Natural Calcium Carbonate Research Articles

The Compressive Strength of Unsaturated polyester reinforced by natural and synthetic Calcium Carbonate

A modifications on the ultimate compression strength of unsaturated polyester (UPE) carrying out, by adding nano Chicken eggshells fibers (E.S) as a natural source of calcium carbonate or synthetic nano calcium carbonate particles (CaCO3) in different weight percentages ranging from (1-5%). The ratio (1% eggshell fibers) and (3% CaCO3) are the best weight ratios that selected according to ultimate compressive strength of Unsaturated Polyester composites. Ultamite compressive strength was improved from (73.84 N/mm2) for UPE to (85.54 N/mm2) for (UPE/1% E.S) composite and to higher value (87.88 N/mm2) for (UPE/3%CaCO3) composite. The partictes with nano-sized of titanium dioxide (TiO2) was used to reinforce the two best composites, to get more improvement in there ultamite compressive strength to reach to (94.27 N/mm2) for (UPE/1%E.S) and to (100.18 N/mm2) for (UPE/3%CaCO3) composites.

FABRICATION OF A HIGH-THROUGHPUT 3D-PRINTED OSTEOGENIC CORAL-CONTAINING SCAFFOLD

In 2021 the bone grafting market was worth €2.72 billion globally. As allograft bone has a limited supply and risk of disease transmission, the demand for synthetic grafting substitutes (BGS) continues to grow while allograft bone grafts steadily decrease. Synthetic BGS are low in mechanical strength and bioactivity, inspiring the development of novel grafting materials, a traditionally laborious and expensive process. Here a novel BGS derived from sustainably grown coral was evaluated. Coral-derived scaffolds are a natural calcium carbonate bio-ceramic, which induces osteogenesis in bone marrow mesenchymal stem cells (MSCs), the cells responsible for maintaining bone homeostasis and orchestrating fracture repair. By 3D printing MSCs in coral-laden bioinks we utilise high throughput (HT) fabrication and evaluation of osteogenesis, overcoming the limitations of traditional screening methods.MSC and coral-laden GelXA (CELLINK) bioinks were 3D printed in square bottom 96 well plates using a CELLINK BIO X printer with pneumatic adapter Samples were non-destructively monitored during the culture period, evaluating both the sample and the culture media for metabolism (PrestoBlue), cytotoxicity (lactose dehydrogenase (LDH)) and osteogenic differentiation (alkaline phosphatase (ALP)). Endpoint, destructive assays used included qRT-PCR and SEM imaging.The inclusion of coral in the printed bioink was biocompatable with the MSCs, as reflected by maintained metabolism and low LDH release. The inclusion of coral induced osteogenic differentiation in the MSCs as seen by ALP secretion and increased RUNX2, collagen I and osteocalcin transcription.Sustainably grown coral was successfully incorporated into bioinks, reproducibly 3D printed, non-destructively monitored throughout culture and induced osteogenic differentiation in MSCs. This HT fabrication and monitoring workflow offers a faster, less labour-intensive system for the translation of bone substitute materials to clinic.Acknowledgements: This work was co-funded by Enterprise Ireland and Zoan Biomed through Innovation Partnership IP20221024.

Excitation functions of proton-induced nuclear reactions on natCaCO3 up to 60 MeV

47Sc could be used in SPECT imaging and is also suitable for targeted therapy of small tumours. Application of 47Sc is quite promising as theranostic with its diagnostic pair 44Sc or 43Sc. Excitation functions for the production of 47Sc and its accompanying impurities through proton bombardment of natural calcium carbonate (natCaCO3) targets were experimentally evaluated and compared with both previous measurements and TALYS predictions. The integral production yields of 47Sc, as well as the main impurities 44m,46,48Sc, were calculated. The consistency of the results with available experimental data was verified for each reaction. The target yield was determined using the measured activity of the produced radionuclides.

