Energy Consumption Of Process Research Articles

Evaluation of primary frequency regulation in Dominican Republic mine using scooptrams and electric trucks as battery storage systems

The use of electric vehicles in the mining sector aligns with the growing demand for tools that reduce energy consumption in productive processes. This study investigates how electric mining vehicles with vehicle-to-grid (V2G) technology can be integrated into power grids to improve system stability and frequency regulation. In the context of mining operations and the provision of auxiliary services (such as primary frequency regulation) to an interconnected electrical system, a regulatory framework that enables V2G integration should be established. This issue is addressed through a case study involving DIgSILENT PowerFactory simulations. The goal is to evaluate the productive process of a mine and the contribution of V2G technology to the primary frequency regulation of the electrical system under different scooptram integration parameters and battery electric trucks. This study also explores the challenges of V2G implementation in the absence of a regulatory framework. Different configurations of electric scooptrams and shovel that can affect frequency regulation are assessed. The obtained optimal configuration involves two truck loaders and three shovel loaders; the capacity of the current electrical infrastructure can support this configuration without affecting the capacity of the mine's electrical system. The simulations verify that applying V2G technology to mining vehicles helps stabilise the frequency of electrical systems and reduces the probability of component failure.

Optimization of Energy Consumption in Formaldehyde Production Process Using Reboiled Absorption Process

Formaldehyde is a crucial chemical building block in various industries, and its production often involves energy-intensive processes. This study focuses on optimizing energy consumption in formaldehyde production, explicitly employing the reboiled absorption process with a production capacity of 27,000 tons per year. The objective of this article is to develop a more energy-efficient process of formaldehyde synthesis by addition or refrigerant cycle stream to preserve the energy, reducing energy consumption and improving the sustainability of the process. The reboiled absorption process involves the absorption of formaldehyde gas into a liquid absorbent, followed by reboiling to release the absorbed formaldehyde. A comprehensive analysis of the entire production system compares unmodified and modified process simulations, heat integration, and energy analysis. Beside the energy consumption of the process, the number of stages within the absorption process contributes to the product mass flow rate of the overall process by increasing the surface area which mass transfer can occur. However, adding too many stages to the process may negatively impact the energy efficiency of the process. Therefore, optimizing energy consumption and absorption processes in formaldehyde production is essential to improve the sustainability of the process and increase the overall profitability of the production process. The results show that the proposed method dramatically improves the sustainability of CH2O synthesis by reducing overall energy consumption and emissions by 93.978%, reducing energy consumption from 153,735,360.4 kJ/h to 9,256,646.618 kJ/h. Copyright © 2024 by Authors, Published by Universitas Diponegoro and BCREC Publishing Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Enhancing Machinability and Sustainability: The Effects of Hybrid MQL+CO2 Cooling on the Drilling of AA7075T6 with TiO2 and C-Reinforced Composites

This study investigates the impact of various auxiliary cooling techniques on machinability, energy consumption, carbon emissions, and economic factors in the drilling process of AA7075T6 aluminium alloy using TiO2 and C-reinforced composites. The study employed various cooling conditions (dry, MQL, CO2, and hybrid MQL+CO2), with different cutting speeds and feed rates, to evaluate their effects on drilling characteristics. The findings indicated that the combined MQL and CO2 cooling notably enhanced the drilling process by reducing cutting forces by 32% and surface roughness by 65% compared to dry cutting. This synergy between lubrication and cooling significantly improves machinability, resulting in higher-quality machining outputs with smoother surfaces and more precise circularity. Energy analysis revealed that the MQL+CO2 method reduces energy consumption to 64% observed under dry conditions, underscoring its efficiency through better heat dissipation and reduced friction. Furthermore, this method demonstrates a significant reduction in carbon emissions, contributing to environmental sustainability. Economically, although initial costs associated with the implementation of cooling systems are higher, they are offset by reduced tool wear and energy costs, making it a viable solution for sustainable manufacturing practices.

