Sustainable Calcite Scale Inhibitors via Oxidation of Lignosulfonates

Deposition of inorganic scales in wells, flow lines, and equipment is a major problem in the water treatment, geothermal, or upstream oil and gas industries. Deployment of scale inhibitors has been adopted worldwide for oilfield scale prevention. Commercial synthetic scale inhibitors such as polymeric carboxylates and sulfonates or nonpolymeric phosphonates offer good scale inhibition performance but often suffer from one or more limitations including biodegradability, calcium compatibility, and thermal stability. Lignin-based biomaterials such as sodium lignosulfonates are natural, sustainable, and widely available polymers that are accepted for use in environmentally sensitive areas. Here we show that, although lignosulfonates perform relatively poorly as calcite scale inhibitors in dynamic tube blocking tests, oxidized lignosulfonates show a much improved inhibition effect by a factor of 20-fold. The oxidized lignosulfonates are easy to prepare in a 1-step reaction and show excellent calcium compatibility and thermal stability, useful for downhole squeeze treatments in high temperature wells. This present study unequivocally establishes oxidized lignosulfonates as a new class of sustainable green scale inhibitors, thereby bridging the gap between materials derived directly from nature and the classic synthetic polymeric scale inhibitors.

Optimization of preparation conditions of medium and highly substituted carboxymethyl inulin through response surface methodology

This article introduces the synthesis optimization of carboxymethyl inulin using response surface methodology. The important factors affecting the degree of substitution (DS) were determined by Plackett-Burman design, including sodium hydroxide concentration, monochloroacetic concentration, and etherification temperature. Further optimization was conducted using the Box-Behnken response surface design. The coefficient of determination (R2) of the response surface model was 0.9827, and the adjusted R2 value was 0.9516, which proved the significance of the model. The optimized results of the predicted response showed that the molar ratios of sodium hydroxide to monochloroacetic acid and fructose to furan were 3.67 and 2.21, respectively. The maximum DS of 1.67 was obtained at 30 °C alkalization for 30 min and 50.30 °C etherification for 4 h, and the reaction efficiency (RE) reached 76.01 %. Under the optimized conditions, the Experimental DS was 1.68, suggesting that the experimental and predicted values of DS were in good agreement. The characterization results confirmed the synthesis of CMI. In this work, we have provided an effective method for the preparation of moderately to highly substituted CMI in 95 % ethanol.

Resistance of Pastes from Carbonated, Low-Lime Calcium Silica Cements to External Sulfate Attack

This paper presents the results of a study on the evaluation of resistance of pastes from carbonated, low-lime calcium silica cements to external sulfate attack. The extent of chemical interaction between sulfate solutions and paste powders was assessed by quantifying the amount of species that leached out from carbonated pastes using ICP-OES and IC techniques. In addition, the loss of carbonates from the carbonated pastes exposed to sulfate solutions and the corresponding amounts of gypsum formed were also monitored by using the TGA and QXRD techniques. The changes in the structure of silica gels were evaluated using FTIR analysis. The results of this study revealed that the level of resistance of carbonated, low-lime calcium silicates to external sulfate attack was affected by the degree of crystallinity of calcium carbonate, the type of calcium silicate, and the type of cation present in the sulfate solution.

On the mechanism of calcium carbonate polymorph selection via confinement

Organisms deposit various biominerals in the course of their biomineralisation. The most abundant of these is calcium carbonate, which manifests itself in several polymorphs. While organisms possess the ability to...

