Azf Toulouse Plant

ACKNOWLEDGEMENT

We would like to acknowledge and thank our lecturer Ir. Ben Lee See Kim for giving us this opportunity to conduct and complete this case study based on our chosen title AZF Toulouse explosion. He had also indirectly helped us in many ways by giving hint on which part to be considered for the case study and what type of resources we could have used for the final report. Once again would like to thank him for approved the assignment title which we foremost interested to analyse our case study based AZF Toulouse explosion. At the same time, appreciation for the teamwork by each members should be considered too since it was major contribution towards our case study success.  Each member has contributed greatly to this project and everyone does their job well which has increases the capability of what the team can accomplish. This teamwork has to be recognised by everyone and know that great things can happen due to members work together as one unit with full cooperation. The research conducted for this assignment was also successfully done with all the help from the different parties.

SUMMARY

INTRODUCTION

The engineering profession in which knowledge of the mathematical and natural sciences gained by study, experience, and practice is applied with judgment to develop ways to utilize, economically, the materials and forces of nature for the benefit of mankind. An engineer applies knowledge of math and the physical sciences to the efficient design and construction of usable devices, structures and processes. Thus engineering design is one of the main aspects of engineering.

Due to use of engineering in science and technology and the development of the society, there is a high demand in creating new technologies and infrastructure. The role of the engineer in this circumstance is to respond to the need by building or creating something along a certain set of guidelines or specification which performs the given function. Just as importantly, that device, plan or creation should perform its function without fail. Everything, however, is bound to fail perform its given function after surpassing a certain threshold. Hence, the engineer must struggle to design in such a way as to avoid failure, and, more importantly, catastrophic failure which could result in loss of property, damage to the environment of the user of that technology, and possibly injury or loss of life. However, through the various shortcuts done in engineering design to reduce costs of construction and fabrication, failure is bound to occur. Through analysis and study of engineering disasters, modern engineering designers can learn what not to do and how to create designs with less of a chance of failure.

In the 20th century, an industrial zone developed around the AZF plant. A large plant was in the East of it, on an island separated from AZF by a narrow, shallow, rather stagnant arm of the river. This plant belonged to the Societe Nationale de Poudres et Explosifs (SNPE), a state-owned company, part of the French Department of Defence, now sold to a private company. It manufactures rocket fuels and a few important reagents, including phosgene, sold to the nearby Tolochimie plant, South of AZF, which uses it as an intermediate in complex organic chemistry syntheses. A municipal cogeneration plant, burning garbage and selling electricity to the French grid managed by Electricite de France (EDF) is 1.5 mile away. A few minor plants, a large busy centre, a major transformer and control centre of the EDF grid and a small commercial centre grew in the North-West corner of the plant. This group, locally known as the “Chemical Pole”, is separated from the city by a sort of high levy over which were built a local road.

The AZF Toulouse plant used to make ammonia after the Haber process and to oxidize part of it into nitric acid. The required hydrogen is made by controlled oxidation of methane into carbon monoxide and carefully purified. Ammonium nitrate is made by neutralization of nitric acid with ammonia, using the heat of neutralization to vaporize part of the water. Most of the serious problems encountered in the Ammonium nitrate industry arise from its hygro scopicity. In humid atmosphere, ammonium nitrate captures water from the air; the particles get covered by a thin layer of saturated water solution. In dry air, water vaporizes and leaves a multitude of fine crystals between close particles, progressively welding them. Because ammonium nitrate is used as a fertilizer by spreading large amounts of the particles over wide fields, this caking effect must be controlled; otherwise much time would be lost in breaking down the cakes formed. Because production of ammonium nitrate is continuous while its sale is seasonal, large storages of the fertilizer exist everywhere. Large heaps of solidified ammonium nitrate used to be broken by explosives, which lead to a few major accidents. 

At 10.17 am on 21 September 2001, a severe explosion (detonation) occurred in shed 221. The detonation, felt several kilometres away, corresponded to a magnitude of 3.4 on the Richter scale. Significant dust fallout from the installations and a crater were observed outside the plant. A large cloud of dust from the detonation and red smoke drifted to the north-west. The appearance of the smoke is linked to the emergency shutdown of the nitric acid manufacturing installation. Before rapidly dissipating, the cloud containing ammonia and nitrogen oxides sickened witnesses who complained of eye and throat irritations. The atmospheric pollutants released after the detonation lead to the formation of nitric acid (HNO3), ammonia (NH3), nitrogen dioxide (NO2) and nitrous oxide (N2O) from ammonium nitrate. As a precautionary measure, the local governmental authority (“Prefecture”) requested that the population of Toulouse confine themselves to their homes. This measure, the efficiency of which was limited owing to the damage to numerous homes, nevertheless reduced the number of traffic problems after the accident.

The concept of failure is crucial to understanding engineering as engineering design has as its first and foremost objective the anticipate failure. Thus, colossal or enormous disasters that do occur are ultimately failures of design. However the lessons learned from those disasters can do more and contributed greatly to advance knowledge of engineering. It has much more contribution than all the successful machines and structures in the world.  Indeed, failures appear to be inevitable during the prolonged period success. Failure, in turn lead to greater safety margins and, hence leads to new successes.  

Therefore, the various failures of engineering design has occurred in the many different fields of engineering which has cause massive disasters in the history of engineering. The engineering disaster that is studied in this report is the AZF Toulouse disaster.

METHODOLOGY

The method used on to analyse AZF Toulouse explosion which occurred on September 2001 where most data was obtained from journal. This method included obtaining information about the disaster based on research papers and journal articles done by experts throughout the years since the occurrence of the event. Many of these journals were obtained through online journal archive websites which had a large collection of the journals in them. The journal provides a comprehensive study and allows a better research based on the experts take on the disaster. The journal articles and research papers also allow more information and more analysis on the disaster able to be studied for the use of this report.

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