High Material Costs Research Articles

In situ reconstruction of proton conductive electrolyte from self-assembled perovskite oxide-based nanocomposite for low temperature ceramic fuel cells

In the development of low temperature solid oxide fuel cells (LT-SOFCs), also called ceramic fuel cells, the lack of highly conductive and the high manufacturing cost of dense electrolyte materials severely delay their wide development. In this work, we depart from the classic substitution approach to achieve sufficient ionic conduction (0.01 S cm−2 level at temperature ≥600 °C), a superionic conductive electrolyte material was obtained from a self-assembled hybrid oxide that was derived from the perovskite oxide precursor through alkali metal ion substitution. Moreover, the hybrid oxide was further in-situ reconstructed into a nanocomposite of oxide/carbonate-hydroxide under fuel cell condition. The nanocomposite possesses dominated proton conductivity as verified by the benefited hydration effect, versatile oxygen ionic blocking cell experiment, and concentration cell investigation. Specifically, an outstanding ionic conductivity of 0.185 S cm−1 and an excellent peak power density of 1012 mW cm−2 were demonstrated at 550 °C under an typical H2/air atmosphere. This research offers a rational design strategy to achieve low temperature, high-performance semiconductor-based functional composite electrolytes for efficient and sustainable energy conversion in SOFC technology.

Materials Design and Mechanistic Understanding of Tellurium and Tellurium-Sulfur Cathodes for Rechargeable Batteries.

ConspectusThe market demand for lithium-ion batteries (LIBs) has been proliferating in wide applications, from portable electronics and electric vehicles to renewable energy storage, due to their advantages of high energy density and reliable life cycles. Currently, further development of LIBs is hindered by the limited specific/volumetric capacity and high cost of conventional intercalation-type cathode materials. In this context, sulfur (S) has gained intensive attention as a conversion-type cathode because of its abundance, low cost, and high theoretical capacity (1675 mAh g-1). However, the insulating nature of S causes severe issues of sluggish redox kinetics, low S utilization, and unsatisfactory practical capacity. So far, extensive efforts have been devoted to boosting Li-S redox kinetics and enhancing cycling stability by inhibiting the shuttle effect, including developing functional electrolyte additives, introducing redox catalysts, and tailoring the S cathode structure. Partially substituting S atoms in S8 rings with high-electrical-conductivity elements (e.g., selenium, 1 × 10-3 S m-1) at the molecular level proves to be an effective strategy for tackling the above-mentioned challenges in Li-S batteries. It is noteworthy that tellurium (Te), with remarkable electrical conductivity (2 × 102 S m-1) and high density (6.24 g cm-3), is a promising battery electrode material that can realize fast electron transport and deliver volumetric capacity comparable to that of S or Se. Additionally, Te-S molecular regulation is one facile strategy to reshape Li-S chemistry, accelerate redox kinetics, and manipulate the lithiation/delithiation behaviors. Te is an effective eutectic accelerator that prevents polysulfide dissolution in Li-S batteries under the dissolution-deposition mechanism. Meanwhile, the Li-Te electrochemistry can contribute to reversible capacity in Li-TexSy batteries through Te-Li2Te conversion and enhance the materials utilization of TexSy.This Account highlights state-of-the-art advancements in applying Te or TexSy as high-capacity cathodes for rechargeable batteries. First, battery configuration and reaction pathways in Li-Te batteries are discussed, followed by the introduction of cathode design strategies to improve cathode structure stability. The limitations of this Te-only cathode are outlined in terms of the abundance, cost, and energy density. Second, the role of Te in Li-S chemistry is clarified by the analysis of the crystal structure, electrochemical behaviors, solid electrolyte interphase composition, and energy profiles. Third, recent progresses on quasi-solid-state Li-Te batteries have been introduced, focusing on flexible gel polymer electrolytes with adjustable ionic conductivity. Afterward, advancements in interface engineering by the atomic layer deposition technique in metal-Te batteries are highlighted. Additionally, mechanistic analysis in emerging zinc-TexSy batteries with outstanding areal capacity is demonstrated. Finally, we provide insightful perspectives on the future directions of material design in Te-based energy storage technologies. This Account is expected to deepen the fundamental understanding of metal-Te/TexSy chemistry and offer inspiration for the further development of Te-based high-energy-density rechargeable batteries.

