Effect Of Solids Concentration Research Articles

Impact of Solid Particle Concentration and Liquid Circulation on Gas Holdup in Counter-Current Slurry Bubble Columns

In this study, in a three-phase reactor with a rectangular cross-section, the effects of liquid circulation rates and solid particle concentration on gas holdup and bubble size distribution (BSD) were investigated. Air, water, and glass beads were used as the gas, liquid, and solid phases, respectively. Different liquid circulation velocities and different solid loads were applied. The results demonstrate that increasing solid content from 0% to 6% can decrease gas holdup by 50% (due to increased slurry phase viscosity and promotion of bubble coalescence). Also, increasing the liquid circulation rate showed a weak effect on gas holdup, although a slight incremental effect was observed due to the promotion of bubble breakup and the extension of bubble residence time. The gas holdup in counter-current slurry bubble columns (CCSBCs) was predicted using a novel correlation that took into account the combined effects of solid concentration and liquid circulation rate. These findings are crucial for the design and optimization of the three-phase reactors used in industries such as mining and wastewater treatment.

Slurry Transportation Characteristics of Potash Mine Cemented Paste Backfills via Loop Test Processing

This study evaluated the properties and processing of cemented paste backfills (CPBs) for potash mining through loop tests. The CPBs were made with steel slags as the binder, granulated potash tailings as the aggregate, and waste brine water as the liquid phase. The effects of solid concentration and steel slag dosage on the transport and mechanical properties of CPBs were assessed. The loop test demonstrated that all CPB slurries performed well, exhibiting strong long-distance pipeline transport capabilities. The 28-day compressive strength of the backfills exceeded 1 MPa, meeting the design requirements for backfill strength. The key rheological parameters, including yield stress (τ0) and viscosity coefficient (η), were comprehensively and theoretically analyzed based on the variations in pressure loss per unit distance of the filling slurry measured during the loop test. The empirical formulas for CPB pressure loss, accounting for varying flow rates and pipeline diameters, were derived with an error margin under 2%. The response surface analysis showed that the affecting extents of factors on pressure loss in CPB slurry were ranked as follows: solid concentration > cementing agent content > flow rate. This study offered valuable guidance for the processing of potash mine backfill operations.

Effect of Solid Content on Rheological, Mechanical, and Thermal Properties of Adipic Acid‐Based Flame Retardant Polyurethane Dispersion

ABSTRACTThe solid concentration of polyurethane dispersion is an important aspect of the coating application. In the present work, anionic waterborne polyurethane was prepared by reacting PPG‐100, adipic acid, and THPP‐based monophosphate polyester diol with IPDI. The formulation was done by varying solid concentrations of dispersion. The chemical structure was confirmed using FTIR and NMR. The surface morphology of coated panels was analyzed by SEM that shows as solid concentration increases surface roughness increases. The rheological property indicates that the solid concentration of FRPUDs increases viscosity and storage modulus whereas loss modulus decreases. The thermal degradation rate increases from 348°C to 354°C with increased solid concentration. LOI increases from 26% to 29% with increase in solid concentration. Tensile strength increases from 10.5 to 14.8 MPa with an increase in solid concentration in dispersion. Flexibility or elongation increases from 268% to 299% with a decrease in solid concentration. Scratch hardness in coating increases with increase in solid concentration.

In Situ Crosslinked Biodegradable Hydrogels Based on Poly(Ethylene Glycol) and Poly(ε-Lysine) for Medical Application.

Hydrogels have emerged as promising biomaterials due to their excellent performance; however, their biocompatibility, biodegradability, and absorbability still require improvement to support a broader range of medical applications. This paper presents a new biofunctionalized hydrogel based on in situ crosslinking between maleimide-terminated four-arm-poly(ethylene glycol) (4-arm-PEG-Mal) and poly(ε-lysine) (ε-PL). The PEG/ε-PL hydrogels, named LG-n, were rapidly formed via amine/maleimide reaction by mixing 4-arm-PEG-Mal and ε-PL under physiological conditions. The corresponding dry gels (DLG-n) were obtained through a freeze-drying technique. 1H NMR, FT-IR, and SEM were utilized to confirm the structures of 4-arm-PEG-Mal and LG-n (or DLG-n), and the effects of solid content on the physicochemical properties of the hydrogels were investigated. Although high solid content could increase the swelling ratio, all LG-n samples exhibited a low equilibrium swelling ratio of less than 30%. LG-7, which contained moderate solid content, exhibited optimal compression properties characterized by a compressive fracture strength of 45.2 kPa and a deformation of 69.5%. Compression cycle tests revealed that LG-n demonstrated good anti-fatigue performance. In vitro degradation studies confirmed the biodegradability of LG-n, with the degradation rate primarily governing the drug (ceftibuten) release efficiency, leading to a sustained release duration of four weeks. Cytotoxicity tests, cell survival morphology observation, live/dead assays, and hemolysis tests indicated that LG-n exhibited excellent cytocompatibility and low hemolysis rates (<5%). Furthermore, the broad-spectrum antibacterial activity of LG-n was verified by an inhibition zone method. In conclusion, the developed LG-n hydrogels hold promising applications in the medical field, particularly as drug sustained-release carriers and wound dressings.

