/s4_2

Page 1

23rd AFA Int.’l Technical Conference & Exhibition June 29 – July 1, 2010 Ramada Plaza Tunis Hotel, Tunisia

Start-up experience of the MOPCO urea granulation plant

Harald Franzrahe Process Manager, Uhde Fertilizer Technology

Netherland


23th AFA International Technical Fertilizer Conference 2010

Start-up experience of the MOPCO urea granulation plant Dr. Harald Franzrahe, Process Manager Uhde Fertilizer Technology B.V.

Abstract : The construction and commissioning of a large scale industrial project is an activity which needs to be precisely controlled and managed in order to prevent any harm to personal and equipment. After successful completion of these activities the plant is ready for its first start-up. During the first start-up of a chemical plant raw material and chemicals are introduced into a new and untried plant. For the first time all equipment, machines and instrumentation are subjected to the full operating rigor of the process. It is a phase in which many things can go wrong and which could pose significant hazards to the plant and the operating personal. For a successful start-up careful attention must be paid to details and the operating procedures. With a plant based on proven technology it is possible to utilize a large pool of information gained from previous start-up operations. In such a case the combination of experience of the licensor, the contractor and the operating company ensure a trouble free and safe start-up. Based on the commissioning and start-up of the MOPCO plant in Damietta, Egypt we would like to present the elements which made this start-up efficient and safe.

2010-AFA-Paper.doc

Page 1


1 Introduction In 2006 the Suez-based Egyptian company Misr Oil Processing Company (MOPCO) has awarded Uhde Dortmund, Germany, a contract to construct a turnkey fertiliser complex. It was the fourth contract for almost identical fertilizer plants to be won by Uhde in Egypt. This contract was for an ammonia/urea complex with a capacity of 1,200 tonnes per day of ammonia and 1,925 tonnes per day of urea granules, and includes all utilities and offsites. Uhde's scope of supply included the entire engineering (basic and detail), supply of the equipment, construction and commissioning. Parts of the contract were handled by Uhde's subsidary Uhde Engineering Egypt, based in Cairo. The complex is located in the Damietta free trade zone, some 200 kilometers east of Alexandria, and started operation in September 2008. Since then they have been running without any serious problems. The ammonia plant is based on Uhde's proprietary ammonia process while the urea plant uses Stamicarbon's synthesis technology. The urea granulation process is licensed from Uhde Fertilizer Technology.

2 The UFT Fluid Bed Urea Granulation Technology Figure 2-1 shows the process flow diagram of the UFT Fluid Bed Urea Granulation process. Heart of the plant is the granulator, where urea solution with a concentration of 97% is atomized into fine droplets and sprayed onto the particles in the fluidized bed. Formaldehyde is added to the urea solution as granulation additive and to improve storage properties. Crushed oversize and fines coming from the screens are utilized in the granulator as seed material and the particles continuously grow to their desired size by accretion. In the first cooler the product is cooled down and via bucket elevator lifted to the screens, which separate coarse, fine and on-size material. The on-size material is cooled down in the final cooler to the storage temperature and sent to storage. For the final cooler there are two options, one is a fluidized bed cooler, the other option is a bulk flow cooler, which is operated with cooling water instead of air. All fluidized beds are fluidized by air. The exhaust air, containing some amount of dust, is cleaned in commercially available wet dust scrubbers, granulator scrubber and cooler scrubber. The dust is recycled to the urea synthesis section as 45% urea solution. The major advantage of the UFT fluid bed urea granulation process is the melt concentration of 97% urea. In this way the evaporating water is utilized as additional coolant to remove the heat of crystallization. This leads to the following features: 2010-AFA-Paper.doc

Page 2


Single stage evaporation unit in urea synthesis section

Low biuret concentration in final product

Low quantities of fluidization air needed in granulator

Lower investment cost due to smaller granulator, less fluidization air, smaller scrubbing unit and single stage evaporation unit

Low steam consumption in evaporation and granulation

Low electrical energy consumption due to low amount of air required

Figure 2-1 Schematic of UFT granulation process

2010-AFA-Paper.doc

Page 3


EXHAUST AIR

RECYCLE MATERIAL (Fines/Crushed)

UREA - SOLUTION ATOMIZATION AIR

GRANULES FLUIDIZATION AIR Figure 2-2 Schematic of the UFT granulator

Figure 2-2 shows a simplified drawing of the granulator which is the core of the UFT process. The urea melt is injected through proprietary two phase nozzles into the fluidized bed. The urea solution nozzles are located in the fluid bed and require low pressure atomization air. Ambient air is used as fluidizing gas for the granulator. Atomization air and fluidization air are extracted from the top of the granulator, together with some entrained dust, washed in wet scrubbers and discharged to a stack.

