Recovery Cycle Research Articles

An efficient and template‐free synthesis of mesoporous silica from coal fly ash

AbstractIn the study, the desilication liquids and acid‐leached residues derived from the “alumina extraction process” of coal fly ash (CFA) were used as raw materials to prepare sodium silicate precursor. Then, the mesoporous silica with controllable pore structure properties was synthesized by an efficient, template‐free process from obtained sodium silicate. The effect of the sodium silicate properties and synthesis conditions on the pore structure properties of disordered mesoporous silica were investigated. The resulting material was characterized by N2 adsorption–desorption, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) and tested as an adsorbent for removal of lead ions (Pb2+). The results showed that the precursor with high modulus (3.0) and concentration (60 g·L−1) was beneficial for the synthesis of mesoporous silica with high specific surface area. The mesoporous silica with specific surface area of 690 m2·g−1 and pore volume of 1.28 cm3·g−1 was synthesized at mild aging temperature (40°C) and pH value of 8. Moreover, the materials possessed an adsorption capacity of 303 mg·g−1 for lead ions after amino modification. The adsorption efficiencies for lead ions were maintained at ~90% after five recovery cycles. Overall, the utilization efficiency of SiO2 in CFA reached up to 93%.

Brazil’s Formal E-Waste Recycling System: From Disposal to Reverse Manufacturing

This study investigates the post-regulation scenario of waste electrical and electronic equipment (e-waste) reverse logistics in Florianópolis, an island in southern Brazil, following Decree N° 10240/2020. Employing a case study approach, involving observation and semi-structured interviews, the research explores key stakeholders’ roles. The results indicate collaborative efforts among the municipal cleaning service provider, recycler, and manager entity, supporting effective e-waste take-back systems. This cooperation not only strengthens the formal recycling market but also yields socio-environmental benefits. The study reveals that optimal outcomes arise from the collaboration between the public cleaning service provider and the business sector, fostering a mutually beneficial relationship. Concerning e-waste value recovery, there is a notable inclination to extend the life cycle of small equipment, emphasizing reuse and remanufacture cycles, while larger electrical and electronic items follow to recycling and recovery cycles. In summary, this research contributes to aligning stakeholders in e-waste reverse logistics, emphasizing compliance with legislation and fostering a deeper understanding of roles, functions, and alliances. The study provides a strategic and structured perspective on e-waste management in a city renowned for selective waste collection and considered a national benchmark for reverse logistics, reinforcing its commitment to sustainability.

Biomarkers in Endurance Exercise: Individualized Regulation and Predictive Value.

The high interindividual variability of exercise response complicates the efficient use of blood-based biomarkers in sports. To address this problem, a useful algorithm to characterize the individual regulation and predictive value of different candidate markers will be developed. Forty-nine participants completed two identical exercise trials. Blood samples were collected before, immediately after, 3 hours after, and 24 hours after completion of exercise. Plasma concentrations of interleukin (IL-) 1RA, IL-6, IL-8, IL-10, IL-15, creatine kinase (CK), cortisol, c-reactive protein (CRP), lactate dehydrogenase (LDH), and thiobarbituric acid reactive substances (TBARS) were measured. Individualized regulation was analyzed using k-means clustering and a Group Assignment Quality (GAQ) score. Regression trees with a bootstrapped-aggregated approach were used to assess the predictive qualities of the markers. For most of the markers studied, a distinction can be made between individuals who show a stronger or weaker response to a particular endurance training program. The regulation of IL-6, IL-8, IL-10, and CK exhibited a high degree of stability within the individuals. Regarding the predictive power of the markers, for all dependent variables, the most accurate predictions were obtained for cortisol and IL-8 based on the baseline value. For CK, a good prediction of recovery of maximal strength and subjective feeling of exhaustion can be made. For IL-1RA and TBARS, especially their reregulation can be predicted if the baseline level is known. Focusing individual variations in biomarker responses, our results suggest the combined use of IL-6, IL-8, IL-10, and CK for the personalized management of stress and recovery cycles following endurance exercise.