Fabrication and characterization of hierarchically macroporous Al2O3 ceramic supported ZnO/ZnS photocatalyst

Hierarchically macroporous Al2O3 ceramic carriers were prepared by direct-foaming combined gel-freezing method. ZnO/ZnS photocatalyst was loaded on the porous carrier through hydrothermal method. The effects of solid content, polyvinyl alcohol content, stirring speed, and sintering temperature on the pore structure, porosity, and compressive strength of the porous carrier were investigated. The pore forming mechanism was also studied. The morphology of ZnO/ZnS photocatalyst was adjusted by changing the pH value during hydrothermal process. The results show that the porous ceramic contains four different sizes of pores, spherical pore, through pore, unidirectional pore, and interstitial pore. The pore structure and strength can be regulated through optimizing process parameters. The porosity and compressive strength of porous carrier prepared with 1.2 % PVA content, 22 % solid content, 1500 r/min stirring speed and 1500 °C sintering temperature are 89.4 % and 1.45 MPa, respectively, which is suitable to be used as the photocatalyst carrier. When the pH value is 10, the size and distribution of ZnO/ZnS photocatalyst are matched with the pore structure of porous carrier. The supported ZnO/ZnS has high photocatalytic activity and good reusability.

Effect of solid loading and particle size on bubble behavior and flow field structure in slurry bubble column

The complexity of fluid dynamics in a slurry bubble column reactor introduces significant uncertainty in reactor design and scale-up. This paper investigates the hydrodynamic performance of the gas–liquid–solid system within the reactor by employing computational fluid dynamics-population balance modeling numerical simulations alongside particle image velocimetry (PIV) experiments. The effect of superficial gas velocity and particle conditions on the overall gas holdup were analyzed, focusing on the effects of particle size and solid concentration on bubble size, bubble behavior, flow field structure, and local gas holdup distribution at high superficial gas velocities. Bubble size was evaluated using calibrated image measurements, and the impact of varying solid conditions was thoroughly explored. The results revealed that an increase in solid size correlated with higher gas holdup and smaller bubble sizes, whereas a greater solid concentration resulted in decreased gas holdup and larger bubble sizes. PIV experiments indicated that bubbles exhibited a tendency to migrate toward the central region of the reactor, leading to the formation of larger bubbles that accelerated the rise of surrounding bubbles, while smaller bubbles near the wall moved downward. As the slurry bed height increased, the range of local gas holdup distribution expanded, resulting in a symmetrical distribution of radial local gas holdup in the fully developed stage at a height of 0.16 m.

Crosslinked Biodegradable Hybrid Hydrogels Based on Poly(ethylene glycol) and Gelatin for Drug Controlled Release.

A series of hybrid hydrogels of poly(ethylene glycol) (PEG) were synthesized using gelatin as a crosslinker and investigated for controlled delivery of the first-generation cephalosporin antibiotic, Cefazedone sodium (CFD). A commercially available 4-arm-PEG-OH was first modified to obtain four-arm-PEG-succinimidyl glutarate (4-arm-PEG-SG), which formed the gelatin-PEG composite hydrogels (SnNm) through crosslinking with gelatin. To regulate the drug delivery, SnNm hydrogels with various solid contents and crosslinking degrees were prepared. The effect of solid contents and crosslinking degrees on the thermal, mechanical, swelling, degradation, and drug release properties of the hydrogels were intensively investigated. The results revealed that increasing the crosslinking degree and solid content of SnNm could not only enhance the thermal stability, swelling ratio (SR), and compression resistance capacity of SnNm but also prolong the degradation and drug release times. The release kinetics of the SnNm hydrogels were found to follow the first-order model, suggesting that the transport rate of CFD within the matrix of hydrogels is proportional to the concentration of the drug where it is located. Specifically, S1N1-III showed 90% mass loss after 60 h of degradation and a sustained release duration of 72 h. The cytotoxicity assay using the MTT method revealed that cell viability rates of S1N1 were higher than 95%, indicating excellent cytocompatibility. This study offers new insights and methodologies for the development of hydrogels as biomedical composite materials.