Experimental investigation on the preparation of macroscopic 0–1 mm powdered coal by a vertical spindle mill

The vertical spindle mill (VSM) is the key equipment to realize the preparation of 0–1 mm fuel used in powdered-coal-fired circulating fluidized bed combustion technology (PC-CFB). In this paper, a pilot-scale VSM test system was set up to explore the feasibility and operating performance of coarse-grained pulverized coal preparation. The effects of loading force, table revolution rate, and ventilation rate on the product size distribution, as well as the energy consumption of the grinding process were emphatically discussed. The results show that the product size of VSM increases with the decrease of loading force and the increase of ventilation rate, but too small a loading force will affect the normal output of VSM. Additionally, the product size of VSM decreases firstly and then increases with the increase of table revolution rate. Further, the energy consumption of the powdered coal preparation process was quantitatively described, and a semi-empirical model of comminution energy based on the powdered coal particle size distribution was proposed and verified by the measured values with an average accuracy of ±30 %. This model can estimate the power consumption of the mill, which can be used as an input parameter of the heat balance calculation model for the PC-CFB pulverizing system.

Process Energy and Material Consumption Determined by Reaction Sequence: From AAO to OHO

The anaerobic-anoxic-oxic (AAO) process is one of the most widely used processes for treating industrial organic wastewater, and it has shown significant effectiveness in the removal of organic compounds, as well as denitrification and phosphorus removal. However, for the treatment of industrial organic wastewater, this anaerobic preposition and aerobic postposition process has exposed various limitations. Therefore, for this type of wastewater, the oxic-hydrolytic and denitrification-oxic (OHO) treatment process has been proposed and developed based on the principles of three-sludge separation and fluidization. This study integrated operational data from 203 coking wastewater treatment plants worldwide, and the two-step nitrification-denitrification activated sludge model No.3 (TCW-ASM3) was used for comparative analysis of the pollutant removal efficiency and total operating cost of the AAO process and the OHO process in the face of characteristic pollutants in coking wastewater. The results indicate that the full-scale OHO process achieved removal efficiencies of up to 3784 mg/L for chemical oxygen demand (COD) and 297 mg/L for total nitrogen (TN). The theoretical total cost for OHO and AAO were 9.75 and 14.38 CNY/m3, respectively. The pre-treatment aerobic process effectively reduces the biological toxicity of high-toxicity and refractory industrial wastewater, and the three-sludge system provides a stable living space for functional microorganisms, the combination of multi-mode denitrification processes offers new possibilities for treating similar types of industrial wastewater.

Ultrasound-assisted extraction of bioactive compounds from longan seeds powder: Kinetic modelling and process optimization

Investigating the extraction of bioactive compounds represents a hopeful direction for maximizing the value of longan fruit byproducts. This study explored the influence of ultrasonic-assisted extraction (UAE) parameters—specifically ultrasonic power ratios, temperatures, and exposure times—utilizing water as a green solvent on several properties of the longan seeds extract (LSE). These properties encompassed the energy consumption of the UAE process (EC), extraction yield (EY), total phenolic contents (TPC), total flavonoid contents (TFC), and antioxidant activity (DPPH). Additionally, the study sought to optimize the conditions of UAE process and examine its thermodynamic properties. A three-level, three-factor full factorial design was utilized to assess the effects of different factors on LSE properties. Results indicated that EC, EY, TPC, TFC, and DPPH were significantly influenced by power ratios, temperatures, and exposure time. Moreover, the proposed models effectively characterized the variations in different properties during the extraction process. The optimized extraction conditions, aimed at minimizing EC while maximizing EY, TPC, TFC, and DPPH radical scavenging activity, were demonstrated as an ultrasonic power ratio of 44.4 %, a temperature of 60 °C, and an extraction time of 17.7 min. Optimization led to 563 kJ for EC, 7.85 % for EY, 47.21 mg GAE/mL for TPC, 96.8 mg QE/mL for TFC, and 50.15 % for DPPH radical scavenging activity. The results emphasized that the UAE process exhibited characteristics of endothermicity and spontaneity. The results provide valuable insights that could inform the enhancement of extraction processes, potentially benefiting industrial utilization and pharmaceutical formulations.

Local Self-Assembly of Dissipative Structures Sustained by Substrate Diffusion.