Properties of Inorganic Polymers Based on Ground Waste Concrete Containing CuO and ZnO Nanoparticles

The effect of copper oxide and zinc oxide nanoparticles (NPs) on the mechanical and thermal properties of ground waste concrete inorganic polymers (GWC IPs) has been investigated. NPs are added to GWC IPs at loadings of 0.1, 0.5, 1, and 2% w/w. The phase composition and microstructure of NPs GWC IPs have also been examined using X-ray diffraction (XRD), Raman spectroscopy and scanning electron microscope (SEM/EDS) techniques. Results show that the mechanical properties of GWC IPs are improved (23 MPa) due to addition of NPs (1% ZnO). In particular, GWC IPs embedded with 0.5% CuO and 1% ZnO NPs exhibited relatively improved compressive strength. The addition of NPs decreases the macroporosity and increases the mesoporosity of IPs matrix and decreases relatively the ability of IPs matrix to water absorption. The antimicrobial activity of GWC IPs doped with 0.5 and 1% CuO NPs against E. coli was also determined.

A facile ligand-free route to calcium carbonate superstructures

By capturing the inherent transition behavior, CaCO3 superstructures with well-defined morphologies and amorphous-to-vaterite polymorph nature were obtained in a large scale and ligand-free manner.

Pharmaceutical Standardization and Physicochemical Characterization of Traditional Ayurvedic Marine Drug: Incinerated Conch Shell (Shankha Bhasma)

Natural resources such as plants, animals and minerals have always been used by mankind to develop drugs and marine world is no exception. Marine by-products like conches, pearls, mother of pearl shells, corals and so forth have been used by traditional Ayurvedic practitioners for centuries. The unique methods of these preparations are scientifically designed to eliminate unwanted impurities and convert them into bioavailable form. In this study, Conch (Xanchus pyrum) was used as a marine resource of calcium carbonate and was converted pharmaceutically from its aragonite form to calcite. All the steps of preparations and changes in the properties therein were documented and validated. Further, traditional as well as modern analytical tools were used to study its physical and chemical characters to develop a monograph. The physical characterization included particle size, X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Thermogravimetric Analysis (TGA) and Fourier Transform Infra-red (FTIR). Metal composition and heavy metal limits were determined using Inductively Coupled Plasma Optical Emission Spectrometry (ICPOES). This study revealed the rearrangement of aragonite crystals into calcite form by grinding, trituration with aloe vera juice and incineration under controlled conditions. Moreover, the finished product was found to be devoid of organic matrix that is nacre. This study creates a foundation for the development of a master formula for commonly used Shankha Bhasma in Ayurvedic medicines.

HPAM–HABS induced synthesis of a labyrinth-like surface of calcite via rhombohedral lattice growth from the nanoscale

A labyrinth-like structure is generated during the phase transformations from nano- to micron-sized via a terrace-ledge-kink growth model of a rhombohedral crystal.

Protein-Mediated Precipitation of Calcium Carbonate

Calcium carbonate is an important component in exoskeletons of many organisms. The synthesis of calcium carbonate was performed by mixing dimethyl carbonate and an aqueous solution of calcium chloride dihydrate. The precipitation product was characterized by means of scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) measurements. In addition, the turbidity of the reaction solution was acquired to monitor the kinetics of the calcium carbonate structure's growth in the investigated system. In this study, samples of CaCO₃ particles obtained with individual proteins, such as ovalbumin, lysozyme, and a mixture of the proteins, were characterized and compared with a control sample, i.e., synthesized without proteins. The obtained data indicated that the addition of ovalbumin to the reaction changed the morphology of crystals from rhombohedral to 'stack-like' structures. Lysozyme, however, did not affect the morphology of calcium carbonate, yet the presence of the protein mixture led to the creation of more complex composites in which the calcium carbonate crystals were constructed in protein matrices formed by the ovalbumin-lysozyme interaction. It was also observed that in the protein mixture, ovalbumin has a major influence on the CaCO₃ formation through a strong interaction with calcium ions, which leads to the coalescence and creation of a steric barrier reducing particle growth. The authors proposed a mechanism of calcium carbonate grain growth in the presence of both proteins, taking into account the interaction of calcium ions with the protein.

