Deposition Of Inorganic Salts Research Articles

Chemical Analysis of Groundwater and Wastewater in the Area of the Tengiz Deposit of the Atyrau Region of the Republic of Kazakhstan

This article analyzes the content of the chemical composition of groundwater and wastewater of the Tengiz deposit located in the Zhyloy district of Atyrau region of the Republic of Kazakhstan. This analysis is necessary to determine the deposition of inorganic salts in oilfield equipment. The analysis shows that the content of chloride anions and magnesium cations prevails in groundwater and wastewater. Thus, the content of chloride anions exceeds the content of other anions up to 2-3 times of sulfate anions in groundwater and wastewater and up to 2.5-5 times of bicarbonate anions in groundwater and 17-27 times in wastewater. Among the cations, the maximum values are characteristic of magnesium cations, whose content exceeds the calcium content by more than 3.5 times in wastewater and more than 6.5 times in groundwater. In addition, the magnesium content exceeds more than 5 times the content of the sum of sodium and potassium ions. Thus, according to the results of the study, it was determined that the main salts affecting the oilfield equipment at the Tengiz field are magnesium chloride salts.

Advanced treatment of high-salinity wastewater by catalytic ozonation with pilot- and full-scale systems and the effects of Cu2+ in original wastewater on catalyst activity

In this work, heterogeneous catalytic ozonation for the treatment of bio-treated saccharin sodium production wastewater (BSSW) was comprehensively investigated with pilot- and full-scale systems, with special emphasis on the effects of Cu2+ in the original wastewater on catalyst activity. The results of semi-batch and continuous experiments show that heterogeneous catalytic ozonation was effective in removing organic compounds from high-salinity wastewater and that Cu2+ in the original wastewater had a substantial effect on the performance of the process. The retention of 0.15 mM Cu2+ in BSSW increased the chemical oxygen demand (COD) removal by 31% in semi-batch reactor with heterogeneous catalytic ozonation. The stable COD removal efficiencies ranged from 74% to 66.4% for a 9-month operation, indicating that Cu2+ with an appropriate concentration in the original BSSW not only improved the COD removal efficiencies but also inhibited catalyst deactivation; catalyst deactivation was mainly caused by the deposition of inorganic salts on the catalyst surface. Cu2+ combined with some anions to inhibit the formation and deposition of inorganic salts that could easily cause deactivation. The deposited copper salts were readily eliminated, especially during backflushing operations. Moreover, in a full-scale study, heterogeneous catalytic ozonation with 0.15 mM Cu2+ in BSSW exhibited stable COD removal efficiencies (51%–83%) after over 3 years of operation. This study offers a new idea for using the inherent properties of wastewater to perform advanced treatments on high-salinity industrial wastewater through heterogeneous catalytic ozonation.

PREVENTING INORGANIC SCALE FORMATION IN THE UZEN AND ZHETYBAI FIELDS BY USING SCALE INHIBITORS

Development of the oil industry in Kazakhstan at the current stage is characterized by a decrease in the quality of the raw material base. In the total balance of fields under development, the fields that have entered the late stage of development prevail and, consequently, there is a significant deterioration in their structure, an increase in the share of hard-to-recover oil reserves, watering of beds and well production.One of the main challenges during the development of the field is the deposition of inorganic salts in the oilfield equipment. This article describes the main reasons for the formation of solid inorganic deposits in oil fields, methods of scale inhibitors, as well as the classification of scale inhibitors. Presents the physical and chemical characteristics of the objects under study: the properties of oils and watersof Uzen and Zhetybai oil fields and the chemical reagents – inhibitors of scale formations. Based on the results of laboratory studies, scale inhibitors were selected, which showed high efficiency (90 - 100 %) to prevent the precipitation of CaCO3, CaSO4 and BaSO4 under the conditions of Uzen and Zhetybai oil fields. The study was conducted in the center of scientific and laboratory research branch of KMG Engineering LLP "KazNIPImunaygas".