Bio-inspired mineralization of CO2 into CaCO3: Single-step carbon capture and utilization with controlled crystallization

CO2 mineralization which involves the reaction of CO2 with alkaline earth metal cations to form carbonates, is a promising pathway that could be crucial for combating global warming via long-term CO2 utilization and storage. However, due to the large abundance of natural calcium carbonate (CaCO3) and advanced milling techniques, micron-ranged CaCO3 is conventionally produced via the top-down method because it is more economically attractive than mineralization or precipitation unless particles with functional properties are generated so that a higher product value is achieved. In this study, inspired by the natural formation of nacre, which is produced naturally via controlled crystallization (using environmental CO2) in the marine environment, we produce CaCO3 particles with different morphologies via single-step CO2 capture and mineralization. We used a gas diffuser reaction setup to bubble CO2 in liquid media containing CO2 absorption promotor, water-soluble polymer, and surfactant as crystal growth modifiers, and Ca2+ to form functional CaCO3. First, different inorganic and organic CO2 absorption promoters and their combinations were investigated for their effectiveness on Ca2+ conversion to CaCO3. Ca2+ conversion and pH of the reaction system with various concentrations of CO2 absorption promoters were monitored every 5 min. Second, the effect of the polymer combined with different concentrations of surfactant on CaCO3 properties was studied. It was found that the combination of triethanolamine and ammonium hydroxide as absorption promotors results in 53.2% Ca2+ conversion into stable CaCO3 particles within 5 min of CO2 bubbling. Absorption promotors themselves could not regulate the particle shape; however, with increasing concentrations, smaller particles agglomerated to form bigger rhombohedral particles. Polymer and surfactant-mediated mineralization of CO2 produces spherical and hollow, stable calcite particles that could serve as dies, heavy metal adsorbents, supports to catalysts, functional composite fillers, etc.

Dielectric properties of nanocrystalline CaCu3Ti4O12 (CCTO) ceramics fabricated from Algerian limestone raw material

Algerian natural limestone was used to fabricate the perovskite CaCu3Ti4O12 phase (CCTO) to replace commercial calcium carbonate (CaCO3) powder by a solid-state method. X-ray diffraction analysis of CCTO ceramics sintered at 1010 °C manifested the formation of well-crystallized pure (CCTO) phase with narrow crystallite size (43–99 nm) without any additional phases after sintering beyond 4 h. Thermal analysis by DSC indicated that CCTO phase is stable up to 1151 °C, afterwards it decomposes into CaTiO3 and TiO2 and accompanied by the segregation of the CuO/Cu2O phase. Scanning electron microscopy observations of the ceramics sintered at 1010 °C showed that most of the grains have an average particle size in the narrow range of 1–2 μm. The sintered pellet at 1010 C° for 14 h showed the optimum density (>94%). This study highlights the importance of using natural calcium carbonates (extracted from Guelma limestone in Algeria) as potential replacement to commercial counterpart for the fabrication of dense well-crystallized perovskite-type ceramics with controlled particle size distribution as promising candidates for electronic applications.

Synthesis of Aliphatic Polyanhydrides with Controllable and Reproducible Molecular Weight.

