Energy Reuse Research Articles

Shape recovery effect and energy absorption of reusable honeycomb structures

When using auxetic honeycomb structures to create repeatable energy-absorbing components, a key challenge is selecting the appropriate unit configuration for effective functional integration. In this work, four typical honeycomb structures were prepared, and the mechanical behaviors, shape recovery effects, and energy absorption properties of three types of auxetic honeycomb structures re-entrant honeycomb (RH), arrow honeycomb (AH), and star honeycomb (SH) were compared with those of hexagonal honeycomb (HH) through quasi-static loading–unloading tests. The findings indicate that the 3D printed polyurethane (TPU) honeycomb structures demonstrate robust shape recovery, stable energy absorption, notable stress softening characteristics. The recovery behaviors can be characterized by three distinct phases, namely hyperelastic, transitional, and viscoelastic. The unit configuration significantly influences the shape recovery capability, with apparent elastic modulus and stability of the energy absorption efficiency determining the overall shape recovery capability. The loading method also affects the energy absorption and dissipation patterns in different honeycomb structures. In terms of specific energy absorption (SEA), AH has the highest rating, with RH and SH at 86 % and 50 % of the SEA of AH respectively. The number of reusable cycles is primarily dictated by the specific configuration of the unit type. In scenarios involving reusability, the energy absorption capacity of the TPU honeycomb can only reach 70 % of its original energy absorption capacity. This study may inform the application of auxetic materials in reusable energy absorbers.

Analysis of the Factors Influencing the Purchase of Electric Vehicles in Brazil

The transport sector, and especially the increase in individual vehicle ownership, contribute significantly to air pollution. The transition to electric vehicles (EVs) is seen as a sustainable alternative to reduce emissions of polluting gases. However, in Brazil, the EV market has not yet reached a significant size. Given this scenario, this study aims to analyze the factors that influence the decision to buy EVs in Brazil, highlighting personal, psychological, economic, performance, and environmental variables and barriers. The aim is also to develop a model with guidelines that can help stakeholders. The quantitative stage of the study involved a survey of 514 respondents. The data were analyzed using statistical methods, including structural equation modeling (SEM), which allowed for a deeper investigation of the proposed hypotheses. The survey findings reveal that, in the Brazilian context, performance factors—such as autonomy, availability of recharging infrastructure, and maintenance—are the main drivers influencing EV purchase decisions. Environmental factors, including energy reuse, pollution reduction, and minimizing environmental impacts, have also gained significant importance. Economic factors are crucial, particularly concerning cost–benefit perceptions. The differences between Brazil and other regions highlight the importance of accounting for cultural and economic variations when analyzing consumer behavior towards EVs.

A Review: Recent Advances of Piezoelectric Photocatalysis in the Environmental Fields.

Piezoelectric photocatalysis can effectively suppress the recombination of electron holes during the course of photocatalysis, which has been widely applied in environmental and energy catalysis. Its advantage is that when the piezoelectric effect happens, a built-in electric field is formed inside the catalyst, which improves the separation efficiency of photogenerated charge carriers and obtains more excellent photocatalytic performance. The efficient conversion of mechanical energy to chemical energy can be realized through the synergistic effect of the piezoelectric effect, and photocatalysis is greatly significant in solving the energy crisis and providing environmental protection. Therefore, we organized a more complete review to better understand the mechanism and system of piezoelectric photocatalysis. We briefly introduce the principle of the piezoelectric effect, the existing types of piezoelectric photocatalysts, the practical application scenarios, and the future challenges and feasible methods to improve catalytic efficiency. The purpose of this review is to help us broaden the idea of designing piezoelectric photocatalysts, clarify the future research direction, and put it into more fields of environmental protection and energy reuse.

