Plastic Mixtures Research Articles

Conversion of municipals waste into syngas and methanol via steam gasification using CaO as sorbent: An Aspen Plus modelling

The conversion of wastes specially (plastic and food waste) for energy and value-added products through gasification is under investigation. This investigation configures an integrated simulation process model for steam gasification, syngas treatment, methanol production and purification for plastic waste ((Polyethylene(PE) + polyethylene terephthalate (PET)), food waste (vegetable and fruits) and their blend using a simulation tool Aspen Plus®. The impact of three process parameters such as temperature (650–900 °C), steam/feedstock ratio (1.0–2.0) and CaO/feedstock ratio (0.5–2.0), on syngas composition and downstream product methanol. H2 and methanol yield increases with the increase of temperature in all cases. In the case of plastic, H2 and methanol yield were increased from 75.68 to 92.77 kmol/h and 709.60 to 960.13 kg/h respectively with the injection of steam flowrate. A similar H2 and methanol yield trend was obtained for food and mixture of plastic and food waste with a little variation. In the case of food waste, methanol has ascending order and maximum final methanol production 476.56 kg/h at 1800 kg/h steam flowrate. The gas composition profile which define the H2-CO/CO + CO2 ratio increase from 1.27 to 1.88 governing methanol production for plastic. CaO is added to capture the CO2 to get the augmented syngas composition for methanol production. The general trend of H2 production was ascending, whereas methanol is descending with an increase of temperature and CaO flowrate for most cases. Maximum 978 kg/h MeOH noticed at temperature of 700 °C, steam flowrate of 1000 kg/h and CaO flowrate of 500 kg/h for plastic. Although, its flowrate extensively affected the CO and CO2 flowrates that need to be optimized for a desired composition to maintain a good H2-CO/CO + CO2 ratio for methanol production.

Bifunctional metal-loaded micro-mesoporous zeolites for waste plastics conversion to high quality liquid product

A series of micro-mesoporous zeolitic catalysts synthesized using recrystallization of two different zeolites (HZSM-5 and beta) were impregnated with Pt and other notable metals. The resulting bifunctional catalysts were characterized and tested for the hydrocracking of a model municipal waste plastic mixture. Actual waste plastic mixture of the same composition was also employed for the comparison. The hydrocracking experiments were carried out in a Parr stirred batch reactor at 325, 350, and 375 °C. The other reaction conditions were fixed at the initial cold H2 pressure of 20 bar, reaction time of 60 min, and plastic to catalyst ratio of 20:1 by wt. The inclusion of the Pt metal has shown to increase the hydrocracking activity of the micro-mesoporous supports. The Pt micro-mesoporous ZSM-5 catalysts have shown the better activity while Pt micro-mesoporous beta catalysts have shown better selectivity towards liquid. The presence of Pt metal has also produced a better quality liquid product with fewer unsaturated hydrocarbons and results in lower coke formation as determined by the TGA analysis of the spent catalysts.

Enhancing Pullulan Soft Capsules with a Mixture of Glycerol and Sorbitol Plasticizers: A Multi-Dimensional Study.

The plasticizer is crucial in the plant-based soft capsule. However, meeting the quality requirements of these capsules with a single plasticizer is challenging. To address this issue, this study first investigated the impact of a plasticizer mixture containing sorbitol and glycerol in varying mass ratios and the performance of the pullulan soft film and capsule. The multiscale analysis demonstrates that the plasticizer mixture exhibits superior effectiveness in enhancing the performance of the pullulan film/capsule compared to a single plasticizer. Furthermore, thermogravimetric analysis, Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy indicate that the plasticizer mixture enhances the compatibility and thermal stability of the pullulan films without altering their chemical composition. Among the different mass ratios examined, a 15:15 ratio of sorbitol to glycerol (S/G) is identified as the most optimal, leading to superior physicochemical properties and meeting the requirements for brittleness and disintegration time set by the Chinese Pharmacopoeia. This study provides significant insights into the effect of the plasticizer mixture on the performance of pullulan soft capsules and offers a promising application formula for future use.