Achieving Housing Affordability in the U.S. through Sustained Use of AI and Robotic Process Automation for Prefabricated Modular Construction

The rising housing issues occasioned by high costs in the United States (US) are traceable to the high costs of building materials and construction. This study proposes the combined leveraging of AI and Robotic Process Automation (RPA) for prefabricated modular construction as a strategic means of reducing high costs of housing and increasing efficiency in construction. It argues that doing so would pave way for housing affordability in the US. Deploying descriptive survey and qualitative method alongside the applicable interpretive and descriptive techniques, the study demonstrates in the course of its analysis that AI and RPA are viable means of reducing costs of construction and housing, and increasing efficiency. It submits that amidst the established constraints to the ideal extent of leveraging AI for construction activities, the leveraging of AI and RPA for prefabricated modular construction yields huge positive results among which are reduced costs of construction and housing and increased efficiency in construction. Government and construction organizations are charged to play enabling roles in the adoption and sustainability of AI and RPA in construction activities, including prefabricated modular construction, so as to achieve reduced costs of housing and increase efficiency in construction.

Dynamic Field Nulling Method for Magnetically Shielded Room Based on Padé Approximation and Generalized Active Disturbance Rejection Control

Magnetically shielded rooms (MSRs) provide a near-zero field environment for magnetoencephalography (MEG) research. Due to the high cost of high-permeability materials and the weak shielding capability against low-frequency magnetic disturbance, it is necessary to further design active compensation coils combined with a closed-loop control system to achieve dynamic nulling of environmental magnetic disturbance. To enhance the performance of the dynamic nulling system, this paper proposes a novel controller design method based on Padé approximation and generalized active disturbance rejection control (GADRC). First, a precise closed-loop model of the dynamic nulling system is established. On this basis, the delay element of the optically pumped magnetometer (OPM) is approximated using the Padé approximation method, and the controller is designed within the GADRC framework. The system’s stability and disturbance suppression capability are analyzed using frequency-domain methods. To validate the effectiveness of the proposed method, simulations and experiments are conducted, achieving a shielding factor greater than 40 dB at 0.1 Hz. After filtering out power frequency interference, the peak-to-peak field fluctuation is reduced from 320.3 pT to 1.8 pT.

Titanium-Cerium Redox Flow Batteries for Grid-Scale Electrical Energy Storage

The development of redox flow batteries (RFBs) has gained increased attention due to the need of mitigating emission pollution from fossil fuels by developing renewable energy storage system. Among all the different types of RFBs, all vanadium one (VRFBs) are the most prevalent type because crossover contamination is avoided by using only one metal element. However, VRFBs still suffer from limitations such as low output voltage, low efficiency, and high material cost. Titanium (Ti) and cerium (Ce), on the contrary, are available in abundance and have lower cost. Moreover, the standard potential of Ti-Ce combination is much higher than that of VRFBs (1.61 vs. 1.23 V). Herein, we have studied and compared the performance of Ti-Ce RFBs with sulfuric acid (SA) and methanesulfonic acid (MSA) serving as the supporting electrolyte. We applied an asymmetric electrode configuration, i.e., carbon felt for Ti side and carbon paper for Ce side, to further promote the batteries performance. Cyclic voltammetry (CV) and linear sweep voltammetry (LSV) were used to analyze the mass transport and reaction kinetics of the Ti-Ce system. Electrochemical impedance spectroscopy (EIS) was used to analyze the contribution of different types of polarization. Ti-Ce RFBs demonstrated an energy efficiency around 80 % at 100 mA/cm2, and excellent capacity retention.

