Assessment of liquefied natural gas (LNG) regasified through gas interchangeability in energy consumption sectors

Abstract

Cusiana and Cupiagua fields represent 51% of Colombia natural gas production. However, some studies predict that in 2023, the reserves of the fields will decrease significantly causing an imbalance between supply and demand of natural gas within the country. Therefore, in order to face the situation, innovative strategies must be developed and implemented to provide energy security for the coming years. One of the strategies that has been applied in different countries is the incorporation and implementation of liquefied natural gas (LNG) technologies. However, it is necessary to evaluate the supply and demand of the country to determine the scale of LNG production and regasification technology, as well as the technical feasibility of its incorporation into the country’s energy matrix, taking into account the main sectors of final consumption. Therefore, in this work an analysis of the supply and demand of natural gas in the country from different sectors of energy consumption is made. In addition, an analysis was made on the natural gas currently marketed in Colombia by means of a gas interchangeability methodology. A set of novel equations was presented to determine the mole fraction of propane and methane in the equivalent mixture considered by Dutton’s method, as well as the number of moles associated with the hydrocarbon equivalent in methane and propane, parameters required to establish the mole fraction of nitrogen and inert chemical species such as carbon dioxide in the equivalent mixture and the percentage of propane and nitrogen equivalent. It was determined that the LNG regasified at the SPEC-LNG plant is an interchangeable gas from a conventional point of view mainly with the gas produced at Cusiana. However, when evaluating all the Dutton indexes, these are not interchangeable since it presents an incomplete combustion factor (ICF) outside the recommended limit.