Utilization of a mixture of waste plastic materials and granite particles as a partial replacement of coarse aggregate in concrete blocks

Due to an increase in population, there is a rapid rise in industrialization and urbanization in the country which marshalled the way for infrastructure development which has resulted in heavy usage of natural resources such as Fine Aggregates (Sand), Coarse Aggregates, etc. which are non-renewable. In this paper, we discuss about a method for reusing the plastic wastes and as well as safeguarding the natural aggregates by incorporating them into concrete. It aims at finding out the optimum percentage replacement for natural coarse aggregate with a mixture of plastic and granite pieces coarse aggregate, which can give us the same or more strength and has the same amount of workability as compared to nominal concrete. In this paper, we have worked on the M20 grade of concrete moulds/blocks. Tests were carried out on fine aggregates, high density waste plastics, coarse aggregates, cement, and plastic-granite coarse aggregate to determine their physical properties. Cubes of sizes 0.15 m × 0.15 m × 0.15 m were casted and were tested for 7-days & 28-days of compressive strength.

Optimization of Vat-Polymerization binder formulation for 3D printing ceramic slurry using D-optimal mixture experimental design

The aim of the present study was to optimize a formulation of the vat-polymerization binder of 3D printing ceramic slurry using a D-optimal mixture experimental design. The selected methodology was based on an extreme vertices approach with 13 combinations, selecting three types of resin monomers (TMPTA, NPG2PODA, HDDA) and one type of plasticizer (TXIB) as independent variables, while mechanical properties (including tensile strength and elongation at break), volume shrinkage, viscosity, and curing depth were considered as response variables. The experimental data were analyzed to generate statistical models and response surfaces for analyzing the effects of component fractions on individual responses. Analysis of variance was performed. This method was applied to predict the optimal formulation. Based on the DoE results, the mixture of resins and plasticizer with an optimized composition ratio after curing showed better mechanical properties, lower volume shrinkage, lower viscosity, and an appropriate curing depth. Furthermore, a ceramic slurry containing 55 vol% Al2O3 was prepared to evaluate the printability of the optimized mixture. The relatively dense ceramic parts and smooth surface were successfully manufactured after de-binding and sintering. Our findings demonstrate the efficiency, reliability, and feasibility of the D-optimal mixture experimental design in modeling, predicting, and optimizing the formulation of the TMPTA/NPG2PODA/HDDA/TXIB composite. Overall, this study can be helpful in designing experiments and optimizing the vat-polymerization of 3D printing ceramic slurry.

Kinetic Analysis of Thermal Degradation of Recycled Polypropylene and Polystyrene Mixtures Using Regenerated Catalyst from Fluidized Catalytic Cracking Process (FCC).

The pyrolysis process is a thermochemical recycling process that in recent years has gained importance due to its application in plastic waste, which is one of the biggest environmental problems today. Thus, it is essential to carry out kinetic and thermodynamic analyses to understand the thermocatalytic degradation processes involved in plastic waste mixtures. In this sense, the main objective of this study is to analyze the degradation kinetics of the specific mixture of polypropylene (25%) and polystyrene (75%) with 10% mass of regenerated FCC catalyst which was recovered from conventional refining processes using 3 heating rates at 5, 10 and 15 K min-1 by thermogravimetric analysis (TGA). The obtained TGA data were compared with the isoconversional models used in this work that include Friedman (FR), Kissinger Akahira Sunose (KAS), Flynn-Wall-Ozawa (FWO), Starink (ST) and Miura-Maki (MM) in order to determine the one that best fits the experimental data and to analyze the activation energy and the pre-exponential factor; the model is optimized by means of the difference of minimum squares. Activation energy values between 148 and 308 kJ/mol were obtained where the catalytic action has been notorious, decreasing the activation energy values with respect to thermal processes.