(Invited) Challenges and Successes of an Industrial Start-up to Global Electrolyzer Company

Hydrogen generation via electrolysis has gained much attention internationally as not only a sustainable source of fuel for the transportation, but as a carrier of energy to capture stranded renewable energy due to the carbon-free chemical cycle and response characteristics of the technology. The barrier to entry preventing this technology from being widely adopted is the overall cost associated with both the upfront capital expense as well as the operating cost incurred over the product life. The majority of this cost is driven by 1) low electrical efficiencies due to the high ohmic resistance of thicker membranes required by electrolysis systems to electrochemically compress generated hydrogen for storage and the overpotential associated with the water splitting oxygen evolution reaction (OER) catalysts typically used, 2) high cost of system and cell stack materials, which need to be durable for up to 100,000hrs at potentials approaching 2V in both reducing and oxidizing environments, and 3) the lack of a robust supply chain for high volume manufacturing to further drive down cost through economies of scale.Nel Hydrogen has worked to commercialize this technology, originally developed for aerospace and miliary applications where cost and efficiency were not the drivers. Since the founding of Proton Energy Systems in 1996 and to the present as Nel Hydrogen we have worked to address these problem areas in an attempt to develop products that can serve cost sensitive markets, such as energy capture and storage. During this talk, I will look back on the challenges we faced as an industrial start-up dealing with uninterested suppliers, creating relationships, and establishing partnerships, all while developing our first 28cm2 products to the point today, where we are producing and siting multi-MW systems.

High-Rate and Durable Zinc-Based Flow Batteries for Large-Scale Energy Storage

Large-scale energy storage is a key enabling technology for the widespread adoption of renewable energy such as wind and solar power. Among various technologies, zinc-based flow batteries stand out as one of the most promising candidates due to the high energy density, low cost, and use of earth-abundant active materials. However, the low operating current density and short cycle life resulting from notorious zinc dendrite formation, large internal resistance, and sluggish reaction kinetics pose a great challenge for their practical applications. Although great efforts have been made to address these issues, previous works mainly focused on one specific aspect, making it challenging to boost the overall performance of zinc-based flow batteries. In this presentation, a systematic study on the effects of key components on the electrochemical performance of zinc-bromine flow batteries will be presented. Our results show that all key components (electrodes, electrolytes, membranes, and flow fields) can exert a significant influence on the electrochemical performance. More impressively, a high areal capacity of >200 mAh/cm2 and an operating current density of as high as 400 mA/cm2 can be achieved by optimizing the design and operating parameters. Underlying mechanisms and perspectives for further improvement will be discussed during the presentation.

Protic Ionic Liquids as Electrolytes for Metal-Hydride Batteries

Nowadays, the most popular and effective energy storage systems are Li-ion batteries, despite some limitations such as high cost, flammability, temperature restrictions, and use of critical raw material (e.g. Co) [1]. This raises the challenge of the demand for alternative systems. One potential alternative is the Ni-MH battery, which are recognized for their good cyclability, competitive energy density, low memory effect, wide range of operating temperatures, low cost, and environmental friendliness [1]. Their practical use, however, is constrained due to their low specific energy density, high self-discharge rate, and electrode ageing [2,3].This work is focused on the study of the negative electrode of the Ni-MH battery and its interaction with the electrolyte. The objective aims to improve the performance of the negative electrode of Ni-MH batteries by substituting the conventional water-based KOH 8.7 M electrolyte by a Protic Ionic Liquid (PIL) to overcome aforementioned drawbacks [4]. PILs can exchange a labile proton, thereby supporting the main redox reaction, hydrogenation, at the negative electrode of Ni-MH battery.Thus, a series of twelve PILs or their combinations were synthesized and tested in a half-cell configuration. The charge/discharge cycle tests were carried out. Results showed that Pyrrolidinium Acetate (PyrrAc), Ethanolammonium Acetate (EOAAc) mixed with g-butyrolactone (GBL), and Diethanolammonium Acetate (DEOAAc) exhibited promising performance in half-cell configuration (Table 1).PyrrAc was shown to be an optimal electrolyte and has been further studied in terms of long-term performance and system degradation. The morphology of the aged negative electrodes was observed by Scanning Electron Microscopy (SEM) (Fig. 1). For instance, after 7 cycles of charge/discharge, formation of cracks was observed in the electrode (Fig. 1 (right)) due to hydrogen ab/desorption.The utilization of PyrrAc as electrolyte resulted in no initial capacity loss and, moreover, exhibited an increase in capacity during the first cycles, which can be recognized as an activation of the electrode (similar to the one observed in aqueous electrolytes). In order to obtain a complete understanding of the electrode stability, the electrolytes after cycling as well as calendar corrosion were studied using Inductively Coupled Plasma - Optical Emission Spectrometry (ICP-OES).[1] M.A. Hannan, M.M. Hoque, A. Mohamed, and A. Ayob, Renewable and Sustainable Energy Reviews, 69 (2017) 771–789.[2] B. Puga et al., ChemElectroChem, 2 (2015) 1321–1330.[3] J. Matsuda, Y. Nakamura, E. Akiba, J Alloys Compd, 509 (2011) 7498–7503.[4] T. Meng, K. H. Young, D. F. Wong, and J. Nei, Batteries, 3 (2017) 4. Figure 1

