strategy and commenced in October, 2012. The YPFB fertilizer project consists of a 1200 MTPD ammonia plant licensed with KBR tech-nology, a 2100 MTPD urea plant licensed with technology of Toyo Engineering Company (TEC) of Japan, and all offsite and utility facili-ties, as well as a 5000 metric ton ammonia stor-age tank, and a 42,000 metric ton urea bulk stor-age. In 2017, the first ever fertilizer plant in the coun-try was successfully commissioned and inaugu-rated into commercial operation, which has intro-duced Bolivia to the production of fertilizer on a world scale and with state of the art technology.

Location The YPFB fertilizer plant is located at a green-field site close to Bulo Bulo, which is a town in central Bolivia in the Cochabamba Department (see Figure 1). It is about 660 kilometer from La Paz (the capital city) and 200 kilometer from Santa Cruz, a major city of Bolivia. The site is shown in Figure 2

Figure-1. Area Map

Figure-2. Overview of YPFB Fertilizer Complex

Feed Stocks and Transportation The natural gas for the YPFB fertilizer plant is supplied to the plant through a domestic gas com-pany. The plant design is based on the natural gas composition listed in Table-1.

B

2 2018AMMONIA TECHNICAL MANUAL

Composition CH4 mol% 91.046 C2H6 mol% 6.480 C3H8 mol% 0.029 CO2 mol% 1.857 N2 mol% 0.588 Total Sulfur (as H2S) mg/Nm3 50 Mercury in Natural Gas µg/Nm3 0.6

Table-1. Natural Gas Composition Water for ammonia production and utilities of the plant comes from the Icha River about 5 kilome-ters away from the plant site. The plant is designed for balanced ammonia and urea production, i.e. normally all ammonia prod-uct converted to urea. The urea product is pres-ently transported from the plant site to the market by container trucks. Railway transportation to and from the plant site is still under construction. Due to the remote location of the plant site, it was necessary for the plant to be self-sufficient with all the utilities required for the construction, commissioning, startup and normal operation of the facility. Equipment had to be engineered and constructed to meet the size and weight limita-tions of the transportation infrastructure of the area.

Project Execution Development of the project was managed by YPFB which was supported by external consult-ing and project management service providers. A key feature of the project execution strategy was to ensure that a safe, efficient and reliable plant was designed and constructed on the strength of proven technology and experienced contractors, suppliers and vendors. As the major investor, YPFB assumed full re-sponsibility for the project. Comprehensive and effective management was achieved by adopting international good practices in contracting and

project management. The contract for Engineer-ing, Procurement, Construction Management (EPCM), as well as providing a certain period of operation and maintenance services after plant startup was awarded to Korea S Company, under a lump-sum-turnkey, fixed price arrangement. Contracts for the ammonia plant license, basic engineering design packages, and supply of li-censer’s proprietary equipment were awarded to KBR. KBR also provided an operator training simulator, a steam dynamic study and start-up advisory service to ensure a safe, fast and effi-cient startup of the ammonia plant.

Process Design Features of YPFB Ammonia Plant This project had to achieve several objectives in-cluding being self-sufficient in steam and power balance, having high efficiency (low energy con-sumption) and having high reliability. To achieve these objectives, this ammonia plant de-sign was tailored to YPFB requirements and is based on KBR Purifier™ Process with a gas tur-bine driven air compressor. All the components of the YPFB ammonia plant were designed based on well proven technology features (1)(2)(3). The salient features of YPFB ammonia plant are discussed below:

For natural gas pretreatment, in addition to normal sulphur removal, a Mercury Removal Unit is added upstream to prevent mercury from causing damage to the downstream equipment and catalyst.

The Process Air Compressor (PAC) is driven by a Gas Turbine (GT), and the hot gas tur-bine exhaust (GTE) is used as the preheated combustion air for the Primary Reformer as shown in Figure 3. This configuration im-proved the thermal efficiency of the GT from around thirty percent to over ninety percent, allowed more steam export to the urea plant for its turbine-driven CO2 compressor and also eliminated the forced draft fan and com-bustion air preheater (Figures 3 and 4)


Figure 3. Configuration of GT-PAC and Primary Refromer

Figure 4. YPFB Primary Reformer & GT-PAC

Mild operating conditions for the Primary Reformer. The reformer radiant tube outlet temperature is only about 700◦C (1292◦F), about 100◦C (180◦F) colder than the conven-tional plants. This lower temperature in-creases equipment life, improves operational reliability, and makes the operation with lower steam to carbon ratio (lower energy consumption) viable.

