Gravitational Separation Research Articles

Robust bio-inspired superhydrophilic and underwater superoleophobic membranes for simultaneously fast water and oil recovery

Designing a stable and uniform hydrophilic material for separation of oil and water is strongly desired for sustainable management of oily wastewater. Herein, a stable and uniform bio-inspired coating onto the non-woven fabric substrate with superhydrophilicity and underwater superoleophobicity via rapid co-deposition of dopamine and polyethylenimine was demonstrated. Ammonium persulfate outperformed other oxidants (e.g., Cu2+-H2O2 and NaIO4) to rapidly trigger the co-deposition of dopamine and polyethylenimine for homogeneous superhydrophilic and underwater superoleophobic surface engineering. Furthermore, the co-deposition conditions, i.e., concentration of ammonium persulfate and exposure duration, have a positive dependence on the hydrophilicity and underwater oleophobicity of the coated fabric membranes. Specifically, the superhydrophilicity and underwater superoleophobicity (underwater oil contact angle of 165.4 ± 1.1°, sliding angle of 2.5 ± 0.5°) can be obtained for the coated fabric membranes at the optimal co-deposition condition (i.e., 28.5 mmol L−1 persulfate and coating duration of 7 h), showing a great potential in gravitational oil-water separation (permeation flux >115,000 L m−2 h−1; oil rejection >99.2%). Integrating with a superhydrophobic copper mesh, the oil-water mixed solution can be continuously and sufficiently separated, realizing simultaneous recovery of pure oil and water from oily wastewater. In addition, the bio-inspired coating displays a strong long-term chemical robustness and stability in extreme environments (i.e., acidic/alkaline solutions and oils). The study provides a facile, cost-effective and practical strategy in constructing superhydrophilic and underwater superoleophobic interfaces for sustainable treatment of oily wastewater.

RESEARCH OF GRAVITY SEPARATOR OF RAPESEE

Rapeseed contains up to 40…49% oil, 21…33% protein, 6…7% fiber. Rapeseed oil is used in the production of fats and margarine, as well as in the metallurgical, paint, soap, textile industries. Insufficient study of the process of purification of rapeseed seeds constrains its prevalence in Ukraine. Recently, the purification of rapeseed from difficult-to-separate weeds and impurities is carried out by hitting the reflective surface using the elastic properties of the seeds. The cleaning machines used a single blow and have a low separation quality. The construction of the gravitational multilevel separator of rapeseed is considered in the work and its parameters with the possibility of repeated blows of heap particles with reflective surfaces are substantiated. Based on the analysis of experimental studies of the elastic characteristics of rapeseed and impurities, the rational height of the fall of the seed heap, which is in the range of 0,2…0,4 m, was determined. Theoretical calculations allowed to determine the flight lengths of particles with repeated rebounds from the impact surface and made it possible to justify the dimensions of the impact deck in the transverse direction 0,2 m and – 1,5 m in the longitudinal. As a result of the production tests it was found that the most acceptable initial speed is Vo = 2 m/s, and the angle of inclination of the deck α = 300 . The production conditions of the separator proved that when the rapeseed seed heap is clogged up to 15%, the yield of the purified fraction is 68% of the seeds of the first class.

Эффективность анаэробной переработки органических отходов в биофильтрах с использованием кондуктивного носителя

Additional anaerobic treatment of the liquid fraction of the methantenk’s effluent to the content of organic substances that ensure subsequent effective processing under aerobic conditions can be carried out in a biofilter. Processing makes it possible to obtain an additional amount of biogas, reduce the volume of sludge residues. To accelerate the processes of wastewater treatment and optimize the processes of anaerobic processing of wastewater, the use of conductive carriers of inorganic biomass is promising. (Research purpose) The research purpose is in studying the effect of conductive biomass carriers on the efficiency of anaerobic processing of organic waste in biofilters. (Materials and methods) The liquid fraction of the effluent obtained as a result of the gravitational separation of the effluent of the methantenk was used as a substrate for the biofilter. The article describes experimental studies on a test bench that includes two identical bioreactors, in one of which there was placed a biomaterial carrier made of carbon tissue. The article presents a technological scheme and an experimental installation for anaerobic post-treatment of the liquid effluent fraction. (Results and discussion) In the course of experimental studies for 25 days, they showed high stability of the operation of the developed and manufactured experimental installation. In the recycled effluent of a bioreactor with a conductive carrier, the organic substances of the effluent are more fully processed into biogas. The specific (in terms of unit volume of the bioreactor) yields of biogas and methane increased by 14.0 and 22.5 percent; the specific methane yield per gram of raw and decomposed organic matter increased by 22.2 and 7.3 percent. (Conclusions) The use of a biofilter in combination with the immobilization of microorganisms on a conductive carrier allowed to increase the efficiency of fermentation of organic waste by 6 percent, increase the specific yields of biogas and methane, and reduce the volume of sludge residues.

