Production of Synthesis Gas by Plasma–Steam Gasification of Solid Fuels with Different Ash and Volatile Matter Contents: An Experiment and Thermodynamic Calculations

Reduction in Specific Energy Consumption of Overall Biogas Upgrading and Biomethane Liquefaction Process: Energy and Exergy Analysis

Volatile matter values for solid fuels are used to assess their burning rates and, thus, provide a basis for the buying and selling of these fuels. The major factors that affect volatile matter yields are the type of fuel, moisture contents, and the heating rates used in the tests. This paper reports the results of experiments designed to improve the reliability and application of test methods for the determination of volatile matter in various solid fuels. The macro thermogravimetric analysis studies described herein include the rapid drying of analysis samples of coal and the effect on volatile matter yields, the heating of various chars at high temperatures to reach a state of constancy, the measuring of decomposition moisture, an “elusive” constituent in coal, and the cocombustion of coals and other solid fuels. The presence of residual moisture and decomposition moisture in the coal during the volatile matter tests increases the measured volatile matter yields even though the residual moisture has been factored out. The rates of heating solid fuels during volatile matter tests affect the volatile matter yields because of the presence of different types of moisture in the fuel that are released at different temperatures. The heating rates used in volatile matter tests affect the type of compounds released and the total volatile matter yields of coals and biofuels. The experiments reported in this paper were instrumental in the decision of ASTM Committee D05 on Coal and Coke to recently revise the classic volatile matter standard test method D3175 to change the temperature for drying sparking coals from 600°C to 107°C. The role volatile matter plays in the combustion of fuel blends is discussed in this article.

This paper investigates the application of alternative fuels in tube-and-wing aircraft configurations. Potential alternative fuel choices include biofuel, liquid hydrogen, liquefied natural gas, and ammonia. A comprehensive mission range starting from 2000 nautical miles to 8500 nautical miles is explored, designed, and analyzed using GENUS, an in-house built multidisciplinary design analysis and optimization platform. This paper aims to give a comprehensive study of different alternative fuel options and capacity combinations over different mission ranges. The different gradients of these trends demonstrate the additional benefits of using alternative fuels. The objectives of this study are 1) to determine how different fuel properties affect the designs and performance of aircraft and 2) to quantify the reduction of greenhouse gas (GHG) emissions by utilizing alternative fuel. The results show cryogenic fuel, which requires fuselage fuel tanks and/or external fuel tanks, will noticeably increase energy consumption due to drag and weight penalties. Yet, the high specific energy density properties of liquid hydrogen (LH2) will offset the penalties and result in a reduction in specific energy consumption (MJ/pax/nm), especially in a high-capacity, long-range mission. A 20.8 and 13.7% reduction in specific energy consumption is calculated between the use of kerosene-based jet fuel and LH2 for a 400 and 800 pax design with an 8500 nm mission range, respectively. In addition, the use of LH2 and biofuel can significantly reduce life cycle GHG emissions if the fuel is produced through sustainable pathways.

Modeling of heat transfer and energy analysis of potato slices and cylinders during solar drying

It is shown that when forming the composition of coal charges for coking, it is necessary to solve not only the problem of producing metallurgical coke with high physical and mechanical characteristics, but also to ensure optimal operating conditions and preservation of the furnace stock, taking into account the bursting pressure of coal raw materials. The article defines the bursting pressure, i.e. the pressure exerted by a coal mass that has passed into a plastic state, provided that it is deprived of the ability to expand freely. The main reason for the development of the burst pressure is the pressure in the plastic layer of vapour-gas products of thermal decomposition of coal, which is transmitted through the semi-coke-coke to the refractory wall of the heating wall of the coking chamber, causing its deflection. Based on the study of the plastic-viscous properties of coal concentrates by the Giseler method, the connection between the peculiarities of the plastic state of coal of different degrees of metamorphism and the bursting pressure (Pb), which it develops during coking, was confirmed. The minimum values of Pn were recorded for coals of grades DG, G, and GZh (Pbav = 2.5 kPa), the maximum values were recorded for coking and low-sintering coals (Pbav from 7.9 to 25.3 kPa). The correlation between the bursting pressure and genetic and technological properties of coal raw materials (volatile matter yield and vitrinite reflectance) was established. The regression equations for predicting the bursting pressure were developed taking into account the vitrinite reflectance, vitrinite and fuseness content, maximum fluidity temperature and volatile matter yield of the charge. The developed equations are characterised by high correlation coefficients r (0.89-0.9), which indicates their statistical significance and the possibility of using them to predict this indicator. The use of the proposed equations makes it possible to predict the bursting pressure using the data on the properties of coal concentrates, which must be determined at a coke plant to control the quality of raw materials. Keywords: bursting pressure, plastic-viscous properties, component composition, petrographic characteristics, volatile yield. Corresponding author D.V. Miroshnichenko, e-mail: dvmir79@gmail.com

