Second law analysis of hydrogen liquefiers operating on the modified Collins cycle

Syed, Mahaboobbasha; Sherif, S. A.; Везироглу, Т. Н.; Sheffield, John

doi:10.1002/er.733

Cited by 9 publications

(3 citation statements)

References 8 publications

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“…All devices were energetically sustainable. 56 for the same lifetime, 4.2 -6.3 times higher for Ga-based cells and 1.6 -2.4 times higher for Si-based PV cells.…”

Section: Gyr For Different Concentrator's Ghgmentioning

confidence: 85%

Design guidelines for concentrated photo-electrochemical water splitting devices based on energy and greenhouse gas yield ratios

Dumortier

Haussener

2015

Energy Environ. Sci.

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Solar irradiation concentration is considered a viable strategy for reducing the energy and financial investment of photo-electrochemical hydrogen generation. We quantified and compared the sustainability benefit of this approach to non-concentrating and conventional approaches using life cycle assessment coupled to device performance modeling. We formulated design guidelines to reduce the environmental impact of a device. Model devices were composed of a concentrator module (with tracking, supporting, and framing components), photoabsorbers, membrane-separated electrocatalysts, and a cooling circuit. We selected eight concentrator types covering five concentrating technologies. For each device we studied the effect of the irradiation concentration ratio, electrode to photabsorber area ratio, manufacturing requirements, incoming irradiance, and efficiency of components on sustainability utilizing two indexes: i) the energy yield ratio, and ii) the greenhouse gas yield ratio. Both indexes combine the performance of the system and its environmental impact. Two design guidelines were formulated based on the analysis: i) any concentration-stable photoabsorber and electrocatalyst is equally feasible at concentrations larger than 55, as their performance prevails over their energy demand, and ii) the system needs to be designed at an optimum concentration which depends on: performance, the relative surfaces of the photoabsorber and electrode, and irradiance. The study quantified and confirmed that concentrating solar irradiation has a beneficial effect on sustainability, energy yield, and greenhouse gas emissions compared to non-concentrated approaches. This was true for all concentrating technologies investigated. Consequently, this study provides an eco-performance-based rationale to further pursue the research and development of concentrated photo-electrochemical devices.Broader context: Solar energy is the most abundant energy source but it is distributed and intermittent requiring its conversion and storage for meaningful use. Photoelectrochemical (PEC) conversion approaches provide a practical and impactful storage approach through the development of devices which efficiently and continuously produce low cost hydrogen for several years. A fundamental requirement for any novel technology is its sustainability, which can be assessed by analysis of greenhouse gas emission and energy requirements during all phases of its lifetime. Recent research on these devices focus not only on material selection for photoabsorbers and electrocatalysts, but also on their design. Concentrated solar irradiation has been suggested as an approach to reduce the cost of PEC devices as it replaces a large fraction of expensive materials by less costly collection and concentrating components. However, this approach needs to ensure that the beneficial effects are not overshadowed by additional energy requirements and emissions, and potential efficiency reduction. This article examines the effects of design, material selection, and operatin...

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“…All devices were energetically sustainable. 56 for the same lifetime, 4.2 -6.3 times higher for Ga-based cells and 1.6 -2.4 times higher for Si-based PV cells.…”

Section: Gyr For Different Concentrator's Ghgmentioning

confidence: 85%

Design guidelines for concentrated photo-electrochemical water splitting devices based on energy and greenhouse gas yield ratios

Dumortier

Haussener

2015

Energy Environ. Sci.

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“…Kanoglu [20] has carried out the exergy analysis of a multistage cascade refrigeration cycle used for natural gas liquefaction. Syed et al [21] have used exergy approach to analyze hydrogen liquefiers operating on the modified Collins cycle. Kanoglu et al [22] have performed first-and second-law analyses of the simple Linde-Hampson cycle used in gas liquefaction systems.…”

Section: Introductionmentioning

confidence: 99%

Exergy destruction in the double inlet pulse tube cryocooler (DIPTC): A parametric study

Dash

Nandi

Das

2009

Int. J. Energy Res.

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SUMMARYIn this paper the exergy analysis of a double inlet pulse tube cryocooler (DIPTC) has been performed. The pulsating mass flow has been modelled by a sinusoidal approximation using phasor analysis. The corresponding values were used to find out the average exergy flow through and exergy destructions in various components. The effect of different parameters on the exergy flow and exergy destruction has been studied over a large range of parameters. The parameters considered here are frequency, cold end temperature, valve coefficients of orifice valve and double inlet (DI) valve, system average pressure and initial phase angle of compressor outlet pressure. A higher sensitivity of the losses in a DIPTC system is observed with operating frequency and initial phase angle of compressor pressure within some specific range of these parameters. It was observed that for a DIPTC system there is a critical cold end temperature below which the losses are significant and also there exists a critical frequency below which there will practically be no cooling. It was found that the losses in the DIPTC are more sensitive to the orifice valve opening in comparison to the DI valve opening. A Grassmann diagram has also been constructed for the DIPTC.

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“…He determined the optimum flow rates of cryocoolers sharing the same size recuperator in order to maximize liquid production. Syed [13] presented a second law analysis of a modified Collins cycle for hydrogen liquefaction by comparing heliumrefrigerated and hydrogen-refrigerated systems. Remeljej and Hoadley [14] and Kanoglu [7] studied natural gas liquefaction cycles using the principles of exergy analysis.…”

Section: Introductionmentioning

confidence: 99%

Performance analysis of gas liquefaction cycles

Kanoğlu

Dinçer

Rosen

2007

Int. J. Energy Res.

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SUMMARYRelations are developed for first-and second-law analyses of the simple Linde-Hampson cycle used in gas liquefaction systems. An expression for the minimum work requirement, which is applicable to any gas liquefaction system, is developed with the help of a Carnot refrigerator. It is shown that the minimum work depends only on the properties of the incoming and outgoing gas streams and the environment temperature. Numerical calculations are performed to obtain the performance parameters of different gases while parametric studies are done to investigate the effects of liquefaction and inlet gas temperatures on various first-and second-law performance parameters. As the liquefaction temperature increases and the inlet gas temperature decreases, the liquefied mass fraction, the coefficient of performance (COP) and the exergy efficiency increase while actual and reversible work consumptions decrease. The exergy efficiency values appear to be low, indicating significant potential exists for improving efficiency and thus decreasing the required work consumption for a specified amount of liquefaction.

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Second law analysis of hydrogen liquefiers operating on the modified Collins cycle

Cited by 9 publications

References 8 publications

Design guidelines for concentrated photo-electrochemical water splitting devices based on energy and greenhouse gas yield ratios

Design guidelines for concentrated photo-electrochemical water splitting devices based on energy and greenhouse gas yield ratios

Exergy destruction in the double inlet pulse tube cryocooler (DIPTC): A parametric study

Performance analysis of gas liquefaction cycles

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