Polyanhydrides have been synthesized for decades by melt-polycondensation of diacid monomers and 5 to >10 times mole excess acetic anhydride to diacid monomers to form polymers with a polydispersity ranging from 2.5 to 6 and low reproducibility. Hydrophobic segments in polyanhydrides are beneficial to hinder the characteristic hydrolytic cleavage of an anhydride bond that provides stable polyanhydrides at room temperature. The objective of this work is to synthesize aliphatic polyanhydrides with various hydrophobic segments, controllable and reproducible molecular weight, and low polydispersity that are essential for potential use as drug carriers. A series of polyanhydrides of suberic, azelaic, sebacic, and dodecanedioic acids with controlled molecular weight, reduced polydispersity, and standard deviation of molecular weights, have been synthesized. All synthesized polyanhydrides were thoroughly characterized by NMR, Fourier transform infrared spectroscopy, and gel permeation chromatography. Molecular weights of the synthesized polyanhydrides are highly controllable, depending on the degree of activation of the dicarboxylic acid monomers, i.e., the amount of acetic anhydride used during synthesis. Polyanhydrides have been synthesized in triplicate by melt-polycondensation, using various mole ratios of acetic anhydride to diacids. The standard deviation of the molecular weights of the polyanhydrides is minute when using 1 equivalent of acetic anhydride during the activation of dicarboxylic acids, whereas if excess acetic anhydride is used, the standard deviation is very high. The effect of safe and natural inorganic catalysts, Calcium oxide, Zinc oxide, and Calcium carbonate on polymerization is also studied. As-synthesized poly(sebacic acid) can offer convenience to use in controlled drug delivery applications. In vitro drug release study using Temozolamide (TMZ), a medication used to treat brain tumors such as glioblastoma and anaplastic astrocytoma, shows 14% TMZ release after the first hour and 70% release over one day from the poly(sebacic acid) wafers.

Ceresana publishes new report on global market for mineral fillers

Ceresana has analyzed the filler industry for the sixth time. The market researchers expect the global filler market to grow at an average annual rate of 4.8%: demand for natural calcium carbonate (GCC), precipitated calcium carbonate (PCC), kaolin, talc, wollastonite, mica, carbon black (industrial carbon black) and other fillers is expected to reach a volume of more than 80 million tonnes by 2030.

New Calcium Carbonate Nano‐particulate Pressed Powder Pellet (NFHS‐2‐NP) for LA‐ICP‐OES, LA‐(MC)‐ICP‐MS and µXRF

A new matrix‐matched reference material has been developed – NFHS‐2‐NP (NIOZ Foraminifera House Standard‐2‐Nano‐Pellet) – with element mass fractions, and isotope ratios resembling that of natural foraminiferal calcium carbonate. A 180–355 µm size fraction of planktic foraminifera was milled to nano‐particles and pressed to pellets. We report reference and information values for mass fractions of forty‐six elements measured by six laboratories as well as for 87Sr/86Sr (three laboratories), δ13C, δ18O (five laboratories) and 206,207,208Pb/204Pb isotope ratios (one laboratory) determined by ICP‐MS, ICP‐OES, MC‐ICP‐MS, isotope ratio mass spectrometry, WD‐XRF and TIMS. Inter‐ and intra‐pellet elemental homogeneity was tested using multiple LA‐ICP‐MS analyses in two laboratories applying spot sizes of 60 and 70 µm. The LA‐ICP‐MS results for most of the elements relevant as proxies for palaeoclimate research show RSD values < 3%, demonstrating a satisfactory homogeneous composition. Homogeneity of 87Sr/86Sr ratios of the pellet was verified by repeated LA‐MC‐ICP‐MS by two laboratories. Information values are reported for Pb isotope ratios and δ13C, δ18O values. The homogeneity for these isotope systems remains to be tested by LA‐MC‐ICP‐MS and secondary‐ion mass spectrometry. Overall, our results confirm the suitability of NFHS‐2‐NP for calibration or monitoring the quality of in situ geochemical techniques.

Utilization of Scallop Shells (Placuna placenta) for Potential Water Filter Prototype in Jaring Halus Village, Jaring Halus-Langkat District and the Characterization Test

Indonesia is a maritime country that has abundant marine wealth. Unfortunately, most fishers still live in poor conditions, including Jaring Halus Village, Secanggang District, Langkat Regency, North Sumatra Province. Previous research has shown that there is much coastal waste, such as Scallop Shells (Placuna placenta), that are not treated, even though it has the potential to help people who are experiencing water crises to get clean water sources. This study aimed to characterize the shells of Scallops and produce calcium carbonate as an activated carbon product to produce clean water. The method used to characterize the mashed scallop shells is X-Ray Diffraction (XRD). In this study, three different sizes, namely 25 μm, 90 μm, and 150 μm, will be compared, and the size and quality selected to produce the best calcium carbonate were tested at different temperatures, namely 800°C, 900°C, 1000°C, and 1100°C. In the x-ray diffraction analysis test, the smallest particle is 25 μm, which has the highest intensity compared to other sizes. The best particle size, which is heated/calcined at a temperature of 1100, has the highest intensity, which can remove all impurities and produce natural calcium carbonate, which is more stable. Based on the study results, it can be concluded that the best calcium carbonate is produced from particles with a size of 25 μm which are calcined at the highest temperature of 1100°C.