Novel ensemble modelling for prediction of fundamental properties of bitumen incorporating plastic waste

Plastic asphalt mixtures (PAMs) have garnered attention recently, but their field application has been limited due to a lack of understanding of asphalt mix behavior following modification. A modelling tool that can calculate the plastic influence on the characteristics of asphalt mixtures is required to close this gap. Hence, this study offers a performance analysis of various machine learning (ML) models in predicting the performance of PAMs through its various properties. These models include three methods, decision tree (DT) as an individual technique, adaboost regressor (AR), and bagging regressor (BR), as ensemble techniques for prediction of fundamental properties of PAMs i.e. air voids (Va), marshall flow (MF), marshall stability (MS), tensile strength ratio (TSR), and indirect tensile strength (ITS). A series of experimental works and their results on the PAMs properties were collected through literature, to develop ML models and compare their accuracy. The comparative findings demonstrated that the BR model had the largest coefficient of determination (R2) and the lowest statistical errors, making it the model with the best predictive ability. According to the study's findings, ensemble approaches can be effectively utilized to forecast different properties of PAMs. Comparing ensemble models to the single model that served as their base learner, ensemble models were able to increase prediction accuracy. Furthermore, cross validation was performed to check the accuracy of developed models. SHAP analysis was conducted to examine the effects of input parameters on the fundamental properties of PAMs.

The effect of pre-microwave irradiation on the floatation of polystyrene, polyethylene terephthalate, and polyvinylchloride using numerous traditional depressants

The absence of an effective technique for separation of an individual plastic from a mixture of plastics, is one of the most important concern in plastics waste management. The recently introduced floatation technique used to separate the selected engineering plastics including, polystyrene (PS), polyethylene terephthalate (PET), and polyvinylchloride (PVC) from each other. The floatation was assisted by using the traditional depressants (chemical agents). The effects of plastics surface pre-microwave irradiation at different microwave output powers, 20–100% studied on the floatation of each plastic. Also, the effect of depressant concentration, 400–2000 mg/L on the plastics floatation was evaluated. The results showed the pre-microwave irradiation of the plastics surface at different microwave output powers and depressant concentrations had important influence on the sink-float behavior of the studied plastics with the exception of PET. It seemed, the number and type of the active sites on the plastics surface changed after microwave irradiation. There was not any regular trend for the floatability of a plastic with increasing the microwave output power. The results reinforced by the traditional identification techniques including contact angle (θ) measurement, scanning electron microscope (SEM) images, and attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) spectra analysis. The driven equations by a design of experiment software (Design-Expert ®) showed suitable conformity between the predicted and actual plastics flotation values.

UTILIZATION OF PLASTIC WASTE AS A SUBSTITUTIONAL MATERIAL FOR PAVING BLOCK MANUFACTURING

Besides reducing environmental pollution, the use of garbage or plastic waste can also be used as an alternative to building materials. The potential for utilizing plastic waste still needs to be developed, by conducting research on plastic waste to be substituted into paving block making materials, by replacing some of the sand material in normal paving blocks. The research used is an experimental method. In this test the test object was made by adding additives/mixture of plastic waste as a filler/mixture in the paving block mix with a percentage of plastic mixture of 2.56%, 5.26%, 8.11%, 10.11%. Then the paving block is tested for compressive strength at the age of 28 days which is possible to have reached the maximum compressive strength value. The results of the paving block compressive strength test will increase according to the increase in the percentage of plastic mixture. The compressive strength of paving blocks with a plastic mixture of 0%, 2.56%, 5.26%, 8.11% and 10.11% obtained compressive strengths of 10.44 MPa, 10.64 MPa, 10.95 respectively MPa, 11.15 MPa and 11.33 MPa. The increase in compressive strength of normal paving blocks (0% mixture of plastic waste) was 1.83%, 4.6%, 6.35% and 7.86%. The highest compressive strength occurs in paving blocks with a mixture percentage of 10.11% plastic waste, according to the SNI-03-0691-1996 standard the compressive strength is included in the quality level D which can be used for parks and other uses.

