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In this study, a new solar-based fuel cell-powered oxygenation and ventilation system is presented for COVID-19 patients. Solar energy is utilized to operate the developed system through photovoltaic panels. The method of water splitting is utilized to generate the required oxygen through the operation of a proton exchange membrane water electrolyser. Moreover, the hydrogen produced during water splitting is utilized as fuel to operate the fuel cell system during low solar availability or the absence of solar irradiation. Transient simulations and thermodynamic analyses of the developed system are performed by accounting for the changes in solar radiation intensities during the year. The daily oxygen generation is found to vary between 170.4 kg/day and 614.2 kg/day during the year. Furthermore, the amount of daily hydrogen production varies between 21.3 kg/day and 76.8 kg/day. The peak oxygen generation rate attains a value of 18.6 g/s. Moreover, the water electrolysis subsystem entails daily exergy destruction in the range of 139.9–529.7 kWh. The maximum efficiencies of the developed system are found to be 14.3% energetically and 13.4% exergetically. • Solar and fuel cell-based oxygenation system is presented for COVID-19 patients. • Transient simulations and thermodynamic analyses conducted on the developed system. • Daily hydrogen production varies between 21.3 kg/day and 76.8 kg/day. • Maximum energy and exergy efficiencies of the developed system are 14.3% and 13.4%. [ABSTRACT FROM AUTHOR]

In this research study, a new solar energy-based integrated system is developed for treating industrial brine wastewater. An integrated solar-powered evaporation and membrane-based water treatment technique is utilized. Both forced convection as well as falling film evaporators are incorporated to treat high-concentration rejected brine. The system performance is assessed through a comprehensive thermodynamic investigation at varying operating parameters. The energetic performance is evaluated to vary from 12.5% to 15.9% across the year. Furthermore, the peak efficiency in terms of exergy is found to be 11.1%. Also, the membrane-based wastewater treatment subsystem is found to entail an energetic performance of 73.3% and an exergetic performance of 34.6% in terms of efficiencies. Moreover, an energetic performance of 15.4% and an exergetic performance of 2.9% is found for the evaporation-based subsystem. The exergy destructions in each system component are evaluated and the power generation subsystem is determined to have the highest exergy destruction rate of 15.4 MW. To investigate the effects of varying design parameters and operating conditions on the system performance, several parametric studies are also performed. • A new solar energy-based system developed for treating industrial brine wastewater. • Both evaporation and membrane-based water treatment techniques utilized. • Energy efficiency of the overall system varies between 12.5% and 15.9% annually. • Peak exergy efficiency of the overall system found to be 11.1%. [ABSTRACT FROM AUTHOR]

• New renewable hydrogen production system utilizing rice husk biomass. • Multigeneration of clean hydrogen, cooling, freshwater and electricity. • Peak hydrogen production rate reaches 0.3 kg/s. • Overall performance entails energetic and exergetic ratios of 46.8% and 47.8%. A new solar energy-based rice husk gasification system is introduced that produces renewable hydrogen as well as cooling, freshwater and electricity. The hydrogen production rate under design operating conditions is 0.0603 kg/s. Also, the peak rate of hydrogen production at a higher biomass feed rate of 5 kg/s is evaluated to be 0.3 kg/s. Moreover, the performance of the system introduced is evaluated through comprehensive thermodynamic analyses. The overall design efficiency considering energetic performance is 46.8% and the corresponding exergetic efficiency becomes 47.8%. In addition to this, the net rate of energy production attained by the combined cycle is 12.9 MW. Also, the system introduced provides a rate of cooling of 911.4 kW and a freshwater production rate of 410.9 kg/s. Higher steam to biomass and lower oxygen to feed ratios are found to improve system performances. Several other sensitivity analyses are conducted to investigate the performance under varying conditions. [ABSTRACT FROM AUTHOR]

In the present study, a new ammonia synthesis and fuel cell system integrated with solar energy is developed. The excess energy from a solar photo-voltaic plant is utilized for ammonia synthesis, which acts as an energy storage medium. Two different locations in Canada are considered for system modelling and simulation. The thermodynamic performance of the developed system is analyzed on a transient basis taking into account the variations in solar intensities across the year. The maximum energetic performance evaluated in terms of energy efficiency is 15.72%. Also, the peak exergetic efficiency of the solar-based system is determined as 16.55%. In addition, the daily discharge time capacity is found to reach 8.9 h at the peak. Furthermore, the ammonia synthesis rate obtains a value of 64.8 mol/s at the peak synthesis rate. The daily capacity of energy discharge entails the maximum value of 8502.4 kWh. The dynamic simulation results of each subsystem are discussed comprehensively presenting the applicability of the developed system for intermittency mitigation. Image 10 • A new ammonia synthesis and fuel cell system integrated with solar energy. • Maximum energetic performance in terms of efficiency reaches 15.72%. • The peak exergetic efficiency of the solar-based system is determined as 16.55%. • Daily discharge time and energy capacity found to reach 8.9 h and 8502.4 kWh [ABSTRACT FROM AUTHOR]

