Ratio Of Energy Output Research Articles

Investigation of the Effect of Temperature on the Biofuel Performance of Hydrochar Obtained from Kidney Bean Shell

In this study, hydrochar products were obtained from kidney bean shell (KBS) biomass at different temperatures using the hydrothermal carbonization (HTC) method. Hydrochar products were produced at three different temperatures (200, 220 and 240 C) and a holding time of 90 minutes. Biomass/water ratio was taken as 1:10. Analysis techniques such as Thermogravimetric analysis (TG), Ultimate analysis and Fourier Transform Infrared Spectroscopy (FTIR) were used in the characterization of raw materials and hydrochar products. In addition, the fuel properties (high heating value, energy yield and energy densification ratio) of raw KBS and hydrochar products were also investigated. As the HTC temperature increases, the high heating value of hydrochar products increases. Among hydrochar products, the highest high heating value belongs to the product obtained at 240 C. The combustion behavior of raw and hydrochar a product was examined using the thermogravimetric analysis method and combustion parameters (Ti, Tb and Tm) were determined. As a result, this study has shown that the hydrochar product produced from KBS by hydrothermal carbonization method can be used as a biofuel material.

Environmental impact and energy balance assessment in ethanol production from sugarcane molasses: A life cycle analysis in southern India

Blending ethanol with fossil fuels is regarded as an important measure to reduce overall greenhouse gas emissions and the carbon footprint. However, there is a lack of comprehensive studies addressing overall greenhouse gas emissions and energy utilization during ethanol production from sugarcane in South India. This study represents a pioneering attempt to determine the emissions and resource utilization, enabling a comparison of the carbon footprint of the ethanol production process with that of using fossil fuels. The study employed the Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET) model to calculate greenhouse gas emissions and resource utilization. Data was obtained from field studies conducted at Gayatri Sugars Limited, Telangana state, India. The collected data was input into a life cycle analysis (LCA) model in which two cane trash treatment methods were evaluated: burning and mulching. In terms of emissions, the CO2 emissions for one ton of sugarcane were 43.86 kg during cultivation, 45.98 kg during transportation, 69.05 kg during burning of cane trash, and 6.37 kg during the production of one ton of ethanol. The overall energy yield ratio was found to be 15.795 MJ/MJf. Emissions from sugarcane farming and transportation stages were high, significantly contributing to a high carbon footprint. The net emission was significantly lower for the mulching process, which also improved soil characteristics and fertility. The outcomes provide valuable insights for academia, industrial decision-makers, and policymakers at both state and central government levels.

Improving the value of planting and breeding waste compost in agricultural applications: A zucchini cultivation case and circular agricultural models analysis

An important way of utilizing agricultural wastes to improve soil quality is the use of planting and breeding waste compost (PBWC). However, the impact of compost on agricultural production systems is unclear. Therefore, in order to study the effect of PBWC on crop growth, soil environment, and circular agriculture, PBWC [sheep manure (SM): tail vegetable (TV): corn straw (CS) = 6: 3: 1] was used based on chemical fertilizer reduction for zucchini production. In zucchini production systems, R9 (chemical fertilizer reduction by 30 % + 9,000 kg ha−1 PBWC) treatment was most effective in improving the quality and yield of zucchini fruits, mainly by improving the soil microenvironment, manifested in (1) increasing soil alkali-hydrolyzable nitrogen (AN) available potassium(AK), and soil organic matter (SOM), reducing EC, and improving C/N. (2) Increasing the richness and metabolic capacity of bacterial community. (3) Increasing the abundance of Proteobacteria, a phylum with absolute dominance (up to 32.46 %). Then, an optimization model of “summer corn − greenhouse zucchini − fattened sheep” was constructed to analyze the effect of changes in fertilizer dosage usage on the whole model. Compared with the local traditional recycling model, the optimized system reduced the ratio of inorganic to organic nitrogen input from 2.8:1 to 1.4:1, increased the recycling rate of nitrogen (N), phosphorus (P), and potassium (K) by 31.28 %, 50.84 %, and 30.25 %, respectively, and the net energy yield ratio (EYR) increased by 1.04. The optimized recycling system had significant economic and environmental benefits, which would become the basis for moving towards more sustainable farming. Overall, the circular agriculture model with PBWC returning as the core achieves sustainable production by improving material recycling and soil microenvironment. Therefore, chemical fertilizer reduction by 30 % combined with 9000 kg ha−1 PBWC can be used in practical production to improve the productivity of the circular agriculture model and achieve high yield and high quality crops.

