Optimal Design of Combined LNG/LPG Regasification System

In compatibility of liquefied natural gas (LNG) calorific values between importing countries has become one of the important technical and commercial issues in the LNG industry. Until now, heavy hydrocarbon removal (HHR) system, or nitrogen dilution system has been used in controlling the calorific value; however, these methods can make the process more complicated and less profitable. This is especially the case for offshore plants. A new concept of "Rich LNG" may bring the fundamental and economic solution for the calorific compatibility problem by combining the existing chains of LNG industry. But, in "Rich LNG", the natural gas liquids (NGL) removal must be efficiently performed by utilizing abundant available cold energy during the LNG regasification process in offshore or onshore. In this study, a multi-objective and mixed-integer nonlinear programming technique is applied for generating the complete Pareto optimal sets for a new calorific value adjustment process.