ДОСЛІДЖЕННЯ ПРОЦЕСУ СЕПАРУВАННЯ НАСІННЯ НА СЕПАРАТОРІ ГРАВІТАЦІЙНО-КАСКАДНОГО ТИПУ

Different designs of separators are used for separating seeds. The principle of separator operation is based on various physical, mechanical and aerodynamic properties of seeds. Gravitational separators are promising because energy is not spent on separation process in this type of separators. A gravity-cascade separator was proposed, in which the separator sections are connected like “scissors”. The sieve length was theoretically justified, taking into account the condition for passing a small fraction of seeds into the sieve holes. The influence of sieves tilt angle and seed flow rate from hopper on the quality index of separation process was studied experimentally

Functional-characteristics of Zanthoxylum schinifolium (Siebold & Zucc.) essential oil nanoparticles

Zanthoxylum schinifolium (Siebold & Zucc.) is a folk and popular aromatic plant due to its exceptional biological properties. However, its use is limited in the industry due to its essential oil volatility and rapid degradation. In the current work, nanotechnology was applied to optimize physicochemical characteristics, long-term stability, and antioxidant performance of essential oil isolated from Z. schinifolium (ZSEO). Chromatographic analysis of isolated sonochemical ZSEO showed that linalool (57.54 %) is the main component. A distinctive and stable ZSEO nanoemulsion (ZSEO-NE) was successfully fabricated through designing an energy-saving, efficient, and applicable approach. response surface methodology (RSM) based on Box–Behnken design was the approach used for optimization processes. Double homogenization processes were successfully applied based on the sonochemical cavitation phenomenon, together with a high-pressure micro-fluidization homogenizer to form nano-scale size droplets. Octenyl succinic modified starch (OSA-MS) was the wall material and surfactant used. Tween-80 was used as a non-ionic surfactant. refined, bleached, and deodorized sunflower oil was served as a carrier material. dynamic light scattering (DLS) technique was used to analyze the droplet hydrodynamic diameter (DHD) (nm), polydispersity index (PdI), ζ-potential (mV). Optical microscopy, Fluorescence microscopy, and confocal laser scanning microscopy (CLSM) were applied for microstructure studies of ZSEO-NE. Gravitational separation and stability of physicochemical properties during long-term storage were evaluated. The optimum values of the mean DHD, PdI, and ζ-potential of ZSEO-NE ranged from 128.8 nm, 141.0, and -44.0 mV, respectively. The findings of the RSM analysis showed considerable agreement between the predictive values and the actual values, in a clear indication that the quadratic model obtained from the BBD matrix covers the experimental range of the current study. Treatment of ZSEO-NE showed maximum stability and less susceptible to droplet aggregation without noticeable separation between aqueous and organic phases during long-term storage.

Fabrication and characterization of Pickering emulsion gels stabilized by zein/pullulan complex colloidal particles.

Zein particles are unsuitable as stabilizers of Pickering emulsions because of their high hydrophobicity. However, few studies have reported on the use of a strong hydrophilic neutral polysaccharide to regulate its wettability. In this work, zein/pullulan complex particles (ZPPs) were formulated by an anti-solvent method to fabricate Pickering emulsions. The presence of pullulan increased the size, decreased the zeta, and provided excellent resistance to the gravitational separation of zein. Scanning electron microscopy (SEM) revealed that the shape of zein particles changed from spherical as they became aggregated ZPP nanoparticles. Fourier transform infrared (FTIR) spectroscopy indicated that the flocculation phenomenon of ZPPs was related to the hydrogen bond between zein and pullulan. Moreover, the hydrophobicity of zein was modified by hydrophilic pullulan to endow the ZPPs with nearly neutral wettability when the mass ratio was 15:1, allowing for the preparation of stable Pickering emulsions. In contrast to zein, the ZPPs contributed to building a compact interface layer around the droplets and smaller emulsion droplets. Under a certain ZPP concentration, the size and viscosity of emulsion increased with an increase in the oil volume fraction, indicating that the Pickering emulsions stabilized by ZPPs showed better stability against coalescence. Confocal laser scanning microscopy (CLSM) revealed that the ZPPs constructed a dense filling layer on the surface of oil droplets, thus further emphasizing that ZPPs can potentially be used in fabricating Pickering emulsion gels. Zein/pullulan complex particles are an excellent Pickering emulsion gel stabilizer that can be used in the delivery system of bioactive substances in food formulations. © 2020 Society of Chemical Industry.