Trinity – III. Quasar luminosity functions decomposed by halo, galaxy, and black hole masses as well as Eddington ratios from z = 0–10

ABSTRACT We present the redshift evolution of quasar luminosity functions (QLFs) decomposed by halo mass, galaxy mass, supermassive black hole (SMBH) mass, and Eddington ratio, as well as SMBH/radiative energy output ratios from trinity, a flexible empirical model that self-consistently infers the halo–galaxy–SMBH connection that match observational data. Key findings include: (1) The normalization of quasar luminosity function increases by ∼3–4 dex from z ∼ 10 to z ∼ 4, due to the fast mass build-up of different SMBH populations; (2) From z ∼ 4 to z ∼ 1, less massive galaxies and SMBHs make up bigger and bigger fractions of QLFs, due to the active galactic nuclei (AGNs) downsizing effect; (3) At z ∼ 0, massive haloes/galaxies/SMBHs are responsible for most bright quasars due to low Eddington ratios among all SMBHs; (4) The bright ends of QLFs are dominated by SMBHs that are at least 0.3 dex overmassive relative to the median SMBH mass–galaxy mass relation; (5) QLFs at z ∼ 6–7 are dominated by SMBHs accreting at Eddington ratios 0.1 < ηrad < 1, but super-Eddington AGNs contribute more significantly to QLFs towards z ∼ 9–10.

Developing a framework to evaluate the life cycle energy and greenhouse gas emissions of space heating systems using zeolite 13× as an adsorbent material

The wide use of fossil-based space heating systems results in significant greenhouse gas (GHG) emissions. Using solar energy for space heating can help reduce GHG emissions. However, solar energy generation is intermittent and the energy needs to be stored for continuous supply. The zeolite 13× adsorbent heat storage system for space heating is a promising alternative. There is very limited research on the life cycle GHG footprint of this type of adsorbent storage system. In this study, we developed a framework that integrates engineering design with life cycle assessment to evaluate the energy and emission performances of a zeolite 13×-based heating system charged by a solar air collector. A simulation model was developed for this adsorbent storage system. The life cycle GHG emissions of the residential heating system are estimated to be 0.1160 kg CO2 eq per kWh of the heat delivered over a 20-year lifetime. The operational phase contributes 74 % of the overall emissions because of the energy required by the humidifiers. The material production stage accounts for 25 %, mainly attributed to the upstream emissions in the manufacturing of photovoltaic thermal (PVT) air solar systems. The net energy ratio (NER), which is the ratio of energy output to fossil energy input, is 2.9. The continuous days without sunlight, the adsorbent vessel length-to-diameter ratio (L/D), and the pellet diameter of the zeolite 13× storage appear to be the parameters most sensitive to both emissions and NER. The uncertainty analysis shows emissions and NERs of the space heating system in the range of 97.2–152.3 g CO2 eq/kWh and 2.4–3.0, respectively. Compared with other alternative heating systems in the market, the adsorbent system has a much better GHG performance. The research highlights the importance of selecting a suitable space heating system given the high influence of operational energy on the life cycle emissions and the range of electricity generation emissions in different provinces.

Energy efficiency of lithium-ion batteries: Influential factors and long-term degradation

As the integration of renewable energy sources into the grid intensifies, the efficiency of Battery Energy Storage Systems (BESSs), particularly the energy efficiency of the ubiquitous lithium-ion batteries they employ, is becoming a pivotal factor for energy storage management. This study delves into the exploration of energy efficiency as a measure of a battery’s adeptness in energy conversion, defined by the ratio of energy output to input during the discharge and charge cycles. Energy efficiency values were systematically calculated over the course of the battery lifespan, revealing a predominantly linear trend in the efficiency trajectories, as substantiated by the Mann–Kendall (MK) trend test. Subsequently, a linear model was proposed to represent the efficiency degradation. Further analysis shows that ambient temperature, discharge current, and cutoff voltage all affect energy efficiency in different ways. Using the energy efficiency and its behavior observed in this study, Battery Management Systems (BMS) can improve the energy efficiency of batteries by adjusting operating conditions or developing better management strategies.