Catalytic ozonation of bio-treated coking wastewater in continuous pilot- and full-scale system: Efficiency, catalyst deactivation and in-situ regeneration

In this study, the performance of catalytic ozonation in the treatment of bio-treated coking wastewater (BCW) using pilot- and full-scale systems was investigated. Additionally, the removal efficiency of organic pollutants from BCW, the deactivation mechanism of MnxCe1-xO2/γ-Al2O3, and backflushing optimization for in-situ catalyst regeneration, which have not been previously investigated, were analysed. Results of the 12-month pilot scale experiments showed that catalytic ozonation resulted in the effective removal of organic pollutants when backflushing was applied as an in-situ catalyst regeneration strategy. The effluent chemical oxygen demand (COD) content decreased from 150 to 78 mg L−1, and remained below a discharge limitation of 80 mg L−1, and the stable COD removal efficiencies (from 56.0% to 47.9%) indicated that catalyst deactivation, which primarily resulted from the deposition of inorganic salts on the surface of the catalyst that limited interaction between ozone and active sites and/or prevented electrons transfer, was primarily inhibited by backflushing. The catalyst regeneration via in-situ air- and water-backflushing was attributed to the scrubbing, collision, and/or the loosing effect. Additionally, in the full-scale experiment, the catalytic ozonation process with in-situ alternative backflushing exhibited a stable COD removal efficiency (above 45.6%) for 885 days when water- and air-flushing strengths of 10 L m−2 s−1 and 15 L m−2 s−1, respectively, were applied with a 7-day regeneration interval. Therefore, the results of this study provide new insights into catalytic ozonation and support its engineering application in BCW treatment.

Crystal Crosslinked Gels for the Deposition of Inorganic Salts with Polyhedral Shapes.

Biomineralization has been given a great deal of attention by materials chemists because of its low environmental load and sustainability. With the goal of synthesizing such processes, various methods have been developed, especially for inorganic salts of calcium. In this report, we focused on the deposition of inorganic salts, such as calcium carbonate and calcium phosphate using crystal crosslinked gels (CCG), which are prepared by crystal crosslinking of metal-organic frameworks (MOFs). Due to the crystalline nature of MOFs, CCGs intrinsically possess polyhedral shapes derived from the original MOF crystals. As the result of deposition, the obtained inorganic salts also exhibited a polyhedral shape derived from the CCG. The deposition mainly occurred near the surface of the CCG, and the amorphous nature of the deposited inorganic salts was also confirmed.

CONTROL DEPOSITS OF PARAFFIN, ASPHALT-RESIN COMPONENTS OF OIL

The current situation in the oil sector of Russia is characterized by a constant increase in the share of tight oil reserves, defined by low-permeability reservoirs and high viscosity. In addition, the production of oil and gas in most major fields is complicated by the removal of mechanical impurities, asphalt-resin-wax (ARW) and hydrate deposits as well as deposition of inorganic salts in wells. One of the most important problems in the oil industry is the deposition of paraffin deposits on the walls inner surfaces of tubings in the extraction and transportation of oil. AFS - natural composite material that consists of organic and mineral compounds. Deposits in their essence are represent «the greasy» suspension, or emulsion highly adhesive to various surfaces. The most important in the problem of these compounds formation is not the allocation of paraffins in the reservoir fluid flow but their deposition on the surface of process equipment. Moreover, for the paraffins to deposit on pipe wall the necessary condition is that temperature to be lower than that one of the liquid pumped. In the result of paraffin deposition inside the tubing the cross section of the pipe narrows, increasing the resistance to fluid flow and rod string displacement; the load on the head balancer SK increases, disturbing its balance and delivery rate decreases. All currently existing methods of dealing with AFS are mainly on non-regular basis allowing only to a certain extent to increase the turnaround time of the process equipment.

Impact of Complex Layering Structures of Organic and Inorganic Foulants on the Thermohydraulic Performance of a Single Heat Exchanger Tube: A Simulation Study

Crude oil fouling in preheat trains in refineries is usually dominated by organic matter deposition at high temperatures. However, malfunction of desalting equipment, human or technical errors, or changes in feedstock may lead to substantial deposition of inorganic salts or corrosion products, compromising heat exchange performance, pressure drop (hence throughput), and even safety. Understanding how such abnormal deposition and the resulting complex deposit structure affect the thermohydraulic performance of heat exchangers is key to developing adequate monitoring tools for the early detection, diagnosis, and control of the underlying causes. Here, a novel multicomponent fouling deposit formulation is applied to the simulation of deposits composed of organic and inorganic foulants within a single heat exchanger tube. The model enables the tracking of changes and history of local composition in the fouling deposit, thermoconductivity profiles including layering effects, and impact on the overall thermohyd...

