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1.
Chemosphere ; 353: 141420, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38378051

RESUMO

The optimal utilization of biomass relies heavily on the specific material and individual needs. Cereal biomass by-products can potentially be employed in thermochemical processes such as pyrolysis and gasification. To compare biomass sources, ultimate analysis, biochar potential, proximate analysis, thermal gravimetric analysis, price per megajoule generated heat, surface texture, and availability are used. A global survey of biomass wastes and opportunities for heat generation is presented in the current article. Here, nine different cereal-based agricultural waste products (barley, wheat, millet, oats, rice, rye straw, sorghum straw/stalk, and maize cob) are studied. Cereal wastes are compared based on calorific value, water content, volatile matter, ash content and ash chemical composition, bulk density, charring properties, availability, and transportation. According to the estimate, 156 million metric tonnes per year, or 6% of India's total emissions, could be eliminated by rice husk alone. Wheat straws, on the other hand, can cut emissions by 2%. Additionally, processing these nine feedstocks might result in the production of 40 GW of electrical energy, which would increase the installed capacity of India's national electric grid by 9%.


Assuntos
Grão Comestível , Pirólise , Biomassa , Agricultura , Índia
2.
Environ Sci Pollut Res Int ; 31(12): 18171-18187, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36823466

RESUMO

Renewable cooling via absorption chillers being supplied by various green heat technologies such as solar collectors has been widely studied in the literature, but it is still challenging to get positive economic outcomes from such systems due to the large expenses of solar thermal systems. This study offers the use of a new generation of solar collectors, so-called eccentric reflective solar collectors, for driving single-effect absorption chillers and thereby reducing the levelized cost of cooling. This article develops the most optimal design of this system (based on several different scenarios) using multi-objective optimization techniques and employs them for a case study in Brazil to assess its proficiency compared to conventional solar-driven cooling methods. For making the benchmarking analyses fair, the conventional system is also rigorously optimized in terms of design and operation features. The results show that the eccentric solar collector would enhance the cost-effectiveness by 29%. In addition, using optimally sized storage units would be necessary to get acceptable economic performance from the system, no matter which collector type is used. For the case study, at the optimal sizing and operating conditions, the levelized cost of cooling will be 124 USD/MWh and an emission level of 18.97 kgCO2/MWh.


Assuntos
Energia Solar , Luz Solar , Temperatura Baixa , Temperatura Alta , Transição de Fase
3.
Chemosphere ; 346: 140409, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37832893

RESUMO

Biomass, including municipal solid waste, and solar energy are two of the inevitable sources for future decarbonized energy systems. Fresnel lens thermal collectors using cheap micro-structured foils is an interesting emerging medium-temperature solar thermal design that might be of high practical value, provided that its fluctuating output is managed. This study proposes a hybrid solar-waste solution using this type of collector for multi-generation via an Organic Rankine Cycle. The cycle is specially designed for supplying low-grade heat, power, and industrial heat (which is a very critical sector to be decarbonized) taking advantage of the generated stable solar-waste medium-temperature heat at zero emission level. To achieve this optimal design, the article conducts a thorough energy-exergy-economic-environment (4E) analysis of the system and employs the non-dominated sorting genetic algorithm (NSGA II) for the optimizations. A benchmarking analysis is also conducted to show the importance of industrial heat supply in this cycle. The results show that this hybridization, owing to the cheap and flexible heat delivery of the waste incinerator as well as the low cost of the solar collectors, is very effective for efficient and cheap multi-generation. Especially for industrial heat supply, the competitive levelized cost of energy (LCOE) of 23.96 €/MWh is obtained, which is way lower than today's achievable costs in the industry.