50% excess air used for the Secondary Re-former, shifting more reforming duty from the Primary to the Secondary Reformer. This reduction in primary reforming duty results in a further energy reduction, smaller Primary Reformer and lower equipment cost.

Secondary Reformer using the KBR special design of a non-metallic mixing chamber with no metallic burner or mixer leading to increased reliability. (Figure 5)

Figure-5. Seconary Reformer

Mild operating conditions for the reforming

waste heat boiler. The boiler was manufac-tured based on KBR proprietary natural-cir-culation, water-tube, and floating-head de-sign with a proven record of high reliability and minimum downtime in cases requiring bundle replacement (Figure 6)

Figure-6. Reforming Waste Heat Boiler and

Steam Drum


CO2 removal system used BASF two stage OASE® white design (Figure 7)

Figure-7. OASE CO2 Removal System

The cryogenic purification unit (the heart of

the KBR PurifierTM Technology) located just upstream of the ammonia synthesis loop, serves to remove inerts, excess nitrogen, and generates highly pure and dry syngas with a H2/N2 ratio of 3/1 for the synloop. The puri-fier allows reduction of the energy consump-tion (both fuel consumption for Primary Re-former and power consumption for syngas and refrigeration compressors are lower), and also stabilizes the whole plant operation (Fig-ure 8).

Figure-8. KBR Cryogenic Purification Unit

Efficient and compact ammonia synthesis loop configuration (Figure 9) with KBR horizontal converter (Figure 10) and the unitized chiller (Figure 11), with a total of only 7 pieces of equip-ment in the high pressure loop. The result is lower cost, lower plot area and lower loop pres-sure drop. KBR proprietary design of the cold wall horizontal converter eliminated the neces-sity of heavy-duty crane for installation.

Figure-9. Ammonia Synthesis Loop Configuration

Figure-10. YPFB Ammonia Converter

Figure-11. YPFB Unitized Chiller


Plant Performance The performance test run for the ammonia plant was conducted in May, 2017. The plant demon-strated that all performance guarantees including capacity, product specification and energy con-sumption were all met as shown in Table-2.

Guarantee Test Value Results

Ammonia Production Capacity MTPD 1200 1211

NH3 wt% min. 99.8 99.8 H2O wt% max. 0.2 0.2 Oil ppmw max. 5 3 Temp ºC max. 40 24 Press kg/cm2 (g) min. 22 27

CO2 Production Capacity MTPD 1550 1591

CO2 vol% (dry) min. 99.5 99.6 Inert vol% (dry) max. 0.5 0.4 Temp ºC 38 35 Press kg/cm2 (a) 1.8 1.7

Net Specific Energy (Gcal/MT) 6.52 6.51 (feed+fuel-steam credit+power)

Table-2. Comparison of Guarantees and the Average of Measured Values in the Test Run

Period.

Project Milestones

The project was kicked off in October, 2012 with the major project milestones as listed in Table-3. First ammonia production was achieved 57 days after initial introduction of the natural gas feed to the primary reformer, and the performance test run was successfully accomplished 38 days after initial ammonia production. The rapid successful startup of the ammonia plant is attributed to the quality of the engineering design, construction, and commissioning by all parties involved.