Effect of solids concentration and operational variables on the performance of a geometrically optimized concentrator hydrocyclone employing a pseudoplastic fluid

The employment of hydrocyclones in thickening operations is an attractive option when compared to centrifuges and filters due to their low operating, maintenance, and acquisition costs. However, the performance of hydrocyclone separation is impaired as the concentration of solids and the viscosity of the suspension increases. Using geometric optimization techniques, the Federal University of Uberlândia developed one concentrator hydrocyclone named HC. When working with diluted and Newtonian slurries, the HC could generate a stream 45 times more concentrated than the one fed into it. In this study, the HC performance was evaluated when operating pseudoplastic fluids containing up to 10% solids by volume. The combination of the underflow diameter and vortex finder length with an adequate supply of pressure energy maintained the thickening potential of the HC even when the rheology of the fluid was changed. For different working suspensions, the HC hydrocyclone achieved a minimum water split to underflow of 5%, a maximum concentration ratio of 7.0, and a maximum efficiency of 49%. The encouraging results obtained by the HC validated the benefits of the geometric optimization, as they point to a significant advance in the thickening operation of non–Newtonian sludges with a flow behavior index greater than 0.5.

Valorization of the solid fraction of wine lees through optimized accelerated autolysis: Effect of temperature, pH and solid concentration on free-amino acid concentration

Winemaking, as an agro-industrial process, generates substantial amounts of by-products, notably grape pomace and wine lees. The latter constitutes the residue left behind during the racking or bottling of wine, consisting mainly of dead yeast cells, ethanol, phenolic compounds, tartrates, and other compounds. Within the framework of by-products’ valorization, the rich content of dead yeast cells in wine lees render them conducive to the production of a yeast extract substitute through autolysis. In the present study, the effect of pretreatment, temperature, pH, and solid concentration on the efficiency of white wine lees autolysis was investigated. Moreover, the effect of enzyme addition and dynamic thermal protocols were investigated. Efficiency assessment was based on the increase of free α-amino nitrogen (FAN) found in the autolysate. The finding revealed a significant increase of FAN in all cases, with treated and untreated white wine lees reaching a maximum increase of 477% and 834%, respectively. Furthermore, the amino acid profile of autolysates was significantly affected by the autolysis temperature. These results hold promise for the comprehensive, holistic valorization of wine lees, suggesting their potential use as a nutrient source for microorganisms, such as wine yeast, or even as a grape must nitrogen modulator. Consequently, this by-product can be integrated back into the same industrial process from which it originates, namely winemaking. This not only aligns with the principles of circular economy but also underscores the potential for sustainable development within wineries.

High temperature flexible 2D metasurface based on optimal design for thermal insulation and electromagnetic wave absorption skin

The development of radar stealth skin with long term stable service and flexible deformability is the premise and foundation of improving the battlefield survivability of deformable aircraft. Aiming at the bottleneck problem of mismatch between the flexible configuration and the electromagnetic configuration of the existing stealth composite materials, a new type of SiO2 fiber paper (SFP) with flame retardant, thermal insulation, low dielectric constant and super-hydrophobic was prepared by combining the papermaking process with surface modification. The effects of solid content and high temperature environment on the mechanical properties, thermal insulation properties, dielectric properties and hydrophobic properties of SFP materials were studied in detail. Based on this, the optimal design and construction method of radar stealth metasurface suitable for flexible deformation are proposed, and the high temperature resistant flexible stealth skin metasurface is obtained. The metasurface has been demonstrated to achieve an effective wave absorption of −8 dB in the 10.9–16.4 GHz range at 400 μm thickness, making it an ideal candidate for flame retardant, flexible, thermal insulation and radar stealth skin under extreme conditions. It provides theoretical basis and technical support for the innovative development of high-speed deformable stealth aircraft.