Multistage data center cooling system for temperature gradation and matching

A prototype of a multistage cooling system with a cooling capacity of 20 kW is assembled and studied. The traditional single-stage system is split into two sub-systems according to the temperature level, which reduces the temperature difference and irreversible heat transfer loss, and further improves the system's energy efficiency. The system mainly features three modes including free-air cooling, refrigeration-based cooling and waste heat recovery, which can achieve efficient cooling while capable of recovering the waste heat to the surrounding heat users. The efficiency of the proposed cooling and heat recovery system was assessed by measuring its energy reuse effectiveness (ERE). The energy savings and environmental benefits of the system were analyzed across five cities in China, each representing different climates. Results indicate that the system achieved an ERE of 0.91 in Beijing, 38.9 % lower than the national average of the city. Additionally, an economic analysis showed a payback period of less than two years for the proposed system across all climates considered, which is 30 % shorter than that of a single-stage cooling system.

Energy management strategy of integrated adaptive fuzzy power system in fuel cell vehicles

Fuel cell vehicles are a reliable solution to address energy shortages. However, when the road conditions are complex, the system distributes power unevenly between fuel cells and lithium batteries, and cannot effectively absorb the energy generated by braking. In response to this issue, an adaptive control strategy is adopted to allocate the required power of the car to two types of batteries in real time. Fuzzy logic is used to continuously optimize the relevant parameters of the controller based on the vehicle state, and a multi-island genetic algorithm is used to optimize the control strategy, enhancing the global search ability of the control strategy and increasing the vehicle’s ability to absorb and reuse the energy generated by braking. The experiment findings denote that the optimized control strategy increases the remaining capacity of lithium batteries by an average of 1.67%, increases energy recovery by an average of 135 W, increases the overall energy recovery rate by an average of 2.8%, and reduces vehicle fuel consumption by an average of 0.24 L/100 Km. It can be concluded that the optimized adaptive fuzzy control strategy can reduce the probability of over-charging and discharging of lithium batteries and improve the battery life. Meanwhile, the optimized strategy can improve the energy reuse rate, reduce vehicle fuel consumption, lower usage costs. The optimized strategy provides a reference for subsequent research on energy management of fuel cell vehicles.

Visible-light driven O2-to-H2O2 synchronized activation of peroxymonosulfate in Z-scheme photocatalytic fuel cell for wastewater purification with power generation

Antibiotics are recognized as emerging contaminants with non-biodegradation, complex structures, and abundant chemical energy, which are difficult to treat and recover energy through traditional wastewater treatment processes. A Z-scheme photocatalytic fuel cell (PFC) system, comprising C3N5 and CuO/Cu2O dual-photoelectrodes, has been developed for simultaneous power generation and degradation of antibiotics, such as berberine hydrochloride (BH). Especially, the C3N5 with its suitable energy potential for peroxymonosulfate (PMS) activation is synchronized with CuO/Cu2O, resulting in enhancing the performance of PFC system. Moreover, the interaction between PMS and Cu(I)/Cu(II) active sites on the photocathode can enhance the formation of highly reactive species (HRS) in the PFC-PMS system, thereby improving photocatalytic oxidation performance. Under visible-light illumination for 120 min, PFC-PMS system can rapidly and effectively oxidize BH (ca. 99.2 %, k = 0.0039 min−1) with simultaneous power generation (0.018 mW cm−2). This approach presents a promising approach for both water cleanup and energy reuse applications.

NiTi alloy helical lattice structure with high reusable energy absorption and enhanced damage tolerance

NiTi alloy lattice structures are crucial for reusable energy absorption due to their shape memory effects. However, existing NiTi alloy lattice structures always suffer from localized deformation bands during loading, causing local strains to exceed the recoverable strain limit of the alloy and significantly reducing their reusable energy-absorbing capacity. In this study, we developed a NiTi alloy helical lattice structure (HLS) to effectively prevent localized deformation bands. This is attributed to its struts distributing stress and strain uniformly through torsional deformation, thereby alleviating local stress concentrations and suppressing the formation of localized deformation bands. Additionally, its unit cells provide mutual support and reinforcement during deformation, effectively preventing the progression of localized deformation bands. The NiTi alloy HLS exhibits superior reusable energy absorption compared to previously reported reusable energy-absorbing materials/structures and enhanced damage tolerance under large compression strain. This study provides valuable insights for the development of high-performance reusable NiTi alloy energy-absorbing lattice structures.