Figure 2-3 Fluidized Bed

2010-AFA-Paper.doc

Page 4


3 The start-up of a new plant A plant which has been built has to undergo a series of steps before it can be taken into operation. These are Phase 1 - Erection Phase 2 - Mechanical completion Phase 3 - Pre-commissioning Phase 4 - Commissioning Phase 5 - Start-up and testing Phase 6 - Production Ideally each phase should be completed before the next stage is begun. In reality this is seldom the case. Due to today's short schedules and inadvertent delays there is usually some overlap between the various phases. These overlaps, with conflicting interests, pose a high potential for hazardous and potentially dangerous situations. The final phases of the construction process, when many different activities are ongoing, require the co-operation of people with very different working styles and goals. Therefore in order to minimize the risk to people, equipment and plant a close coordination between the various parties and a permanent awareness of the activities of the different groups and any resulting hazards is essential. Typical Hazards during the final phases :  not all plant sections are completed  some erection work, usually not process related, is still on-going e.g. cladding, insulation  safety devices and alarms are not tested  escape routes are blocked e.g. scaffolding, missing grating  DCS and ESD systems are not fully operational  Instrumentation is not installed or not calibrated  operating team is still unfamiliar with the plant Most important of all : the step from erection to start-up conditions implies a significant change in the work culture on site. Erection work and construction personal, while working in potentially hazardous situations, tend not to view an partially operating plant as hazardous. In addition they now are faced with additional constraints on when and where they can work. This can lead to conflicts and serious accidents. The following are only a few of the potentially hazardous situations the author has experienced during various start-ups :  construction workers, who are not aware that piping is pressurized, start dismantling flanges.  welding on 'live' systems or near electronic equipment  blocked access to control valves or machinery e.g. by housekeeping 2010-AFA-Paper.doc

Page 5


 DCS programmers disable safety systems in order to modify or tune "their" system  instrumentation adjust or modify instruments which are in already operating systems  operators who are unfamiliar with the new plant operate it according to wrong parameters  operators are not aware of changes that were made since their last shift  damage to equipment due to sudden process fluctuations and instability

4 Recommendations for a successful start-up It is absolutely essential that there is an interdisciplinary awareness of the plant activities. No discipline can consider the plant as their own. All activities must be coordinated between all parties. Therefore an efficient chain of communication must be set up and implemented. Don't    

compromise between safety, product quality and plant availability rush safety related issues reduce manpower below acceptable levels reduce manpower at the cost of expertise (particularly relevant to vendor specialists)  forget to update the documentation an procedures  forget to coordinate all activities with all involved parties.

Do  give people time to adjust to the new situation  provide time for training  ensure that everybody is aware of what is going to happen next, this includes contractors, welders, operators, painters, insulators, housekeeping, etc.  install a rigorous work permitting system  a safety review before carrying out plant modifications  set up a safety team to monitor the work activities and to enforce safe procedures

2010-AFA-Paper.doc

Page 6


5 Systematic approach to Plant commissioning Before a new plant can be operated the following steps must be undertaken 5.1

Mechanical completion check 1. Has the plant been erected according to the design ? This requires checking the piping and instrumentation according to PIDs and Isometrics. 2. Has the equipment and the machinery been installed correctly and is it complete ?

5.2

Pressure testing All piping and equipment that operates under pressure must be pressure tested. Similarly all equipment and piping that operates below atmospheric pressure must be vacuum tested. These activities usually requires that the items tested are isolated from the remainder of the plant

5.3

Pre commissioning Includes all work necessary before chemicals can be introduced into the plant and includes flushing and cleaning of all piping, apparatus and equipment. Normally there should be no more access into or work done on parts of the plant which have been pre-commissioned.