Insight into the kinetics and thermodynamic analyses of co-pyrolysis using advanced isoconversional method and thermogravimetric analysis: A multi-model study of optimization for enhanced fuel properties

Waste management is quite challenging and it has become a major concern across the globe. The most common wastes are in the form of polymers or plastics that are composed of a mixture of various commodity plastics like PE, PP, PVC, HDPE, LDPE, etc. Pyrolysis is found to be a promising technology for managing wastes as well as converting them into valuable hydrocarbons. The present study investigated to discern the synergism in thermal degradation behavior and to identify the interaction between polymer molecules in co-pyrolysis. The advanced isoconversional model was employed for trustworthy estimation of activation energy as the thermal effects on a reaction deviate the temperature of a sample from the set heating value. The results were also compared with the model-free methods to understand the synergism, reactivity, and thermodynamic system with the progress of the conversion. The activation energy was found to be lowest when the polymers were used in a certain proportion and the synergy effect was more significant when PP content was > 40 % in the mixture. The positive synergetic effect could be attributed to the intermolecular hydrogen transfer from a less stable polymer to a free radical de-propagating chain of the other polymer during thermal degradation. The complex governing thermochemical reaction mechanism was determined using the Criado master plot and the analysis revealed that with increasing PP content in a binary mixture the reaction mechanism shifted from R2 to R3. The high regression coefficient value (R2 > 0.99) in the regenerated TGA profiles signified a good agreement between the theoretical and experimental results. While thermodynamic analysis showed that the process was endothermic and non-spontaneous in nature. Moreover, the radical reaction during co-pyrolysis of polymers enhances intermolecular hydrogen transfer resulting in the formation of iso-alkane and iso-alkene along with secondary radicals, which undergo β-scission to form alkenes/dienes and short primary radicals. As a result, the enhanced intermolecular hydrogen transfer phenomenon initiates the co-pyrolysis reaction at a relatively lower activation energy compared to individual polymer molecules.

Pyrolysis-plasma/catalytic reforming of post-consumer waste plastics for hydrogen production

Different types of single waste plastics and a range of real-world mixed waste plastics from several different industrial and commercial sources have been processed in a pyrolysis-plasma/catalytic experimental reactor system for the production of hydrogen. The hydrocarbons produced from the pyrolysis stage were catalytically (Ni/MCM-41) steam reformed in a low temperature, non-thermal plasma/catalytic reactor. The polyolefin plastics, high density polyethylene, low density polyethylene and polypropylene produced the highest yield of hydrogen at 18.0, 17.3 and 16.3 mmol g−1plastics respectively. The aromatic structured polystyrene produced a lower hydrogen yield of 11.9 mmol g−1plastics and polyethylene terephthalate with an aromatic and oxygenated structure produced only 10.2 mmol g−1plastics and a high yield of carbon oxide gases. The real-world mixed plastic waste produced yields of hydrogen in the range of 13.4–16.9 mmol g−1plastics. The lowest hydrogen yield of 13.4 mmol g−1plastics was produced from the mineral water bottle packaging waste due to the high content of polyethylene terephthalate in the plastic waste mixture.