Sustainability Indicators to MSW Treatment Assessment: The Rio de Janeiro Case Study

The Brazilian Policy foresees the waste management hierarchy, according to which energy reuse from waste is preferred to final disposal. However, less than 0.2% of the country’s waste goes to energy production. This paper proposes sustainability indicators to support the decision to choose the best process to treat municipal solid waste (MSW) through bioenergy generation technologies. Then, we conduct a case study for Rio de Janeiro. Incineration and gasification were not economically feasible—despite TRL 9 and 8. However, the projects presented a null net present value by increasing the gate fee to 94.69 and 255.39 USD/ton of MSW, respectively. The social indicators (job creation, salary increase with the absorption of waste pickers, population served, reduction in MSW sent to landfill) did not indicate the best technology. The results of the environmental indicators for incineration and gasification were, respectively, 0.45 and 0.37 t CO2eq/tMSW for GWP, 1.49 and 1.23 MWh/tMSW for energy intensity, 1.24 and 6.14 m3/tMSW for water intensity, 39.3 and 27.9 m2/tMSW for land use and 0.135 and 0.088 t SO2eq/tMSW for acidification. Gasification presented better results on 60% of the environmental indicators. However, incineration scored better in the important ones, water and energy intensities, in addition to the technical–economic aspect.

Energy saving starts in the kitchen

The field of sustainable construction and interior design demands innovative solutions to optimize energy efficiency and minimize environmental impact. This need has been further amplified by the European Community's Directive on Energy Efficiency 2012/27/EU and its subsequent revisions. The kitchen, as a central hub of domestic energy use, presents a significant opportunity for improvement. This paper introduces a novel application of heat pump technology for energy reuse in household appliances. The proposed SMACK (SMArt energy-Conserving Kitchen) system embodies a holistic approach, merging eco-sustainability with advanced design principles. SMACK's modularity enables customization and scalability to meet diverse requirements. A comprehensive assessment indicates potential average energy savings approaching 50%, contingent upon appliance configuration. Importantly, this study incorporates preliminary real-world measurements on a minimal appliance, offering empirical insights into the SMACK system's performance. The SMACK project signifies a major step towards environmentally conscious design, setting a new standard for sustainable technology integration within the home.

Delocalized Deformation Enhanced Reusable Energy Absorption Metamaterials Based on Bistable Tensegrity

Delocalized Deformation Enhanced Reusable Energy Absorption Metamaterials Based on Bistable Tensegrity

Analysis of Circular Economy Practices in A Manufacturing Company

Objective: This study aims to investigate circular economy practices in an organization in the manufacturing sector, with the aim of evaluating their impact on the company's maturity levels in relation to the circular economy. Theoretical Framework: The theoretical framework of this work is based on the concepts of the circular economy, which proposes the reduction, reuse, recovery and recycling of materials and energy at all stages of the product life cycle. Also noteworthy are the circular economy maturity assessment models, which allow measuring the level of implementation and integration of these practices in organizations. Method: The research was conducted through a documentary approach, using the sustainability reports of a large company in the manufacturing sector. The analysis was based on a specific maturity scale for the circular economy, evaluating the different stages of implementation of these practices by the company. Results and Discussion: The results revealed that the investigated company has circular economy practices predominantly in an intermediate stage of maturity. The discussion of the results emphasizes the importance of moving to more advanced stages of maturity to maximize the environmental and economic benefits of the circular economy. Research Implications: This research offers practical and theoretical insights into how companies can develop and improve their circular economy strategies. Implications include the need for more robust policies and practices to promote sustainability and efficiency in manufacturing. Originality/Value: This study contributes to the literature by highlighting the current stage of implementation of the circular economy in a large manufacturing company, highlighting areas for improvements and advancements. The research is valuable in providing a clear and detailed overview of the practices and challenges faced by organizations in the transition to the circular economy.

