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weld overlays) are in passive state

actices’ give guidelines about the necessity and sizing of emergency relief systems, aiming at protection of the plant under emergency conditions. Traditionally, disposal of the ammonia containing gases from such emergency relief systems (safety valves or rupture discs) from urea plants has been done as direct discharge into the atmosphere. Recently a study was conducted by Stamicarbon to see whether this practice is acceptable from a safety point of view, taking into account progressing insight gained in the subject of emergency relief in recent years.

ase and thus the efficiency of the reactor will go down. However, by changing the internals of the reactor (using a different type of trays) the efficiency in the reactor can be improved. In the past two types of trays were used in Stamicarbon Urea plants: the conventional trays and the high efficiency trays. Now a new type of trays is introduced, which improves the efficiency of the reactor and thus results in savings of the high-pressure steam consumption. These trays are called the Siphon Jet Pumps. The first trays have successfully been installed in SKW Piesteritz. In this paper the Siphon Jet Pumps are introduced and several aspects around these trays are discussed.

ia inside the process equipment is essential from a safety,environmental andeconomica lpoint of view

ay the equipment is constructed  eliminates most of the measuring principles available. Radio-active level measurements are common practice in urea synthesis equipment, but there is a tendency in the market to eliminate radio-active level measurements in Urea plants, due to several reasons (maintainability, public aversion against radio-activity, legislation, etc). During the symposium of 2008 the radar level measurement was introduced as an alternative for radio-active level measurements in the Urea synthesis equipment, based on experience of a few radar measurements in operation at that moment. Currently, 4 years ahead, radar technology became Stamicarbon’s standard for level measurement applications in the urea synthesis. This document gives an update on our latest developments, experiences and requirements, which results in a reliable radar level measurement in Urea synthesis equipment.

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.

n the system is checked by opening atmospheric valves and breaking the vacuum on a defined frequency of one month. We could not check the blockage on this defined frequency, we performed a blockage test after a period of 10 months; blockage was found in valves V-16 & V-17 in the leak detection system of the HP Stripper. After further investigation it revealed that the blockage in the leak detection system was inside the stripper top dome. We tried to de-block the system with instrument air having a pressure of 7 bar and with low pressure steam but this failed. Then on the running plant we tried to de-block using an argon cylinder having a pressure of 100 bar and de-blocked the lines at 30 bar. The root cause of the blockage was corrosion inside the leak detection tube due to moisture ingress through the atmospheric valves. The equipment condition was found healthy on inspection during a turnaround.

. The Urea Synthesis section had a nameplate capacity of 908 tonnes per day, while the urea granulation section consists of two trains (North and South), each with a nameplate capacity of 544 tonnes per day. These two trains are independent of each other. Over the last 20 years, the Fort urea plant has been operated at rates up to 1250 tonnes per day while producing good quality granular product. Well over 6 million tonnes of urea have been produced. It was decided to convert the Fort Saskatchewan granulation trains to Stamicarbon technology. The conversion project was completed in three months1 and the granulation plant was restarted on September 30, 2003. This paper presents a summary of the project, the changes completed, the operating results, potential savings in operating costs, and the product characteristics associated with the conversion.

d upon natural gas produce a ratio of 1.3 to 1.5 carbon dioxide to ammonia of which about 18% is in the form of flue-gas. •Ammonia plants based upon coal gasification produce a ratio of 2.7 to 2.8 ton per ton of ammonia

gas (GHG) emissions is estimated to be less than 1%, great efforts have been made to understand what the main sources are and in what proportion, so that appropriate mitigation measures can be taken. As for any other chemical, GHG emissions attributable to urea are associated with its life cycle, from the extraction of raw materials to its application and disposal. Since ammonia and carbon dioxide are the raw materials for producing urea, the impact of an ammonia plant is an important consideration when assessing the carbon footprint of urea. This paper focuses on carbon dioxide and nitrous oxide emissions related to ammonia and urea production, and discusses available measures to reduce direct and indirect emissions. Some urea applications such as urea deep placement (UDP) and diesel exhaust fluid (DEF) are also briefly discussed, to illustrate the potential of urea applications to reduce GHG emissions.

o the atmosphere can environmentally wise be benchmarked against the alternatives of incineration, heating and combustion technologies. The paper explains Stamicarbon’s objections regarding the use of flare systems as environmental mitigation strategy in the urea melt plant and clarifies the most environmental and economical sensible solution available in Stamicarbon’s technology portfolio: the thermal treatment and catalytic DeNOX. An example case of a world scale urea plant is used for quantification and the outcome of the paper reveals Stamicarbon’s bridge that connects today to tomorrow.

their absence, the current WHO Air Quality Guidelines or comparable guidelines set by other internationally recognized bodies. So there are no globally-applicable emission limits; they differ region by region according to standards set by the local authorities. For the licensor this means that every new project, whether grassroots or revamp, needs a tailor-made approach in close co-operation with the engineering contractor, owner of the facility and local authorities. 

a emission reduction in the urea finishing section • Key take-aways  

or transporting their product, plant owners are low.

ily meet the emission levels prescribed by law. Because it recovers waste water for re-use and produces ammonium salts that can be processed and sold, this technology is environmentally friendly in comparison with other cleaning methods that can produce additional emissions (for example, NOx and CO2 in the case of flaring). It has a CAPEX advantage because it requires less infrastructure investment than do other technologies. It requires neither the catalyst needed in SCR (selective catalytic reduction) nor the high operating temperatures and costly construction materials associated with incineration. Last but not least, wet scrubbing is simple to operate and it does not entail the extra safety precautions needed with, for example, flaring.

ine for this discussion by focusing on three key questions: Which acid should preferably be used? Which outlet for the resulting ammonium salt is preferred? Should the dust and NH3 scrubbing be combined in one scrubber?  

and the 1st stage evaporator heater, the steam consumption can be lowered considerably. For instance, for a urea melt plant with prilling as finishing technique, the turbine extraction steam consumption can be lowered from 868 kgsteam/tonproduct to 558 kgsteam/tonproduct. The design challenges for the critical equipment in this low energy concept with respect to corrosion and sizing have been addressed and solved.

d by Stamicarbon and IPCOS combines the benefits from MPC and Nonlinear optimization of Urea plants into one solution.

rojects: Reference projects (Conventional)