Behavior of concentrated emulsions prepared by acid-hydrolyzed insoluble microalgae proteins from Chlorella protothecoides.

Microalgae are a promising alternative source to meet the increasing global demand for protein. The insoluble microalgae protein fraction that makes up over half of the protein composition of the biomass has shown potential to serve as a functional emulsifier after acidic hydrolysis. However, creaming was observed due to the flocculation of emulsion droplets, suggesting a preferable use in concentrated emulsions. In this study, we examined the emulsifying behavior of the untreated insoluble microalgae protein fraction and two of its hydrolysates obtained in 0.5 mol L-1 HCl for 4 h at 65 °C (Hydrolysates 65) or 85 °C (Hydrolysates 85), at a concentration of 3% (w/w), and elevated levels of oil (50-70%). The results showed an increase in droplet size and apparent viscosity with increasing oil content in the emulsions. The emulsions made with Hydrolysates 85 had the smallest droplet size and the highest apparent viscosity. The gravitational separation was hindered when oil content was increased. The Hydrolysates 85 stabilized emulsions had a gel-like structure and were stable against coalescence or creaming during a 7 day storage test. The results suggest that the thermal acid-treated fraction Hydrolysates 85 may, in particular, be a good emulsifier to formulate concentrated emulsion-based foods with oil content over 50%, such as mayonnaise, salad dressings, or dips. © 2020 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Mercury (Hg) Contaminated Sites in Kazakhstan: Review of Current Cases and Site Remediation Responses.

Mercury (Hg) emissions from anthropogenic sources pose a global problem. In Central Asia, Kazakhstan’s central and northern regions are among the most severely Hg-contaminated territories. This is due to two former acetaldehyde (in Temirtau) and chlor-alkali (in Pavlodar) plants, discharges from which during the second half of the 20th century were estimated over 2000 tons of elemental Hg. However, the exact quantities of Hg released through atmospheric emissions to the environment, controlled discharges to the nearby aquatic systems, leakages in the cell plant, and contaminated sludge are still unknown. The present review is the initiation of a comprehensive field investigation study on the current state of these contaminated sites. It aims to provide a critical review of published literature on Hg in soils, sediments, water, and biota of the impacted ecosystems (Nura and Irtysh rivers, and Lake Balkyldak and their surrounding areas). It furthermore compares these contamination episodes with selected similar international cases as well as reviews and recommends demercuration efforts. The findings indicate that the contamination around the acetaldehyde plant site was significant and mainly localized with the majority of Hg deposited in topsoils and riverbanks within 25 km from the discharge point. In the chlor-alkali plant site, Lake Balkyldak in North Kazakhstan is the most seriously contaminated receptor. The local population of both regions might still be exposed to Hg due to fish consumption illegally caught from local rivers and reservoirs. Since the present field data is limited mainly to investigations conducted before 2010 and given the persisting contamination and nature of Hg, a recent up-to-date environmental assessment for both sites is highly needed, particularly around formerly detected hotspots. Due to incomplete site remediation efforts, recommendations given by several researchers for the territories of the former chlor-alkali and acetaldehyde plant site include ex-situ soil washing, soil pulping with gravitational separation, ultrasound and transgenic algae for sediments, and electrokinetic recovery for the former and removal and/or confinement of contaminated silt deposits and soils for the latter. However, their efficiency first needs to be validated. Findings and lessons from these sites will be useful not only on the local scale but also are valuable resources for the assessment and management of similar contaminated sites around the globe.