Analysis of Supply Chain Performance Improvement in the Fish Processing Industry

This study aims to identify the supply chain condition of the red snapper fish processing industry, assess the supply chain performance, and recommend performance improvements based on the performance measurement results. The study was conducted in Brondong District, Lamongan Regency, East Java, Indonesia. The methods used are the Supply Chain Operations Reference (SCOR) model and the Analytical Hierarchy Process (AHP), which measure effectiveness and efficiency parameters. Data were collected through interviews and field observations with expert respondents representing fishermen, collectors, and the fish processing industry. The results showed that the supply chain performance of the fishermen, collectors, and fish processing industry was 67.52% (poor), 88.11% (average), and 95.09% (excellent). The low performance was mainly in the fish catch composition accuracy and raw material handling practices. Root cause analysis was conducted to identify the leading causes, such as poor raw material quality, high raw material costs, and low cash-to-cash cycle time. Recommendations for improvement include handling raw materials training, using better cooling technology, and accelerating debt payments. Implementing lean supply chain management with the 5S system will improve operational efficiency and final product quality. Support from all stakeholders and government is essential for successfully implementing this strategy. Further study on the impact of lean implementation on environmental and social sustainability and exploration of new technologies for efficient fish handling and processing is needed.

Magnesium hydrogen storage: Temperature control via particle swarm with nonlinear inertia strategy

Magnesium-based hydrogen storage has garnered significant attention in the field of hydrogen storage due to its notable advantages, including high hydrogen storage capacity and low material cost. However, the relatively high thermodynamic stability of magnesium-based hydrogen storage materials necessitates heating the material to a specific temperature during the hydrogen charging and discharging processes, severely limiting the practical application and further development of this technology.Therefore, this paper aims to design a temperature control system for a magnesium-based solid-state hydrogen storage bottle. The system employs an optimized particle swarm optimization (PSO) algorithm to determine PID parameters, enabling rapid preheating of the hydrogen storage bottle and maintaining a stable operating temperature. Furthermore, by incorporating an appropriate penalty function, the system effectively suppresses temperature overshoot, preventing adverse effects on hydrogen storage performance caused by transient high temperatures, thereby ensuring the safety and stability of the hydrogen storage process.

Approaches for hysterectomy and implementation of robot-assisted surgery in benign gynaecological disease: A cost analysis study in a large university hospital

BackgroundAs a minimally invasive technique, robot-assisted hysterectomy (RAH) offers surgical advantages and significant reduction in morbidity compared to open surgery. Despite the increasing use of RAH in benign gynaecology, there is limited data on its cost-effectiveness, especially in a European context. Our goal is to assess the costs of the different hysterectomy approaches, to describe their clinical outcomes, and to evaluate the impact of introduction of RAH on the rates of different types of hysterectomy. MethodsA retrospective single-centre cost-analysis was performed for patients undergoing a hysterectomy for benign indications. Abdominal hysterectomy (AH), vaginal hysterectomy (VH), laparoscopic hysterectomy (LH), laparoscopically assisted vaginal hysterectomy (LAVH) and RAH were included. We considered the costs of operating room and hospital stay for the different hysterectomy techniques using the “Activity Centre–Care program model”. We report on intra- and postoperative complications for the different approaches as well as their cost relationship. ResultsBetween January 2014 and December 2021, 830 patients were operated; 67 underwent VH (8%), 108 LAVH (13%), 351 LH (42%), 148 RAH (18%) and 156 AH (19%).After the implementation and learning curve of a dedicated program for RAH in 2018, AH declined from 27.3% in 2014–2017, to 22.1% in 2018 and 6.9 % in 2019–2021.The reintervention rate was 3–4% for all surgical techniques. Pharmacological interventions and blood transfusions were performed after AH in 28%, and in 17–22% of the other approaches.AH had the highest hospital stay cost with an average of €2236.40. Mean cost of the hospital stay ranged from €1136.77-€1560.66 for minimally invasive techniques.The average total costs for RAH were €6528.10 compared to €4400.95 for AH. ConclusionImplementation of RAH resulted in a substantial decrease of open surgery rate. However, RAH remains the most expensive technique in our cohort, mainly due to high material and depreciation costs. Therefore, RAH should not be considered for every patient, but for those who would otherwise need more invasive surgery, with higher risk of complications. Future prospective studies should focus on the societal costs and patient reported outcomes, in order to do cost-benefit analysis and further evaluate the exact value of RAH in the current healthcare setting.