The coupling between energy-consuming molecular processes and the macroscopic dimension plays an important role in nature and in the development of active matter. Here, we study the temporal evolution of a macroscopic system upon the local activation of a dissipative self-assembly process. Injection of surfactant molecules in a substrate-containing hydrogel results in the local substrate-templated formation of assemblies, which are catalysts for the conversion of substrate into waste. We show that the system develops into a macroscopic (pseudo-)non-equilibrium steady state (NESS) characterized by the local presence of energy-dissipating assemblies and persistent substrate and waste concentration gradients. For elevated substrate concentrations, this state can be maintained for more than 4 days. The studies reveal an interdependence between the dissipative assemblies and the concentration gradients: catalytic activity by the assemblies results in sustained concentration gradients and, vice versa, continuous diffusion of substrate to the assemblies stabilizes their size. The possibility to activate dissipative processes with spatial control and create long lasting non-equilibrium steady states enables dissipative structures to be studied in the space-time domain, which is of relevance for understanding biological systems and for the development of active matter.

Off-design performance analysis of supercritical CO2 mixture Brayton cycle with floating critical points

The thermodynamic performance of supercritical CO2 (sCO2) Brayton cycle deteriorates significantly due to the mismatch between the cold source temperature and the working fluid’s critical point. Here, we present the first study on the off-design performance of a novel supercritical CO2 mixture Brayton cycle with floating critical points. A distillation based regulation subsystem is integrated into the power cycle to dynamically adjust the circulating composition of the binary CO2 mixture, thereby making its critical point float with the ambient temperature and achieving good temperature matching. The off-design behavior of the system operating with the representative mixture is investigated based on an in-house code. The influence of trigger conditions of critical point regulation on energy consumption of the regulation process is investigated. When the maximum temperature difference of the design points for consecutive days is set to 3 °C, the equivalent power consumption can be limited to 2.34 × 106 MJ per year, which affects the annual efficiency by less than 1 %. The results confirms that using the floating critical point method can improve the annual efficiency by 7 %-10.9 % and improve the specific output power by 6.1 %-9.4 % compared to the sCO2 cycle, depending on the power plant locations.

Enhancing subsequent kraft fiber dewatering properties by using fiber polyamide-epichlorohydrin (PAE) treatment to prepare a dry pulp product,

The energy needed for the dewatering and drying of wet paper web represents around half of the energy consumption of papermaking processes. The present work examined whether the dewatering and drying of paper could be enhanced during a previous pulp drying process by pretreating the fibers with polyamide-epichlorohydrin (PAE). According to the hypothesis, the cured PAE restrains swelling and water absorption of water-wetted fibers by forming a fiber-bound, self-crosslinked polymer-network on the fiber surfaces. The hypothesis was tested by adding PAE to never-dried kraft pulp slurry followed by pulp thickening, drying, and final curing of the PAE-resin. After this, the PAE-treated fibers were dispersed in water, and their water retention values (WRV) and Shopper-Riegler values (○SR) were measured. The PAE pretreatments notably decreased the fibers´ WRV and ○SR, indicating improved water removal of paper web in the paper machine forming and drying section. Compared to chemical crosslinking pretreatments, which also can be used to decrease fibers WRV and ○SR-value, a notable advantage of PAE-pretreatment is milder required curing conditions of the PAE, which makes implementation of the method easier in practice. Due to decreased fiber-to-fiber bonding capability, the PAE-treated specialty fibers could take advantage especially as a bulking aid of paperboard, tissue, and absorbent materials.

Process-based modeling of energy consumption for multi-material FDM 3D printing

Purpose This paper endeavors to create a predictive model for the energy consumption associated with the multi-material fused deposition modeling (FDM) printing process.Design/methodology/approach An online measurement system for monitoring power and temperature has been integrated into the dual-extruder FDM printer. This system enables a comprehensive study of energy consumption during the dual-material FDM printing process, achieved by breaking down the entire dual-material printing procedure into distinct operational modes. Concurrently, the analysis of the G-code related to the dual-material FDM printing process is carried out.Findings This work involves an investigation of the execution instructions that delineate the tooling plan for FDM. We measure and simulate the nozzle temperature distributions with varying filament materials. In our work, we capture intricate details of energy consumption accurately, enabling us to predict fluctuations in power demand across different operational phases of multi-material FDM 3D printing processes.Originality/value This work establishes a model for quantifying the energy consumption of the dual-material FDM printing process. This model carries significant implications for enhancing the design of 3D printers and advancing their sustainability in mobile manufacturing endeavors.