Energetic-environmental-economic assessment of utilizing weak black liquor to produce syngas for replacing evaporation based on coal water slurry gasification

As the main pollutant of paper mills, black liquor has brought great pressure to the wastewater treatment process of paper mills. Based on the coal-water slurry gasification (GS-CWS) technology, this paper designed the gasification system of black liquid coal-water slurry (GS-BLCWS) by utilizing weak black liquor of pulp mills, investigated and modeled the energy requirements of the GS-BLCWS. Feasibility assessment of the GS-BLCWS and the traditional alkali recovery systems (TARS) were carried out, including energy efficiency, economic feasibility and environmental impacts. The comparison results showed that the steam demands of two technologies can be self-sufficient. But the total energy efficiency of GS-BLCWS (69.78%) is higher than that of the TARS integrating GS-CWS (63.07%), and the energy output ratio of black liquor increased from 9.9% to 69.78%. From an economic point of view, GS-BLCWS can generate syngas, which can be used for drying in the papermaking workshop and shows better economic efficiency. Meanwhile, GS-BLCWS has lower environmental impacts that there is no emission of sulfur oxides and particulate matter. Considering the short payback period (5.81 years) of GS-BLCWS, the small environmental impact, and the self-sufficiency of steam and electricity, it has broad application prospects.

Evolution between bright and dark pulses in a MoxW1-xTe2 based fiber laser.

We proposed an erbium-doped fiber laser mode-locked with a MoxW1-xTe2-based nonlinear optical modulator for the first time to our best knowledge. This fiber laser can deliver bright pulses, bright-dark pulse pairs, dark pulses, bright-dark-bright pulses, and dark-dark-bright pulses. The modulation depth and saturation intensity of the MoxW1-xTe2-based saturable absorber were about 7.8% and 8.6 MW/cm2, respectively. When 10% of the laser in the cavity was output, conventional soliton pulses with central wavelength of 1560.1 nm can be obtained in the cavity. When 70% of the laser was output, dual-wavelength domain-wall dark pulses appeared in the laser cavity. This experiment revealed that an appropriate increase in the ratio of output energy can improve the chance of dark pulses in fiber lasers. The mode-locking states in this fiber laser can evolve with each other between bright pulses, bright-dark pulse pairs and dark pulses by adjusting the polarization controller. The results indicated that the MoxW1-xTe2 can be used to make modulators for generating dark pulses. Furthermore, our work will be of great help to improve the chance of the generation of dark pulse in fiber lasers.

Steam co-gasification characteristics of black liquor char and petroleum coke coupled with TiO2 direct causticization

The isothermal steam gasification experiments of a ternary mixture (BTP) containing black liquor char (BLC), causticizing agent (TiO2) and petroleum coke (PC) were carried out at 850 °C based on a thermogravimetric analyzer (TGA) and a horizontal fixed-bed reactor. A co-gasification process of BLC and PC coupled with TiO2 direct causticization was explored from the aspect of reaction rate as well as the characteristics of gaseous products and gasification residues (GR). The results show that in comparison to the weighted average (BTPtheo) of the independent gasification of TiO2 direct causticized BLC and PC, significant synergistic effects could be aroused during the coupled co-gasification process due to promoting action of mNa2O·nTiO2 on gasification of organic carbon. Specifically, the maximum reaction rate of BTP reaches 7.0%/min, which is 2.9 times that of BTPtheo. The content and yield of effective gas components, i.e., H2+CO, in the gas products, as well as its lower heating value (LHV) of BTP are 81.1%, 2059 mL/g, and 9343 kJ/m3, respectively, which is 6.8%, 137.3%, and 5.5% higher than that of BTPtheo. The carbon conversion and energy output ratio of BTP reaches 95.0% and 1.13, respectively, which is increased by 61.6% and 135.4% relative to the theoretical superposition value. In addition, the relative loss of inorganic salts in BTP during the whole thermochemical conversion process is effectively controlled at a lower level of about 9.4%. Since the Na-containing salts in GR of BTP are mainly mNa2O·nTiO2 with higher thermal stability, and GR maintains good particle flowability, it is conducive to downstream alkali recovery.

