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ACCIDENT AT FERTIBERIA, S.A. IN THE ESCOMBRERAS VALLEY Self-sustaining decomposition of NPK 15-15-15 fertiliser 26 to 30 January 2002. Accident Location. E scombreras Valley (Cartagena, R egi o n of Murcia). Murcia. Spain. Escombreras Valley. Industry in E scombreras V alley.
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ACCIDENT AT FERTIBERIA, S.A. IN THE ESCOMBRERAS VALLEY Self-sustaining decomposition of NPK 15-15-15 fertiliser 26 to 30 January 2002
Accident Location • Escombreras Valley (Cartagena, Region of Murcia) Murcia Spain Escombreras Valley
Fertiberia S.A. – the Company • Activity: Manufacture of fertilisers subject to the Directive 96(82) EC of the European Council, 9th December. • Subject also to corresponding Spanish regulations for storage and/or processing of the following substances: • Anhydrous ammonium 16.600 tons • Ammonium nitrate 1.800 tons • Solid ammonium nitrate 33,5% 10.000 tons • Fertiberia has presented the regional governement with documentation concerning: • Policy for the prevention of serious accidents • Security control systems • Risk evaluation • Internal Emergency plan
Product: Compound Fertiliser NPK 15-15-15 (I) • Materials in the compound • Anhydrous ammonium 21,60 Kg/Tm • Potassium chloride 252,50 “ “ • Monoammonium phosphate 276,10 “ “ • Liquid ammonium nitrate 299,70 “ “ • Clay 165,60 “ “ • Talc (superficialanti-agglomerant) 8,00 “ “ • Fuel oil (superficialanti-agglomerant) 3,00 “ “ • Granulometry: • > 5 mm 1,0 % • 5 a 2 mm 93,0 % • 2 a 1 mm 5,0 % • < 1 mm 1,0 % Maximum humidity 1,5 % Density 1,02 Kg/dm3
Product: Compound Fertiliser NPK 15-15-15 (II) • Specifications: • Total Nitrogen (N) 15,0 % • Nitric5,2 % • Ammoniacal 9,8 % • Total Phosphorus (P2O5) 15,0 % • Soluble in water and neutral ammonium citrate 15,0 % • Phosphorus soluble in water 13,5 % • Total Potassium (K 2O) 15,0 %
Product: Compound Fertiliser NPK 15-15-15 (III) • Not classified as a dangerous product. • Not affected by regulations concerning serious accidents. • Not included in regulations concerning Transportation of Dangerous Goods (IMDG, ADR, RID). • Not included in current legislation on labelling and use of dangerous substances. • Classified as TYPE C (ONU 2071) by IFA, not subject to Self-Sustaining Decomposition in the trough test. • Not included by Fertiberia in its risk evaluation.
Storage conditions • Stored in an old silo that until 1995 had been used for ammonium sulphate storage. Reinforced concrete structure and lateral enclosure, lightweight sheet roofing and compacted floor. • Dimensions: 130 x 33,5 metres. • The quantity in storage has varied since 15/12/00 with several additions and reductions of material. • At the onset of the accident, 15.365 tonnes of the product being stored. • The material occupied the entire width of the silo, and about 65% of its length, with free space at both ends. The height of the material was more than 8 metres at its highest point.
Storage conditions Cross section
Operative Structure CECOP DIRECTION COMMITTEE ADVISORY COMMITTEE INFORMATION GROUP OPERATIONS DIRECTOR CECOPAL ADVANCED CONTROL GROUP CHEMICAL SECURITY LOGISTICS AND SUPPORT HEALTH INTERVENTION PUBLIC ORDER
Chemical Security Group • Head of Industry Departament, Head of Environmental Quality Departament of the Regional Government • Head of Environmental Departament of Cartagena • Head of the Health Departament • Specialized technicians of the Regional Government (Civil Protection, Environment, Health) • Technicians of Fertiberia • Technicians of TIPS • Department of Chemical Engineering of the University of Murcia
Decomposition NPK 15-15-15 (I) • Conditions for decomposition: • Redox components (NH4 andNO3) • A catalyst (Cl, Mn, Co, Cu,…) • All components concentated in a narrow zone (e.g. granule) • A solid matrix (heat conveyor) • Sufficient heat generation, good thermal conductivity, low heat dissipation. • Compound fertilizer 15-15-15 provides the first three conditions.
Decomposition NPK 15-15-15 (II) • The solid matrix is a result of the conversion of • NH4NO3+KCl KNO3+NH4Cl • although the presence of insoluble phosphates or inert material could also contribute to the formation of this decisive solid matrix. • Given that the molar relationship NH4/NO3 is greater than 1,6 in this case, the predominant reaction is the one with the most exothermic characteristics: 5NH3+3HNO3 Chloride and acid 4N2+9H2O • This reaction is catalysed by chlorides or Cu, Cr, Co... • Intermediate substances: HCl, Cl2,NO, NO2, N2O,NH3 and NH4Cl • If the molar relationship NH4/NO3 had been less than 1,6, higher concentrations of Nox would have been measured.