Mixed rare earth metals production from surface soil in Idaho, USA: Techno-economic analysis and greenhouse gas emission assessment

Rare earth elements are crucial for the development of cutting-edge technologies in various sectors, such as energy, transportation, and health care. Traditional extraction of rare earth elements from soil and ore deposits primarily involves chemical leaching and solvent extraction. Environmental-based biological rare earth element extraction, such as bioleaching, can be a promising alternative to mitigate pollution and hazardous wastes. We investigated the sustainability aspects (techno-economic and environmental impact) of mixed rare earth metals production from soil in Idaho, USA. We focused on the bioleaching of surface soil using techno-economic analysis and “cradle-to-gate” life cycle assessment. The system boundary included collection, transportation, bioleaching, and molten salt electrolysis. Our results revealed that the mixed rare earth metals (including Nd, Ce, and La) production costs approximately $10,851 per metric ton and generates 1.9 × 106 kg CO2 eq./ton. Our results showed that most emissions are due to energy consumption during bioleaching. Over a 100-year time horizon ultrasound-assisted bioleaching can reduce greenhouse gas emissions by approximately 91 % compared to the traditional bioleaching process by decreasing the organic acid leaching process time and energy consumption. Our work demonstrates that higher solids loading in leaching with biological reactions can promote economic feasibility and reduce chemical wastes.

Subnanometer‐sized CuOx Clusters on TiO2 as Active Photocatalysts for Ammonia Production from Photocatalytic Nitration Reduction Reaction

AbstractThe Haber‐Bosch process is commonly used to produce ammonia while consuming energy and yielding huge emissions of carbon dioxide. Finding an alternative way to produce ammonia sustainably is a promising research direction with less CO2 emission. Photochemical nitrate reduction reaction (NtRR) to ammonia (NH3) could solve the nitrate pollutant problem in water and approach to produce ammonia with a more environmentally friendly process and lower energy consumption. In this work, the subnanometer‐sized copper oxide clusters decorated on titanium oxide nanoparticles (CuOx‐TiO2) were synthesized through the hydrothermal method and calcination treatment. CuOx‐TiO2 demonstrated impressively conversion rate of NO3− to NH3 with a yield of 153.09 μg‐gcat−1‐h−1 in KNO3 solution. The characteristic structure analysis revealed CuOx clusters with ~less than 1 nm decorated on TiO2 nanoparticles. From in‐situ X‐ray absorption fine structure (XAFS) spectroscopic technique, the transformation of the oxidation state of Cu clusters and the changes of local structure in the CuOx‐TiO2 were observed. The photocatalytic reaction mechanism of nitrate reduction on the CuOx‐TiO2 was successfully revealed. These discoveries have broad implications for the functional advancement of catalysts based on subnanometer‐sized clusters. Our findings may pave the way for exploring advanced ammonia synthesis routes with reduced energy consumption and carbon emissions.

The operation strategy of river water source heat pump cold source system in a chemical industrial park in a region with hot summers and cold winters

At present, the energy consumption of the whole process of buildings in China accounts for 45 % of the total energy consumption of the country, and the carbon emissions account for 50.6 % of the total emissions of the country. Among the energy consumption of buildings, air conditioning energy consumption occupies a major proportion, about 2/3. Traditional air conditioning cooling mainly uses refrigerants such as Freon to circulate and cool under high temperature and high pressure, which not only has high energy consumption but also can cause the external environment temperature to be too high. River water source heat pump is a renewable energy technology that can use water bodies including groundwater, surface water such as rivers, lakes, reservoirs and oceans. This project mainly studies the operation strategy of related units using river water as the cold source in a chemical industrial park in Chongqing, from unit selection, establishment of energy consumption model to unit operation strategy analysis and research, to achieve the best state of energy utilization.

A self-reinforcing cycle hypothesis in heart failure pathogenesis.