PENGARUH PENAMBAHAN PLASTIK BEKAS TIPE POLYETHYLENE TEREPHTHALATE (PET) TERHADAP DAYA LEKAT CAMPURAN LASTON LAPIS AC-WC

The problem in this research is the increasing amount of plastic waste that is difficult to decompose creates an idea for me to use as one of the additives or mixtures in making asphalt mixtures. The types of plastic waste that are mostly found are drink bottles and plastic bags. This type of plastic can only be recycled only once with the name PET (Polyethylene Terephthalate). The addition of plastic to the asphalt mixture aims to optimize the characteristics of the AC-WC smooth asphalt mixture and reduce the amount of waste. Plastic mixing is carried out by means of a dry method whose plastic content is 5%, 10% 15% and 30% of the weight of optimum asphalt content. From the Marshall test conducted with the addition of PET plastic waste, the Stability value at 5% was 2005,967 kg, compared to the absence of additional plastic waste with a record number of 1961,534 kg. Density value with the addition of plastic at 5% level was 2.355% decreased compared to the elimination of the addition of this plastic mixture with a value of 2.359%. The value of Flow with the addition of plastic at a 5% level of 3,200% has increased compared to without the addition of plastic with a value of 3,100%. The value of VIM with the addition of plastic at a level of 5% is 4.453% compared without the addition of this element from the plastic waste that is difficult to decompose with a value of 4.297%. VFA value with the addition of plastics at 5% level was 73.493% decreased compared to no plastic additions amounting to 74.216%. The VMA value with the addition of plastic at 5% level was 16,801%, an increase compared to without the addition of plastic with a magnitude of 16,665%. MQ value with the addition of plastic at 5% content of 626,865 kg / mm has decreased compared to without the addition of plastic 632,753 kg / mm.

Synergistic effects during co-pyrolysis and co-gasification of polypropylene and polystyrene

The thermal conversion of waste plastic products can provide a promising solution to the issues of environmental pollution, waste management, and energy needs. However, our present understanding on the thermal reforming of different kinds of plastic wastes mixtures during their co-pyrolysis and co-gasification for syngas production and energy recovery is insufficient. Non-selective urban polypropylene (PP) and polystyrene (PS) waste plastics were chosen for the investigations reported here. Thermal degradation properties of PP and PS as well as their blends in different mass ratios were investigated via thermogravimetric (TG) analysis. Co-pyrolysis and CO2-assisted co-gasification of PP-PS blends were then conducted using a fixed-bed reactor at a temperature of 1173 K. Experimental results from the blends were then compared with the weighted value calculated from their component feedstocks to quantify the degree of synergistic effect. TG results showed that the co-treatment of PP and PS enhanced the respective devolatilization process. The co-pyrolysis of PP and PS enhanced their thermal cracking, leading to synergistic increases in the yields of H2, light hydrocarbons (HC) and total syngas. In co-gasification, the reforming reaction involving CO2 was synergistically enhanced, resulting in the increased yields of H2 and HC. The gasification reactivity of carbon black improved during the co-processing of PP and PS due to the synergistic effect between the two different kinds of plastics. Higher synergistic effects were observed from the plastic mixtures having higher PS content that resulted in increased yield of syngas. Co-gasification of PP-PS blends having 40% PP content (2P3S) exhibited the maximum synergistic effect on H2, CO, and total syngas showing increased yields by 88.8%, 77.7%, and 74.2% respectively. The lowest synergistic effect was observed for HC that showed increased yield of only 25.1%. The optimal CO2 consumption was also observed from the co-gasification of 2P3S. Each gram of 2P3S feedstock consumed approximately 1.80 g of CO2 to result in highest recovered energy of 27.49 kJ/g and the maximum overall energy efficiency of 43.2%. The results revealed that enhanced thermal cracking and CO2 reforming reaction, along with the improved reactivity of carbon black were mainly responsible for increased yields of H2, HC, CO and total syngas during co-gasification. This study contributes to the fundamental understanding of co-processing of non-separated waste plastics for enhanced syngas production and energy recovery, elucidating the synergistic effect between the various kinds of plastics during their co-pyrolysis and co-gasification.