Reduction of Salt Deposits on the Surface of Oilfield Equipment by Management of Electrochemical Parameters of the Medium

Corrosion activity of the environment is caused by the presence in it of salt ions that are directly involved in the corrosion process causing deposition of inorganic salts on the surface of the equipment. Removal of such active salt ions from the working environment or modifying them from the active to the inactive state significantly reduces the rate of corrosion of the equipment and the amount of salt deposits.

Enhanced removal of sodium salts supported by in-situ catalyst synthesis in a supercritical water oxidation process

For practical applications of supercritical water oxidation to wastewater treatment, the deposition of inorganic salts in supercritical phase must be controlled to prevent a reactor from clogging. This study investigated enhanced removal of sodium salts with titanium particles, serving as a salt trapper and a catalyst precursor, and sodium recovery by sub-critical water. When Na(2)CO(3) was tested as a model salt, sodium removal efficiency was higher than theoretically maximum efficiency defined by Na(2)CO(3) solubility. The enhanced sodium removal resulted from in-situ synthesis of sodium titanate, which could catalyse acetic acid oxidation. The kinetics of sodium removal was described well by a diffusion mass-transfer model combined with a power law-type rate model of sodium titanate synthesis. Titanium particles showed positive effect on sodium removal in the case of NaOH, Na(2)SO(4) and Na(3)PO(4). However, they had negligible effect for NaCl and negative effect for Na(2)CrO(4), respectively. More than 99% of trapped sodium was recovered by sub-critical water except for Na(2)CrO(4). In contrast, sodium recovery efficiency remained less than 50% in the case of Na(2)CrO(4). Reused titanium particles showed the same performance for enhanced sodium removal. Enhanced salt removal supported by in-situ catalyst synthesis has great potential to enable both salt removal control and catalytic oxidation.

Effect of precipitation procedure and detection technique on particle size distribution of CaCO 3

The deposition of inorganic salts (“scales”) such as calcium carbonate is an important flow assurance problem during crude oil production. The knowledge of the features of the precipitated solids, mainly the particle size and morphology, is crucial to understand the nature of the solids and to avoid or reduce the effect of their deposition. For instance, the use of additives is one of the most usual procedures to mitigate this problem. Additives interact with scale-forming substances either by increasing the induction time, or by inhibiting crystal growth, changing the morphology of solids. In this work, CaCO 3 was precipitated by two different experimental methods: by mixing sodium carbonate and calcium chloride at 25 °C (method 1), and by changing the pH (method 2). Precipitated solids were analyzed by means of the following techniques: laser diffraction (LD), focused-beam reflectance measurement (FBRM), scanning electron microscopy (SEM), and X-ray diffraction (XRD), in order to select a method for the determination of particle size of solids similar to scales, in order to study these deposits at the beginning of their formation and to evaluate the effect of additives in the scales particle size. Results were compared to those of scale deposits extracted from crude oil pipelines. SEM and XRD characterization showed that both the precipitation methods lead to calcium carbonate as a mixture of calcite, aragonite and vaterite, with rhombohedral morphology for method 1 and spherical for method 2. The effects of temperature, kinetics and Mg 2+ presence in the morphology of CaCO 3 were evaluated. Thus, the solids obtained by static bottle test and real scales are mainly formed by long needle-shaped aragonite. The comparison of the several particle size characterization methods determinates that an LD is a fast and sensitive technique for spherical and non-spherical solids, and it is a convenient technique for the analysis of scales extracted from oil pipelines.

