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This paper proposes a novel combined cooling, heating, and power (CCHP) system integrated with molten carbonate fuel cell (MCFC), integrated solar gas-steam combined cycle (ISCC), and double-effect absorption lithium bromide refrigeration (DEALBR) system. According to the principle of energy cascade utilization, part of the high-temperature waste gas discharged by MCFC is led to the heat recovery steam generator (HRSG) for further waste heat utilization, and the other part of the high-temperature waste gas is led to the MCFC cathode to produce CO 3 2−, and solar energy is used to replace part of the heating load of a high-pressure economizer in HRSG. Aspen Plus software is used for modeling, and the effects of key factors on the system performances are analyzed and evaluated by using the exergy analysis method. The results show that the new CCHP system can produce 494.1 MW of electric power, 7557.09 kW of cooling load and 57,956.25 kW of heating load. Both the exergy efficiency and the energy efficiency of the new system are 61.69% and 61.64%, respectively. Comparing the research results of new system with similar systems, it is found that the new CCHP system has better ability to do work, lower CO 2 emission, and can meet the cooling load, heating load and electric power requirements of the user side at the same time. • A novel CCHP system coupling MCFC and ISCC system is proposed in this paper. • The effects of key factors on the system performances are analyzed and evaluated. • Performance variation rules of the new system with the change of DNI are revealed. • The new system performances are obviously improved compared with similar systems. [ABSTRACT FROM AUTHOR]

Hydrogen is rapidly turning into one of the essential energy carriers for future sustainable energy systems. The main reason for this is the possibility of off-peak excess power production and storage of renewable stations such as wind farms, photovoltaic plants, etc. For hydrogen (itself) or its sub-productions methanol, ammonia, etc. Such energy systems are so-called power2X technologies. For hydrogen and other biogases, using a fuel cell is a promising method for returning the fuel to the power grid or electric cars in the form of electricity. In this paper, a novel hybrid energy system consisting of a molten carbonate fuel cell (MCFC) and different options to generate hydrogen from the waste heat of the MCFC is investigated. The system consists of two scenarios of weather using proton exchange membrane electrolyzer (PEME) of vanadium chloride (VCL) cycle. The article presents a comprehensive thermodynamic, economic, and environmental analysis of the system optimized by tri-objective optimization (as an innovative optimization) methods. The aim of the optimization task here is to minimize the costs and emissions while maximizing efficiency. A parametric study is conducted to see the effect of different design parameters on the system's performance. Results demonstrate that fuel utilization factor, stack temperature, and current density have the most critical effect on the system performance. In addition, the system coupled with the VCL cycle exhibits better performance than the system with PEME. In addition, at the optimized point, the efficiency, cost rate, and emission become 69.28%, 3.73 ($/GJ), and 1.16 kg/kWh, respectively. In addition, the produced hydrogen in VCL and PEME are 585 kg/day and 293 kg/day respectively. • The hybrid system based on gasifier and MCFC is modeled from 4E perspectives. • The cutting-edge tri-objective optimization is considered to minimize cost and emission and maximize the efficiency. • Two novel methods of producing hydrogen from waste heat is presented and analyzed in detail. • In optimum conditions, the exegetic efficiency and unit product cost become 69.28% and 3.73 ($/GJ) respectively. [ABSTRACT FROM AUTHOR]

Due to a high conductivity of about 0.1 S·cm−1, Li-Na-K carbonate eutectic and Sm-doped ceria composite material is a good electrolyte candidate for hybrid fuel cells operating between 500 °C and 600 °C. The present paper aims at a deeper understanding of the species and mechanisms involved in the ionic transport through impedance spectroscopy and thermal analyses, in oxidizing and reducing atmospheres, wet and dry, and during two heating/cooling cycles. Complementary structural analyses of post-mortem phases allowed us to evidence the irreversible partial transformation of molten carbonates into hydrogenated species, when water and/or hydrogen are added in the surrounding atmospheres. Furthermore, this modification was avoided by adding CO2 in anodic and/or cathodic compartments. Finally, a mechanistic model of such composite electrical behavior is suggested, according to the surrounding atmospheres used. It leads to the conclusions that cells based on this kind of electrolyte would preferably operate in molten carbonate fuel cell conditions, than in solid oxide fuel cell conditions, and confirms the name of "Hybrid Fuel Cells" instead of Intermediate Temperature (or even Low Temperature) Solid Oxide Fuel Cells. [ABSTRACT FROM AUTHOR]

• A novel integrated gas turbine, MCFC and ORC system with CO 2 recovery is proposed. • The exergy utilization diagram (EUD) methodology is applied to reveal the energy conversion process more clearly. • The temperature matching of the new system is optimized in this paper. • When the CO 2 capture rate is 0.85, the thermal efficiency of the new system is 62.34% and the exergy efficiency is 60.08%. A huge amount of energy is consumed by recovering CO 2 in the gas turbine (GT) exhaust gas with the traditional method because of the low CO 2 concentration. A new system integrated with gas turbine, MCFC and ORC with CO 2 capture is proposed in this article. CO 2 in the gas turbine exhaust gas is concentrated by the MCFC electrochemical reaction. Compared with traditional CO 2 capture methods, it effectively decreases the energy consumption of CO 2 capture. The mid-temperature exhaust gas heat is recovered by two stages organic Rankine cycle systems. The influences of the major parameters on the new system performance are deeply studied. Also, the thermal and economic performances of the new system are compared with those of the reference system without CO 2 capture and with CO 2 capture based on the traditional mono-ethanol ammine (MEA) method. The results show that, when the CO 2 capture rate is 0.85, the thermal efficiency of the new system is 62.34%, 3 percentage points higher than that of the gas steam combined cycle system without CO 2 capture; and the exergy efficiency is 60.08%, 2.47 percentage points higher than that of the gas steam combined cycle system without CO 2 capture. Its economic performance will be improved with the reduction of the MCFC cost in the future. [ABSTRACT FROM AUTHOR]

The paper presents a mathematical model of a molten carbonate fuel cell with a catalyst in the anode channel. The modeled system is fueled by methane. The system includes a model of the steam reforming process occurring in the anode channel of the MCFC fuel cell and the model of the cell itself. A reduced order model was used to describe the operation of the molten carbonate fuel cell, whereas a kinetic model describes the methane steam reforming. The calculations of the reforming were done in Aspen HYSYS software. Four values of the steam-to-carbon ratio (2.0, 2.5, 3.0, and 3.5) were used to analyze the performance of the reforming process. In the first phase, the reaction kinetics model was based on data from the literature. [ABSTRACT FROM AUTHOR]