Characteristics of sandy soil treated using EICP-based urease enzymatic acceleration method and natural hemp fibers

This study presents the use of biocementation process with EICP-based urease enzymatic acceleration method and natural hemp fibers to improve the strength of sandy soil. The amount of hemp fibers mixed in the sandy soil is varied up to 20% by volume. Different tests are used, and results are observed. From real-time bender element tests, the optimum amount of natural hemp fibers for mixing in biocemented sand is found to be 2.5% by volume, based on shear wave velocity and initial shear modulus. Moreover, the process of biocementation requires a few days before the start of reaction, and the reaction fully occurs at 4-day while finishes at 6-day. Using pH meter, it is found that the process of biocementation reaches its maximum value at 3-day, because the solution pH in sand becomes higher than 7. After that, the biocementation reaction rate decreases due to the reduction of the solution pH. From spectophotometer, the ammonification occurs from 0-day to 4-day, and reaches its maximum at 4-day. After that, it gradually decreases showing the gradual end of biocementation reaction. The SEM results show that the surface of natural hemp fibers and precipitated calcium carbonate (CaCO3) crystals are rough indicating the potential for bonding between them. The SEM results also show that the precipitated CaCO3 fills within the voids between sand particles and natural hemp fibers, resulting in the enhancement of sandy soil strength. The XRD results show the relationship between the occurrence of CaCO3 and the process of biocemented in sand. Finally, the direct shear tests confirm the improvement of sandy soil properties via increasing cohesion and internal friction angle due to biocementation and hemp fibers.

تقنيات ترميم صينية نحاسية أثرية بمتحف الفن الإسلامي بالقاهرة

A copper tray dating back to the Mamluk era, kept in the stores of the Museum of Islamic Art in Cairo, registered under No. 9315. It was broken into six separate parts with several holes. Its edge is serrated by a line in the prominent Naskh script. The tray suffers from various deterioration factors, such as pits and holes in different places of the tray, and the wrong restoration, as it was welded incorrectly with the aim of assembling some of its separate parts. Various examinations and analyses were carried out. The results of the X-ray diffraction analysis showed the presence of Cuprite (Cu2O), Atacamite and Paratacamite. Treatment and conservation of the tray was carried out, including mechanical cleaning and chemical cleaning. The assembly process was carried out for the separate parts. The holes were completed using mixture of epoxy with natural oxides and calcium carbonate with microballoon as a filler. The tray was also isolated using 3% benzotriazole to protect it from exposure to corrosion.

The Impact of Natural Calcium Carbonate and Ubiquinone on Bone Mineral Density in Rabbits

