OPTIMIZATION OF SKIKDA LNG PLANT OPERATION USING A MIXED NON-LINEAR PROGRAMMING MODEL OPTIMISATION DES REGIMES D'EXPLOITATION DE L'USINE DE LIQUEFACTION DE SKIKDA PAR UN MODELE DE PROGRAMMATION NON LINEAIRE EN VARIABLES MIXTES

摘要

Algeria is one of the largest worldwide exporters of liquefied natural gas. LNG plants are characterized by their relatively low number and very high investment and operating costs. The high operating costs of this type of facilities are mainly due to the fuel consumption of liquefaction plants which in stable operating reaches about 15%In presence of important fluctuations of the demand, the energy consumption increases in a significant manner. These fluctuations are owed to the nature of the market evolution characterized by the confirmation more and more important of the spot market. In this context there is place to define an approach to optimize LNG plant operation taking into account :All the susceptible actions to assure the maximal flexibility of the system (LNG plant, LNG storage, port);The random nature of deliveries toward LNG tankers;The stocks level of LNG;The different possibilities of regulation of the liquefaction unit (stop of one or several liquefaction trains, recycle or operating at partial load). For this, a non-linear programming model with mixed variables was implemented enabling to minimize the whole of energy and maintenance costs as well as assuring the delivery of all the required LNG amounts. An application of the model developed on the Skikda plant GL1K will be given.