Hydraulic dual-module hybrid driving system with adjustable waste energy recovery for industrial vehicles

The energy dissipation of industrial vehicle during hydraulic cylinder operations is significant, and the limitations of energy recovery and reuse further exacerbate the issue of energy waste and low energy efficiency. To address these challenges, we propose a hydraulic dual module hybrid driving system (DHDS) for cylinder. This system incorporates a Main drive module with a Power-assisting module, enabling the recovery and reuse of gravitational energy to assist in cargo lifting through the bidirectional operation of the Power-assisting module. Based on the DHDS, we design a multi-mode control strategy (MMCS) with adjustable power distribution capability, allowing for the optimization of recovered energy utilization under various conditions. Furthermore, experiments and simulations are conducted to evaluate the ability of the MMCS to redistribute recovered energy and assess the energy efficiency of the DHDS. Using a DHDS-equipped forklift as an example, simulation platform and test bench are constructed to demonstrate its performance in several designed working cycles. Compared to a 1.2-t electric forklift, the DHDS-equipped forklift with MMCS achieves a battery saving efficiency of 12.70%–40.53 % and a gravitational energy recovery efficiency of 24.80%–62.85 %.

Turning Data Center Waste Heat into Energy: A Guide to Organic Rankine Cycle System Design and Performance Evaluation

This study delves into the adoption of the organic Rankine cycle (ORC) for recovering waste heat from data centers (DCs). Through a literature review, it examines energy reuse with a focus on electric power generation, the selection of working fluids, and system design principles. The objective is to develop a thorough framework for system design and analysis, beginning with a quantity and quality investigation of waste heat available. Air cooling systems, chosen often for their simplicity, account for about 70% of used cooling methods. Water cooling demonstrates greater effectiveness, albeit less commonly adopted. This study pays close attention to the selection of potential working fluids, meticulously considering the limitations presented by the available sources of heat and cold for vaporization and condensation, respectively. It reviews an ORC-based system setup, incorporating fluid streams for internal processes. The research includes a conceptual case study where the system is designed and simulations are conducted in the DWSIM environment. The simulation model considers hot air or hot liquid water returning from the data center cooling system for ORC working fluid evaporation. Ambient water serves for condensing, with pentane and isopentane identified as suitable organic fluids. Pentane assures ORC net electric efficiencies ranging between 3.1 and 7.1% when operating pressure ratios increase from 2.8 to 6.4. Isopentane systems, meanwhile, achieve efficiencies of 3.6–7.0% across pressure ratios of 2.7–6.0. Furthermore, the investigation provides key performance indicators for a reference data center in terms of power usage effectiveness (PUE), energy reuse factor (ERF), energy reuse effectiveness (ERE), and greenhouse gas (GHG) savings. This study concludes with guidelines for system analysis, including exergy considerations, and details the sizing process for evaporators and condensers.

The growth evolution of SnSe-doped SnTe alloy by in-situ selenization substitution method

In the era of increasing environmental pollution and energy crisis, the development of thermoelectric materials to achieve the reuse of waste heat energy is of great significance. SnTe, as an environmentally friendly thermoelectric material, its high electronic-thermal conductivity and coupled high electrical conductivity originated from intrinsic high carrier hole concentration leads to the unsatisfactory thermoelectric properties. With a lot of research going on to optimize thermoelectric performance by decoupling the thermo-electrical contradiction, the entropy engineering strategy, which can independently modulate lattice thermal conductivity is proved to be feasible by increasing the internal configurational entropy through doping. However, due to the uncontrollable growth microscopic process and the perturbation of film quality, the desired precise phase doping remains a challenge. In this work, we report an instantiation of the entropy increase of SnSe-doped SnTe alloy thin films prepared by two-step magnetron sputtering and selenization method. The microstructure and physical properties of thin films were investigated for replaying and controlling the growth evolution of in-situ selenization substitution. When the reaction temperature and duration were adjusted to 300℃ and 30 mins respectively, the desired pure phase doping was obtained. This work provides a new method of doping modification of SnTe materials, and the product as a new functional material expands the thermoelectric material library. In particular, it has positive reference significance for the development of synthesis controllability and structure establishment of complex polycrystalline materials.

