Thermodynamic study of the simultaneous production of electrical power and refrigeration capacity from regasification of liquefied natural gas

The thermal energy conversion of natural gas (NG) using appropriate configuration cycles represents one of the best nonrenewable energy resources because of its high heating value and low environmental effects. The natural gas can be converted to liquefied natural gas (LNG), via the liquefaction process, which is used as a heat source and sink in various multigeneration cycles. In this paper, a new configuration cycle is proposed using LNG as a heat source and heat sink. This new proposed cycle includes the CO2 cycle, the organic Rankine cycle (ORC), a heater, a cooler, an NaClO plant, and reverse osmosis. This cycle generates electrical power, heating and cooling energy, potable water (PW), hydrogen, and salt all at the same time. For this purpose, one computer program is provided in an engineering equation solver for energy, exergy, and thermo-economic analyses. The results for each subsystem are validated by previous researches in this field. This system produces 10.53 GWh electrical energy, 276.4 GWh cooling energy, 1783 GWh heating energy, 17,280 m3 potable water, 739.56 tons of hydrogen, and 383.78 tons of salt in a year. The proposed system energy efficiency is 54.3%, while the exergy efficiency is equal to 13.1%. The economic evaluation showed that the payback period, the simple payback period, the net present value, and internal rate of return are equal to 7.9 years, 6.9 years, 908.9 million USD, and 0.138, respectively.

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Conventional and advanced exergoeconomic assessments of a new air separation unit integrated with a carbon dioxide electrical power cycle and a liquefied natural gas regasification unit

Energy Conversion and Management ◽

10.1016/j.enconman.2018.02.016 ◽

2018 ◽

Vol 163 ◽

pp. 151-168 ◽

Cited By ~ 18

Author(s):

Mehdi Mehrpooya ◽

Hojat Ansarinasab ◽

Mohammad Mehdi Moftakhari Sharifzadeh ◽

Marc A. Rosen

Keyword(s):

Carbon Dioxide ◽

Natural Gas ◽

Electrical Power ◽

Liquefied Natural Gas ◽

Air Separation ◽

Separation Unit ◽

Power Cycle ◽

Air Separation Unit

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Design and Performance Test of 2 kW Class Reverse Brayton Cryogenic System

Energies ◽

10.3390/en13195089 ◽

2020 ◽

Vol 13 (19) ◽

pp. 5089

Author(s):

Keuntae Lee ◽

Deuk-Yong Koh ◽

Junseok Ko ◽

Hankil Yeom ◽

Chang-Hyo Son ◽

...

Keyword(s):

Heat Exchanger ◽

Natural Gas ◽

Performance Test ◽

Cooling Capacity ◽

Liquefied Natural Gas ◽

Cryogenic System ◽

Operating Pressure ◽

Power Cables ◽

Turbo Expander ◽

Refrigeration Capacity

With the increased commercialization of high-temperature superconducting (HTS) power cables cooled using liquid nitrogen and the use of liquefied natural gas as fuel, the need for large-capacity reverse Brayton cryogenic systems is gradually increasing. In this paper, the thermodynamic design of a reverse Brayton cryogenic system with a cooling capacity of the 2 kW class at 77 K using neon as a refrigerant is described. Unlike conventional reverse Brayton systems, the proposed system uses a cryogenic turbo-expander, scroll compressor, and plate-type heat exchanger. The performance test conducted on the fabricated system is also described. The isentropic efficiency of the cryogenic turbo-expander was measured to be 86%, which is higher than the design specification. The effectiveness of the heat exchanger and the flow rate and operating pressure of the refrigerant were found to be lower than the design specifications. Consequently, the refrigeration capacity of the fabricated reverse Brayton cryogenic system was measured to be 1.23 kW at 77 K. In the future, we expect to achieve the targeted refrigeration capacity through further improvements. In addition, the faster commercialization of HTS power cables and more efficient storage of liquefied natural gas will be realized.

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Liquefied natural gas (LNG) and DC electric power transfer system by cryogenic pipe of superconducting DC power transmission (SCDC)

Journal of Physics Conference Series ◽

10.1088/1742-6596/2088/1/012019 ◽

2021 ◽

Vol 2088 (1) ◽

pp. 012019

Author(s):

Sataro Yamaguchi ◽

Yury Ivanov ◽

Linda Sugiyama

Keyword(s):

Natural Gas ◽

Transmission Lines ◽

Power Transmission ◽

Electrical Power ◽

Liquefied Natural Gas ◽

Gas Pipeline ◽

Long Distance ◽

Hybrid Energy ◽

Transport Distance ◽

Transmission Pipeline

Abstract We propose a hybrid energy transmission pipeline that combines the liquefied natural gas (LNG) cryogenic pipelines and superconducting direct current (DC) electrical power transmission cable system (SCDC). The system design is based on experimental data from the SCDC Ishikari project in Japan and related laboratory experiments. The particular structure of the hybrid cryogenic pipe connects the thermal radiation shield of the pipe that contains the DC high temperature superconducting (HTS) electrical cable to the LNG pipe and significantly reduces the heat leak into the SCDC pipe. Because the specific heat of LNG is higher than that of liquid nitrogen and the LNG transfer rate is quite high, the thermal loss of the SCDC cable becomes only 1/100 that of present-day conventional copper cables, far below the factor 1/10 reduction achievable by a stand-alone SCDC transmission lines. The LNG temperature rises by less than 2 K over a 100 km transport distance, which is negligible in actual use. LNG also saves significantly on pumping power compared to a natural gas pipeline. To liquefy the LNG at cryogenic temperature from natural gas at ambient temperature requires a large refrigerator that consumes enormous power. The gas pipeline, however, needs a compressor to produce high-pressure gas, which also consumes a massive amount of power. Due to these considerations, the proposed hybrid system is a viable design for the long-distance joint transportation of LNG and electricity.

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