Freshwater scarcity is a growing concern worldwide due to increasing demand and climate change. A promising method that could provide fresh water is seawater desalination. Presently, both thermal- and membrane-based desalination technologies consume a high amount of specific energy (measured in kWh/m3), which limits the use of seawater for drinking purposes. The development of hybrid desalination technologies has the potential to significantly reduce the energy consumption and cost of desalination, making it a more viable solution to address freshwater scarcity. By integrating the advantages of several desalination techniques and eliminating their drawbacks, hybridization can improve system performance. In the current study, a hybrid desalination system was developed by integrating the vacuum membrane distillation (VMD) output into the multi-effect distillation (MED) input. The results indicated a drop in specific thermal energy consumption (STEC) at various feed flow rates and a decrease in STEC in hybrid mode compared to stand-alone VMD.

The aim of this research is to develop a fundamentally new design scheme for a pneumatic separator of grain materials that will ensure a significant reduction in specific energy consumption of the preliminary grain cleaning process while maintaining high indicators of technological efficiency. The relevance of the work is determined by the necessity to solve a complex of problems in existing aspiration systems: high energy consumption (40–50% of total energy costs), significant non-uniformity in air flow velocity distribution (non-uniformity coefficient up to 25–35%), losses of full-value grain to waste (up to 3–5%), and insufficient adaptability to variable characteristics of grain material. The work presents a systematic analysis of existing designs of air systems for grain cleaning machines according to the principle of air flow creation (suction, pressure, combined), direction of air movement (ascending, horizontal, variable), and design features of aspiration channels (uniform cross-section, confusor, diffusor, variable cross-section). It has been established that the most energy-intensive are classical vertical systems with ascending flow, where air velocity approaches the floating velocity of the main crop grain (8.5–11.0 m/s depending on the crop). Three main directions for reducing energy consumption have been identified: ensuring air recirculation, optimization of geometric parameters, and using the method of indirect separation of light particles by deflecting their trajectory. An original design scheme of a pneumatic separator with a closed aspiration system has been proposed, implementing the principle of thin-layer movement of grain material with acceleration and deflection of light impurities trajectory by cross air flow. Theoretical justification of the acceleration chute parameters has been performed to ensure material movement in a single-grain layer, and mathematical dependencies between initial layer thickness, grain outflow velocity from the hopper, and required velocity at the entrance to the separation zone have been obtained. Research results showed that the most effective method for reducing specific energy consumption is the application of the light impurities deflection method combined with the use of closed aspiration. Reducing the grain flow thickness to a single layer allows minimizing resistance and pressure losses in the aspiration system. It has been established that accelerating grain material to a velocity of 2 m/s ensures the formation of a single-layer flow with specific productivity of 3.5 kg/(m·s), which corresponds to the indicators of general-purpose grain cleaning machines such as OVS-25. The proposed separator design combines structural simplicity, manufacturing efficiency, and the potential for significant reduction in energy consumption of the pneumatic separation process for grain materials.

Mosques are used five times a day according to the prayer schedule, which follows the sun's position. Indoor thermal conditions in air-conditioned mosques are maintained with a cooling time pattern that follows prayer times. Therefore, an effective air conditioning operating strategy is needed for energy efficiency. This study aims to investigate the effect of air conditioning intermittent operation time strategies on the energy usage of a mosque. It involves reducing the cooling period before prayer time and swapping active air conditioning periods from pre-prayer calls to post-prayer in the base case. Field measurements in Universiti Teknologi Malaysia – Kuala Lumpur (UTMKL) mosque and simulation using DesignBuilder software were conducted to predict annual specific energy consumption. The results indicate a reduction in specific energy consumption of 5% by operating the air conditioning 10 minutes before the call to prayer. Shifting the pre-prayer call-post prayer cooling period results in an insignificant reduction in energy consumption of 0.3-0.6%; however, it can accommodate extended periods of comfortable conditions for people who perform prayers outside of congregational prayers on time. Furthermore, the results indicate that the cooling period after the prayer time affects the cooling load of the following prayer. This study provides information for architects, engineers, and other stakeholders towards improving energy consumption in religious buildings with intermittent occupancy.