Performance analysis and multi-objective optimization of organic Rankine cycle for low-grade sinter waste heat recovery

In order to enhance the sinter waste heat recovery (WHR) rate efficiently, the organic Rankine cycle (ORC) for power production was applied to take the low-grade sinter cooling flue gas (SCFG) expelled from the waste heat boiler as the heat source. The system thermodynamic, thermo-economic and multi-objective optimization models were constructed firstly, and then R245fa was chosen as the ORC working fluid. Furthermore, the variations of system thermodynamic and thermo-economic performances with the ORC thermal parameters under different inlet temperatures of SCFG were analyzed in detail, and the ideal parameter combination was established through the multi-objective optimization approach. The results show that, the optimal inlet temperature of SCFG is determined to be 160 °C, and under the aforementioned condition of inlet temperature of SCFG, the optimal ORC thermal parameters are determined to be 95 °C for the working fluid evaporation temperature, 10 °C for the working fluid superheat degree, 28 °C for the working fluid condensation temperature and 9 °C for the pinch-point temperature difference in evaporator by considering the system thermodynamic and thermo-economic performances comprehensively. Meanwhile, the WHR rate of SCFG under the above ORC parameter combination could reach 64.86 %, showing remarkable energy-saving effect.

Instant Protection Spray for Anti-Infection and Accelerated Healing of Empyrosis.

Distinct from common injuries, deep burns often require a chronic recovery cycle for healing and long-term antibiotic treatment to prevent infection. The rise of drug-resistant bacteria has caused antibiotics to no longer be perfect, and continuous drug use can easily lead to repeated infection and even death. Inspired by wild animals that chew plants to prevent wound infection, probiotic extracts with a structure similar to the tailspike of phage are obtained from Lactobacillus casei and combined with different flavones to design a series of nonantibiotic bactericides. These novel antibacterial agents are combined with a rapid gelation spray with a novel cross-angle layout to form an instant protection spray (IPS) and provide a physical and anti-infectious barrier for burns within 30 s. This IPS is able to sterilize 100.00% and 96.14% of multidrug-resistant Staphylococcus aureus (MRSA) in vitro and in vivo, respectively. In addition, it is found to effectively reduce inflammation in MRSA-infected burns in rats and to promote tissue healing.

Thermodynamic and thermo-economic analysis, performance comparison and parameter optimization of basic and regenerative organic Rankine cycles for waste heat recovery

In order to recycle the sinter waste heat efficiently, the possibility of taking the low temperature flue gas emitted from sinter waste heat boiler as heat source of organic Rankine cycle for power generation is investigated in the current study. The thermodynamic and thermo-economic models of basic organic Rankine cycle (BORC) and regenerative organic Rankine cycle (RORC) were constructed, and R236ea, R245fa and R601a were selected as the working fluids of BORC and RORC. Subsequently, the parametric effects on the thermodynamic and thermo-economic performances under various working fluids for BORC and RORC were analyzed and compared, and then the suitable thermal parameters of BORC and RORC were established through the multi-objective optimization. The results show that, the thermal efficiency of RORC is apparently greater than that of BORC for the given thermal parameters, while the levelized energy cost of RORC is a little bigger than that of BORC. The net output power of R236ea is the largest in the whole optimal conditions, and the flue gas waste heat recovery rate of R236ea for BORC is also the largest at a respectable 65.07 %, while the levelized energy cost of R601a is the smallest for BORC and RORC, showing better thermo-economic performance.

Application of Reversible Four-Dimensional Printing of Shape Memory Alloys and Shape Memory Polymers in Structural Engineering: A State-of-the-Art Review.

The rapid development and advancements in field of shape memory alloys (SMAA) has tremendously increased the progress in four-dimensional (4D) printing. The conventional 4D printing will require skilled manpower but utilization of reversibility aspect achieved using self adjusting external stimuli will eliminate the necessity of sophisticated devices and human intervention in 4D printing. The components created using reversible 4D printing can be reused after each recovery cycle that suits the current industry requirements. This review is divided into three sections: The first section starts with a detailed illustration of different mechanisms associated with SMAA and shape memory polymers SMPP along with an illustration of realistic 3D-printed SMAA and SMPP. The second section of this paper deals with the different methods of manufacture with the advantages and disadvantages of different types of SMAA. The third section deals with the mechanisms associated with SMPP, namely (1) Thermo-responsive mechanism, (2) Chemo-responsive mechanism, and (3) Photo-responsive mechanism along with a detailed insight into the aspect of repeatability and reversibility. The fourth section presents an exhaustive review of the application of SMAA and SMPP in civil engineering. The last section of this work throws light on the challenges faced in 4D reversible printing of SMAA and SMPP along with the potential solutions and presents directions for future research.