Advanced treatment and reuse of dye wastewater using thermo-irreversible on/off switch starch with disruption of dissolution/precipitation dynamic equilibrium

The development of irreversible on/off switching materials is a potential strategy for unidirectional capture and encapsulation of pollutants, preventing the pollutant leakage problem resulting from the reversible dissolution of flocculants. Herein, a thermo-irreversible on/off switch starch (TISS) is prepared through modifying starch by etherification grafting glycidyl phenyl ether and 2,4-bis(dimethylamino)-6-chloro-[1,3,5]-triazine. It breaks the dissolution/precipitation dynamic equilibrium across heating–cooling cycles by thermal-induced irreversible coil-to-globule self-assembly of polymer chains, resulting in a 50-fold decrease in polymer solubility. Particularly, TISS shows a superior double-locking effect on pollutants and flocculants through its unique irreversible conformation memory capability, leading to a high-quality reuse water. 99.9 % of reactive brilliant red dye and 97.9 % of TISS remain fixed within sludge flocs even after prolonged immersion in cold water at 24 °C for 60 days. Furthermore, direct recycling and reuse of dye-bath energy can be realized through the isothermal flocculation and dyeing method, showing a 75 % decrease in energy consumption after three cycles compared to traditional dyeing techniques. This work presents a novel approach to constructing an irreversible pollutant delivery system using thermo-irreversible on/off switch starch, addressing the problems of high energy dissipation and water quality fluctuations during wastewater treatment.

Net CO2 removal of rice husk biochar as soil amendment depending on energy reuse in the production stage

Net CO2 removal of rice husk biochar as soil amendment depending on energy reuse in the production stage

Numerical investigation on performance optimization of steam ejector considering full geometric parameters and working conditions

As an energy-saving device for energy transduction, a steam ejector has been crucial in energy saving and emission reduction, energy consumption reduction, and energy reuse. An optimization method of full geometric parameters and a preferred method of working conditions were considered to rise the entrainment ratio of a steam ejector and improve its entrainment capacity. The related models of the ejector were established and numerically simulated. The influence of geometric parameters on the entrainment capacity of the ejector researched by adopting the control variable method and the 11-factor 5-level orthogonal test. The effect of working conditions on the entrainment ratio for the optimized ejector discussed, and the preferred method of working conditions of the ejector proposed. The results show that the entrainment ratio of the optimized ejector by the control variable method rises by 30.8 % to that of the original ejector, and the entrainment ratio of the new ejector by orthogonal test rises by 78 %. The constant cross-section diameter is a critical parameter affecting the entrainment capacity of the ejector. Contrasted with the original ejector, the maximum entrainment ratio under preferred working conditions rises by 242%–471 % via using the preferred method of working conditions. Considering the optimization of full geometric parameters and working conditions, the influence of the optimized process on the entrainment capacity of ejectors is evident, which provides an effective way and reference for the optimization research and development of other types of ejectors.

Toxicity of the sunscreen UV filter benzophenone-3 (OBZ) to the microalga Selenastrum capricornutum: An insight into OBZ’s damage to photosynthesis and respiration