Исследования техногенного воздействия взрывного разрушения горных пород при освоении месторождений полезных ископаемых открытым способом

The topicality of this research is defined by the increasing volume of mining operations near settlements and production infrastructure, as well as by the increasing unit capacity of mining and haulage equipment and, consequently, by the growing volume of rock mass simultaneously blasted and prepared for excavation. Changes in the mining conditions at the operations of UK Kuzbassrazrezugol JSC have been analyzed. A brief analysis of research results on various factors affecting the degree of man-made impact of the blasting operations is presented. One of the ways to safely increase the volume of simultaneously blasted rock mass is the introduction of energy-saving environmentally friendly technologies in production and use of plastic explosives, which would ensure higher completeness of chemical transformations and the efficiency of the blast through the use of special fuel mixtures containing surfactants instead of diesel fuel in the compositions of granular industrial explosives. This will increase the contact surface area of the fuel and the oxidizer by several orders of magnitude as well as the stability and the energy-output ratio of the blasting charges with the zero oxygen-combustible balance. Reducing the consumption of explosives, energy intensity of mining, the man-made impact of blasting operations on the environment, the seismic action of the blast, the radius of the hazardous zone - all of this can be achieved by using charges placed in hoses of variable diameter when blasting wet and dry rock masses. The article shows the dependence of changes in the load on the atmosphere with increasing distance from the blast epicenter and with increasing weight of simultaneously detonated explosives in surface mining operations, as well as the dependence between the yield of fines and the size of the gap between the charge and the charging chamber.

Thermal model in digital twin of vertical PV system helps to explain unexpected yield gains

The business case of novel integrated applications of solar energy is often regarded as a straightforward extrapolation of standard solar parks. But when the design of the solar park is remarkably different from typical solar parks, the operating conditions of the PV panels could also be changed. We have applied the digital twin to an R&D location with nine rows of eight bifacial PV panels in a vertical east/west orientation with varying row-row distances. We simulated the in-plane irradiances, based on measured GHI, which turned out to be in good agreement with observations of in-plane irradiances. But, using default free-standing PV heat transfer coefficients, the modelled module temperatures were too high and the simulated module powers too low. Applying an in-house developed method, we found that the heat transfer coefficient Uc is nearly double, and the vertically placed modules operate at a much lower temperature. The adjusted value for Uc leads to a 2.5% higher annual energy yield and higher performance ratio, partially offsetting the energy loss due to the less than optimal configuration. In conclusion, the digital twin increased the understanding of the vertical PV system and support future decision making, for instance for the application of vertical PV in combination with agriculture, where the low ground coverage ratio of vertical PV matches well with the needs from the agricultural sector.

Defining an Annual Energy Output Ratio between Solar Thermal Collectors and Photovoltaic Modules

Photovoltaics (PV) and Solar Thermal (ST) collectors are sometimes competitors, as investment capacity, energy demand, and roof space are limited. Therefore, a ratio that quantifies the difference in annual energy output between ST and PV for different locations is useful. A market survey assessing the average price and performance both in 2013 and 2021 was conducted, showing a factor of 3 cell price decrease combined with a 20% efficiency increase, while ST showed negligible variation. Winsun simulations were conducted, and the results were plotted on the world map. Despite variations due to local climate, the ratio of energy production (ST/PV) increases at lower latitudes mainly due to (a) higher air temperature increasing ST output but decreasing the PV output; (b) solar radiation reducing ST efficiency to zero while having a minor impact on PV efficiency. The ratio was calculated for several ST operating temperatures. For latitudes lower than 66°, the ratio of a flat plate at 50 °C to a PV module ranges from 1.85 to 4.46, while the ratio between a vacuum tube at 50 °C and a PV module ranges from 3.05 to 4.76. This ratio can support the decision between installing ST or PV while combining different factors such as energy value, system complexity, and installation cost.

Efficiency of cycling exercise: Quantification, mechanisms, and misunderstandings.