Assuntos
Incineração , Energia Solar , Incineração/métodos , Temperatura Alta , Resíduos Sólidos/análise , Temperatura
4.
Chemosphere ; 343: 140226, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37741369

RESUMO

The sorption-enhanced gasification systems, which integrate the gasification process with an in-situ CO2 capture system, have emerged as environmentally friendly solutions. This study proposes an innovative solar-based SEG system aimed at co-generating power and hydrogen while ensuring environmental sustainability. The suggested system comprises municipal solid waste gasification, in-situ calcium looping CO2 capture process, steam and humid air gas turbine secondary power cycles, and a CO2 liquefaction system. Comprehensive analysis including energy, exergy, and exergoeconomic evaluations are conducted to assess the overall system performance. The annual electrical energy efficiency of the system is calculated to be 11.9%, resulting in a net electrical power generation of 19.48 MW. The annual total energy efficiency is determined to be 54.8%. To convert the captured CO2 into a liquid form, a dual-pressure Linde-Hampson cycle with a coefficient of performance of 1.9 is employed. Among the system components, the carbonator reactor exhibits the highest exergy efficiency at 88.7%, while the sorption-enhanced gasifier, calciner, and combustion chamber show relatively higher exergy destruction. The heliostat field is identified as the most expensive component in the SEG system. The levelized cost of electricity (LCOE) for the produced electricity is calculated to be 60.1$/MWh.


Assuntos
Dióxido de Carbono , Vapor , Resíduos Sólidos , Hidrogênio
5.
Glob Chall ; 7(4): 2200203, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37020616

RESUMO

This work reports a technical, economic, and environmental investigation of the possibility of using a recently developed smallscale crossflow wind turbine (CFWT) to supply the energy demand of buildings for different integration scenarios. For this purpose, three CFWT-assisted building energy system configurations with heat pumps, with and without batteries, and two-way interaction with the local grid in two residential building models in Iran and Germany are investigated. Triobjective optimization with a Nondominated Sorting Genetic Algorithm (NSGA-II) is performed for finding the optimal configuration of the energy system in different configurations. For economic assessment, the Capital Budgeting Analysis method is used with four indicators, namely, payback period (PP), net present value (NPV), internal rate of return (IRR), and profitability index (PI). The results show that due to different energy market regulations and prices, different integration scenarios and system configurations can outperform others in Germany and Iran. Overall, due to the exchange rate instability and low energy tariff in Iran, in order for the project to be feasible, either the CFWT cost must fall to below 30% of its current cost or the local electricity price should increase significantly to get a Levelized cost of energy of as low as 0.6 $ kWh-1.

6.
ISA Trans ; 131: 246-263, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35525606

RESUMO

In the framework of the backstepping algorithm, this article proposes a new function approximation technique (FAT)-based compound learning control law for electrically-driven robotic manipulators with output constraint. The Fourier series expansion is adopted in the learning-based design to approximate unknown terms in the system description. The accuracy of FAT approximation is also studied by defining an identification error, which is derived from a serial-parallel identifier. Furthermore, the output constraint is taken into account by integrating the error transformation, the performance function and the dynamic surface control in a compact framework. Following this idea, new compound adaptation laws are then constructed. The proposed compound learning controller confirms that all the signals of the overall system are uniformly ultimately bounded, ensuring the tracking error within the predefined bounds during operation. Different simulation scenarios applied to a robotic manipulator with motor dynamics illustrate the capability of the control algorithm.


Assuntos
Dinâmica não Linear , Robótica , Redes Neurais de Computação , Algoritmos , Robótica/métodos , Simulação por Computador
7.
Ultrason Sonochem ; 58: 104701, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31450312

RESUMO

The most crucial step towards conducting experimental studies on thermophysical properties and heat transfer of nanofluids is, undoubtedly, the preparation step. It is known that good dispersion of nanoparticles into the base fluids leads to having long-time stable nanofluids, which result in having higher thermal conductivity enhancement and lower viscosity increase. Ultrasonic treatment is one of the most effective techniques to break down the large clusters of nanoparticles into the smaller clusters or even individual nanoparticles. The present review aims to summarize the recently published literature on the effects of various ultrasonication parameters on stability and thermal properties of various nanofluids. The most common methods to characterize the dispersion quality and stability of the nanofluids have been presented and discussed. It is found that increasing the ultrasonication time and power results in having more dispersed and stable nanofluids. Moreover, increasing the ultrasonication time and power leads to having higher thermal conductivity and heat transfer enhancement, lower viscosity increase, and lower pressure drop. However, there are some exceptional cases in which increasing the ultrasonication time and power deteriorated the stability and thermophysical properties of some nanofluids. It is also found that employing the ultrasonic horn/probe devices are much more effective than ultrasonic bath devices; lower ultrasonication time and power leads to better results.

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