Development of Concentration Technology for Medium-Impregnated Hematite Quartzite of Kryvyirih Iron Ore Basin

Introduction. Trends in developing Ukraine’s metallurgy in the context of using its mineral raw base indicate prospects for mining hematite quartzite deposits. Problem Statement. The problem of producing high-quality hematite ore concentrates is associated with the fact that aggregates of martite, goethite, marshallit quartz, and other low hard minerals can be easily reground while crushing and grinding. This results in increased content of fine particles (slimes), which decreases selectivity of separating ore and non-metallic minerals. One of the ways to solve this problem is gentle ore grinding Purpose. Developing a technology of dry and wet concentration for hematite quartzite from Kryvyi Rih Iron Ore Basin. Materials and Methods. While conducting the research, a set of methods are used including generalization of research data; chemical and mineral analysis of ore and concentration products prior to and after concentrating by magnetite and gravitation methods; mathematical modeling of processes; technological testing in laboratory and industrial conditions. Results. Magnetic and gravitation separation is used for hematite ore concentration. Sintering ore with Fe content of 55.1% and concentrates of 62.32-64.69% Fe have been produced from hematite ore. Iron extraction in marketable products makes up 73.6-80.49%. Conclusions. There have been developed technologies for dry and wet concentration for hematite quartzites of Kryvyi Rih Iron Ore Basin. For the first time, magnetic separation has been suggested to be used for hematite ore concentration. This has enabled producing concentrates with an iron content over 64.0%, decreasing ore grinding front by at least 40% as compared with the initial one, and reducing operation and capital expenses by over 30%.

Improving the Efficiency of the Separation Process of Liquid Heterogeneous Systems

For efficient separation of liquid heterogeneous systems in oil and gas industry, various types of sedimentation tanks, separators, hydrocyclones, etc. are used, the principle of which is based on gravitational and centrifugal separation of heterogeneous masses of different densities. In order to ensure the best hydrodynamic conditions for the process of suspensions separation in a hydrocyclone and to prevent clogging of the discharge hole, an apparatus that contains only the cylindrical part of the housing is proposed. The presence of a taper displacer ensures the maintenance of optimal hydrodynamic conditions along the entire length of the apparatus, from the inlet to the discharge hole. The taper of the displacer affects the distribution profile of the tangential velocities of the fluid in the near-wall region, ensuring the constancy of the velocity profile along the radius and the specific flow rate over the cross section of the apparatus. Basing on the results of studies carried out on a real product (a mixture of PVCR with water) at a pressure and flow rate corresponding to the production ones, an industrial prototype of the apparatus has been designed and produced.

Gravitational separation of Ar∕N<sub>2</sub> and age of air in the lowermost stratosphere in airborne observations and a chemical transport model

Abstract. Accurate simulation of atmospheric circulation, particularly in the lower stratosphere, is challenging due to unresolved wave–mean flow interactions and limited high-resolution observations for validation. Gravity-induced pressure gradients lead to a small but measurable separation of heavy and light gases by molecular diffusion in the stratosphere. Because the relative abundance of Ar to N2 is exclusively controlled by physical transport, the argon-to-nitrogen ratio (Ar∕N2) provides an additional constraint on circulation and the age of air (AoA), i.e., the time elapsed since entry of an air parcel into the stratosphere. Here we use airborne measurements of N2O and Ar∕N2 from nine campaigns with global coverage spanning 2008–2018 to calculate AoA and to quantify gravitational separation in the lowermost stratosphere. To this end, we develop a new N2O–AoA relationship using a Markov chain Monte Carlo algorithm. We observe that gravitational separation increases systematically with increasing AoA for samples with AoA between 0 and 3 years. These observations are compared to a simulation of the TOMCAT/SLIMCAT 3-D chemical transport model, which has been updated to include gravitational fractionation of gases. We demonstrate that although AoA at old ages is slightly underestimated in the model, the relationship between Ar∕N2 and AoA is robust and agrees with the observations. This highlights the potential of Ar∕N2 to become a new AoA tracer that is subject only to physical transport phenomena and can supplement the suite of available AoA indicators.

Improvement of formation fluid separation efficiency

Producers and researchers pay attention to the improvement of high-quality and productive separation of liquid heterogeneous systems in the oil and gas industry. To perform these operations, various designs of sedimentation tanks, separators, hydrocyclones, etc. based on gravitational and centrifugal separation of inhomogeneous masses of various densities are used. A further noticeable increase in the diameter of the rotor, for example, up to 1500 mm, is associated with the search for new design forms of separators. This is due to serious design studies and restructuring of the production base.