Objective: The aim of this study was to investigate the effect of ubiquinone and/or calcium carbonate (CaCO3) on bone mineral density in rabbits at healing site in mandibular bone postoperatively. Materials and Methods: Sixty healthy white male New Zealand rabbits almost the same age, weight and circumstance were used in this study. All animals were submitted to operation in the mandibular bone region. The groove of 2mm diameter and 6mm length was drilled by the heavy-duty dental engine. After operation rabbits were randomly divided into six groups (each group 10 rabbits) five rabbits for each period; control group (groove was not filled by anything) and treated groups which subdivided into five groups as follows: group I (groove was filled with Ubiquinone), group II (groove was filled with CaCO3), group III (groove was filled with CaCO3: Ubiquinone as a ratio (1:1)), group IV (groove was filled with CaCO3: Ubiquinone as a ratio (1:2)) and group V (groove was filled with CaCO3: Ubiquinone as a ratio (2:1)). Estimated BMD using Densitometry analysis was measured after 15 and 30 days respectively. Results: Statistical analysis showed significant differences between all groups (control and treated). The estimated BMD showed significant increase group I(101±1.05), group II(111±2.23), group III(125±3.54), group IV(126±5.13) and group V(133±6.29) comparing to control group (92±0.15) at follow-up times at 15 day. Also in the present study we found that significant decrease in BMD after 30 days of operation in group I(144±3.45), group II(153±6.24), group III(160±8.94), group IV(165±9.11) and group V(182±12.56) compare to control group(109±1.25) respectively. Adding the ubiquinone and/or CaCO3 showed a significant increase in BMD manifested by bone healing like space-filling and newly formed bone trabeculae and a high number of lacunas compared with the control group. Conclusion: This study concluded that the addition of ubiquinone and/or CaCO3 was successfully increasing in bone healing by increasing BMD compared with the control group. Keywords: Ubiquinone, CaCO3, Bone healing, BMD (Bone Mineral Density).

Dispersed filler based on synthetic calcium carbonate – requirements for applications quality

The introduction of fillers into various materials improves its technological, physical and mechanical properties, and leads to a decrease in cost. The main areas of application of natural and synthetic calcium carbonate as highly dispersed fillers are: the construction industry, the production of Portland cement, mineral fertilizers, glass, paper, polymer composite materials, paints and varnishes, and rubbers. A promising direction at present is the use of production by-products as fillers, for example, conversion calcium carbonate - a waste product from the production of a complex mineral fertilizer - nitroammophoska. However, its use in the above areas is limited by the content of water-soluble nitrogen-containing impurities, impurities of heavy metals, strontium carbonate, phosphates, etc. The analysis of scientific, technical and patent literature on methods of purification of conversion calcium carbonate has been carried out. These methods are based on the extraction of impurities from the initial product of calcium carbonate production - a melt of calcium nitrate tetrahydrate by precipitation with various reagents, followed by the isolation of an insoluble precipitate (impurities) and processing of the purified melt into calcium carbonate and nitroammofoska. A method is proposed for the extraction of acid-tonic-soluble iron-containing impurities from the initial calcium nitrate melt in order to obtain a cleaner by-product - conversion calcium carbonate, which will expand the scope of its application. An effective method is to dilute the initial calcium nitrate melt with a 60% solution of ammonium nitrate to a calcium content of 12-13%, followed by the isolation of an acid-insoluble precipitate in a vacuum filter, conversion of the purified calcium nitrate solution with ammonium carbonate and separation of the resulting suspension in a drum filter. The described method can reduce the amount of iron-containing impurities by more than 50%.

Poultry eggshell effects on microporous poly(lactic acid)-based film fabrication for active compound-releasing sachets

Poultry eggshells (ES) were used to create microporous structures as an alternative and sustainable filler in a poly(lactic acid)/polybutylene succinate (PLA/PBS) blend designed for sachet use. Crude chicken eggshell (CES) and duck eggshell (DES) are utilized as natural calcium carbonate (CaCO3) sources by systematically varying filler content. Using CES and DES as sustainable fillers produces smaller pore diameters (ranging from 300 to 500 nm), a higher pore density (~ 106 pores/mm2) and greater pore homogeneity within the PLA/PBS matrices. Poultry ES also improves calcium dispersion within the PLA/PBS matrices, compared to the highly variable pore sizes which cause the calcium agglomeration clearly observed in the PLA/PBS/CaCO3 composites. Moreover, the organic residuals contained in the crude poultry ES promote interfacial adhesion in PLA/PBS matrices, resulting in uniform micropore distribution. The obtained morphologies of the PLA/PBS/poultry ES composites permit oxygen and water permeation comparable to those of conventional plastics currently used as active compound-releasing sachets. The stress–strain curves also reveal slightly improved toughness with 0.3 phr poultry ES. Lastly, poultry ES also induces crystalline PLA and PBS in α-forms with Xc,PLA of 20–30% and Xc,PBS of 30–50% and maintains high tensile strength, similar to that of PLA/PBS/CaCO3 composites.