5.4

Commissioning The last step before the plant goes into operation. It normally includes the 'water run' and / or dry run. During this time equipment is tested and adjusted to meet the later operating requirements. After the commissioning is completed the plant is ready for start-up. This is the first time the plant is operated as a whole.

5.5

Start-up This is one of the most critical phases as chemicals are introduced and the plant is brought to operating conditions for the first time. It is a phase which requires many rapid decisions and sometimes adjustments or repairs to system under operating conditions. It requires significant manpower with an excellent knowledge of the process. It is also the phase when product appears for the first time. Usually it is not onspec and provisions must be found to store it separately in order to reprocess it later. Also wastes (e.g. lube oil) must be collected and processed properly.

2010-AFA-Paper.doc

Page 7


To co-ordinate and complete all these activities it is essential to break down the plant into separate systems. As far as possible these systems should be independent of each other. For each system a detailed procedure for checking, pressure testing, flushing and commissioning must be developed. These procedures must be reviewed on a daily basis and adapted to the current situation of the plant. They can be particularly useful for planning the next steps of the erection in order to obtain complete systems. Typical commissioning systems in a granulation plant are :  urea melt feed to granulator  urea recycle to evaporation unit  urea formaldehyde dosing and storage  solid handling  fluidization air system  atomization air system  cooler air systems  scrubbers

Figure 5-1 Typical commissioning system with activities

2010-AFA-Paper.doc

Page 8


6 Developing a commissioning system 1. Check of mechanical completion. Prepare checklists for each equipment, machinery and instrumentation. 2. Prepare marked-up PID for the system. 3. Develop a stepwise work procedure. 4. Check for possible hazards for people working on this system, to other systems or other erection work on-going in the effected plant area (e.g. steam blowing). 5. Check how to block in or isolate the system (e.g. blind flanges). 6. Check on how to flush (e.g. which instruments and control valves must be removed). 7. Check that all removed items are reinstated and that finished system is tight. 8. Check that all blind flanges are removed. 9. Check what other activities are influenced by or will influence this system.

Figure 6-1 Commissioning System with a marked-up PID

2010-AFA-Paper.doc

Page 9


7 Procedure for modifications In each plant there will be some piping, instrumentation or equipment which needs to be modified in order to achieve performance values. In the final stages of the project there is the tendency to apply 'quick fixes'. This tendency is both, dangerous and counter productive. When the plant is in operation, under pressure and or high temperature and the equipment and piping are full of product and intermediates any mechanical work on these systems must be done with great care and planning. Similarly all interlocks and alarms are activated. It must be ensured that, in particularly, electrical work does not result in a false alarm which could initiate a trip sequence that could shut – down the plant. Therefore it is essential to implement a procedure for modifications. This should include:  a safety review  a HAZOP review for major changes to operations  detailed information of the operators and shift supervisors, not only about what will change but also how to operate the plant during the modifications.  a review of influences on the rest of the complex  an inspection system to ensure that the work is completed successfully and the modified system can be put back into operation.

8 Actual sequence during MOPCO start-up Just before the completion of the MOPCO complex there was a delay due to the gas supply pipeline which was not ready in time. This unfortunate development gave the commissioning and start-up team the chance to fully develop and implement procedures as described above. In addition the plant operators had an opportunity to test and train on the almost completed plant. Therefore the conditions before start-up of the plant were almost ideal. The result of this period of checking, adjusting and training the actual start-up of the complex was without any major problem and the plants were running at almost full capacity within a very short time span. Actually, the bottleneck was the logistics of final product which could not be transported to the harbor. This can be seen in Figure 8-1 which shows the production capacity from first start up in August 2008 until the end of the performance tests in November 2008.

2010-AFA-Paper.doc

Page 10


Figure 8-1 Urea Production from start-up

MOPCO

Guarantees

Prills

> 46.2

46.3

Total Nitrogen

% wt.

46.25 – 46.32

Biuret content

% wt.

0.84 – 0.88

Formaldehyde

% wt.