Oxybenzone (OBZ; benzophenone-3, CAS# 131–57–7), as a new pollutant and ultraviolet absorbent, shows a significant threat to the survival of phytoplankton. This study aims to explore the acute toxic effects of OBZ on the growth of the microalga Selenastrum capricornutum, as well as the mechanisms for its damage to the primary metabolic pathways of photosynthesis and respiration. The results demonstrated that the concentrations for 50 % of maximal effect (EC50) of OBZ for S. capricornutum were 9.07 mg L−1 and 8.54 mg L−1 at 72 h and 96 h, respectively. A dosage of 4.56 mg L−1 OBZ significantly lowered the photosynthetic oxygen evolution rate of S. capricornutum in both light and dark conditions for a duration of 2 h, while it had no effect on the respiratory oxygen consumption rate under darkness. OBZ caused a significant decline in the efficiency of photosynthetic electron transport due to its damage to photosystem II (PSII), thereby decreasing the photosynthetic oxygen evolution rate. Over-accumulated H2O2 was produced under light due to the damage caused by OBZ to the donor and acceptor sides of PSII, resulting in increased peroxidation of cytomembranes and inhibition of algal respiration. OBZ’s damage to photosynthesis and respiration will hinder the conversion and reuse of energy in algal cells, which is an important reason that OBZ has toxic effects on S. capricornutum. The present study indicated that OBZ has an acute toxic effect on the microalga S. capricornutum. In the two most important primary metabolic pathways in algae, photosynthesis is more sensitive to the toxicity of OBZ than respiration, especially in the dark.

Long‐Term Heat‐Storage Ceramics based on Zr‐Substituted λ‐Ti3O5

AbstractHeat‐storage materials are important for energy saving to protect the environment. Here, we show a long‐term heat‐storage material based on zirconium‐substituted lambda‐trititanium‐pentoxide (λ‐ZrxTi3−xO5, 0 < x≤0.06). λ‐ZrxTi3−xO5 exhibits a phase transition to zirconium‐substituted beta‐trititanium‐pentoxide (β‐ZrxTi3−xO5) upon application of pressure. The transition pressures were 600 MPa (x=0.04) and about 1 GPa (x=0.06). When the pressure‐produced β‐phase is heated, the β‐phase returns to λ‐phase. The phase transition temperatures (i. e., heat‐storage temperatures) were 185 °C (458 K) and 183 °C (453 K) for x=0.04 and 0.06, respectively. These heat‐storage temperatures are suitable for the reuse of low‐temperature industrial waste heat, which is considered to be a difficult temperature region to be efficiently collected and reused. The present pressure‐sensitive heat‐storage ceramic, which can store the latent heat energy for a prolonged period, is effective for the sustainable reuse of heat energy that are wasted in power plants and industrial factories.

Reusable energy-absorbers design harnessing snapping-through buckling of tailored multistable architected materials

Abstract Multistable metamaterials are artificially engineered materials that possess microarchitectures capable of maintaining multiple stable configurations. However, the realization of mechanical metamaterials with numerous programmable stable configurations using Double-Curved Beam (DCB) elements remains an ongoing challenge. In this study, we exploit the snapping-through buckling phenomenon exhibited by architected DCB structures to devise a mechanical metamaterial with a unique deformation mode, encompassing Multi-stability, Multi-path, Multi-platform, and Multi-step characteristics, hence referred to as a 4M mechanical metamaterial. By employing DCB as fundamental building block elements, architected metamaterials with two-dimensional (2D) series or parallel lattices are successfully constructed, as well as three-dimensional (3D) tubular geometries, denoted as DCB-n-m-C and DCB-n-m-M metamaterials, respectively. These metamaterials exhibit reversible energy absorption characteristics and the stiffness can be transformed from positive to negative under both small and large elastic deformations. Functional gradient design and tailored deformation capability are given by adjusting the wall thickness of each layer of double-curved beams, thereby demonstrating the multi-path deformation features inherent in 4M metamaterials. DCB-n-m-M metamaterials has multiple energy platforms in the process of snapping-through, which reflects the multi-platform characteristics of 4M metamaterial. Consequently, novel properties such as multistability, programmability, and reusable energy absorption characteristics are achieved. To comprehensively understand the mechanical response of the metamaterials, a thorough investigation into the influence of geometric parameters is conducted, including the number of polygonal edges, the number of the layers, and the aspect ratio Q. This investigation involves a combination of theoretical analyses, numerical simulations, and experimental verifications. The introduced design strategy paves a way for the innovative design of multistable, multi-step, tailored, and reversible deformation metamaterials.