Engineering Months (M)

Kick Off Meeting M+0

Detail Engineering Comple-tion M+25

Construction

Mechanical Completion M+51

Pre-commissioning/Commissioning Power Generator STG Com-menced M+49

ISBL Ammonia Plant Startup Initial NG Feed-in to Primary Reformer M+52

Ammonia Produced M+54

Performance Test Completed M+55

Table-3. Major Milestones of YPFB Project

Safety Performance

The YPFB project team attached great im-portance to the safety and social impacts of the construction and operation. The plant site HSE orientation and training were required and pro-vided for everyone (employees of Korea S Com-pany and YPFB, subcontractors, vendors, licen-sers, etc.) working at the site. Safety drills were also conducted periodically for emergency pre-paredness. A systematic work permit system was imple-mented for managing site activities to avoid safety conflicts and accidents which could arise. It was especially challenging with so many peo-ple from different countries speaking different languages and performing various kinds of work simultaneously at the site. The work safety sys-tem included routine inspections and audits to en-sure the workers on the job were trained, equipped with proper protection, and physically fit for their task. Construction procedures also used safety taps, banners, and barricades to re-strict access to unnecessary personnel.


Thanks to the project team’s commitment to safety, there were no serious accidents that re-sulted in injury or equipment damage. As a re-sult, the project achieved outstanding safety per-formance with 18,694,982 work hours without a single fatality and no lost time injury (LTI). This performance is a meritorious achievement for the first project in the country and on a project of this scale.

Challenges and Lessons Learned

The project encountered many challenges. Be-low are some of the main challenges and lessons learned, as well as good experience gained.

Challenging Climate Conditions

The weather conditions of the area are a tropical climate with a long rainy summer season from September to May. The relentless rain made it impossible to carry out many of the construction and commissioning activities. The high temper-ature and humidity combination can lead to an intolerable heat index. These conditions necessitate a very careful and detailed planning of the site activities to mini-mize the impact on the schedule. A number of measures were implemented on site in order to minimize the impact on construction and com-missioning activities. For example, providing temporary rain shelters where feasible, rearrang-ing daytime activities to cooler night hours, en-forcing frequent rest periods, providing shaded and cooled areas close to the activity areas and ensuring people were kept hydrated with a proper supply of cool potable water.

As mentioned above, water for the plant was from the nearby river. In the rainy season, days of consecutive downpour lead to the river flood-ing with thick mud. The thick muddy water led to the blockage of the water intake, overloaded the raw water filtration system and caused de-mineralized water shortage which in turn limited plant capacity.

Assembling KBR Horizontal Converter at Site

The plant site is remote and inland. Due to limi-tation on the country’s transportation infrastruc-ture, it’s impossible to deliver heavy and larger size equipment like the ammonia converter in one piece to the plant site. Careful review and detailed planning among the converter manufac-ture, ISGEC Hitachi Zosen Limited (IHZL), KBR and Korea S Company overcame the limi-tation and safely delivered the KBR converter to the site by fabricating the converter shell in two pieces, and shipping the converter in four pieces (two shell pieces, the removable head, and the in-ternal basket). This strategy kept the shipping weight well within the limit. Once the four converter pieces arrived at site, the converter assembly activity was carried out fol-lowing the safety and quality procedures devel-oped by IHZL and KBR with close cooperation of all parties involved. After the two shell pieces were welded together, post weld heat treatment (PWHT) and all the required inspection and test-ing was accomplished, the whole converter was successfully assembled under KBR supervision. Figure 12 shows several photos of the converter welding and assembling activities.


Figure 12. Converter Shell Welding and Assembly at Site

Lost Control of GTE Startup Vent Stack Louver

In our GT-PAC plant, two louvers on the GTE startup vent stack are provided for adjusting GTE to Primary Reformer in a controlled manner. While restarting the GT after a plant trip due to power failure, it was found one louver control was lost, and then after two weeks into operation, another damper’s control was also lost. The in-vestigation concluded that the louvers and the control instrumentation of the louvers were not properly constructed and installed to protect the louver control instrumentation from heat im-pingement of the hot (above 560ºC, 1040ºF) GT exhaust, leading to multiple failures and damage to the system. The louver blade angled down while closing and led to downward flow of the hot GTE gas, causing heat impingement on the louver control instrumentation as well as on the handrail of the platform located close to the lou-ver windows. (Figure 13).

Figure 13. GTE Vent Stack

A temporary repair was done by adding a shield box around the louver window and repairing the damaged instrumentation during one short shut-down period.


