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This study presents a novel configuration using the hydrogen-natural gas and ammonia-natural gas blends for practical applications and investigates the system performance comprehensively. Natural gas is blended with hydrogen and ammonia to investigate performance improvement. Wind energy source is employed to the proposed configuration for power generation using wind turbines. The power generated by the wind turbine is employed to the proton exchange membrane (PEM) electrolyser for hydrogen production. A part of hydrogen is employed to the PEM fuel cell for power production. The proposed system is used to investigate the effect of hydrogen and ammonia blends with natural gas to achieve better performance. In order to investigate the H 2 -CH 4 blends, a part of the produced hydrogen is supplied to the mixing chamber from the hydrogen storage tank while ammonia input is supplied to the mixing chamber to improve the performance under NH 3 -CH 4 blends. The results revealed that the combustion energy and exergy efficiencies increase from 84.8% to 94.8% and 62.5%–70.2% respectively and the overall energetic and exergetic efficiencies increase from 37.4% to 40.3% and 36.8%–39.8% respectively with hydrogen addition from 0 to 20%. In the case of ammonia-natural gas blends, the combustion energy and exergy efficiencies increase from 84.8% to 92.9% and 58.9%–64.4% respectively and overall energetic and exergetic efficiencies increase from 37.4% to 39.1% and 36.8%–38.5% respectively. • This study presents wind energy based novel system for combustion applications. • Natural gas is blended with H 2 and NH 3 to investigate the performance improvement. • In H 2 and NH 3 blends with CH 4 , the H 2 and NH 3 fractions are taken from 0% to 20%. • Combustion efficiencies increases with NH 3 addition. • Overall efficiencies increase with NH 3 addition. [ABSTRACT FROM AUTHOR]

This paper presents a novel system of adding clean hydrogen to the natural gas for more effective and more efficient combustion. The proposed system includes a wind-photovoltaic hybrid system where both wind and solar energy sources are simultaneously utilized. A partial amount of electrical power produced by the wind turbines, PEM fuel cell and PV array is fed to the PEM electrolyser while the additional electricity is supplied to the community for use. In the hydrogen-natural gas blends, the fraction of hydrogen is taken from 0% to 20%, respectively, and the natural gas is reduced from 100% to 80% simultaneously to explore hydrogen addition effect in the combustion process. Although natural gas is cleaner than other fossil fuels, adding hydrogen to the natural gas makes it much cleaner and more environmental friendly. The blends of natural gas and hydrogen helps increase the combustion efficiency, decrease oxygen and reduce the emissions, in particular CO 2. The results further reveal that the energetic efficiency of the combustion unit rises from 84.83% to 94.83% while the exergetic efficiency rises from 62.52% to 70.16% with the rise in hydrogen fraction from 0% to 20%. It is also found that the CO 2 emissions decrease with the rise in hydrogen fraction in hydrogen-natural gas blends. • It presents a novel system of adding hydrogen to the natural gas for combustion. • It includes wind-photovoltaic hybrid system where both solar and wind sources are used. • In the hydrogen-natural gas blends, the hydrogen fraction is taken from 0% to 20%. • The energy efficiency of combustion rises from 84.83% to 94.83% with hydrogen addition. • The CO 2 emissions decrease with the rise in H 2 fraction in hydrogen-natural gas blends. [ABSTRACT FROM AUTHOR]

An Energetically Improved Steam-Autothermal Reforming (EISAR) novel concept is proposed in this study, and a novel idea to combine steam methane reforming with CO 2 and steam based autothermal reforming is introduced for practical applications. A urea synthesis unit is also integrated with the proposed system to justify the idea of clean hydrogen production. The CO 2 produced by the steam methane reforming is captured in CO 2 based autothermal reforming and CO 2 produced by the autothermal reforming is captured by urea synthesis system which converts CO 2 into urea by reacting is with ammonia. According to the designed heat management of molten salt, electric power of 4 MW is produced by the steam Rankine cycle which is supplied to a community of 400 households. During the night time, the community of 400 households is fed to be provided with electricity through PEM fuel cell which utilities a part of hydrogen from the storage tank. Both Engineering Equation Solver (EES) and Aspen Plus software packages are employed for system simulation. Several sensitivity studies, cost and carbon emission analyses and multi-objective optimization studies are undertaken for the designed system. The energy and exergy efficiencies for the present are found to be 59.1% and 31.1%, respectively. Furthermore, the results of current analyses and optimization studies are presented and discussed accordingly. • A novel concept of energetically improved steam-autothermal reforming is presented. • Steam methane reforming is combined with two types of autothermal reforming. • Urea synthesis unit in employed to capture produced CO 2 and conversion into urea. • Designed system meets the electrical load for a community of 400 households. • The overall energy and exergy efficiencies are 59.1% and 31.1% respectively. [ABSTRACT FROM AUTHOR]