The use of solar energy to produce solar fuels, such as CO and H2, by the reforming reaction between CH4 and CO2 is a promising technology to alleviate the global warming effect caused by CO2. The carbon dioxide reforming of methane (CRM) reaction is an endothermic reaction, and can only be carried out at a high temperature. The photo-thermochemical CRM method is studied, in which solar energy is directly concentrated on Ni/CeO2 catalyst to reduce the CRM reaction temperature. XRD and SEM are used to characterize the composition and morphology of Ni/CeO2 catalyst. And the synergetic effects of light and heat in photo-thermochemical reactions are investigated. The results show that photo-thermochemical reactions have higher CH4 conversion and production rate of H2 than thermochemical reactions at the same temperature. It is found that photo-generated carriers play an important role in improving CRM performance. These findings provide a promising way to consume CO2 and achieve the goal of carbon neutrality.
The goal of this paper is to present a dynamic model of an integrated energy system based on Near-InfraRed faÃ§ade panels and their validation. The innovative solution has been developed in the framework of the â€˜ENVISIONâ€™ European Project funded by the EU H2020 Programme. The whole system integrates the ENVISION faÃ§ade panels with a mGT, a prototype heat pump, and two thermal storages composing an innovative microgrid. This paper briefly describes the whole system and the model of each component together with the main characteristic equations. The work is mainly focused on the model development and validation of the solar-faced panelsâ€™ systems and the heat pump and its single components. The model will be used to evaluate the impact of the temperature variation of the warm water produced by the panels over the heat pump performance and responsivity and to define the proper integration strategy. The validation of the solar faÃ§ade panels model and the HP model has been carried out using experimental data and the results showed that the realized models have reliability of more than 98%.
This paper intends to present the experimental results of an integrated polygeneration system based on innovative thermal solar faÃ§ade panels working with Near-InfraRed (NIR) radiation. The research goal is the evaluation of thermal energy performances of the integrated system based on innovative NIR faÃ§ade panels and including different other devices for thermal and electrical energy production (i.e. prototype heat pump and CHP mGT). The innovative solution has been developed in the framework of â€˜ENVISIONâ€™ H2020 European Project whose aim is the demonstration of a full renovation concept that harvests energy from all available building surfaces allowing visible aspects to be retained. In this paper, the â€˜ENVISIONâ€™ Southern Demosite, located at the Savona University Campus (one of the venues of the University of Genoa), is presented together with the description of the solar panelsâ€™ main characteristics, their site installation, and the thermal power calculation performed using experimental data.
A transcritical CO2 heat pump-air conditioning system with ejector and integrated mechanical subcooling (EJ-IMS) is proposed for heating and cooling. The energetic and exergetic performance are discussed compared with baseline transcritical CO2 system (BASE), conventional transcritical CO2 with ejector (EJ), and transcritical CO2 system with integrated mechanical subcooling (IMS). The results indicate a maximum coefficient of performance (COP) is achieved for EJ-IMS, which is improved than other studied systems. EJ-IMS can significantly reduce the optimum discharge pressure. The compressor and gas cooler show the highest irreversible loss. EJ-IMS shows the best annual performance factor (APF), and Haikou has the highest APF.
In order to build an accurate model of heavy-duty gas turbine, a dual-driven approach is proposed based on operational data and intelligent genetic programming considering rotational speed, inlet/outlet temperature, pressure and generation power. The input-output thermodynamic characteristics of the compressor are obtained by genetic programming and net generation power of gas turbine is expressed by polynomial fitting formula equation, whose coefficients are obtained by least square method. Results show that all the models to calculate temperature ratio, pressure ratio and air mass flow ratio of compressor have a good accuracy, which of temperature ratio can reach 0.01. The accuracy of model to calculate generation power value can reach 0.04. This method for holistic modelling can be applied to other kinds of heavy-duty gas turbine.
Since the Paris Agreement adopted in 2015, global societies are increasingly aware of the needs to limit global warming to 1.5 ï‚°C and reach global carbon neutrality by 2050. However, current commitments of global societies are not sufficient, party owing to the lack of cost-effective decarbonization measures. The SolarEV City concept is proposed for cost-effective urban decarbonization combining rooftop PV with EV through bi-directional charging in a city scale. In this study, we conducted techno-economic analyses to test the concept in Paris and Ile-de-France. PV+EV systems are found to add value to rooftop PV systems raising self-consumption and self-sufficiency, when the roof coverage by PV is reached to 50-60% for Paris and 20-30% for Ile-de-France, allowing to bypass expensive stand-alone battery storage. The system allows CO2 emissions reduction through accelerated development of EV.
Stricter ecological standards in combination with increasing demand for transportation of perishable cargo, demand changes in shipping industries in the years to come. Until more ecological power systems are implemented, increasing energy efficiency, and reducing carbon footprint have become a priority for shipping industries. Due to smaller greenhouse gas emissions, LNG-powered vessels are gaining more attraction and when LNG is used, considerable waste cold energy can be utilized. In this research, waste cold heat of LNG is used for precooling of outside air for cargo hold ventilation. It is shown that by precooling the air with LNG waste cold heat, the energy consumption of transported refrigerated containers can be reduced up to 25%.
Electrochemically-mediated amine regeneration (EMAR) is a new CO2 capture technology with the potential to exploit the excellent removal eï¬ƒciencies of thermal amine scrubbers while reducing parasitic energy losses and capital costs. Copper ions as an important intermediate active substance, itâ€™s electrochemical characteristics in EMAR system have a great influence on the efficiency of the system. In this study, a systematic study was carried out on the electrochemical characteristics of copper ions in the EMAR system. Anionic NO3- and SO42+ are identified more suitable for this system than Cl-. The reduction performance of copper ions will decrease, when the Cu(â…¡) complex is formed with MEA. However, after CO2 absorption, part of MEA in the solution will react with CO2 to form carbamate, and the reduction performance of the Cu(â…¡) complex will also be improved. For the cycling performance, a low current density is beneficial to improve the circulation performance of copper ions. The minimum regeneration energy consumption of the EMAR system obtained in the experiment is only 51.26 KJ/mol CO2, which is extremely competitive compared with thermal scrubbing CO2 capture process.
The catalytic suppression of the pyrolytic onset temperature of Eucalyptus grandis using three fertilising agents is presented. K2CO3 and K3PO4 successfully decreased the onset temperature with a maximum suppression of -71 Â°C (10.2 % K2CO3) and -49 Â°C (10.5 % K3PO4). Higher loadings may achieve a maximum temperature suppression of Î”T(K2CO3)= – 94 Â°C and Î”T(K3PO4)=-55 Â°C. This implies that substantial energy savings for the synthesis of biochar via pyrolysis are to be expected as a result of this considerable temperature suppression. BET surface area, porosity and ion exchange capacity may have also been enhanced in-situ but is yet to be evaluated.
When coupling the Free Piston Engine (FPE) to the Permanent Magnet Linear Synchronous Machine (PMLSM) to produce electrical energy, its intrinsic multi-directional and non-linear dynamics have been typically described in a simplified mono-directional and linear fashion when considering a system-level modelling approach. This paper presents a detailed, multi-directional, multi-domain model of the FPE and PMLSM. The model was implemented in an opposed-piston free-piston engine configuration and validated against experimental data captured from a prototype with identical parameters. The simulation results indicate a strong correlation to the experimental data, which captured the dominant dynamics of the FPE and proved the satisfactory accuracy and performance of the model. This study considers the characteristic multi-directional nature and non-linearity of the machine dynamics and its interactions with multi-physical domains such as electrical, mechanical, and pneumatic.