Gas-liquid reactor in the synthesis of urea

Dente, Mario; Rovaglio, M.; Bozzano, Giulia; Sogaro, A.; Isimbaldi, A.

doi:10.1016/0009-2509(92)87079-6

Cited by 11 publications

(17 citation statements)

References 6 publications

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“…Data normalisation was performed using Equation as follows:

X = \frac{x - ((x_{\max} + x_{\min}) / 2)}{((x_{\max} - x_{\min}) / 2)}

where x max and x min are the highest and lowest values of variable x , respectively. The ANN model was trained using 125 experimental and/or commercial plant data taken from these references . The training dataset was selected randomly from the available urea synthesis data (85% of the whole data), covering a temperature range of 435–485 K, NH 3 /CO 2 range of 2.0–6.5 and H 2 O/CO 2 range of 0.1–1.4.…”

Section: Resultsmentioning

confidence: 99%

“…It is clear from Figures and , the outputs of the model simulated with ANN exhibit an acceptable agreement with the actual data of the urea reactor and also the experimental data available in the literature. The references for the data used in the ANN model include the following studies and/or documents …”

Section: Resultsmentioning

confidence: 99%

“…It is proved that the rates of reactions and are higher than those of reactions and . Therefore, it is assumed here that reactions and are at equilibrium conditions and equilibrium conversions can be considered for those reactions while reactions and do not reach the equilibrium state.…”

Section: Mathematical Modelling Of Urea Synthesis Reactormentioning

confidence: 99%

“…Urea or carbamide is an organic compound with the chemical formula (NH 2 ) 2 CO. The German chemist, Friedrich Wohler (1828), produced urea by reacting silver isocyanate with ammonium chloride . The synthesis of this organic material from an inorganic compound made a great impact on the development of organic chemistry.…”

Section: Introductionmentioning

confidence: 99%

“…The German chemist, Friedrich Wohler (1828), produced urea by reacting silver isocyanate with ammonium chloride. [5][6][7] The synthesis of this organic material from an inorganic compound made a great impact on the development of organic chemistry. The industrial production of urea is based on the reaction of ammonia (NH 3 ) and carbon dioxide (CO 2 ) at high pressure and temperature to form ammonium carbamate, which is consecutively dehydrated into urea and water.…”

Section: Introductionmentioning

confidence: 99%

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A dual approach for modelling and optimisation of industrial urea reactor: Smart technique and grey box model

et al. 2013

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Urea has the highest demand among all solid nitrogenous fertilisers within the agriculture industry. In this paper, a mathematical model and an Artificial Neural Network (ANN) technique are proposed for the simulation and optimisation of the urea plant in an industrial petrochemical company. The developed mathematical model consists of complex vapour–liquid equilibria for the NH3–CO2–H2O–(NH2)2CO system in thermodynamic and reaction frameworks. The smart technique (e.g. ANN) considers the CO2 conversion in terms of temperature and the molar ratios of NH3/CO2 and H2O/CO2 in the liquid phase. The ANN predictions were compared with the real data and results obtained from the mathematical model. An acceptable agreement was attained between deterministic methods. Through implementation of a systematic sensitivity analysis, it was found that a temperature of 191°C, a pressure of 132 atm and a NH3/CO2 ratio of 2.7 are the optimum process conditions for the urea production. It is concluded that the developed ANN (or connectionist) technique is an efficient tool for modelling complex phase equilibria with reaction in the industrial urea plant.

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“…Data normalisation was performed using Equation as follows:

X = \frac{x - ((x_{\max} + x_{\min}) / 2)}{((x_{\max} - x_{\min}) / 2)}

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Mathematical Modelling Of Urea Synthesis Reactormentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

A dual approach for modelling and optimisation of industrial urea reactor: Smart technique and grey box model

et al. 2013

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New internals for urea production reactors

Bozzano

Dente

Zardi

2003

J of Chemical Tech & Biotech

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Fluid dynamics and its influence on heat and mass transport rates in gas–liquid reactors is, in general, an important starting point for development of a process design. Improvements in the understanding of these aspects can be particularly fruitful in the case of urea reactors where the fluid-dynamic patterns are complicated by the co-current flow of two phases and the bubbling mode of the vapors. The analysis of such systems highlighted the non-optimal design of existing reactors and led to the conception of new reactor internals. Several industrial applications demonstrate the ability of the new configuration to improve reactor efficiency. Both energy-saving and production increases were obtained. This is a further demonstration that even mature technologies can be improved, leading not only to economic advantages, but also to a reduction in their environmental impact

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