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Over the years, solar desalination is a renewable energy-driven method to produce freshwater from saline/ brackish water. Since solar radiation is available only in the daytime, many studies have been undertaken to store solar energy using phase change material (PCM). The aim of this study is to compare the two solar stills (still I as a conventional solar still and still II as a PCM-integrated solar still). In still II, using low-pressure water as thermal energy storage, PCM in a copper tube with a 1 liter capacity has been additionally installed than still I. Five trials have been conducted to compare the performance and yield between stills I and II, with various factors during the experiment. Remarkably, three distinct vacuum pressures − 712 mmHg (for trials 1, 2, and 3), − 690 mmHg (for trial 4), and − 660 mmHg (for trial 5) were used for the investigation to compare the performance of PCM-based solar still with conventional solar still among five trials. Finally, at a vacuum of −712 mmHg and 175 ml of water poured inside the low-pressure system, the distillate yield obtained from still II is 9.375% higher than the yield of still I. [ABSTRACT FROM AUTHOR]

Since carbon dioxide (CO2) has a more substantial impact on climate change, it must be recycled to slow down global warming. In this work, wet impregnation (at a 3 wt.% concentration), drying, and calcination processes were used to synthesise calcium oxide-loaded carbon beads (CaO/CB). In order to produce Ca/CB (catalyst) from the CaO/CB, hydrogen gas was employed for the reduction process. Then, the obtained Ca/CB were used in a packed bed reactor (PBR) to produce carbon monoxide (CO) as a fuel gas from CO2 by thermocatalytic gasification process. The experiments were conducted with non-catalysed CB and the Ca/CB catalyst from 100 to 900 °C and 100 to 300 °C, respectively. The current study reveals that Ca reactive sites on Ca/CB have significantly higher gasification activity than the non-catalysed CB for CO2 reduction. The samples (CB and CaO/CB) were thoroughly characterised by N2 adsorption and desorption isotherms, FESEM with EDX, XRD, TG-DSC, and FTIR spectroscopy. Also, gas chromatography was used to verify the reactant and product species qualitatively and quantitatively. Compared with regular CB, Ca/CB has a maximum CO2 conversion and CO yield of 50.7% at 150 °C. In contrast, CO formation began to occur above 300 °C using regular CB. For this, the PBR was operated with CO2 on a CB-filled and catalyst-filled (Ca/CB) reactive zone at a 100 mL/min flow rate under the same circumstances. These findings lead to the hypothesis that the kinetic barrier for converting CO2 to CO can be overcome by Ca/CB. [ABSTRACT FROM AUTHOR]

The predicted scarcity, increasing cost of petroleum fuels, and environmental degradation are encouraging researchers to search for alternative fuels throughout the world. Hence, it is intended to utilize acetylene-based DF in the compression ignition (CI) engine with minor modifications. An engine of 5 Hp, four stroke, single-cylinder, water-cooled operated in dual-fuel (DF) mode (acetylene gas-diesel), aiming to reduce the emissions, was deployed to investigate its characteristics. In DF mode, gaseous fuel is injected through intake air manifold with 2, 4, and 6 lpm constantly. According to the research findings, the gas rate of 6 lpm provides the best results, having a superior BTE of 30.7%. Various compression ratios (16:1, 18:1, and 20:1) were used to determine the optimal compression ratio (CR) under a volume flow rate of 6 lpm with diesel. Fuel injector pressure (200, 220, and 240 bar) with injector intervals (19°, 23°, and 27°bTDC) were changed consecutive sequence while adjusting CR, and the best outcomes for improved CI fuel efficiency were determined. From the investigational analysis, the peak in-cylinder pressure and net HRR (heat release rate) are assessed for being better by the increment in CR in DF mode of operation with an acetylene gas of 6 lpm at all operating settings. At a 240 bar injection pressure, the BTE is recorded highest (35.1%), and smoke was decreased. An IT of 23obTDC, the CO and HC were found as to be minimum as 28 ppm and 0.04 ppm. [ABSTRACT FROM AUTHOR]