Hojat Ansarinasab; Mahmoud Afshar; Mehdi Mehrpooya
Abstract
In this paper, exergy and exergoeconomic analysis is performed on the recently proposed process forthe coproduction of liquefied natural gas (LNG) and natural gas liquids (NGL) based on the mixedfluid cascade (MFC) refrigeration systems, as one of the most important and popular natural gasliquefaction ...
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In this paper, exergy and exergoeconomic analysis is performed on the recently proposed process forthe coproduction of liquefied natural gas (LNG) and natural gas liquids (NGL) based on the mixedfluid cascade (MFC) refrigeration systems, as one of the most important and popular natural gasliquefaction processes. To carry out this analysis, at first, the proposed process is simulated, and thenthe exergy analysis of the process equipment is performed; finally, an economic model is used for theexergoeconomic analysis. The results include cost of exergy destruction, exergoeconomic factor,exergy destruction, and exergy efficiency. The results of the exergy analysis demonstrate that theexergy efficiency of the proposed process is around 53.83%, and its total exergy destruction rate is42617.5 kW at an LNG and NGL production rates of 68.99 kg/s and 27.41 kg/s respectively. Theresults of exergoeconomic analysis indicate that the maximum exergoeconomic factor, which is69.53%, is related to the second compressor in the liquefaction cycle and the minimumexergoeconomic factor, which is 0.66%, is related to the fourth heat exchanger in the liquefactioncycle. In this process, demethanizer tower holds the highest relative cost difference (100.78) and thefirst air cooler in liquefaction cycle has the lowest relative cost difference (1.09). One of the mostimportant exergoeconomic parameters is the cost of exergy destruction rate. The second heatexchanger has the highest exergy destruction cost (768.91 $/Gj) and the first air cooler in theliquefaction cycle has the lowest exergy destruction cost (19.36 $/Gj). Due to the high value of fuelcost rate (as defined in exergoeconomic analysis) in heat exchangers, their exergy destruction cost ismuch higher than other devices.
Ahmad Mousaei; Mohammad Ali Hatefi
Abstract
A value chain is a series of events that takes a raw material and with each step adds value to it. Global interest in the application of natural gas (NG) in production and transportation has grown dramatically, representing a long-term, low-cost, domestic, and secure alternative to petroleum-based fuels. ...
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A value chain is a series of events that takes a raw material and with each step adds value to it. Global interest in the application of natural gas (NG) in production and transportation has grown dramatically, representing a long-term, low-cost, domestic, and secure alternative to petroleum-based fuels. Many technological solutions are currently considered on the market or in development, which address the challenge and opportunity of NG. In this paper, a decision support system (DSS) is introduced for selecting the best fuel to develop in the value chain of NG through four options, namely compressed NG (CNG), liquefied NG (LNG), dimethyl ether (DME), and gas-to-liquids (GTL). The DSS includes a model which uses the technique for order performance by similarity to ideal solution (TOPSIS) to select the best fuel in the value chain of NG based on the attributes such as market situations, technology availability, and transportation infrastructure. The model recommends some key guidelines for two branches of countries, i.e. those which have NG resources and the others. We believe that applying the proposed DSS helps the oil and gas/energy ministries in a most effective and productive manner dealing with the complicated fuel-related production and transportation decision-making situations.