There in modern feed production, the task of grain grinding efficiency increasing is urgent. One of its promising solutions are the combined two-stage method involving sequential grain grinding first on a roller and then on a hammer’s grinder using. Studies have shown that, in compared with traditional single-stage hammer grinding, this method can significantly specific energy consumption reducing and the crushed product quality improving. In the course of experimental studies, obtained equations of regression were describing as the effect of the roll gap at the first stage and the sieve holes’ diameter at the second stage on the process functional and energy parameters, such as productivity, specific energy consumption, grinding degree, weighted average particle size, crushed product uniformity, and crushed product’s quality index receiving. Based on the obtained data, the optimal parameters of two-stage grinding were determined, ensuring a reduction in specific energy consumption in 30-46%, in depending on the required degree of grinding. In particular, it was found that in order to achieve the optimal degree of grinding, product uniformity and quality index (for fractions 0...2 mm and 0...3 mm), the roll gap’s rational values were 0,5 and 1,5 mm, and the diameter of the sieve’s holes were 4 and 6 mm, respectively. With these parameters, specific energy consumption was achieved in 30 and 46% reducing, productivity in 121 and 135% increasing, and the quality index reaches 95 and 99%. A production check of the improved two-stage grain crushing process by the DV-3 machine in comparison with single-stage hammer grinding the effectiveness of this method confirming. The two-stage grinding made it possible specific energy consumption from 10,5 to 5,8 kWh/t reducing, that is in 44.7% decreasing, and the crushed grain quality (in terms of quality) in 10,7% increasing.

Specific energy consumption reduction during pulsed electrochemical oxidation of phenol using graphite electrodes

Background.The use of solid fuels in household cooking contributes to indoor air pollution and is the cause of more than 4 million deaths around the world annually. Solid fuel use varies with the level of development and ranges from 0% in high-income countries to more than 80% in low- and middle-income countries. Three billion people (more than 40% of the global population) are still dependent on solid fuels like firewood, dung cakes, coal, wood and agricultural residues in these countries.Objectives.The present study aims to analyze the association of certain respiratory diseases (tuberculosis (TB), acute upper respiratory infections (AURI), chronic obstructive pulmonary diseases (COPD), and bronchial asthma) with the use of solid fuels for cooking across sociodemographic groups in India.Methods.The 71st round of the National Sample Survey, conducted in 2014, was used. In total, 54,985 inpatients who received medical treatment from any medical institution during the last 365 days preceding the survey and who reported various diseases, such as infections, cancers, blood diseases, cardiovascular diseases, and respiratory diseases were included in the analysis. Of these inpatients, 2513 participants who reported TB, AURI, COPD and bronchial asthma were considered the dependent variables in the study. The main variable was exposure to different types of fuels used as a primary source of energy for cooking. Multinomial logistic regression was used to explain associations.Results.The results reveal a significant association between solid fuel use and respiratory diseases in India. Overall, more than 60% of the population uses firewood and cow dung as their primary source of energy for cooking and are at a higher risk of TB, COPD and bronchial asthma. In rural areas there is a high dependence on solid fuels (80.5%) and a higher risk of respiratory diseases compared to those residing in urban areas where people are less dependent on solid fuels (22%). Among different socio-demographic groups, the dependence on solid fuels is highest among Scheduled Tribes (87.42%), followed by Scheduled Castes (74.78%) and Other Backward Classes (OBCs) (a term used by the Indian government to categorize castes that face social or educational challenges) (64.47%). Scheduled Tribes have the highest risk of TB, followed by Scheduled Castes and OBCs, respectively.Conclusions.Exposure to solid fuels for cooking increases the potential risk of TB, COPD and bronchial asthma. Access to clean and efficient fuels for cooking is essential to reduce the burden of respiratory disease. Measures are needed to increase the availability of clean fuels for households, especially among socially disadvantaged and marginalized groups, to reduce the burden of respiratory diseases in India.Competing Interests.The authors declare no competing financial interests