Enhanced Liquid Fuel Production from Pyrolysis of Plastic Waste Mixtures Using a Natural Mineral Catalyst

Since plastic wastes are commonly found and accumulate in numerous types and forms, the pyrolysis of plastic waste mixtures seems more feasible to be selected for large-scale production. However, the process typically produces less liquid than individual plastic pyrolysis. This study proposed a viable approach for catalytic pyrolysis by using natural mineral catalysts without modification. Bentonite was selected as a natural mineral catalyst while HZSM-5 was used for performance comparison. The process was evaluated in situ using a fixed-bed reactor at temperatures between 400 °C and 500 °C. The mixture of plastic waste composition was designed based on the non-recycled plastics data. The results showed that 42.55 wt% of liquid yield was obtained from thermal pyrolysis using Malaysia’s non-recycled plastics data. It was then found that using HZSM-5 and bentonite catalysts significantly boosted liquid products to about 56 and 60%, respectively. The presence of catalysts also positively minimized tar formation and eliminated wax formation in the liquid product. Furthermore, the catalytic process showed remarkable improvements in aromatics and alkane compounds in the liquid while only alkenes were found to be high when bentonite was used.

Impact of Plastic Blends on the Gaseous Product Composition from the Co-Pyrolysis Process

The co-pyrolysis of various biomasses mixed with two types of plastic waste was investigated in this study. Mixture M1 consisted of 30% m/m styrene–butadiene rubber (SBR), 40% m/m polyethylene terephthalate (PET), and 30% m/m polypropylene (PP). M2 consisted of 40% m/m PET, 30% m/m PP, and 30% m/m acrylonitrile–butadiene–styrene copolymer (ABS). The SBR, ABS, and PP used in this study were from the automotive industry, while the PET originated from scrap bottles. Co-pyrolysis was performed using wood biomass, agricultural biomass, and furniture trash. Thermal treatment was performed on samples from room temperature to 400 or 600 °C at a heating rate of 10 °C/min under N2 at a flow rate of 3 dm3/min. Based on the findings of the experiments, an acceptable temperature was found for the fixed-bed pyrolysis of biomass–plastic mixtures with varying ratios, and the raw materials were pyrolyzed under the same conditions. The composition of the derived gaseous fraction was investigated. The co-pyrolysis studies and variance analysis revealed that combining biomass with plastic materials had a good influence on the gaseous fraction, particularly in the presence of 6.6–7.5% v/v hydrogen and a lower heating value of 15.11 MJ/m3. This type of gaseous product has great potential for use as a replacement for coke oven gas in metallurgy and other applications.

Kinetic modelling of mixed plastic waste pyrolysis

The study of plastic waste thermal decomposition and kinetics is a crucial step for optimal reactor design and the scale-up of pyrolysis technologies for chemical recycling. Kinetic parameters of individual and mixed plastic waste samples that resemble the main components of plastic waste streams (polyolefins and polyesters) were determined in this study using thermogravimetric analysis. Strong dependencies of activation energy on conversion were found for the mixtures, indicating that the process occurs in multiple steps and there are strong interactions between plastic components, lowering their activation energy during the decomposition. PP and LDPE decomposed via two separate steps whereas others decomposed via a single step process. For plastic mixtures, three dominant partially overlapping steps were identified. Kinetic deconvolution analysis improved model accuracy of mixtures and enabled the study of kinetic contributions and behaviour of individual steps. The models were then applied to predict experimental data at various heating conditions and plastic compositions.