Non‐performance loans, operation, and recycle efficiency analysis—Dynamic Two‐stage Directional Distance Function Recycle with Assurance Regions model

AbstractPrevious studies have failed to analyze a bank's operation performance and non‐performing loans at the same time. Therefore, this research uses the Dynamic Two‐stage directional distance function (DDF) Recycle with Assurance Regions (ARs) model to explore the efficiency of Taiwanese banks in their operation stage and recycling stage. The research results are as follows. (1) The six‐year overall average efficiency is .7966. Taipei Star Bank has the best efficiency, and Fubon, Bank SinoPac, and Union Bank have the worst efficiency rankings. (2) Most banks have good efficiency in the operation stage, while efficiency in the recovery cycle stage fluctuates.

Potential of Variable Geometry Radial Inflow Turbines as Expansion Machines in Organic Rankine Cycles Integrated with Heavy-Duty Diesel Engines

This work evaluates the feasibility of utilizing an organic Rankine cycle (ORC) for waste heat recovery in internal combustion engines to meet the stringent regulations for reducing emissions resulting from the combustion of fossil fuels. The turbine is the most crucial component of the ORC cycle since it is responsible for power production. In this study, a variable geometry radial inflow turbine is designed to cope with variable exhaust conditions. A variable geometry turbine is simply a radial turbine with different throat openings: 30, 60, and 100%. The exhaust gases of a heavy-duty diesel engine are utilized as a heat source for the ORC system. Different engine operating points are explored, in which each point has a different exhaust temperature and mass flow rate. The results showed that the maximum improvements in engine power and brake specific fuel consumption (BSFC) were 5.5% and 5.3% when coupled to the ORC system with a variable geometry turbine. Moreover, the variable geometry turbine increased the thermal efficiency of the cycle by at least 20% compared to the system with a fixed geometry turbine. Therefore, variable geometry turbines are considered a promising technology in the field and should be further investigated by scholars.

Exergoeconomic and Thermodynamic Analyses of Solar Power Tower Based Novel Combined Helium Brayton Cycle-Transcritical CO2 Cycle for Carbon Free Power Generation.

In the present study, a novel combined power cycle for solar power tower (SPT) system consisting of helium Brayton cycle (HBC) and transcritical CO2 (TCO2) for waste heat recovery is being studied for carbon-free generation. The performance of the proposed SPT based combined cycle (SPT-HBC-TCO2 cycle) is compared with SPT based basic cycle (SPT-HBC) based on exergoeconomic and thermodynamic analyses. It is concluded that the SPT-based combined cycle (SPT-HBC-TCO2 cycle) produces a thermal efficiency of 32.39% and exergy efficiency of 34.68% with an electricity cost of 1.613 UScent kWh-1. The exergy and thermal efficiency of the SPT-based combined cycle are enhanced by 13.18% and 13.21% respectively, while electricity cost is reduced by around 2% as compared to the SPT-based basic cycle (SPT-HBC) configuration at base conditions. A notable finding is that, despite the additional expenditures related to the bottoming cycle, the cost of electricity is lesser for the proposed combined cycle. Additionally, a comparison with the related prior published research exhibits that the performance of the current novel system is superior to that of the systems based on steam rankine cycle and supercritical CO2 cycles.

Oscillations of chlorophyll fluorescence after plasma membrane excitation in Chara originate from nonuniform composition of signaling metabolites in the streaming cytoplasm

Excitable cells of higher plants and characean algae respond to stressful stimuli by generating action potentials (AP) whose regulatory influence on chlorophyll (Chl) fluorescence and photosynthesis extends over tens of minutes. Unlike plant leaves where the efficiency of photosystem II reaction (YII) undergoes a separate reversible depression after an individual AP, characean algae exhibit long-lasting oscillations of YII after firing AP, provided that Chl fluorescence is measured on microscopic cell regions. Internodal cells of charophytes feature an extremely fast cytoplasmic streaming that stops immediately during the spike and recovers within ~10 min after AP. In this study a possibility was examined that multiple oscillations of YII and Chl fluorescence parameters (F′, Fm′) result from the combined influence of metabolic rearrangements in chloroplasts and the cyclosis cessation–recovery cycle induced by the Ca2+ influx during AP. It is shown that the AP-induced Fm′ and YII oscillations disappear when the fluidic communications between the analyzed area (AOI) and surrounding cell regions are restricted or eliminated. The microfluidic signaling was manipulated in two ways: by narrowing the illuminated cell area and by arresting the cytoplasmic streaming with cytochalasin D (CD). The inhibition of Fm′ and YII oscillations was not caused by the loss of cell excitability, since CD-treated cells retained the capacity of AP generation. The mechanism of AP-induced oscillations of YII and Chl fluorescence seems to involve the lateral microfluidic transport of signaling substances in combination with the distribution pattern of these substances that was enhanced during the period of streaming cessation.