Box-Behnken experimental design for the production of precipitated calcium carbonate

Calcium carbonate (CaCO3) was synthesized by means of ultrasonic process in the presence of the water-soluble polymer carboxymethyl inulin (CMI). Synthesized CaCO3 crystals were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and BET (Brunauer, Emmett and Teller) isotherm. Applying Box-Behnken experimental design, the effects of the amplitude of sonicator (Amp), biopolymer concentration (BC) and the application time of ultrasound (AT) on the preparation of CaCO3 with respect to specific surface area (SSA) of final product was investigated. The experimental design was studied at three levels. The range of the amplitude of sonicator, polymer concentration and the application time of ultrasound were 25%–50%, 0.25–0.75 g/L and 1–5 min, respectively. The model equation representing specific surface area (SSA) of calcium carbonate was expressed as functions of three operating parameters namely the application time of the ultrasound, the amplitude of sonicator and polymer concentration. The results showed that the application time of ultrasound was the most significant variable that influenced the surface area of the crystals among three variables and the experimental results were in good agreement with those predicted by the proposed regression model. The highest value of specific surface area was obtained at the maximum application time of ultrasound.

Calcium Carbonate

Calcium carbonate is a chemical compound with the formula CaCO3 formed by three main elements: carbon, oxygen, and calcium. It is a common substance found in rocks in all parts of the world (most notably as limestone), and is the main component of shells of marine organisms, snails, coal balls, pearls, and eggshells. CaCO3 exists in different polymorphs, each with specific stability that depends on a diversity of variables.

Carbonatation precipitate – origin, separation and uses

Managers and researchers are looking for new systems with minimum consumption of lime e.g. ultrafiltration. Nevertheless liming and carbonatation are still an important part of juice purification in the sugar industry. The complex process is influenced by many parameters such as lime addition, polysaccharides content and their composition, temperature, mixing intensity, recycling in juice purification etc. Carbonatation precipitate as well as the role of adsorbing nonsugars from the beet is connected with sedimentation and filtration characteristics and seems to be a promising raw material in many industries. Key parameters of the carbonatation lime as a by-product of sugar manufacture are size of crystals and aggregates together with polymorphism of the CaCO3 both for the filtration and for follow-up industrial applications. The common polymorph of carbonatation precipitate is calcite but also needle-like aragonite precipitates were found when deteriorated beet was processed. Carbonatation lime may be used as fertilizer, filler in adhesives or in plastics, and in many ecologic uses. It could be concluded that functional materials based on carbonatation lime is a challenging perspective, however, the extensive knowledge in carbonatation process is of primary importance.

CaCO₃ vaterite microparticles for biomedical and personal care applications

Among the polymorph modifications of calcium carbonate, the metastable vaterite is the most practically important. Vaterite particles are applied in regenerative medicine, drug delivery and a broad range of personal care products. This manuscript scopes to review the mechanism of the calcium carbonate crystal growth highlighting the factors stabilizing the vaterite polymorph in the most cost efficient synthesis routine. The size of vaterite particles is a crucial parameter for practical applications. The options for tuning the particle size are also discussed.

Spinning up the polymorphs of calcium carbonate

Controlling the growth of the polymorphs of calcium carbonate is important in understanding the changing environmental conditions in the oceans. Aragonite is the main polymorph in the inner shells of marine organisms, and can be readily converted to calcite, which is the most stable polymorph of calcium carbonate. Both of these polymorphs are significantly more stable than vaterite, which is the other naturally occurring polymorph of calcium carbonate, and this is reflected in its limited distribution in nature. We have investigated the effect of high shear forces on the phase behaviour of calcium carbonate using a vortex fluidic device (VFD), with experimental parameters varied to explore calcium carbonate mineralisation. Variation of tilt angle, rotation speed and temperature allow for control over the size, shape and phase of the resulting calcium carbonate.

Calcium oxalate crystallization in the presence of amphiphilic phosphoproteins

To gain more insight into protein structure–function relationships that govern biomineralization is an exciting and challenging task.