A novel approach for poly(hydroxybutyrate-co-hydroxyvalerate) production from vegetable wastes and pig manure: Potential in economy, environment and sustainability

Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) is a promising alternative to conventional petroleum-based plastics, owing to its considerable biodegradability and physicochemical properties. However, the high raw material costs limit its large-scale production. This study established a novel integrated process by coupling the anaerobic fermentation of vegetable wastes (VW) and pig manure (PM) with PHBV biosynthesis. The results demonstrated appreciable PHBV yields of 0.326 and 0.261 gPHBV/gVFA for VW and PM, respectively. Considering the magnitude of VM and PM in China, this novel approach could result in CO2 emission reduction by up to 12.70 million tons per year, as indicated by environmental impact assessment. Additionally, a preliminary economic analysis suggested economic benefits of up to 9.81 billion USD per year. These findings demonstrate that this integrated process can play a significant role in enabling large-scale production of PHBV while simultaneously resolving environmental pollution related problems associated with conventional plastics.

Screen printing Ag2Se/carbon nanocomposite films for flexible thermoelectric applications

Flexible thermoelectric generators offer the possibility of harvesting waste heat from the human body. However, intrinsic brittleness and the high production cost of bulk thermoelectric materials limit their applications in flexible thermoelectric generators. Herein, flexible Ag2Se/carbon nanocomposite films on polyimide substrates are prepared by scalable screen-printing followed by facial heat treatment. An optimal film shows a maximum power factor of 1617 μW m−1 K−2 at room temperature and good flexibility. The film consists of mainly Ag2Se grains with a preferred (00Ɩ)-orientation and a small amount of carbon. Microstructure observations reveal that the Ag2Se grains with sizes of nano to micrometers have coherent or continuous grain boundaries, and the carbon is mainly amorphous with slight graphitization. A flexible thermoelectric device assembled with the optimal film exhibits a power density of 29.1 W/m2 at a temperature gradient of 35.4 K. This work demonstrates a cost-effective route to high-performance flexible thermoelectric films.

Evaluation of biocementation of slope soil for erosion control with low-cost materials

In this study, biocementation of slope soil was performed using low-cost, commercially available materials to create a nutrient solution with native Cytobacillus hornekea. The high cost of laboratory-grade materials and microbes for biocementation is one of the main obstacles to its popularity. However, the cost of biocementation has been reduced significantly without reducing the strength when low-cost materials were used instead of laboratory-grade materials in this study. Direct shear test results and SEM also proved the suitability of the low-cost biocementation. Artificial rainfall with an intensity of 50–60 mm/h resulted in soil erosion of around 10% and 2% without and with biocementation, respectively. The amount of produced calcium carbonate was around 3.9% while using the low-cost materials with native microbes which is quite comparable with the laboratory-grade materials (3.4%).

Porphyrin-Based Hole-Transporting Materials for Perovskite Solar Cells: Boosting Performance with Smart Synthesis.

