Energetic analysis on AP-X process for liquefaction of natural gas using open source software

Abstract

The main objective of this thesis is to model a single mixed refrigerant process for offshore natural gas liquefaction using DWSIM as a simulation tools. Liquefied Natural Gas (LNG) in the energy sector is seen as a realistic source for providing cleaner, small to large scale fuel, due to the ever-increasing global environmental protection and high demand of electricity at a competitive rate. In this work, several LNG processes existing and prospective ones are analysed thermodynamically. Due to the growing demand for natural gas in the world today, transporting natural gas from different parts of the world has become a necessity. Liquefying natural gas provides a safer alternative and less expensive to transport, and to increase its storage capacity. The liquefaction process requires natural gas to be cooled using a variety of methods and cryogenic process also depressurized to atmospheric conditions for easier storage and safer. This thesis analyzes the AP-X process for liquefaction of natural gas. The ability AP-X process is analyzed in this study is assumed to be in Qatar. To analyzes the related of thermodynamic factors, the DWSIM software was used to obtain the result. The DWSIM process model was neither accurate nor robust enough to be well suited for optimization and detailed analysis of the AP-X process. With regards to further work, it is recommended to rebuild the model using alternative simulation software, preferably providing a higher level of transparency with respect to process equations and optimization procedures. A self-optimizing control structure for the process was not determined in this thesis, but the procedures and simplifying assumptions were discussed and achieved the final value Coefficient of Performance (COP) at 0.07.