The energetics of cycling represents a well-studied area of exercise science, yet there are still many questions that remain. Efficiency, broadly defined as the ratio of energy output to energy input, is one key metric that, despite its importance from both a scientific as well as performance perspective, is commonly misunderstood. There are many factors that may affect cycling efficiency, both intrinsic (e.g., muscle fiber type composition) and extrinsic (e.g., cycling cadence, prior exercise, and training), creating a complex interplay of many components. Due to its relative simplicity, the measurement of oxygen uptake continues to be the most common means of measuring the energy cost of exercise (and thus efficiency); however, it is limited to only a small proportion of the range of outputs humans are capable of, further limiting our understanding of the energetics of high-intensity exercise and any mechanistic bases therein. This review presents evidence that delta efficiency does not represent muscular efficiency and challenges the notion that the slow component of oxygen uptake represents decreasing efficiency. It is noted that gross efficiency increases as intensity of exercise increases in spite of the fact that fast-twitch fibers are recruited to achieve this high power output. Understanding the energetics of high-intensity exercise will require critical evaluation of the available data.

Performance evaluation and feasibility analysis of 10 kWp PV system for residential buildings in Saudi Arabia

In recent years, Saudi Arabia has begun to introduce a small-scale solar PV system that will significantly impact three key aspects of Saudi Arabia: energy cost, environment, and technology development. This paper aims to evaluate the performance and feasibility of a 10 kWp Photovoltaic system for housing buildings in various locations around Saudi Arabia. The performance of a 10 kWp Photovoltaic plant is first analyzed using Solargis PV Planner software to compare four types of PV modules based on their performance ratio and energy yield. Then, an economic analysis for installing PV systems for residential buildings in eleven main cities in Saudi Arabia is performed using PVsyst software with two electricity tariff scenarios. The simulated results indicate that the a-Si PV technology has the highest energy yield and performance ratio, and all types of PV modules have performance ratios greater than 75%. Furthermore, the results show that Tabuk city is the best location for installing a PV system for residential buildings. The levelized cost of energy (LCOE) is 0.027 $/kWh, and 330.88 tons of carbon dioxide (tCO2) reduction in greenhouse gas emissions per year. The first scenario has a net present value of $23626.1, while the second scenario has a net present value of $9633.6.

Potential of Machine Learning Based Support Vector Regression for Solar Radiation Prediction

AbstractMeasurements of the solar radiation quantities profoundly affect on the energy output ratios. A decline in solar radiation measurements in many countries, which is due to reasons high cost, difficulty of measurement that necessitated developing different methods to estimate the proportion of solar radiation. Many empirical models have been developed using special variables and coefficients, such as Angstrom and Prescott models. The development of machine-learning algorithms makes these algorithms as a possible application instead of the empirical models to decrease the error rate and obtaining better results. In this paper, radial basis function is applied as the kernel function of support vector regression (SVR) method to calculate the amount of monthly average daily of the global solar radiation in four sites in Egypt. Five variables used as input (sunshine duration, air temperature, relative humidity, solar declination angle and extraterrestrial solar radiation). The experimental results have a good estimation in all locations according to root mean square error, however, this study proved that SVR models can be as an efficient machine-learning technique with a higher accuracy.

Fault Location Scheme for Abnormal Grounding Point in Isolated Ground Wire of Large-Scale Clean Energy Transmission

There is a large number of grounding switches along the isolated ground wire for the de-icing in the large-scale wind farm. If any of these grounding switches are left open by accident, this can create an unexpected abnormal grounding point in the isolated ground wire. Based on the analysis of the output power of de-icing devices, the output power of different poles can be applied for the abnormal grounding point fault location. Since the rise of output current to the rated current of de-icing devices requires a long time to build up, the protective relay may lock the de-icing device before the output current reaches the rated current. Thus, the ratio of output energy of two poles can be selected to locate the abnormal grounding point. This study verified this location method by conducting a large number of simulations.