SHS Introduction of Nitrogen in the Composition of Alloy Steel under Gas Pressure

The possibility of producing cast alloyed nitrided steel (up to 1.3 wt % N) by SHS metallurgy is shown. The initial mixture for making alloy cast steel includes iron, chromium, manganese, nickel, molybdenum, vanadium, silicon, and aluminum oxides. Chromium nitride is used as the main nitrogen source. Initial mixtures are shown to be capable of burning over a wide range of reagent ratios, and the combustion temperature exceeds the melting temperature of the condensed combustion products (steel, reducing-metal oxide), which makes it possible to perform their gravitational separation and to make steel in an as-cast form. Experimental studies are carried out in a reactor under nitrogen pressure and in a centrifugal installation under the combined action of overload and pressure to exclude the spread of a mixture during combustion. When the pressure in the reactor is increased from 0.1 to 5.5 MPa, the nitrogen content in steel alloyed with chromium, manganese, nickel, molybdenum, vanadium and silicon is found to increase from 0.4 to 1.3 wt %. Under overload (150g) and an increase in the pressure from 0.1 to 1 MPa, the nitrogen content increases from 0.4 to 0.55 wt %. According to X-ray diffraction and electron-probe microanalysis data, the base of the steel has the γ-Fe lattice and is a solution of alloying elements in iron. The shift of the diffraction peaks and their broadening indicate the dissolution of alloying elements in iron. α-Fe precipitates and point inclusions of vanadium, chromium, and impurity-aluminum nitrides are also detected.

Synthesis of Casting Composite Materials Based on Tungsten Carbides with Nickel Binding by the SHS Metallurgy Method

The paper experimentally demonstrates the possibility of synthesizing cast W–C–Ni composite materials (CMs) by SHS metallurgy from highly exothermic mixtures based on WO3 and NiO oxides and a complex reducing agent consisting of Al, Ca, and graphite at an elevated gas (nitrogen) pressure. It is shown that by varying the WO3 and NiO ratio, the initial mixtures of the contents of carbon, aluminum, and calcium retain the ability to burn in a wide range of values, and the combustion temperature exceeds the melting temperature of the composite and slag (oxide) combustion products. Under the action of gravity there is a separation of the melts of the CM and slag; and with subsequent cooling, the formation of their structure. This paper studies the laws of combustion of mixtures, gravitational separation of combustion products, and the formation of their composition and structure.

CFD Assessment and Experimental Investigation of the Liquid Separation Efficiency Enhancements in a Vertical Gravity Separator

Three design enhancement options for a vertical gravitational flash tank separator were proposed and investigated in this work. Computational Fluid Dynamic (CFD) was used to assess the optimum configurations of the vertical gravitational flash tank separator. A series of experiments were performed to test the CFD proposed configurations of the enhancement design options. This paper also assessed the usefulness of CFD in flash tank design, and this is achieved through experiments and simulations on a range of relevant configurations using water as the working fluid. The results revealed that the combination of the inlet flow direction and extractor had a significant effect on the performance of the vertical flash tank separator which increased by 2%. The results also revealed that there was a good agreement between the CFD simulations and experiments; the CFD simulations underestimated the liquid separation efficiency by approximately 0.02 over the range of conditions tested.

Розробка технологій збагачення середньовкраплених гематитових кварцитів Кривбасу

Introduction. Trends in developing Ukraine’s metallurgy in the context of using its mineral raw base indicate prospects for mining hematite quartzite deposits. Problem Statement. The problem of producing high-quality hematite ore concentrates is associated with the fact that aggregates of martite, goethite, marshallit quartz, and other low hard minerals can be easily reground while crushing and grinding. This results in increased content of fine particles (slimes), which decreases selectivity of separating ore and non-metallic minerals. One of the ways to solve this problem is gentle ore grinding Purpose. Developing a technology of dry and wet concentration for hematite quartzite from Kryvyi Rih Iron Ore Basin. Materials and Methods. While conducting the research, a set of methods are used including generalization of research data; chemical and mineral analysis of ore and concentration products prior to and after concentrating by magnetite and gravitation methods; mathematical modeling of processes; technological testing in laboratory and industrial conditions. Results. Magnetic and gravitation separation is used for hematite ore concentration. Sintering ore with Fe content of 55.1% and concentrates of 62.32-64.69% Fe have been produced from hematite ore. Iron extraction in marketable products makes up 73.6-80.49%. Conclusions. There have been developed technologies for dry and wet concentration for hematite quartzites of Kryvyi Rih Iron Ore Basin. For the first time, magnetic separation has been suggested to be used for hematite ore concentration. This has enabled producing concentrates with an iron content over 64.0%, decreasing ore grinding front by at least 40% as compared with the initial one, and reducing operation and capital expenses by over 30%.