Perovskite solar cells (PSCs) are becoming a promising and revolutionary advancement within the photovoltaic field globally. Continuous improvement in efficiency, straightforward processing methods, and use of lightweight and cost-effective materials represent superior features, among other notable aspects. Still, long-term stability and durability are issues to address to facilitate widespread commercial adoption and practical application prospects. Research has focused on overcoming these challenges, and charge transport materials play a critical role in determining charge dynamics, photovoltaic performance, and device stability. Conventional hole-transporting materials (HTMs), spiro-OMeTAD and PTAA, contribute to remarkable power conversion efficiencies owing to high thin-film quality and matched energy alignment. However, they often show a high material cost, low carrier mobility, and poor stability, which greatly limit their practical applications. Now, this review outlines recent advances in synthetic approaches to porphyrin-based HTMs to tune the charge dynamics by optimizing their molecular structures and properties. The main structural features comprise porphyrins of A4-type, trans A2B2-type, and photosynthetic pigment analogues. Strategies include well-established routes to provide the required macrocycles, such as condensation of pyrrole or dipyrromethanes with suitable aldehydes, metalation of the porphyrin inner core, and postfunctionalization of peripheral positions. These functionalizations involve conventional procedures (e.g., halogenation, esterification, transesterification, nucleophilic oxidation, reduction, and nucleophilic substitution) as well as metal-catalyzed ones such as Suzuki-Miyaura, Sonogashira, Buchwald-Hartwig, and Ullmann cross-coupling reactions. As HTMs can also protect the perovskite layer from the external environment, porphyrin structures play a pivotal role in chemical, mechanical, and environmental stability, with their high hydrophobicity ability as the most significant parameter. The impact of porphyrins on the hole hopping of other HTMs while acting as an additive or an interlayer, passivating defects, and improving charge transport is also highlighted to provide real insights into ways to develop efficient and stable porphyrin-based materials for PSCs. This perspective aims to guide the scientific community in the design of new porphyrin molecules to place PSCs as an outperformer in photovoltaic technologies.

How the Chemical Properties of Polysaccharides Make It Possible to Design Various Types of Organic-Inorganic Composites for Catalytic Applications.

Recently, the use of plant-origin materials has become especially important due to the aggravation of environmental problems and the shortage and high cost of synthetic materials. One of the potential candidates among natural organic compounds is polysaccharides, characterized by a number of advantages over synthetic polymers. In recent years, natural polysaccharides have been used to design composite catalysts for various organic syntheses. This review is devoted to the current state of application of polysaccharides (chitosan, starch, pectin, cellulose, and hydroxyethylcellulose) and composites based on their catalysis. The article is divided into four main sections based on the type of polysaccharide: (1) chitosan-based nanocomposites; (2) pectin-based nanocomposites; (3) cellulose (hydroxyethylcellulose)-based nanocomposites; and (4) starch-based nanocomposites. Each section describes and summarizes recent studies on the preparation and application of polysaccharide-containing composites in various chemical transformations. It is shown that by modifying polysaccharides, polymers with special properties can be obtained, thus expanding the range of biocomposites for catalytic applications.

Concurrent and Aerobic Exercise on Maximal Oxygen Consumption in Adults with Obesity: Study Protocol for a Randomized Controlled Trial

Background. Concurrent and aerobic physical exercise are strategies for treating overweight and obesity. Most interventions have utilized cardiovascular or guided execution machines, which often involve high-cost materials not easily accessible to the general population. Objective. Identify the effect of 12 weeks of exercise (concurrent vs. aerobic training) based on the polarized training intensity distribution model on maximal oxygen consumption, muscle strength, and body composition. Materials and methods. A randomized controlled trial with two groups, concurrent vs. aerobic training (n = 28), in overweight and obese individuals. Both groups will perform 36 sessions, 3 times a week, on alternate days. Results. Current evidence has not demonstrated the superiority of concurrent over aerobic exercise on VO2max, muscle strength, and body composition. Additionally, the few randomized studies with concurrent exercise and the methodological limitations in their designs justify the importance of comparing both types of exercise to determine the best strategies for overweight and obese individuals regarding the mentioned outcomes.