Heart failure is a progressive syndrome with high morbidity and mortality rates. Here, we suggest that chronic exposure of the heart to risk factors for heart failure damages heart mitochondria, thereby impairing energy production to levels that can suppress the heart's ability to pump blood and repair mitochondria (both energy-consuming processes). As damaged mitochondria accumulate, the heart becomes deprived of energy in a 'self-reinforcing cycle', which can persist after the heart is no longer chronically exposed to (or after antagonism of) the risk factors that initiated the cycle. Together with other previously described pathological mechanisms, this proposed cycle can help explain (1) why heart failure progresses, (2) why it can recur after cessation of treatment, and (3) why heart failure is often accompanied by dysfunction of multiple organs. Ideally, therapy of heart failure syndrome would be best attempted before the self-reinforcing cycle is triggered or designed to break the self-reinforcing cycle.

Energy optimization of hydrogen liquefaction process via process knowledge combined with multivariate Coggin's algorithm

Sustainable and cost-effective transportation of hydrogen is one of the major challenges to futuristic hydrogen value chain. Hydrogen, in its produced form, exhibits low energy density and large volume, rendering it highly unsuitable for transportation, particularly over extended distances. Liquefaction is one of the promising approaches to improve hydrogen's energy density and to make it more compact. However, liquefaction is an energy intensive process, raising the cost of transportation. In this study, the specific energy consumption of the hydrogen liquefaction process is aimed to reduce through knowledge-based optimization followed by optimization using the multivariate Coggin's algorithm to improve energy and economic profiles of the process. Design variables, composite curve, exergy, and economic analyses are performed to evaluate and compare the thermodynamic, economic, and environmental feasibility of the optimized process. The results depict a significant reduction (14.3%) in specific energy consumption to 9.40 kW/kgLH2 without increasing process complexity. Further key improvements include a massive drop in refrigerant flowrates (9.2%), annualized cost (m$ 0.15), and annual CO2 emissions (1008.45 tCO2/annum). The largest exergy destruction is observed in CHX-201, reflecting further room for improvement. These results underscore the potential for optimizing hydrogen liquefaction processes to enhance energy efficiency, process economics and environmental impact, providing valuable insights for researchers and industry professionals seeking to advance hydrogen liquefaction technologies. However, challenges remain in the comprehensive evaluation of chemical exergy for ortho- and para-hydrogen and in conducting advanced exergy analyses to further optimize hydrogen liquefaction processes without adding complexity.

Recovery of rare earth elements from sedimentary rare earth ore via sulfuric acid roasting and water leaching

Rare earth elements were extracted using a sulfuric acid roasting-water leaching process. The effect of acid roasting on a new type of low-grade sedimentary rare earth ore found in Guizhou Province, China was analyzed using X-ray diffraction and scanning electron microscopy. A systematic study was conducted on process parameters such as amount of acid, roasting temperature, roasting time, water leaching temperature, and leaching time. The results reveal that the total recovery of rare earth elements reaches 81.37%, which is 3.1 times higher than that achieved through direct acid leaching, under the optimal conditions. In addition, the leaching rate of heavy rare earth elements reaches 72.53%. Rare earth elements and some other valuable metals are transformed into soluble sulfate through the local decomposition of clay minerals under the action of the sulfuric acid attack. The dissolution rates of aluminum, iron, and titanium ions are 34.94%, 17.05%, and 62.77%, respectively. The precipitation rate of Ti reaches 99%, and the loss of rare earth ions in the solution is less than 1%. Meanwhile, the results of a leaching kinetics analysis indicate that the leaching process of rare ions is controlled by diffusion. Precious metal ions such as iron and aluminum in the leaching solution can reduce the adsorption of rare earth ions by kaolinite. This study efficiently recovered rare earth ions under conditions of low calcination temperature and direct water leaching, resulting in reduced energy consumption of the extraction process and acidity of the leaching solution. These findings provide a solid foundation for the further separation and extraction of rare earth ions.

Production of ammonium nitrate for nitrogen recovery in a single bioreactor operating at pH 3