Decomposition NPK 15-15-15 (III) • Analyses near to the silo confirm the presence of HCl, Cl2,NO andNH3 so that NH4NO3+NH4Cl was in fact present. • The major constituents of the cloud were nitrogen and water vapour (from the reaction and from the water used in extinction). The cloud would also probably contained nitrous oxide and ammonium chloride. References • KIISKI, H. (2000) Self-sustaining decomposition of NPK fertilisers containing ammonium nitrate. Proceeding Nº 450. The International Fertiliser Society. London • SHAH, KD y THOMPSON, D.C. (2000). Safe handling and storage of granulated and blended compound fertilizers containing ammonium nitrate. Nº 448. The International Fertiliser Society. London
Strategic Decisions (I) • The main objective was to protect the lives and health of those involved in the extinction, of the workers of Escombreras Valley, of citizens in general and to protect the environment. • Under the guidance of the group of experts forming the Chemical Security Group and facing the possibility of an increase in decompositon temperature to 300ºC, causing massive generation of nitrous gases, the following strategic decisions were made:
Strategic Decisions (II) • To order the halt in activity in Escombreras Valley and the Port of Escombreras, except for that strictly necessary to guarantee plant security. • 27/01/02 – production in the Valley is paralysed and all ships are ordered to leave port. • 28 /01/02 –plants further away from the accident are authorized to resume activity. • 29 /01/02 - all plants and the port are authorized to resume activity. • 30 /01/02 – extinguished. • To attack the fire by cooling with large quantities of water. • To alert and inform the population.
Problems and Solutions (I) • Difficulty in locating the focus of the decomposition. (Thermal vision camera) • Increase in mist produced by water from extinguishing the combustion, hindering access to the silo. • Need to cool the compound by pumping water using fire monitors from the exterior through holes opened in the roof, while the fertilizer was being dissolved in the water runoff. • In a second phase, the silo doors were blocked shut, damming the water and causing refrigeration and continuous dissolving of the compound.
Problems and Solutions (III) • To control certain components of the vapour cloud, near the silo and in population nucleii that could become affected by the cloud: • The Pollution Control and Detection Network was used to measure nitrous gases. • Periodic measurements of NOx, Cl2, NH3 and HCl by colorimetric tubes and manual aspiration pump were carried out near the silo and in Alumbres, Vista Alegre, Santa Lucía, and Roche. These components were not detected in any of these towns.
Detection stations ALUMBRES TORRECIEGA S. GINES LO CAMPANO BASTARRECHE CENTRO DE CONTROL (Ayuntamiento. de Cartagena) Silo de FERTIBERIA ESCOMBRERAS
Problems and Solutions (IV) • Avoidance of marine contamination by the water runoff. • Four reservoirs were quickly constructed to contain this runoff.
Problems and Solutions (V) • On the 29th when temperature measurements reached approximately 70ºC, part of the concrete wall of the silo was demolished to allow the entry of heavy machinery for the extraction of the compound. • At 17.30 h on the 30th, the end of the incident was announced.
Evolution of the cloud • Climatic conditions: Weak anticyclonic circulation at all levels of the atmosphere. Stable and dry conditions with strong temperature inversions at low levels (up to 1.000m.), which impede vertical air movement, guaranteeing stability and aiding the formation of fog and mist banks. Winds were generally weak throughout the period.
Information • Two press conferences daily by the Vicepresident of the Regional Government • Direct information to the press through the Press Office of the Regional Emergency Coordination Centre. • Direct telephone calls to citizens through the Vocal Response Unit of the same centre.
People Affected • Only 5 people were attended in accident and emergency units at Cartagena hospitals. • Of these, 4 complained of itchy eyes and throat and were discharged. • Only one person was hospitalised due to previous asthma problems.
Possible causes (I) • Atypical conditions at the start of the decomposition process: • One flank of the stored product was exposed between 20/11/2001 and 15/01/2002. • During this period, heavy rainfall in the area with possible water entry through roof. • Height of storage • Presence of animal excrement from pigeons within the silo. • Addition of new load of material on this flank on 15/01/2002.
Possible causes (II) • Chain reaction - self-sustaining decomposition • Initial increase in temperature: • Spark caused by motor • Arson • Exothermic reaction due to contact with decomposing organic material • Increase in Ammonium Nitrate or Potassium Chloride concentrations • Error in production process • Dissolution of the crystal and posterior recrystallization in Ammonium Nitrate or Potassium Chloride (for example due to water filtration).
P o t a s s i u m 1 0 0 C h l o r i d e S e l f - s u s t a i n i n g d e c o m p o s i t i o n A m m o n i u m A m m o n i u m P h o s p h a t e N i t r a t e 1 0 0 1 0 0 Possible causes (III) • Slight variation in concentrations of components due to manufacturing tolerances. • An increase in the quantity of Ammonium Nitrate and Potassium Chloride, together with a decrease in Ammoniun Phosphate, can make the compound susceptible to self-sustaining decomposition. Cigar Burning in Fertilizer Mixes Containig Ammonium Nitrate (J.SCI.Food AGR, June 1.965)
Possible causes (IV) • Formation of concentrations of catalysts that promote decomposition: • - Within the product since the production process. • - Catalysts would have been contained within the raw material. • Formation of a solid matrix of decomposition • - Possible because Clay and talc have a high fusion point, do not decompose, conduct heat, and bind products of decomposition and catalysts. • The heat produced is not dissipated – the height of the storage of the compound was much higher than that recommended.