Design and Analysis Performance Solar Power Plant 15 kW By Maximizing Final Yield and Performance Ratio In Small-Medium Office

The 15 kW solar power plant (PLTS) is a new certain in the application of small-medium solar energy usage, especially for the campus environment in Indonesia which can support and become proof of realization green campus program. The existence of 15 kW PLTS become an attention to do advanced analysis in order that production of the specific electric energy or final yield (YF) and performance ratio (PR) from a PLTS can be monitored based on installation location. The value of YF and PR can be used as reference to do identification, trouble operation analysis, and developing of a PLTS. The optimum value of YF and PR on the 15 kW PLTS resulted by doing simulation from a simulator software, which the value resulted from location and configuration of the system installation without watch shading factor. And then the simulation value compared with electric energy real production result on this 15 kW PLTS. The 15 kW PLTS divided be two lines, that are 5 kW and 10 kW line. From simulation result, showed that in the 5 kW line have value of optimum production is 5264.8 kWh with PR 83,1% and in the 10 kW line have value of optimum production is 7687.2 kWh with PR 83.12%. Real production in line 5 kW is 1326.9 kWh with difference 74.79% with simulation and in line 10 kW is 1643.3 kWh with difference 78.62% with simulation. The shading and existing disturbances resulted in a decrease in electrical energy production and performance in the line 5 kW is YF 0.91 hours/day with CF 2.79% and in the line 10 kW is YF 3.07 hours/day with CF 11.73%.

Management of off-specification compost by using co-hydrothermal carbonization with olive tree pruning. Assessing energy potential of hydrochar

In this work the management of a waste called off-specification compost (OSC) was proposed via hydrothermal carbonization (HTC). The composition of this residue makes it not suitable for agronomic purposes because of the Spanish regulation requirements. Therefore, a way of management and/or valorisation needs to be found. The energy recovery through co-HTC with olive tree pruning (OTP) was evaluated. Blending of OSC with lignocellulosic biomass allows to obtain a coal-like product with physicochemical properties similar to those of a lignite, characterised by its high carbon content. Blends of 25, 50 and 75% of OSC with OTP were analysed. The individual OSC does not present good parameters for being used as solid fuel based on its chemical composition, however, the blend of 75% of biomass with 25% of OSC does. With a higher heating value of 26.19 MJ/kg, this blend shows the best energy yield and energy densification ratio. Thermogravimetric and kinetic analysis reveal that as biomass content in the blend increases, the more the hydrochar behaves as a solid fuel, therefore OSC can be used for energy purposes while its current use of landfill disposal can be reduced.

Evaluation of the Potential of Agricultural Waste Recovery: Energy Densification as a Factor for Residual Biomass Logistics Optimization

The use of residual forms of biomass, resulting from processes of transformation of the agri-food and/or forest industries, presents itself as an alternative with high potential for energy recovery, given the existing availability, both from the perspective of quantities, but also from the perspective of geographic distribution. In this work, samples of four by-products originating from the agri-food industry were collected, namely coconut shells, sugarcane bagasse, cashew nutshells, and palm kernel shells, which were characterized in the laboratory by determining their Thermogravimetric and Elemental analysis, subsequently calculating the High Heating Value, Low Heating Value, Hardgrove Grindability Index, Mass Yield, Energy Yield, and Energy Densification Ratio. The values obtained show the potential to optimize logistical operations related to transportation, demonstrating that energy densification operations, especially if associated with physical densification processes, enable the use of these residual forms of biomass in the replacement of fossil fuels, such as coal.

Microwave processing of sunflower achenes and its influence on their quality and enzymes activities.

Stricter requirements to environmental compatibility and smaller energy-output ratio highlight the importance of implementing the super high-frequency drying of the crop seeds. The study is aimed at the development of drying optimal parameters and modes of sunflower (Helianthus annuus L.) seeds in a settled small-size conveyor microwave unit. In-gel activity of 6 functionally key enzymes (formate dehydrogenase, glutamate dehydrogenase, malate dehydrogenase, diaphorase, leucine aminopeptidase and non-specific esterases) in polyacrylamide gels after disk electrophoresis was analyzed in order to count on an additional assessment of the temperature influence caused by electromagnetic radiation of the tested drying unit on the sunflower achenes metabolism. The correlation analysis showed the existence of the statistically significant (р < 0.05) negative dependence between the seed materials heating temperature with germination energy (correlation coefficient -0.783) and achenes germination (-0.797). These two parameters (without processing 88 and 96%, respectively) began to reduce sharply when reaching the heating temperatures of 55℃ and more. Enzymes de-activation also started within this range. Considering the collected data about drying of the seed material, the optimal heating conditions were within 26-27 minutes at 800 W and heating temperature 38-40° С. With these parameters the quality of the processed seeds was preserved, and the costs for drying were relatively low (2.61 MJ per 1 kg of the water removed).