Ammonium nitrate (AN), i.e. NH4NO3, is extensively utilized in agricultural, mining, and civil construction sectors, with an annual production of approximately 16 million tons. Although the biological nitrification processes has been proven to be an important alternative to overcome the intensive energy consumption of the conventional chemical process for AN production, it necessitates ample chemical input for stable performance. This study marks the first demonstration of stable AN production from ammonium-rich wastewater employing a purely microbial-derived one-stage process, without the need for external chemical addition. This process functioned through an acidophilic ammonia-oxidizing bacteria (AOB), i.e., Candidatus (Ca.) Nitrosoglobus, which oxidized the ammonium in the feed to nitrite while simultaneously reducing the reactor pH to 3.2−3.4. Under these pH conditions, nitrite was chemically oxidized to nitrate with the provision of oxygen. Long-term bioreactor operation (>230 days) revealed consistent AN production from high ammonium wastewater at a nitrogen loading rate of 0.15 kg N/m3/d. Batch tests revealed that microbial ammonium oxidation was the rate-determining step in the overall AN production process. Further microbial enrichment and process optimization can enhance the microbial ammonium oxidation rate. In summary, the proposed acidic one-stage bioprocess presents a promising avenue for AN production from ammonium-rich wastewater.

Holistic evaluation of ceramic clay properties with Sargassum spp. ash replacement

This paper aims to analyze the effect of adding sargassum ash as a mineral additive in ceramic clays sintered in a conventional oven to obtain construction materials with lower consumption of raw materials while providing an appropriate destination to stranded sargassum. The characterizations of the components were performed by X-ray fluorescence spectroscopy, loss on ignition, X-ray diffraction, particle size distribution, and real specific mass. The specimens were sintered in an electric oven and exposed to maximum temperatures of 800 ºC, 900 ºC and 1000 ºC. The influence of 10 % and 20 % sargassum ash content on ceramic clay performance was evaluated through physical and mechanical tests. Samples with 10 % sargassum ash sintered at 900 °C and 1000 °C had the best mechanical properties. A Life Cycle Assessment (LCA) was used to compare ceramics with sargassum ash to other conventional materials, such as ceramic clay used in tiles. The high energy consumption in the sintering process is the greatest contribution to most environment impact. As such, it is possible to add 10% sargassum ash sintered at 900 °C as a clay replacement, reducing environment impacts and enhancing the performance of the materials.

Mechanism analysis and performance evaluation of clean and efficient recovery of N-heptanol/N-hexanol from wastewater via extractive distillation with green mixed entrainer

A clean and sustainable process for separating n-heptanol/n-hexanol/water industrial mixing system by extractive distillation via mixing organic solvent with ionic liquid as an entrainer was proposed. The mechanism of intermolecular microscopic interaction was explored by quantum chemistry calculation. By using multi-objective optimization, the optimal operating parameters of the process were obtained. In addition, process intensification technology was introduced, which improved the problems of high cost and high energy consumption in the conventional extractive distillation process. Finally, multiple performances were evaluated and analyzed for different processes. It was found that the coupled heat integration and heat pump technology to assist the extractive distillation process saved 10.45% in terms of economy, reduced gas emissions by 49.00%, and reduced energy consumption by 48.99% compared to the basic extractive distillation process. This confirmed the reliability and feasibility of implementing the process intensification technology. This work demonstrates the application of organic solvent mixed with ionic liquid as entrainer and process intensification technology in the extractive distillation process, providing guidance and reference for the design of the extractive distillation process.

Streamlining IoT-driven Data Using Blockchain

The integration of Internet of Things (IoT) technology has revolutionized data collection and analytics, creating vast networks of interconnected devices generating large volumes of data. However, this rapid expansion of IoT ecosystems introduces significant challenges related to data security, integrity, scalability, and privacy. Blockchain technology, with its decentralized and immutable nature, emerges as a compelling solution to address these challenges. This paper explores the synergy between IoT and blockchain, examining how blockchain can streamline IoT-driven data by providing secure data exchanges, enhancing transparency, and facilitating scalability. The study investigates the key mechanisms through which blockchain can mitigate common IoT data issues. It considers blockchain's role in ensuring data integrity by utilizing cryptographic methods, enabling traceability through distributed ledgers, and protecting against unauthorized data manipulation. Furthermore, it explores the potential of blockchain-based smart contracts to automate processes and improve interoperability among IoT devices. The paper delves into specific use cases, such as smart cities, demonstrating how blockchain can effectively streamline IoT data across various industries. The findings highlight that while blockchain offers substantial benefits, it also introduces unique challenges, including high energy consumption, latency concerns, and complex integration processes. This concludes with a discussion of Security concerns, Comparison with existing solutions. By addressing these challenges, blockchain can become a pivotal technology in streamlining IoT-driven data, paving the way for more secure, efficient, and trustworthy IoT ecosystems.