Recent progress in research and development of rare-earth free iron nitride permanent magnet

The high cost of rare earth materials, unstable supply and high demand remain big problems to solve for permanent magnet industries. Thus α″-Fe16N2 has been picked up as one of the most promising rare earth-free magnet candidates because of its use of environmental-friendly raw materials, confirmed giant saturation magnetic flux density (2.9 T), and reasonably high magnetic anisotropy constant (1.8 MJ/m3). Also, α”-Fe16N2 metastable with film form exhibits high tetragonality (c/a=1.1) by interstitial introduction of N atoms, leading to a high magnetocrystalline anisotropy constant (Ku = 1.0 MJ/m3). but synthesis of bulk form has lower properties than thin film (<230 nm) because of magnetic interaction, experimentally low anisotropy, and low density. In this paper, we review the synthetic methods of metastable α”-Fe16N2 with powder and bulk form and discuss the approaches to enhance magnetocrystalline anisotropy of α”-Fe16N2.

Preliminary study of mixing used cooking oil and lemon peel essential oil as an alternative fuel to replace biodiesel

Biodiesel is an environmentally friendly renewable bio-energy with many advantages over diesel fuel. The disadvantage of biodiesel is that the price is still relatively expensive so it cannot compete with diesel fuel. This high price is due to the high cost of raw materials and manufacturing process costs. Raw materials such as palm oil, methanol and methyl acetate are expensive, and the transesterification and interesterification processes require long process stages that require a lot of energy supply. The solution to overcome this problem is to use cheap raw materials and a simple manufacturing process. Used cooking oil is household waste that has prospects as a raw material. Another ingredient used is lemon essential oil. Lemon essential oil can be made yourself by extracting lemon peel waste using a boiling or steaming process. The lemon essential oil used is also small, namely a maximum of 5% of the mass of used cooking oil. It is hoped that mixing used cooking oil with lemon essential oil can replace biodiesel. Lemon essential oil is a bio-additive that can improve the quality of used cooking oil to approach the physical properties of biodiesel. With this new process, it is hoped that it can produce fuel that is cheap but of good quality. The aim of the research is to obtain a new fuel to replace biodiesel that is cheaper and more efficient, namely with cheap raw materials and fewer process stages so that it will reduce production costs. The research began with the activation of zeolite as an adsorbent for purifying used cooking oil with variables including zeolite mass of 400 grams, calcination temperature of 300⁰C, activation time of 2 hours and zeolite size > 80 mesh. The second stage of the research was purifying used cooking oil with zeolite using a variable volume of 3 liters of used cooking oil and a purification time of 1 hour. The third stage of the research was mixing purified used cooking oil with lemon essential oil with variable volume of essential oil (3, 4, 5, 6, 7% oil volume) and mixing temperature (30, 40, 50⁰C), mixing time 60 minutes, stirring speed 500 rpm and oil volume 150 mL. After the mixing time and the sample temperature reached room temperature, an analysis of the density, acid number, viscosity and FFA of used cooking oil with bio-additive lemon essential oil was carried out. The analysis results are compared with the biodiesel standard SNI 7182-2015 to see whether the product/sample approaches the physical properties of biodiesel

Titanium hexacyanoferrate/carbon nanotube composites as the cathode material for aqueous sodium/zinc ion batteries

Aqueous zinc ion batteries (AZIBs), featuring its low cost and environmental protection, are regarded as the promising alternative for traditional energy storage devices acting on clean power generation and electrical vehicles. Prussian blue analogues (PBAs) have received a lot of attention for a potential cathode candidate in AZIBs due to its competence in accommodating various ions with good electrochemical stability. However, conventional PBAs have some inherent problems in Zn ions de-intercalation involving of high discharge potential separation, low structural stability, and high raw material cost. Herein, titanium hexacyanoferrate/carbon nanotube composite (TiHCF-CNT) is synthesized and applied to the cathode materials for aqueous sodium/zinc ion batteries at the first time. The resultant material exhibits not only a high capacity for 134.6 mAh g−1 at 0.05 A g−1, but also excellent cycling stability of 93.7 % capacity retention after 300 cycles at 0.3 A g−1. Na+ in the electrolyte can decrease the resistance of electrolyte and co-insert in the material structure with Zn2+, thus elevate the electrochemical performances remarkably. Moreover, the defects in the structure are identified as Ti vacancies, and these defects can be occupied by Zn2+ reversibly at the charging-discharging process, which lead to a high reversible capacity and cycle stability accordingly.