Cascading the Transcritical CO2 and Organic Rankine Cycles with Supercritical CO2 Cycles for Waste Heat Recovery

Concentrating solar power (CSP) applications can benefit from the superior thermophysical and chemical properties of supercritical CO2 (sCO2), which offers greater cycle efficiency in contrast to supercritical or superheated steam cycles. The transcritical CO2 (TCO2 cycle) excels in low-grade waste heat recovery (WHR), while the organic Rankine cycle (ORC) is also a potential option for WHR from sCO2 cycles. This study focuses on the thermodynamic assessment and optimization of combined power cycles, incorporating multiple bottoming cycles, to enhance overall thermal efficiency. The configurations employed include recompression, partial cooling, and main compression intercooling within the sCO2 cycle. Waste heat recovery is achieved using both TCO2 and ORC. The parametric analysis explores key variables such as turbine inlet temperature, main compressor inlet temperature, recuperator effectiveness, pressure ratios in the bottoming cycles, and condensation temperatures of the bottoming cycles. Furthermore, this research conducts performance analysis of the proposed combined cycle configurations. The results underscore the substantial enhancement of combined cycle performance with regard to thermal and exergy efficiency. A rise in the highest temperature that can occur in the sCO2 cycle leads to improved thermal efficiency. The Main Compressor Inlet Temperature (MCIT) exhibits an efficiency increase of up to 40°C–45°C, attributed to pseudocritical effects, followed by a decline. Among the various configurations, the combined partial cooling cycle generates the highest net output power. The study finds that the combined main compression model consistently outperforms other layouts, yielding a 2-2.5% increase in efficiency. Optimization of the intermediate pressure value for the partial cooling (PC) and main compression (MC) cycles at 10 MPa further contributes to enhanced performance. This study not only presents the optimized operating conditions for each combined cycle but also offers a comparative analysis of these models under different boundary conditions. The findings from this research significantly advance the utilization of waste heat and the development of clean power generation.

Advanced Exergy-Based Analysis of an Organic Rankine Cycle (ORC) for Waste Heat Recovery.

In this study, advanced exergy and exergoeconomic analysis are applied to an Organic Rankine Cycle (ORC) for waste heat recovery to identify the potential for thermodynamic and economic improvement of the system (splitting the decision variables into avoidable/unavoidable parts) and the interdependencies between the components (endogenous and exogenous parts). For the first time, the advanced analysis has been applied under different conditions: constant heat rate supplied to the ORC or constant power generated by the ORC. The system simulation was performed in Matlab. The results show that the interactions among components of the ORC system are not strong; therefore, the approach of component-by-component optimization can be applied. The evaporator and condenser are important components to be improved from both thermodynamic and cost perspectives. The advanced exergoeconomic (graphical) optimization of these components indicates that the minimum temperature difference in the evaporator should be increased while the minimum temperature difference in the condenser should be decreased. The optimization results show that the exergetic efficiency of the ORC system can be improved from 27.1% to 27.7%, while the cost of generated electricity decreased from 18.14 USD/GJ to 18.09 USD/GJ.