Reducing the energy intensity of the mechanical refining-based pretreatment process for producing lignocellulosic-derived sugars without significantly affecting enzymatic hydrolysis sugar yields is challenging. This work investigated the impact of different refining conditions on energy consumption, enzymatic sugar yields, minimum sugar selling price, and environmental impacts for the conversion of corn stover to sugars. A positive proportionate correlation between specific energy consumption and enzymatic sugar yields was observed when changing the refiner plate gap was changed, which agrees with other reported works. However, the correlation between specific energy consumption and enzymatic sugar yields is not straightforward when the rotational speed and refiner plate design change. We observed that, for a corn stover material with low consistency disc refining, specific energy consumption decreased by >50% by decreasing the rotation speed without affecting enzymatic sugar yields. By changing refiner plate designs, a 45% reduction in specific energy consumption could be achieved without affecting the glucose yield, albeit still with a detrimental impact on the xylose yield. Our high-fidelity disc refining model was able to predict the energy consumption for different refiner plate geometry designs and operating conditions. Techno-economic and life-cycle analyses indicate that the plate design and operating conditions have a direct impact on overall process power consumption and sugar yields, with sugar yields strongly dictating the minimum sugar selling price, the life cycle greenhouse gas emissions, and fossil energy consumption. To minimize the environmental impact and maximize process economics, optimization of the mechanical refining process should target maintaining high sugar yields, while lowering refining energy consumption.

<div class="section abstract"><div class="htmlview paragraph">Transportation sector in India accounts for 12% of total energy consumption. Demand of energy consumption is being met by the imported crude oil, which makes transportation sector more vulnerable to fluctuating international crude oil prices. India is mindful of its commitment in 2016 Paris climate agreement to reduce GHG emissions intensity of its GDP by 40% by 2030 as compared to 2005 levels. To fast track the decarbonization of transportation sector, commercial vehicle manufacturers have been exploring other viable options such as battery electric vehicles (BEVs) as a part of their fleet. As on today, BEV has its own challenges such as range anxiety & high total cost of ownership. Range anxiety can be certainly addressed by optimum sizing of electric powertrain, reduction in specific energy consumption (SEC) & use of effective regeneration strategies. Higher SEC can be more effectively addressed by doing vehicle energy audit thereby estimating the energy losses occurring at each powertrain component of an electric vehicle.</div><div class="htmlview paragraph">The work illustrated in this paper involves drive cycle-based energy audit & range estimation for 4X2 rigid electric truck using simulation approach. It involves strenuous exercise of simulation specific input data generation by doing rigorous component level tests for battery, motor, tires & auxiliaries. Duty cycle data was acquired for 3000 km & condensed cycle of 32 minutes was formed which represents real world usage pattern. Data recorded in component and vehicle tests was used to build robust simulation model in GT-DRIVE. Simulated SEC was validated within 4% with on road trails. 73.5% of battery discharge energy was used to overcome rolling resistance loss, aerodynamic drag loss, electromechanical conversion loss, auxiliary losses, braking losses & differential losses. Effective power at wheels observed to be 26.5% of total battery discharge energy. Sensitivity analysis for RAR, RRC, coasting & braking regeneration limits was carried out and effect of each parameter on final SEC was studied and optimum set of parameter combination was suggested to the OEM. Outcome of this project has also laid down the sophisticated methodology to carry out energy audit of any electric vehicle, which in turn will help to bring simulation predictions much closer to the real-world scenarios.</div></div>

To ensure compliance with dew point requirements and achieve low energy consumption in the natural gas dehydration process, this study utilizes Aspen HYSYS to simulate the natural gas dehydration process, using a gas field gathering station as an illustrative example. Through an in-depth analysis of operational parameters, we have successfully identified the optimal variables that significantly impact the energy consumption of the dehydration system. The Box-Behnken design (BBD) experimental design approach is employed, and parameter optimization is performed using the non-dominated sorting genetic algorithm (NSGA-II). Our findings indicate that variations in Tri ethylene glycol (TEG) circulation rate, reboiler temperature, and steam stripping rate are highly sensitive to energy consumption. Analysis of the Pareto front reveals that under similar dew point conditions before and after optimization, there is a notable reduction in specific energy consumption by 4.18% compared to the pre-optimization state. Conversely, when specific energy consumption is comparable, optimization results show a decrease in dry gas dew point by 1.92°C after optimization. Furthermore, comparison with optimization results obtained using HYSYS's built-in optimizer demonstrates reductions in both TEG circulation rate and steam stripping rate. In summary, the NSGA-II algorithm demonstrates superiority in reducing energy consumption and optimizing parameters by providing globally optimal solutions. This research presents an efficient solution for optimizing energy consumption in natural gas dehydration while enhancing process efficiency and economic benefits.

Study on Main Factors Influencing Acetylene Formation During Coal Pyrolysis in Arc Plasma