A permanent solution was implemented later in the plant’s first turnaround with replacement of the louvers with a revised design. The revised design includes the addition of the shield box and relocation of the louver control mechanism. These changes allow the louver to be reinstalled upside down. With this installation, by closing the louver, the blade would guide the hot GTE flow upward instead of downward to avoid the heat impingement on the louver control instru-mentation, handrail and platform below louver window. The shield box around the louver win-dow also prevents rain from dropping into the stack. Figure 14 shows the revised GTE Vent Stack Louver Arrangement.

Figure 14 GTE Vent Stack (Revised)

Effective Prevention of Foaming in OASE white CO2 Removal System

Key to trouble free, quick startup and stable op-eration of the OASE white CO2 removal system is the effective prevention of the foaming of the OASE solution. Solution foaming can lead to significant operational upsets, and may cause damage to column internals, solution pumps, and heat exchangers in the system. It may also dam-age downstream equipment and catalyst due to solution carried over to the CO2 compressor and/or Methanator. Hence, it is vitally important to ensure removal of the foaming causing agents,

such as greases, oils, dusts, and fine particles from the system.

In the pre-commissioning phase, Korea S Com-pany performed very thorough cleaning of the system. Before loading of the internals into the columns, Korea S Company carried out power brushing of the walls of all the columns in the system to remove particles from the walls and de-greasing of internal packing materials with in-stallation of temporary dip trays (Figure 15). Thanks to the meticulous planning and prepara-tion, the degreasing (pre-cleaning, water flush-ing, alkaline degreasing, water rinsing and OASE solution charging) was completed in only 42 days instead of the typical 2 months.

Figure 15. Temporary Dip Trays

In the commissioning and startup phase, two other important steps were carried out before pro-cess feed introduction to the system. These are the passivation step for forming a magnetite layer (Fe3O4) that protects the carbon steel surfaces from corrosion, and the LTS catalyst de-dusting to prevent fine particles from entering the sys-tem.

In operation, periodic dosing of the anti-foam has been executed routinely.

Thanks to all these well carried-out effective measures, the YPFB OASE white CO2 removal system has been running very smooth and foam-ing free ever since initial startup.


Lack of Industrial Infrastructure

Due to the lack of industrial infrastructure in the area, there is no local facility near the plant site capable of doing equipment maintenance. Korea S Company maintenance shop at the site could do some repairs, but if repairs of special equipment or valves were required, they would have to be transported to Santa Cruz and/or outside the country. Santa Cruz is 3 to 4 hour’s drive one way from the plant site. To get items in and out of the country there was not only long shipping time involved, but also significant time related to customs. YPFB continues to face this challenge today.

Conclusion Despite the challenging site conditions, Korea S Company and KBR succeeded in constructing, commissioning and starting up of Bolivia’s first world-class ammonia plant. The ammonia plant successfully met all its energy consumption, pro-duction, and product quality guarantees. The project was a great success with 18.7 million work hours LTI free.

Acknowledgments Authors acknowledge YPFB, Korea S Company and KBR management for their leadership in

bringing this first fertilizer project to successful reality in Bolivia. Further, contributions of the specialists and engineering team members of Ko-rea S Company and KBR as well as the contribu-tion of the operations, maintenance, construction and related suppliers are highly appreciated and acknowledged.

References 1. Yang Yexin, Gosnell J. H.; “CNOOC Chem-

ical Ltd. New Fertilizer Plant”; AICHE Safety in Ammonia Plants & Related Facili-ties Symposium 2004, Denver, Colorado, USA, September 2004.

2. Jovanovic W., Malhotra A.; “Construction & Commissioning of BFPL’s 2200 MTPD – World’s Largest PurifierTM Ammonia Plant”; AICHE Safety in Ammonia Plants & Related Facilities Symposium 2006, September 2006.

3. Pattabathula V., Morgan C., Hofman M., Colman G., Malhotra A.; “Commissioning of First World Scale KBR PurifierTM Ammo-nia Plant in North America”; AICHE Safety in Ammonia Plants & Related Facilities Symposium 2017, New York, USA, Septem-ber 2017.


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Successful Startup of the First World Scale Ammonia Plant .../fileserver/... · Contracts for the ammonia plant license, basic engineering design packages, and supply of li-censer’s