Membrane autopsy helps to provide solutions to operational problems

Within the lifetime of most membranes some fouling will adversely affect membrane performance and cleaning will be necessary. The cleaning will depend on the type of deposit such as organic fouling, inorganic scaling or colloidal deposition. However strong the circumstantial evidence as to the identity of the foulant, the only reliable method of determining the true identity of the foulant with confidence, is by membrane autopsy. Different deposits affect the performance of the plant in different ways. Deposits such as organic fouling cause reduced output and increased differential pressure along the membranes and often require higher operating pressure to maintain output. Inorganic deposits can be a cause of irreversibly increase in salt passage. All forms of membrane fouling cause a significant increase in plant downtime and maintenance costs. Following an extensive study of membrane fouling during the autopsy procedure, we can usually recommend a protocol for the most suitable cleaning procedure. Cleaning procedures can be supported by proposals for antiscalant treatments to avoid the formation of deposits and in some cases retard membrane fouling. It is common to find deterioration in the salt rejection layer leading to a significant increase in salt passage. In some cases this is associated with an increase in product flow and may be caused by oxidation of the membrane, deposition of inorganic salts, abrasion or even the tearing of the membrane leaves themselves. If the cause of the fouling can be identified, recurrence of the problem can often be prevented, although in some cases, salt rejection performance maybe irrecoverable. This paper considers the results of some autopsies from plants with different problems and presents a general opinion of current operating practice. Photographic evidence is included showing some of the different forms of scale and fouling. Conclusions are given based on the general experiences of the staff carrying out these autopsies.

Treatment of sewage sludge using hydrothermal oxidation – technology application challenges

The objective of this paper is to examine the technical feasibility of hydrothermal oxidation as a sewage sludge treatment option. Hydrothermal oxidation involves treatment at temperatures and pressures below and above the critical point for water, 374.2°C and 22.1 MPa. Subcritical water oxidation (SubCWO) achieves incomplete sludge oxidation (<95% COD removal) and produces high-strength liquors containing significant quantities of volatile fatty acids (VFAs). Controlled liquor recycling into the treatment plant can provide a useful carbon source to support biological nutrient removal (BNR). SubCWO also achieves efficient destruction of the organic component of sludge solids, resulting in significant mass and volume reductions. Supercritical wateroxidation (SCWO) on the other hand can completely oxidize the organic component of sludge (>99.9% COD reduction), produce high quality effluents and disposable ashes and air emissions. The major engineering challenges associated with developing hydrothermal treatment systems, especiallySCWO systems, are solids management, corrosion and safety. Thesolids management challenge relates to scale formation, including deposition of inorganic salts and transport of suspended particles. The corrosion challenge relates to handling highly halogenated and extreme-pH waste streams. Nevertheless, the available body of technical knowledge supports the design of efficient SCWO sludge treatment systems.

The precipitation of ferric phosphate on porous polymer

Polymers with high porosity may be appropriate substrates for the deposition of inorganic salts. Thus the commercially available Porapak N was found to be an appropriate substrate for the deposition of an acidic iron phosphate crystalline phase at 25°C and pH 2.00. The stoichiometry of this acidic ferric phosphate polymorph according to the chemical analysis and spectroscopic results was found to be Fe 2(HPO 4) 3 and its thermodynamic solubility product was found to be 8.6×10 −41 at 25°C. In all cases, a well-defined induction period preceded the onset of acidic ferric phosphate overgrowth, reflecting the time required for the formation of the critical nucleus. The induction times were inversely proportional to the solution supersaturation while the rates of the concomitant crystal growth increased with supersaturation with an apparent order of 1.

Alkaline encrusted cystitis associated with malakoplakia

Alkaline encrusted cystitis is a rare inflammatory condition of the bladder which has been reported sporadically over the past 80 years. It is caused by infection with urea splitting organisms leading to the deposition of inorganic salts on to the surface of the bladder. We present three cases of alkaline encrusted cystitis. In two cases the encrusted area was associated with foci of malakoplakia. The third case occurred in a patient who had received chemotherapy for acute lymphoblastic leukaemia. To our knowledge, these are the first cases of malakoplakia associated with alkaline encrusted cystitis. These two conditions have a number of clinical and aetiological similarities, and may have more in common than has been previously thought.

Deposition of inorganic salts from solution on flat substrates by spin-coating: theory, quantification and application to model catalysts

The theory of spin-coating is applied to predict the amount of inorganic material that is deposited from a solution on a flat substrate on the basis of concentration, density, viscosity and evaporation rate of the solution and the spin speed applied during spin-coating. Measurements by Rutherford backscattering spectrometry (RBS) and inductively coupled plasma optical emission spectroscopy (ICP-OES) confirm the validity of the theory. Applications of the method in the preparation of model catalysts are discussed.