Comparative analysis of supercritical CO2–ORC combined cycle for gas turbine waste heat recovery based on multi-objective optimization

To efficiently recover the waste heat of the gas turbine, this study introduces six innovative types of compound combined cycles, and proposes a multidimensional optimization method for the optimal cycle. In the combined cycle, the supercritical carbon dioxide cycle is used in the top cycle and the organic Rankine cycle is used in the bottom cycle. The working medium used in the organic Rankine cycle is the innovative mixture cyclopentane/R365mfc. Firstly, a parametric study is carried out for the proposed combined cycle to investigate the effects of system operating parameters on exergy efficiency, area per unit power output (APR) of the heat exchanger, and the levelized energy cost (LEC). The results show that the optimal values of objective function correspond to different systematic operating parameters. Secondly, the multi-objective optimization based on the genetic algorithm is used to obtain the optimal systematic parameters, and the six proposed composite combined cycles are optimized respectively. The comparison results show that the composite supercritical carbon dioxide regenerative cycle-organic Rankine simple cycle has the optimal performance parameters, and its exergy efficiency, APR and LEC are 55.68 %, 0.115 m2/kW and 4.23 cent/(kW·h), respectively. The layout of the composite cycle is that the supercritical carbon dioxide regenerative cycle and the organic Rankine simple cycle are used to recover the high temperature and low temperature of the gas turbine exhaust gas, while the organic Rankine simple cycle recovers the cooling heat of the supercritical carbon dioxide regenerative cycle. Finally, the superiority relative of the proposed combined system to the other cycles is also verified. This study has determined that the proposed combined system is appropriate for the waste heat recovery of gas turbines, with the advantages of deep utilization of waste heat, high efficiency, high compactness, and low cost.

Sustainable ultrasound-assisted extraction of Polygonatum sibiricum saponins using ionic strength-responsive natural deep eutectic solvents

The sustainable extraction of saponins was investigated using natural deep eutectic solvents (NADESs) combined with ultrasound-assisted extraction. A novel NADES (butyric acid-urea) that was responsive to ionic strength was designed and used as the extractant. Ultrasound treatment and a catalyst ferric chloride with plant cell wall breaking function were applied to improve the extraction efficiency.Since the solubility of the NADES varied significantly with ionic strength, 95% of NADES was readily separated from the water phase after the addition of sodium chloride, while saponins remained in the water phase for easy collection. The reuse capacity of NADES, the eco-friendliness of the extraction method, and the antioxidant activity of the extract were further evaluated.NADES was continuously recovered and used to extract Polygonatum sibiricum powder: the yield of saponins did not decrease after five cycles of recovery and re-extraction. The penalty point on the “Eco-scale” suggested that the extraction method was “green” (i.e. eco-friendly).Compared with ethanol extracts, the NADES extracts showed a higher saponin concentration and antioxidant activity.The study can contribute to the sustainable and green extraction of hydrophilic active substances in the food and pharmaceutical industries.

Reusability and energy absorption behavior of 4D-printed heterogeneous lattice structures based on biomass shape memory polyester

Uniform triply periodic minimal surfaces (TPMS) have been extensively used due to the good mechanical properties and energy absorption. The hybrid of lattices could combine the advantages of substructures with desirable properties. Moreover, the reusability of TPMS after external loading and the repeated energy absorption capacity are relatively unexplored. Herein, novel heterogeneous TPMS lattices composed of Gyroid and Diamond were designed and manufactured using a biomass shape memory polymer. First, a smooth transition between the adjacent substructures were achieved via structural design. Then, the external force (compression load) and thermal stimulated shape recovery cycles tests were conducted. The results showed that the heterogeneous samples exhibited multiple yielding stages and continuous energy absorption due to the synergistic effect of substructures. The large-deformed TPMS structures were able to recovery to the original shape under thermal stimulation, possessing a high rate of shape fixation and shape recovery (nearly 100 %). After experiencing several cold programming-shape recovery cycles, the total energies of heterogeneous structures did not sharply decrease and no obvious damage was detected by micro-CT, demonstrating a favorable reusability and repeated energy absorption capacity. Therefore, the development of 4D-printed heterogeneous lattice structures have great potentials in smart protective equipment and lightweight smart components.

Socio-behavioral assessment of household solid waste management: The case of Barangay Calicanto, Philippines

The cycle of waste generation, segregation, disposal, and recovery is highly dependent on varying human activities and their awareness towards solid waste management (SWM). This study presents the first reported socio-behavioral assessment focusing on the households in a city in the Philippines to bridge the intention-action gap of SWM stakeholders by imploring socio-behavioral change communication activities through the trials of improved practices (TIPs). Findings reveal the significant contribution of women in household waste management responsibilities, highlighting their active participation in SWM initiatives. Analysis of short-term and long-term committed and accomplished actions demonstrated the willingness of the households to adopt sustainable waste management practices. Collective action of policymakers, waste management authorities, and stakeholders should consider the dynamics within households including their financial capacities, provide education and support, develop waste management infrastructures and systems, and create conducive conditions for behavioral change.