Small calcium isotope fractionation at slow precipitation rates in methane seep authigenic carbonates

Natural calcium carbonate minerals express a range of calcium isotope fractionations, with the precipitated mineral typically enriched in the lighter isotopes of calcium relative to source fluids. Experimental and theoretical evidence shows a strong dependence on precipitation rate, although this relationship has not been well quantified over the range of precipitation rates observed in natural settings. Endmember cases show that average marine carbonate precipitation expresses a large fractionation (δ44/40Ca values lower than seawater by approximately 1‰), while diagenetic carbonate phases assumed to have precipitated or recrystallized at very slow rates show negligible fractionation. The limited examples of quantified precipitation rates in natural settings with measurable, non-zero fractionation represents a barrier for applying mechanistic models of calcium isotope fractionation to geological applications. This study examines a methane seep system in the northern Barents Sea south of Svalbard where authigenic carbonate minerals are precipitating, driven by anaerobic oxidation of methane, and where the apparent calcium isotope fractionation factor and precipitation rate can be constrained by measuring properties of the pore fluids. Pore fluid profiles are analyzed in two shallow cores, and authigenic carbonate nodules are analyzed in one of these cores. The pore fluid profiles point to a transitional, non-steady state which approximates a closed system, where the elevation of pore fluid calcium isotope ratios through carbonate precipitation can be modeled as a Rayleigh distillation system. The apparent fractionation factors for 44Ca/40Ca ratios at these sites are α = 0.99985 and 0.9996, although the carbonate nodules suggest a different calcium isotope fractionation factor may have been expressed under past conditions. Precipitation rates at the two sites are estimated to be 1.4 and 3.5 μmol/m2/h, intermediate between those of typical laboratory experiments and the much slower rates of marine diagenesis. Trace element analyses of the nodules (Mg/Ca and Sr/Ca ratios) suggest that both precipitation rate and mineralogy affect nodule composition. These results provide new constraints for the relationship between precipitation rate and calcium isotope fractionation and can inform modeling efforts leading towards mechanistic understanding of calcium isotope fractionation and trace element distributions in carbonate minerals.

ADVANCED RECOVERY OF CALCIUM CARBONATE WASTE AS A FILLER IN WATERBORNE PAINT

The industry generates large quantities of waste, which must be capitalized and transformed in compounds with high added value. The objective of the present study is to obtain white waterborne paint using calcium carbonate as filler, a waste results from Romanian plant fertilizer manufacturing. The paints are used for protection of surfaces, with the focus on durability. Natural or synthetic calcium carbonate can be successful used as filler in paints, they have an alkaline pH-value and low oil absorption, very important technological properties. The calcium carbonate can significantly improve paint properties as sheen, opacity, viscosity, density and wear resistance. This study is focused on the possibility to replace commercial filler with calcium carbonate waste and establishes the optimal content for obtaining waterborne paints with imposed properties. For obtaining white paint, the resin was mixed with 5-30 g precipitated calcium carbonate /300 mL resin. The properties of paints obtained were determined and comparison with witness. Experimental data demonstrated that precipitated calcium carbonate (PCC) with particle diameters over 0.5 m influenced negative opacity properties. For improved this property grinding for obtaining particles smaller than 0.5 m is necessary. Using calcium carbonate waste, experimentally were obtained for waterborne paint properties close properties with witness. The PCC content can be increased to 30 g/300 mL resin, without affecting the paint properties, less the viscosity which is 14% above the required value.

