Dimensionamento, simulação e análise técnico-económica dos processos de liquefacção de gás natural propane-mixed refrigerant - C3MR e dual-mixed refrigerant - DMR

Abstract

Natural gas (NG) is a source for diversifying the world energy matrix and is commonly considered clean energy. Due to its abundance and advantages, the demand for natural gas has grown significantly for the diversification of the energy matrix. The (International Energy Outlook, 2016) predicts that global consumption of natural gas will increase by around 70% by 2040. After production, natural gas can be transported to the consumer market by pipeline, through liquefied natural gas (LNG), compressed natural gas (CNG), or other forms under continuous study by the scientific community. Liquefied natural gas is an emerging and safe technique for transporting natural gas to distant markets where pipeline transport is ineffective. One of the biggest disadvantages of the NG liquefaction process is the costs associated with the process. This work consisted in designing and simulating two NG liquefaction processes, namely the Propane-Mixed Refrigerant (C3MR) and the Dual-Mixed Refrigerant (DMR) with the help of the Aspen HYSYS v11.0 software and verify their energy efficiency in order to understanding the NG value chain, an analysis of its viability and economics was subsequently carried out. Data on natural gas components and their respective compositions were extracted from the Inhassoro, Pande and Temane wells in Inhambane province and for the present work, the Pande-16 well, Wellhead was used. The two projects require a total capital investment of approximately $730,000,000 for the C3MR cycle and approximately $670,000,000 for the DMR cycle. Project feasibility indicators for the anticipated degree of exploitation over the 25-year useful life show that the C3MR cycle is economically viable compared to the DMR cycle with the net present value (NPV) of around US$4,519,000,000, a payback period (PRI) of 4 years and an internal rate of return (IRR) of 28%. While the DMR cycle is unfeasible as it has an NPV of $1,416,000,000, a PRI of 8 years and an internal rate of return of 13%. Keywords: Natural gas (NG), Liquefied natural gas (LNG), C3MR and DMR processes, pure and mixed refrigerant (TRADUÇÃO NOSSA).