Optimal Lot-Sizing Decisions for a Remanufacturing Production System under Spare Parts Supply Disruption

Remanufacturing is one of the ways forward for product recovery initiatives and for maintaining sufficient production flow to satisfy customer demand by providing high-quality goods with a combination of new and return parts through a circular economy. Recently, manufacturers have been progressively incorporating remanufacturing processes, making their supply chains vulnerable to disruptions. One of the main disruptions that occurs in remanufacturing systems is the shortage of spare parts supply, which results in unexpected delays in the remanufacturing process and could eventually result in a possible loss of sales. In the event of such potential disruptions, remanufacturing facilities must manage their supply chains in an effective and optimal manner such that the negative impact of disruptions to their business can be minimised. In this study, a two-stage production–inventory system was analysed by developing a cost-minimisation model that focuses on the recovery schedule after the occurrence of a disruption in sourcing spare parts for a remanufacturer’s production cycle. The developed model was solved using the branch-and-bound algorithm, where the experimental results demonstrated that the model provides effective solutions. Through numerical experiments, results indicated that the optimal recovery schedule and the number of recovery cycles are considerably dependent on the disruption time, lost sales and backorder costs. A sensitivity analysis showed that the lost sales option seems to be more effective than the backorder sales option in optimising the system’s overall cost due to unmet demand, which becomes lost sales when serviceable items are reduced, thereby shortening recovery time. Furthermore, a case study revealed that a manufacturer’s response to disruption is highly influenced by the spare part costs and overall recovery costs as well as the supplier’s readiness level. The proposed model could assist managers in deciding the optimal production strategy whilst providing interesting managerial insights into vital spare parts recovery issues when disruption strikes.

Novel approach for synthesis of highly active nanostructured MgO/ZnAl2O4 catalyst via gel-combustion method used in biofuel production from sunflower oil: Effect of mixed fuel

A series of MgO/ZnAl2O4 nanocatalysts was prepared in order to conversion of sunflower oil to green fuel through transesterification reaction. The ZnAl2O4 spinel was synthesized using combustion method with different mixtures of urea and citric acid as fuel. MgO was also loaded on the catalysts as the active phase by impregnation method. the physicochemical properties of synthesized MgO/ZnAl2O4 nanocatalysts was evaluated with TGA/DTG, XRD, FESEM, EDX-dot mapping and nitrogen adsorption–desorption technique. XRD patterns of all samples showed crystalline phase of zinc aluminate without any impurities. The porous morphology as well as high degree of active phase dispersion was observed in samples prepared with mixed fuel. Using mixed fuel with urea to citric acid ratio of 0.5 led to create more pores in range of 10–20 nm. It is worth mentioning that the results of the catalytic performance test of the synthesized catalysts revealed that the highest conversion rate of 98.45 % was obtained in the synthesized sample with a ratio of urea to citric acid of 1:2. Furthermore, this sample illustrated superb stability in the reusability examination so that even over after five recovery cycles, the conversion triglyceride just decreased to 91.1 %.

Improvement design and performance assessment of two supercritical carbon dioxide power cycles for waste heat recovery

Waste heat recovery (WHR) from thermal engines and industrial processes is significantly beneficial to cutting fossil fuel consumptions and carbon dioxide emissions. Recompression supercritical carbon dioxide (sCO2) power cycles have many advantages of high efficiency, compact design and environmentally friendly property, and they are regarded as the competitive and promising energy conversion technology for WHR. However, a large space is still left for recompression sCO2 power cycle to improve its capability with regard to waste heat extraction and power output. The novelty of this work is the development of two novel sCO2 power cycles based on the recompression sCO2 cycle aimed at thoroughly and efficiently reusing the waste heat. Thermodynamic and exergoeconomic models are established to perform the quantitative parametric analyses, multi-objective optimizations, exergy and exergoeconomic analyses on the proposed systems. The results indicate that the second proposed system is preferred, since it can significantly improve the net power output by 43.81% and 12.32% while reducing the total product unit cost by 7.24% and 10.39%, compared with the traditional recompression sCO2 cycle and the improved sCO2 cycle, respectively. Although the first proposed system has a better performance in waste heat extraction and net power output, it requires a higher cost.