DEVELOPMENT OF NEW SYNTHESIS ROUTES FOR HYDROXYAPATITE NANOPOWDERS PRODUCTION FROM CHICKEN EGGSHELLS

Hydroxyapatite (HA) nanopowders are attracting interest for surface application to ceramic biomaterials. In this study, we developed innovative and new viable synthesis routes of calcium phosphate nanopowders from the natural calcium carbonate of chicken eggshells. Following the four routes, alternative co-precipitation, vacuum process, brushite, and calcination, we obtained the HA samples, which were then characterized by different methods. The X-ray diffraction /Rietveld method showed the HA phases, monetite and brushite crystallinity with greater symmetry, and nanoscale. Transmission electron microscopy showed the morphology of nanoparticles functionalized nanoparticles smaller than 100 nm in routes A, B and D, and Fourier-transform infrared spectrophotometry and Raman spectroscopy identified the classic chemical groups of calcium phosphates by four routes mainly groups (PO4) 3- and (CO3 -). Scanning electron microscopy analysis revealed a good surface topography to future cell biointeraction in A, B and D routes, and thermogravimetric analysis showed the mass loss profile inherent to each synthesis route with slot at 200 °C. Hence, the eggshell HA and brushite and the specific monetite nanoparticles with different morphology can be prepared from the four new possible and viable routes using different methods.

Epoxy Composites Filled with Natural Calcium Carbonate. 3. Epoxy Composites Obtained in the Presence of Monocarboxylic Derivative of Epidian-6 Epoxy Resin

A monocarboxylic derivative of Epidian-6 with free epoxy and carboxylic end groups (MCDER) has been synthesized using Epidian-6 epoxy resin and sebacic acid. The structure of MCDER was confirmed by a spectral analysis. The thermal stability of MCDER has been established and the formation of cross-linked films based on epoxy-oligomeric mixtures consisting of Epidian-5, TGM-3 oligoesteracrylate, and polyethylene polyamine has been studied in its presence. By means of IR spectroscopy, the chemistry of the mixtures formation has been established. Physico-mechanical characteristics and morphology of the epoxy-oligomeric mixture based samples which were filled with CaCO3 have been determined.

Epoxy Composites Filled with Natural Calcium Carbonate. 2. Epoxy Composites Obtained in the Presence of Monomethacrylic Derivative of Epidian-6 Epoxy Resin

Epoxy Composites Filled with Natural Calcium Carbonate. 2. Epoxy Composites Obtained in the Presence of Monomethacrylic Derivative of Epidian-6 Epoxy Resin

Adsorption of natural CaCO3 nanoparticles on the reservoir rock surfaces in the enhanced oil recovery process: equilibrium, thermodynamics, and kinetics study

The major challenges in using nanoparticles in oil and gas industry projects are high investment costs and environmental problems. Bio-nanoparticles provide a solution to environmental and economic challenges in the nano-assisted EOR processes. In this work, the potential of natural calcium carbonate nanoparticles containing chitin for wettability alteration in enhanced oil recovery was studied. The adsorption behavior of bio-nanoparticles onto calcite-dolomite rock surface was distinguished through kinetics, equilibrium, and thermodynamics assessments. Besides, oil recovery is measured through forced imbibition experiments. The Taguchi experimental design was conducted to optimize the parameters influencing oil recovery factor in forced imbibition experiments, including nanofluid concentration, temperature, and oil type. Results of the adsorption experiment showed that adsorption kinetics of bio-Ca nanoparticles onto calcite-dolomite surface follows the pseudo-second-order model and monolayer, Langmuir adsorption of bio-nanoparticles. The endothermic heat of physical adsorption (physisorption) was found 3.32 kJ/mol. Based on the experimental design, the optimum parameters that can rise to additional oil displacement are a nanofluid concentration of 0.05 wt.%, normal heptane as liquid phase, minimum salinity (Milli-Q-water), and ambient temperature. The oil recovery factor increased by 17.52% at an optimum nanofluid concentration of 0.05 wt.% in comparison to a base fluid without nanoparticle. The results indicate that synthesized bio-Ca nanoparticles have proper EOR potential in both light oil and heavy oil reservoirs at certain conditions.