Effect of solid content, particle size, and deflocculant on rheological properties of kaolin suspensions

In this research, two different particle sizes of kaolin were selected, and their rheological properties were characterized by steady-state and dynamic rheological tests. Stress relaxation in the flow curves was a novel finding; redefinition and interpretation of flow curves were the focus of our research. Two methods were used and compared for determining the yield stress. The results showed that suspensions with higher solid content and smaller particle size showed more compact inter-particle interactions, exerting multiple stress relaxation and a strong yield and viscoelastic characteristic. The thixotropic properties were also strongly affected by solid content and particle size, and the differences were reflected in the structural recovery capability. Finally, the effects on rheological properties by introducing deflocculant were studied; the stress relaxation disappeared gradually, and storage modulus and yield stress increased.Moreover, kaolin suspensions with smaller particle sizes required more deflocculant for adsorption and electrical neutralization, confirming that more positively charged edges were exposed after fragmentation. This study has provided an excellent approach to control and adjust the rheological properties of kaolin suspensions in industrial applications.

Fabrication of ultralightweight, thermal insulation alumina scaffolds by a hybrid sol–gel/freeze‐casting approach

AbstractFreeze casting is an effective way to fabricate the porous ceramics with anisotropic and interconnected porous structures and can be used in various applications, such as filtration, adsorption, and insulation. However, the ceramic‐based scaffolds fabricated by freeze casting have the upper limit of porosity since excessively low solid content in the slurry will lead to structural instability and cracks formation in scaffolds. This study aims at combining the freeze casting and sol–gel method and developing a hybrid process to overcome the limitation of freeze casting. Besides, the effects of solid content and cooling rates on the microstructure of ultralightweight alumina scaffolds (ULASs) and their mechanical and thermal properties were investigated. Aluminum isopropoxide was selected as the precursor to conduct the hydrolysis reaction in acid environment and condensation process by heat treatment. The successfully synthesized alumina scaffolds have ultrahigh porosity (&gt;90%), low bulk density (0.1240–0.2429 g/cm3), and low relative density (0.0314–0.0615). The anisotropic porous lamellar structure was evaluated by scanning electron microscope, µ‐CT, and mercury porosimeter. A lot of nanoscale pores are observed on the lamellae surfaces, forming the dual‐scale porous structure inside the scaffolds and contributing to higher specific surface area. The unique anisotropic structure, high porosity, and stable mechanical properties enable ULASs to deliver a low thermal conductivity of 0.2 W/m/K and large anisotropy in thermal properties, possessing great potential for thermal insulative materials. This sol–gel/freeze‐casting hybrid approach is believed to be extended to different material systems and provide promising potentials in fabricating the porous materials with various functionalities.

Nano-hydroxyapatite Pickering emulsions as edible mayonnaise-like food sauce templates: A novel approach for food design

Pickering emulsions have the potential to enhance product stability and provide opportunities to create functional solutions that align with labelling requirements. The present work aims to develop Pickering emulsions stabilised by nano-hydroxyapatite (n-HAp) particles to replace traditional mayonnaises. The study addresses the effect of n-HAp solid particle concentration (5–15 wt%) and oil-water ratio (50:50, 60:40, 70:30, and 80:20, v/v) on emulsion stability, rheological properties, and oxidative stability. The results indicate that the produced Pickering emulsions have good stability for the tested period of 90 days, except for the 80:20 o/w emulsion that undergone a prompt quick phase separation. The Pickering emulsions produced with higher n-HAp concentration or oil content have a semi-solid structure, rendering them desirable options for replicating the texture of traditional mayonnaises. Regarding oxidative stability, the Pickering emulsions showed considerably improved stability compared to commercial mayonnaises (∼13 times higher), suggesting higher resistance to peroxidation and a longer shelf-life.