0.45 – 0.47

< 0.55

0 – 0.25

0.25 -.0.28

< 0.3

0.3

>3

1.0

Moisture Crushing strength Size distribution 2 – 4 mm 2 – 4.5 mm

kg

4.6 -.4.9 on Ø 3.15 mm

% wt.

93 – 96

% wt.

97 – 99

0.9 – 1.0

> 90

Figure 8-2 Actual production data from MOPCO (2010)

2010-AFA-Paper.doc

Page 11


Even today after almost two years of continuous operation the plant is running very well and easily exceeds the guaranteed figures. This is demonstrated by the data given in Figure 8-2 . This data was presented to UFT by MOPCO in May of 2010. It was also reported that the plant is running for 45 to 55 days before it is necessary to wash the granulator. The capacity of the plant on average is 110% of the nameplate capacity of 1925 mtpd.

9 Conclusions Careful planning and attention to details during the commissioning and start-up of a new plant are essential to prevent hazards to personal and equipment. The additional time required for this systematic approach is easily compensated by a smooth startup and subsequent stable operation. Eliminating unplanned shut downs due to defects in equipment or instrumentation minimize the possibility of damage to the plant, which leads to extended run times during later operation. By careful analysis of hazards, potentially dangerous situations for all personal working on the plant during this time can be largely eliminated. No lost time accidents were reported during this time period at MOPCO. The planning and co-ordination efforts for the start-up were crowned by the exceptionally short and successful start-up of the MOPCO plant in Damietta, Egypt. This is a compliment to the professionalism of the operating, construction and commissioning teams of all companies involved in that project.

2010-AFA-Paper.doc

Page 12


10 Information about Uhde Fertiliser Technology Uhde Fertilizer Technology (UFT) is a licensing company for urea fluid bed granulation technology. Purpose of the company is to provide licenses for UFT fluid bed granulation technology together with a process design package, supply proprietary equipment and commissioning assistance to new clients as well as consultation services, technical assistance and revamp packages to existing clients. Uhde Fertilizer Technology looks back on more than 25 years of experience in licensing urea fluid bed granulation technology. Based on the feed back received from more than 50 plants being in operation all over the world UFT will continue its research and development efforts to maintain its position as world market leader for urea fluid bed granulation technology. Current developments at UFT focus on reduction of energy consumption, reduced emissions and product quality. Attached is a world map showing the location of operating plant using UFT technology and an excerpt from our reference list.

Others

> 80% UFT Market share in operating capacity

2010-AFA-Paper.doc

Page 13


Date of Order 2010 2009

Client

Location

Turkmenhimiya Mary, Turkmenistan Ruwais Fertilizer Abu Dhabi, U.A.E. Industries, Fertil II 2009 Qatar Fertilizer Mesaieed, Qatar Company (QAFCO VI) 2009 CFI Peru San Juan de Marcona, Peru 2009 Hengam Assaluyeh, Iran Petrochemicals 2008 Algeria Oman Fertilizer Arzew, Algeria Project (AOFP) 2008 Qatar Fertilizer Mesaieed, Qatar Company (QAFCO V) 2007 Sorfert Arzew, Algeria 2006 Ruwais Fertilizer Abu Dhabi, U.A.E. Industries, Fertil I 2005 Misr Oil Processing Damietta, Egypt Company (MOPCO) 2003 Saudi Arabian Fertilizer Al Jubail, Saudi Co. (Safco IV) Arabia 2001 Qatar Fertilizer Co. Mesaieed, Qatar (Qafco IV) 2001/04 PIDMCO AYU I + II Assaluyeh, Iran

2010-AFA-Paper.doc

Capacity (MTPD) 1,925 3,500

Status Engineering Engineering

3,850

Engineering

3,850

Engineering

3,250

Engineering

2 x 3,850

Erection

3,850

Erection

3,450 2,500

Erection Running

2,000

Running

3,600

Running

3,500

Running

2 x 3,250

Running

Page 14


Turn static files into dynamic content formats.

Create a flipbook
Issuu converts static files into: digital portfolios, online yearbooks, online catalogs, digital photo albums and more. Sign up and create your flipbook.