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ent requirements, but also high standards in respect of its physical properties. This paper will focus on the causes of caking, like formation of crystal bridges serving as contact points between particles and formation of capillary adhesion forming adhesive contacts. Other subjects that will be discussed are: approaches to cake prevention, the action of anti-caking agents, and the methods of applying them. Finally, a new method of rendering prilled urea cake-resistant, based on coating with a novel, high-quality Stamicarbon coating agent named ADVANCE COAT™ Prill Strength, will be introduced. 

ss caking, consolidation strength)

ctions of the reactor CNO (Carseland Nitrogen Operations) believed that there was only 3mm of original material protecting the carbon steel shell. At the end of 1995 Carseland ordered new liner material for the top dome and the cylindrical section approximately 1 m below the head. Carseland consulted Stamicarbon and potential suppliers of liner material and installation expertise. Carseland decided that for reasons of cost and time it was best placing a new liner overtop of the existing liner in the dome.

on or prilling, it needs to be  If the heater is mechanically damaged (leaking tube heat exchanger) also product can contaminate the steam/condensate system and cause corrosion in the carbon steel lines and equipment.

ise and strength of Stamicarbon technology. 

ondition o Comply with safety and (new) environmental regulations

tem (CCW). The HP Scrubber is equipped with 316 L UG heat exchanger tubes (BC.01 according Stamicarbon Specification A4- 18005). The presence of ammonia in the CCW indicated a leak from tube side (process side) to the shell side (cooling water side). In contrary to the frequent cases of chloride stress corrosion cracks (Cl- SCC) observed in HP Carbamate Condensers, Cl- SCC cracks are seldom observed in HP Scrubbers. The integrity of the said HP Scrubber was compromised, since it was not possible to pinpoint and repair the leak. It was decided by plant management to replace the HP Scrubber as soon as possible. Schoeller Bleckmann Nitec (SBN) in Austria was awarded the contract to supply a new HP Scrubber with a delivery time of only 8 months. Normally a delivery time of 10 to 12 months is anticipated. In order to meet this very short delivery time, SBN and Stamicarbon teamed-up to speed up the engineering and fabrication work. HP Scrubber was transported from Austria to the Middle East by airfreight. In this contribution the difficulty to locate a small leak is described as well as the key issues to manufacture the new HP Scrubber within such short delivery time. 

duction. At the same time, we must expect that society will focus even more on safety and environmental issues associated with fertilizers, such as Health and safety risks from working in fertilizer plants Major accident risks, to avoid disasters like the explosion in Toulouse Terrorist acts, using fertilizers for bomb-making Pollution risks from the manufacturing processes and from the use of fertilizers Climate change and the role of fertilizers and agriculture Use of limited energy and mineral resources, such as phosphates The public perception of Good Citizenship has changed over the years. Today, many people look upon the chemical industry as a burden to future sustainability. This perception will deepen if the industry has a poor safety and environmental performance. It is vital to perform well and to eliminate bad practices. Otherwise we must expect that much stricter regulations will be enforced upon the industry. In this paper I will focus on the 3 first bullet points above, those that are related to safety and product stewardship, with some practical advice on actions the industry should take in order to be in command and avoiding over-regulation. 

role in realizing this vision. Stamicarbon fully …

long to the so-called accident plants. For these plants it is required that the security is improved constantly. The management wants to constantly improve the environmental-protection andupgrading the technological conditions to increase the production and to save energy.

g Bangladesh. It is the first Stamicarbon urea CO2 stripping plant featuring the pool condenser technology, see [1]. In the Kafco-Bangladesh plant, the interconnection between the pool condenser and the reactor is provided by two high pressure (HP) pipelines, a 10” inch liquid and a 10” inch gas line. The plant is commissioned in 1994. After commissioning, operating experience learned that the gas line from the pool condenser to the reactor was sometimes filled with a stagnant liquid level; especially in case of a start-up from a “blocked-in condition“. This resulted in problems with the synthesis hydraulics and limited the maximum plant load to 115%. This problem was mostly overcome after draining of the synthesis loop but causing some environmental problems as well. For a permanent solution to this problem a modification of the HP gas line was implemented during the planned turnaround in 2010.The modification improved the hydraulics of the urea synthesis loop; eliminated gas flow restriction after a “block-in situation” and resulted in an increase of production up to 121% of the design capacity. The 1725 MTPD plant is now able to produce 2100 MTPD.

stagnant process liquid was driven off by generation of heat in the R-101.  The heat was generated when CO2 leaked into the synthesis loop through a passing isolation valve, and the CO2 reacted to form carbamate.  The carbamate reaction generated the heat.  The de-oxygenated process liquid then destabilized the passivation layer and stripped it away, leaving the unprotected stainless steel liner exposed to the highly corrosive carbamate following the 3rd startup. The pinhole and pits were repaired, and the Plant resumed production on July 28th.

nbsp;ammonium sulfate. Given the flexibility of this process, it can well be used to also produce  granulated Urea containing other nutrients. This paper gives the background and highlights the  technology, the design and the current status of the process.

red with the corrosion behavior of the traditionally used fully austenitic stainless steels (316L UG [BC.01] and X2CrNiMoN 25-22-2 [BC.05]). 

out of the exhaust of diesel cars. Diesel trucks but also already private cars are obliged to use DEF in Europe and the US, more continents will follow. The price of DEF at the moment almost doubles the price of urea fertilizer. All urea producers are looking for opportunities to become part of the DEF family. The DEF specification is described by ISO 22241 and DIN V70070 and limits amongst others the amounts of Biuret (< 0.3 wt%), NH3 (< 0.2 wt%) and Formaldehyde (< 5 ppm). DEF is produced by urea producers as a 32.5 wt% - or a 50 wt% aqueous urea solution or as solid product depending on the distance between the producers and the consumers. Urea granules are abandoned as DEF due to its formaldehyde content. Urea prills are sold in China as premium if the biuret content is maintained lower than 0.9 wt% because in that case they can be used for DEF.  Plants with a granulation finishing section which produce DEF from urea solution have difficulties to keep the biuret concentration low enough in their granules due to the increased residence time in the evaporation stage. These challenges are leading to the increased worldwide interest in biuret.

the report. Conclusions and recommendations based on key learning’s are given.