Interactions in plasticizer mixtures used for sugar replacement

In our quest for novel ingredients to be used in sugar replacement strategies, we have investigated the thermodynamics of polycarboxylic acids, such as citric acid. We have demonstrated the applicability of the Flory-Huggins (FH) theory to describe the thermodynamics of polycarboxylic acids solutions. Moreover, for citric acid we can describe the complete phase diagram with the theory. It shows that polycarboxylic acids have similar plasticizing and hygroscopic properties as sugars and polyols.Regarding mixtures of polycarboxylic acids and carbohydrates, the FH theory is able to describe a) the water activity of the mixtures, b) the solubility of ternary mixtures of acids and sugars, c) the lowering of the deliquescence point for binary mixtures of crystals, and d) the melting point depression in eutectic mixtures. Unexpectingly, our investigations show there is a strong non-zero FH interaction parameter between carboxylic acids and carbohydrates. In our prior sugar replacement strategy we have assumed zero interactions between plasticizers. Here, we will readdress this assumption. Carefull investigations of solid-liquid equilibrium of eutectic mixtures involving polycarboxylic acids and/or carbohydrates, shows nearly zero interaction in eutectic mixtures consisting only of two carbohydrates or two polycarboxylic acids. We now hold the hypothesis that there is strong non-zero interaction if the mixture contains plasticizers strongly differing in the amount of hydrogen bonding groups. This strong interaction explains why these mixtures, like polycarboxylic acids and carbohydrates, are excellent candidates as deep eutectic solvents. Furthermore, we conclude that polycarboxylic acids are useful additions to the toolbox of sugar replacers, albeit that there are some limitations to their amounts used.

Separation of plastic mixtures by sink-float combined with froth flotation

Separation of plastic mixtures by sink-float combined with froth flotation

Paving Block from Residue of PS/LDPE/PP Plastic Pyrolysis Mixed with Palm Oil Bottom Ash (POBA)

The residue of plastic mixture pyrolysis can be used for making paving blocks. Fibers in plastics can be used as an adhesive against other materials and can increase the strength of paving blocks. Palm oil bottom ash (POBA) was added to replace the role of cement, which has the same content as cement, i.e., silica (Si). This study aimed to see the effect of palm oil bottom ash and sand added to the residue of plastic mixture pyrolysis (i.e., PS/LDPE/PP) on the quality of paving blocks. The paving block as a test object was made by combining two materials. The residue of plastic mixture pyrolysis and LDPE plastic melt was mixed with a mass ratio of 70:30%, referred to as material I. Furthermore, palm oil bottom ash and sand were mixed with a mass ratio of 100%, 80%, 60%, 40%, and 20%, referred to as material II. The ratio of ingredients I and II used was 1: 1. Testing of the quality of paving blocks includes a compressive strength test and a water absorption test. The test results showed that the ratio of PS/LDPE/PP mixture (50:25:25) had a compressive strength of 104.1 kg/cm2 or 102.08 MPa and the water absorption of 2.4% at the ratio of palm oil bottom ash and sand at 80:20%. Adding palm oil bottom ash can reduce the paving block’s compressive strength, and the residue’s LDPE content can affect water absorption because of its chemical structure properties. Therefore, a reduction in the amount of LDPE residue is needed to obtain optimal water absorption values in paving blocks and add palm oil bottom ash. Based on this compressive strength in this study and SNI 03-0691-1996, these paving blocks can be used for gardens.

Locally Fluorinated Electrolyte Medium Layer for High-Performance Anode-Free Li-Metal Batteries.

Low cycling Coulombic efficiency (CE) and messy Li dendrite growth problems have greatly hindered the development of anode-free Li-metal batteries (AFLBs). Thus, functional electrolytes for uniform lithium deposition and lithium/electrolyte side reaction suppression are desired. Here, we report a locally fluorinated electrolyte (LFE) medium layer surrounding Cu foils to tailor the chemical compositions of the solid-electrolyte interphase (SEI) in AFLBs for inhibiting the immoderate Li dendrite growth and to suppress the interfacial reaction. This LFE consists of highly concentrated LiTFSI dissolved in a fluoroethylene carbonate and/or succinonitrile plastic mixture. The CE of Cu||LiNi0.8Co0.1Mn0.1O2 (NCM811) AFLB increased to a high level of 99% as envisaged, and the cycling ability was also highly improved. These improvements are facilitated by the formation of a uniform, dense, and LiF-rich SEI. LiF possesses high interfacial energy at the LiF/Li interface, resulting in a more uniform Li deposition process as proved by density functional theory (DFT) calculation results. This work provides a simple yet utility tech for the enhancement of future high-energy-density AFLBs.