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Gamba I.L.,CONICET | Damian S.M.,CONICET | Estenoz D.A.,CONICET | Nigro N.,CONICET | And 2 more authors.
International Journal of Chemical Reactor Engineering | Year: 2012

The continuous operation of a stirred tank reactor for styrene polymerization was modeled. The proposed approach consists of an iterative procedure between two modules that considers the fluid-dynamics and kinetics respectively. The kinetic module considers a complex kinetic mechanism and is used to predict the time evolution of global variables, such as conversion and species concentrations, physicochemical properties and molecular structure characteristics of the final product. In order to obtain a 3D representation of the flow field, the simulation of the hydrodynamics of the reactor was carried out with the aid of a commercial computational fluid dynamics (CFD) software package. Because CFD is capable to predict the complete velocity distribution in a tank, it provided a good alternative to carry out residence time distribution (RTD) studies. It was found that the stimulus-response tracer method is reasonably accurate to obtain a complete RTD compared to the particle tracking method. The obtained RTD results showed a good agreement when validated with experimental data and literature information. From the estimates of the kinetic module and the RTD predictions, a statistical calculus allows the determination of the average properties at the reactor outlet. The convergence of the iterative procedure was tested and reasonable predictions were achieved for an industrial reactor. Copyright © 2012 De Gruyter. All rights reserved. Source


Prades F.,University Claude Bernard Lyon 1 | Broyer J.-P.,University Claude Bernard Lyon 1 | Belaid I.,University Claude Bernard Lyon 1 | Boyron O.,University Claude Bernard Lyon 1 | And 3 more authors.
ACS Catalysis | Year: 2013

Fluorinated activating supports (AS) for metallocene complexes were prepared via treatment of silica with AlEt3 or AlEt2F followed by pyrolysis and combustion steps, and a subsequent fluorination step when AlEt3 was used. This new family of activators appears to be universal for metallocene complexes leading to catalysts displaying high activities in ethylene polymerization without the addition of MAO. A productivity of 3200 g gAS -1 was obtained in 1 h with the catalyst rac-Et(Ind)2ZrCl2/AS8/Al(iBu) 3 at 80 C under 10 bar of ethylene. An isotactic polypropylene with a melting transition at 145 C was prepared using rac-Me2Si(2-Me- benz(e)Ind)2ZrCl2 activated by AS9 and Al(iBu) 3. The spherical particle morphology of polyolefins was particularly adapted to slurry processes employed in industry. © 2013 American Chemical Society. Source


Stark C.,TOTAL Petrochemicals
American Fuel and Petrochemical Manufacturers, AFPM - Environmental Conference 2012 | Year: 2012

The rate of change in environmental regulations has never been greater. In addition to the rate of change (and increasing complexity), the amount of continuous and periodic monitoring requirements is also on the rise. As a result, monitoring daily environmental compliance in a large petrochemical facility is an on-going challenge. The process data historian can provide an invaluable source of emissions data for routine emissions calculations, recordkeeping, and reporting. However, modifying data in the process data historian and documenting the justification for the changes is often impractical. Calculating upset emissions using the process data historian can be challenging as the data may become invalid during upset events as monitoring equipment experiences failures or out of range conditions. This paper demonstrates how the process data historian, when supplemented with readily available commercial technologies, can be utilized to provide near real time monitoring of compliance limits. Using traditional web based software technology with direct links to the process data historian combines the best features of both systems and provides a low cost alternative to complex commercial environmental compliance systems or labor intensive desktop tools. This approach can be used to satisfy emissions calculations, reporting and recordkeeping requirements to include Continuous Emissions Monitoring Systems (CEMS), Maintenance Startup and Shutdown (MSS), Green House Gases (GHG), Annual Emission Inventory (AEI) and Upset Emissions. Source


Haubruge H.,TOTAL Petrochemicals
29th International No-Dig Conference and Exhibition 2011, NO-DIG BERLIN 2011 | Year: 2011

Polyethylene pipes are particularly suited to non-conventional pipe installation thanks to their flexibility, deformability, and availability in long lengths. However, the widespread use of modern relining techniques or fast and non-disturbing pipe installation practices call for guaranties of performance, particularly regarding the effect of scratches, notches and impingements that are inherent to those techniques. The paper details how confidence has been gained in Germany as a result of a comprehensive testing protocol over the last 15 years. The milestones that have led to the definition of PE 100-RC materials and pipes, which represent today about 20 % of the German PE pipe market, are illustrated by key test results. The logic followed to translate this experience into a standard PAS 1075 and technical requirements is explained, focusing on the guarantied safety margin. The German experience demonstrates clearly how standardisation is essential to spread confidence among involved parties. Efforts should now be devoted to diffuse this experience into European and International standards dealing with pipe rehabilitation and trenchless technologies. This way, the safety offered by PE 100-RC will permit PE to further grow together with non-conventional installation techniques, to the benefit of all parties. Source


Van Wingerden K.,GexCon AS | Middha P.,GexCon AS | Hoorelbeke P.,TOTAL Petrochemicals
Chemical Engineering Transactions | Year: 2013

The consequences of vapour cloud explosions can be devastating causing numerous fatalities and destruction of large parts of industrial facilities. Recently a technique was suggested to mitigate vapour cloud explosions using flame inhibitors. Flame inhibitors would be injected into the vapour cloud upon gas detection. In case of ignition of the vapour cloud the flame inhibitors assure a considerable reduction of the combustion rates thus also reducing the pressures and drag loads generated by vapour cloud explosions. Experimental results confirm the feasibility of the principle of using flame inhibitors for mitigation of vapour cloud explosions. To design systems for deployment of flame inhibitor clouds in a congested petrochemical facility assuring a considerable reduction of the explosion loads due to vapour cloud explosions it was suggested to use the dedicated CFD-model FLACS. To allow for this the combustion model was extended allowing for describing the effect of flame inhibitors on combustion and a model describing particle laden flow was implemented. The present paper presents the development of the extended combustion model and other models to represent the influence of flame inhibitors on combustion and particle laden flow, and its validation. © 2013, AIDIC Servizi S.r.l. Source

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