• New integrated solar-based ammonia synthesis and fuel cell system developed. • Transient simulation of the developed system performed at varying solar intensities. • Overall system energy efficiency varies between 15.68 and 15.83%. • Exergy efficiency of the overall system varies between 16.44 and 16.67%. • Discharge time capacities found to vary between 2.6 and 8.3 h across the year. Ammonia is considered to be a promising energy storage medium that can address the challenges associated with hydrogen. It is essential to investigate the usage of ammonia for energy storage, especially for the applications of intermittent energy resources. Hence, in the present study, a new integrated solar-based ammonia synthesis and fuel cell system is presented. The excess power generated by a solar photovoltaic system is utilized to synthesize ammonia. Furthermore, a direct ammonia fuel cell is employed for electricity production when low solar energy is available. The system is simulated dynamically on the average day of each month and the performance is investigated through thermodynamic energy and exergy tools. The overall exergy efficiency lies in the range of 16.44%-16.67% while the overall energy efficiency during the year varies between 15.68% and 15.83%, respectively. Also, the discharge time capacity is found to vary between 2.6 and 8.3 h. Moreover, the ammonia synthesis rate reaches a peak value of 64.8 mol s−1 during high solar energy availability. In addition, the maximum energy discharge capacity of the system is evaluated to be 7924.2 kWh. Several parametric studies are also conducted, and the performances are studied comprehensively through energy and exergy efficiencies under various conditions. The developed system entails the advantages of high energy density as well as longer storage times as compared to other energy storage methods. [ABSTRACT FROM AUTHOR]

A new multigeneration system is proposed to utilize solar energy and biomass sources in a combined manner for cleaner production. The useful commodities of electricity, freshwater, cooling, ammonia and hydrogen are produced. A biomass based integrated gasification combined cycle system is used that is integrated with a solar tower thermal power plant. Also, the reverse osmosis entailing saline water treatment system is incorporated. Furthermore, a thermoelectric generator is deployed to generate power through the excess heat contained in the syngas produced. The developed system is analysed and assessed through thermodynamic analyses. The proposed system provides an increase in the overall efficiencies of renewable energy systems through new waste heat recovery approaches. The energy efficiency of the overall system is evaluated as 20.1% and the exergy efficiency of the overall system is determined to be 21.1%. However, the energy efficiency of the solar tower power plant is determined to be 14.7% and the exergy efficiency is found to be 15.6%. The hydrogen and ammonia production rates are 20 g/s and 79 g/s, respectively. A parametric analysis is carried out to assess the effects of varying operating conditions and system parameters on the system efficiencies. • A new integrated system with biomass based integrated gasification combined cycle. • Multigeneration of electricity, cooling, freshwater, hydrogen and ammonia. • Hydrogen and ammonia production capacities of 20 g/s and 79 g/s respectively. • The overall energy and exergy efficiency of the system is 20.1% and 21.1%. [ABSTRACT FROM AUTHOR]

In this study, a novel hybrid thermal energy storage and ammonia fuel cell system is developed and investigated for a solar tower based power plant. An annual analysis of the developed system is performed by considering the monthly average days. Also, the actual power demands as well as the solar intensity changes are taken into account. Thermodynamic approaches of energy and exergy analyses are utilized for system analysis. The energetic efficiency of the proposed power plant varies between 5.3% and 37% while the exergy efficiency ranges between 5.7% and 39%, depending on the corresponding power demands as well as available solar energy. The system simulation results for each month are also described in terms of the specific exergies and enthalpies at the turbine inlets. Furthermore, energy efficiency of the direct ammonia fuel cell is evaluated to be 37% and the exergy efficiency is found to be 34% at the peak power density. At a temperature of 500 °C, a specific thermal energy storage capacity of 266 kJ kg−1 is determined for the hybrid system. • A novel solar tower based power generation system is developed. • A hybrid thermal energy storage and ammonia fuel cell system is introduced. • The energy efficiency of the developed system varies between 5.3% and 37%. • The exergy efficiency of varies between 5.7% and 39%. [ABSTRACT FROM AUTHOR]