Introducing a novel air separation process based on cold energy recovery of LNG integrated with coal gasification, transcritical carbon dioxide power cycle and cryogenic CO2 capture

In this paper, a cryogenic air separation process with LNG cold energy utilization is proposed to produce liquid nitrogen and high pressure pure oxygen gas economically. To reduce the electric energy consumption of air separation products, liquid nitrogen have been produced by condensing the separated pure nitrogen gas with LNG cold energy utilization, and the recycled nitrogen is served to transfer cold energy from LNG stream to cool off air stream in the proposed cryogenic air separation process. The specifications of streams and the major equipments of the air separation process are simulated with Aspen Plus software and the main parameters analysis are performed. The results show that the energy consumption of the proposed air separation process with LNG cold energy utilization decreased about 58.2% compared with a conventional cryogenic air separation process. The compressed pressure of recycled nitrogen has a big impact on the cost of air separation products and utilization efficiency of LNG cold energy. The LNG cold energy could be fully utilized when the recycled nitrogen has been compressed to above 6.5MPa.

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Optimum design and exergy analysis of a novel cryogenic air separation process with LNG (liquefied natural gas) cold energy utilization

Energy ◽

10.1016/j.energy.2015.07.101 ◽

2015 ◽

Vol 90 ◽

pp. 2047-2069 ◽

Cited By ~ 84

Author(s):

Mehdi Mehrpooya ◽

Mohammad Mehdi Moftakhari Sharifzadeh ◽

Marc A. Rosen

Keyword(s):

Natural Gas ◽

Optimum Design ◽

Exergy Analysis ◽

Liquefied Natural Gas ◽

Separation Process ◽

Air Separation ◽

Energy Utilization ◽

Cold Energy

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Intercooled Advanced Gas Turbines in Coal Gasification Plants, With Combined or “HAT” Power Cycle

Volume 2: Coal, Biomass and Alternative Fuels; Combustion and Fuels; Oil and Gas Applications; Cycle Innovations ◽

10.1115/97-gt-039 ◽

1997 ◽

Cited By ~ 3

Author(s):

Paolo Chiesa ◽

Giovanni Lozza

Keyword(s):

Gas Turbines ◽

Coal Gasification ◽

High Efficiency ◽

Combined Cycle ◽

Air Separation ◽

Heavy Duty ◽

Power Cycle ◽

Efficiency Assessment ◽

The One ◽

Conversion Efficiencies

Due to their high efficiency and flexibility, aeroderivative gas turbines were often considered as a development basis for intercooled engines, thus providing better efficiency and larger power output. Those machines, originally studied for natural gas, are here considered as the power section of gasification plants for coal and heavy fuels. This paper investigates the matching between intercooled gas turbine, in complex cycle configurations including combined and HAT cycles, and coal gasification processes based on entrained-bed gasifiers, with syngas cooling accomplished by steam production or by full water-quench. In this frame, a good level of integration can be found (i.e. re-use of intercooler heat, availability of cool, pressurized air for feeding air separation units, etc.) to enhance overall conversion efficiency and to reduce capital cast. Thermodynamic aspects of the proposed systems are investigated, to provide an efficiency assessment, in comparison with mare conventional IGCC plants based on heavy-duty gas turbines. The results outline that elevated conversion efficiencies can be achieved by moderate-size intercooled gas turbines in combined cycle, while the HAT configuration presents critical development problems. On the basis of a preliminary cost assessment, cost of electricity produced is lower than the one obtained by heavy-duty machines of comparable size.

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