Two-Fluid and Discrete Element Modeling of a Parallel Plate Fluidized Bed Heat Exchanger for Concentrating Solar Power

Abstract A novel high-temperature particle solar receiver is developed using a light trapping planar cavity configuration. As particles fall through the cavity, the concentrated solar radiation warms the boundaries of the receiver and in turn heats the particles. Particles flow through the system, forming a fluidized bed at the lower section, leaving the system from the bottom at a constant flowrate. Air is introduced to the system as the fluidizing medium to improve particle heat transfer and mixing. A laboratory scale cavity receiver is built by collaborators at the Colorado School of Mines and their data are used for model validation. In this experimental setup, near IR quartz lamp is used to provide flux to the vertical wall of the heat exchanger. The system is modeled using the discrete element method and a continuum two-fluid method. The computational model matches the experimental system size and the particle size distribution is assumed monodisperse. A new continuum conduction model that accounts for the effects of solid concentration is implemented, and the heat flux boundary condition matches the experimental setup. Radiative heat transfer is estimated using a widely used correlation during the post-processing step to determine an overall heat transfer coefficient. The model is validated against testing data and achieves less than 30% discrepancy and a heat transfer coefficient greater than 1000 W/m2 K.

Effect of Solid Volume Concentration on the Rheological Properties of Debris Flow: A Case Study of Jiangjiagou Debris Flow in China

The Anton Paar MCR 52 intelligent high-speed rheometer was utilized in this paper to conduct rheological tests on the Jiangjiagou debris flow slurry via linear loading. The relationship curves between shear rate and shear stress at different solid volume concentrations were obtained, and predictive formulas for yield stress and viscosity coefficient variations with the shear rate are proposed. Furthermore, the evolution mechanisms of yield stress and viscosity coefficient with changes in solid volume concentration of the debris flow were thoroughly analyzed. The results indicated that the rheological curves of the Jiangjiagou debris flow conformed to the Bingham fluid model. An increase in solid volume concentration continuously promoted the upward trend of the rheological curves, with significant increments observed only at high volume concentrations. A predictive model for debris flow rheological parameters was established based on the linear relationship between the rheological parameters and the solid volume concentration. The rise in solid volume concentration inhibited turbulence in the debris flow, while clay minerals enhanced the debris flow slurry’s ability to capture pore water. Significant shear-thinning effects were observed within the debris flow, which were particularly more pronounced at lower shear rates. The study outcomes hold crucial engineering significance for a better understanding of debris flow rheological properties, the calculation of debris flow dynamic parameters, and disaster prevention and control.

Preparation of MgAl-LDHs loaded with blast furnace slag and its removal of Cu(II) and methylene blue from aqueous solution

ABSTRACT Blast furnace slag (BFS) is a kind of waste produced in industrial production, as well as a valuable secondary resource. In this paper, layered double hydroxides composites (BFS/LDHs) were prepared by aqueous polymerization, with industrial waste BFS as modifier and magnesium nitrate, aluminium nitrate, and urea as raw materials. BFS/LDHs have been characterized by using scanning electron microscopy (SEM), fourier infrared spectrometer (FT IR), x-ray diffraction (XRD), and the specific surface area analyser (BET). The adsorption of BFS/LDHs on Cu (II) and methylene blue (MB) was investigated by batch experiments. The results showed that the adsorption capacity of BFS/LDHs to Cu (II) is stronger than that of MB. What’s more, the solid concentration effect was found in the process of sorption kinetics and sorption isotherms. The sorption kinetics curves of Cu (II) and MB on BFS/LDHs were well fitted by the quasi-second-order kinetics under different adsorbent concentrations. Langmuir and Freundlich sorption isotherm models were used to analyse the adsorption. It showed that the adsorption conforms to Langmuir and Freundlich’s adsorption isotherm models. The BFS/LDHs composites have good recycling availability in this adsorption process of Cu (II) and MB, the removal capacity of which was reduced by 16.1% and 3.8% after being recycled for six times, respectively. More importantly, BFS/LDHs composites are not only expected to become a sewage treatment agent, but also to solve the problem of industrial waste treatment, which is a win–win strategy.

Experimental investigation of filter cake deposition under cross-flow and static filtration conditions

Effects of cross-flow velocity, filtration pressure, and solid concentration on filter cake properties are studied by using a new filtration setup that allows performing filtration tests under a wide range of operating conditions. The main feature of this setup is that pressure and cross-flow velocity are decoupled, so it was possible to independently investigate the effect of these variables on filter cake properties. Filtration tests have demonstrated that particle invasion into filter media pores occurs initially, leading to the formation of an external filter cake. The increased cross-flow velocity creates an erosive shear stress at the surface of the external cake, which limits cake growth, indirectly maintaining a high filtrate flow rate. This high filtrate rate imparts a considerable drag force onto suspended particles, driving a high count into the porous substrate where these particles could deposit. Increasing pressure amplifies this internal particle deposition, particularly where there is no or limited external filter cake to limit filtrate drag and screen particles at the cake surface. The effect of cross-flow velocity on pore blocking and filter cake structure is observed and demonstrated by CT scanning and scanning electronic microscopy.

