Optimum Temperature in the Electrostatic Desalting of Maya Crude Oil
Erik Fetter Pruneda, Enrique Rivero Borrell Escobedo y Francisco Javier Garfias Vázquez*
Facultad de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria, México D.F., C.P. 04510 Tel/fax (52-55) 52 56225158; e-mail: garfiasv@servidor.unam.mx.
Received October 3, 2004 ]]> Accepted March 15, 2005
Abstract
The main variables that impact the crude oil desalting process were analyzed by developing mathematical models that represent the variation of Maya crude oil density, conductivity and viscosity as functions of temperature. An increase in process temperature has two opposite effects. First, a decrease in oil density and viscosity implies a significant increase in the settling rate of water droplets within the oil phase; which allow for a greater amount of oil to be processed. This increases the profit resulting from performing oil desalting. On the other hand, crude oil conductivity increases exponentially with temperature, which implies a higher rate of power consumption. A simulation model was developed to determine the optimum temperature at which a maximum economic benefit occurs. It was concluded that an optimum temperature occurs at 135oC.
Keywords: Maya crude oil, temperature, desalting, viscosity, density, conductivity.
Resumen
Se estudiaron las principales variables que impactan el proceso de desalado de crudo mediante el desarrollo de correlaciones matemáticas que representan la variación de densidad, conductividad y viscosidad del crudo Maya como funciones de la temperatura. La discusión teórica mostró que un incremento en la temperatura de proceso da lugar a dos efectos contrarios. En primera instancia, una disminución en la densidad y viscosidad implica un aumento en la velocidad de sedimentación de las gotas de agua contenidas en la fase orgánica. Lo anterior permite que mayor cantidad de crudo sea procesada en un mismo periodo. Por lo tanto, se incrementan los beneficios económicos derivados de realizar esta operación. Por otro lado, la conductividad del crudo aumenta de manera exponencial con la temperatura, lo cual implica mayor consumo de energía eléctrica. Se desarrolló un modelo de simulación para determinar la temperatura óptima, en la cual se obtiene el máximo beneficio. Se concluyó que la temperatura óptima de desalado es 135°C.
Palabras clave: Crudo Maya, temperatura, desalado, viscosidad, densidad, conductividad.
]]>DESCARGAR ARTÍCULO EN FORMATO PDF
Acknowledgment
Financial support from DGAPA-UNAM (PAPIIT- IN103001) is acknowledged.
References
1. Petróleos Mexicanos (PEMEX). Petroleum Monthly Statistics. México, 2004, http://www.pemex.com, diciembre 2004. [ Links ]
2. Campos, J. A. Unidad de Evaluación y Programación. Refinería Ing. Antonio M. Amor. Entrevista. Salamanca, Guanajuato. 20 de enero, 2004. [ Links ]
3. Pérez, B.; Garfias-Vasquez, F.J. Rev. Soc. Quím. Méx., 2002, 46, 227 - 234. [ Links ]
4. Auflem, I.H. Influence of Asphaltene Aggregation and Pressure on Crude Oil Emulsion Stability. Ph. D. Thesis: Norwegian University of Science and Technology, Trondheim, 2002. [ Links ]
5. Heimbaugh, J. Jr. Dehydratation: the key to desalting crudes. Hydrocarbon Engineering. November 1998, 49-51. [ Links ]
6. Gary and Handwerk. Petroleum refining technology & economics. Marcel Dekker, 3th Edition. New York. 1994. [ Links ]
7. Harris, R. Use desalting for FCC feedstocks. Hydrocarbon Processing. August 1996, 63-65. [ Links ]
8. ASTM D 1298 method. "Standard test method for density, relative density (specific gravity), or API gravity of crude petroleum and liquid petroleum products by hydrometer method", 1986. [ Links ]
9. ASTM D 445 method. "Standard test method for kinematic viscosity of transparent and opaque liquids (and calculation of dynamic viscosity)", 1988. [ Links ]
10. ASTM D 3230 method. "Standard test method for salts in crude oil (electrometric method)", 1997. [ Links ]
11. Warren, K. New tools for heavy oil dehydration. Society of Petroleum Engineers. Richardson, Texas, 2002. [ Links ]
12. ICIS Report. Hydrocarbons and energy section. México, 2003, http://www.icis.com, diciembre 2003. [ Links ]
13. Mexicana de Lubricantes S.A. (MEXLUB). Catálogo. México, 2003, http://www.mexlub.com, noviembre 2003. [ Links ]
]]>