Rheological behavior of dehydrated cranberry suspensions: Analysis of the influence of temperature and solid concentration on Casson’s model parameters

Dehydrated cranberries (Vaccinium macrocarpon) are dried fruits known for their high antioxidant potential. Changes in their mechanical and rheological properties occur when cranberries are exposed to certain conditions, such as drying or immersion in a liquid medium (rehydration). To evaluate the rheological behavior of solid suspensions made from dehydrated cranberries, the effects of different temperatures and concentrations of dissolved solids were evaluated using a factorial experimental design (22) with three replications at the center point. Five models were used to investigate the suspensions' flow behavior: Ostwald de Waelle, Newton, Herschel-Bulkley, Casson, and Bingham. The rheometry of the suspensions showed that the fluids presented non-Newtonian behavior, with a satisfactory fit for the Casson model (R² &gt; 0.94) in all evaluated temperature and concentration ranges. Furthermore, the effects of temperature and solid concentration of cranberry suspensions on the rheological parameters of the fitted model, Casson's initial shear stress (K0c), and Casson's plastic viscosity (Kc) were evaluated. From the response and the contour surfaces, it was found that increasing the concentration of the suspension above 20% resulted in higher initial shear stress, which was influenced by temperature, whose increase resulted in a significant reduction in the shear stress at a concentration of 30%. The plastic viscosity (Kc) was highly influenced by the solid’s concentration, and higher temperatures caused a decrease in the value of this parameter. So, the highest value of plastic viscosity was found for concentrations above 20% and at lower temperatures. Therefore, considering the results and for practical purposes, it can be concluded that the flow of the suspensions is facilitated if rehydration is conducted at high temperatures.

Numerical analysis of solid phase hydrodynamics in a continuous precipitator relevant for plutonium reconversion

The extensive application of solid-liquid flow in various industries, has made it important to comprehend the hydrodynamics inside different process equipment and optimize their operation. In the present work, solid phase hydrodynamics in a continuous precipitator relevant for plutonium (Pu) reconversion has been investigated numerically. Euler-Euler two-fluid simulations were performed to analyse the performance by varying the solid concentration (5, 10, 15, and 20 g/l), impeller speed (500 and 700 rpm) and overflow outlet height (0.65, 0.75 and 0.85 m). The solid phase behaviour in precipitator is analysed by comparing the solid volume fraction and pressure distributions along the height. To enable easy handling of precipitator inside glove-box, the solid mass, volume rate and pressure distributions through overflow outlet at different height is thoroughly investigated. Further, the effect of solid concentration and rotating speed of impeller on radial velocity distribution is analysed. The results show that overflow of solid phase is dependent on dispersed phase concentration and rotating speed of the impeller. Further, the increase in overflow outlet height increases the overflow time. However, the volume fraction of solid remains constant during the steady operation. The study will be helpful to design a glove-box adaptable precipitator for continuous plutonium reconversion.

Effect of solid content on the piezoelectric properties of porous (Ba0.85Ca0.15)(Zr0.1Ti0.9)O3 ceramics

The influence of the solid content of porous (Ba0.85Ca0.15)(Zr0.1Ti0.9)O3 (BCZT) ceramics on the pore morphology and mechanical and piezoelectric properties was systematically investigated. The results show that with an increase in solid content, porosity and pore size decreased, and ceramic connectivity increased, leading to an increase in compressive strength. The best ferroelectric performance was achieved with an Ec of 2.40 kV/cm2 and a Pr of 2.01 μC/cm2 at a solid content of 30 vol%. When the solid content increased, the relative dielectric constant and the piezoelectric constant increased, which affected the piezoelectric energy harvesting performance. At a solid content of 20 vol%, g33 and FOM33 reached maxima of 43 × 10−3 Vm/N and 6.7 p.m.2/N, which were 2.40 times and 1.8 times those of the other solid contents, respectively. This work provides new ideas for the design of porous piezoelectric ceramics and the improvement of their piezoelectric properties for future piezoelectric energy harvesting applications.