INCREASING EFFICIENCY OF LIQUID SYSTEMS SEPARATION FOR FORMATION FLUID GATHERING

Considerable attention is paid to the improvement of the processes of high-quality and productive separation of liquid heterogeneous systems SHAPE \\* MERGEFORMAT in the oil and gas industry from both manufacturers and scientists. To carry out these operations, various types of designs of sedimentation tanks, separators, hydrocyclones, etc. are used, the principle of operation of which is based on gravitational and centrifugal separation of inhomogeneous masses of various densities. It should be noted that when designing separators with a high value of the performance index, it is insufficiently possible to use numerous theoretical studies in the field of hydromechanics of flow in a centrifugal field. This is due to the extreme complexity of the conditions for the flow of the separated fluid in the rotor space. Therefore, experimental studies of intra-rotor flows have become very important at present. So, it was experimentally shown that, during the intensification of the separation process, it is impossible to study the operation of individual parts of the rotor separately, but it is necessary to consider the operation of the system, including the plate package, sludge space, high-pressure channels and an unloading device. Thus, we can conclude that the increase in the performance of separators due to the increase in their size has approached the limit and the use of some more reserves in this direction is obviously associated with the need to overcome great and unjustified difficulties. Further development of this direction is irrational. However, there is a way to intensify the separation process by equalizing the distribution of the rotor and batch flows, improving the packages, eliminating the flotation effect and the destruction of the dispersed phase, adapting the operating mode of the separators depending on changes in the properties of the separated liquid. In industrial conditions, for example, when cleaning a highly paraffinized formation fluid, crusts form in the hydrocyclone, periodically clogging the discharge hole. In order to ensure the best hydrodynamic process conditions for the separation of formation fluid in a hydrocyclone and to prevent clogging of the discharge outlet, an apparatus is proposed that contains only the cylindrical part of the housing. A feature of the proposed design is that the optimal ratio of length to diameter is in the range of 3-5 with other ratios of other characteristics used in the calculation, equal to the ratios of characteristics in known hydrocyclones. This length of the hydrocyclone provides the conditions for the effective separation of the reservoir fluid and the withdrawal of the condensed fraction through the discharge opening. The obtained results of studies performed on a real product at pressure and flow rate, corresponding to the production ones, made it possible to design and manufacture an industrial model of the apparatus. The experimental data can be used to calculate similar hydrocyclones intended for use in other mixtures.

Parametric study and geomechanical design of Ultra-deep-water Offshore Salt Caverns for Carbon Capture and Storage in Brazil

This article describes a new concept to reduce carbon dioxide emissions of offshore oil production of high gas-to-oil ratio reservoirs and high content of CO2, denominated Offshore Salt Cavern Ultra-deep Water CCS (Carbon Capture and Storage) System. This hybrid system is intended for natural gas storage, the gravitational separation between CO2/CH4, and CO2 confinement for final destination. This development emerged from a current demand of some Brazilian pre-salt reservoirs to destinate a gas stream with high CO2 contamination, produced during the oil extraction. These reservoirs have a continuous salt rock layer of 2000 m as caprock making the construction possible of salt caverns by leaching using seawater. In the first stage of technology development, the system will only store a gas stream contaminated with a high concentration of CO2. In the second stage of its development, it will allow not only the separation of natural gas from the CO2 but also its storage and the monetization of CH4. This paper presents the conceptual design of this technology, showing the steps from the parametric study to select the best relation between flowrate, leaching time, structural stability, and the volume of gas with the high content of CO2 storage, up to the final geomechanical design using the set of parameters selected.

Fermentation of tomato juice improves in vitro bioaccessibility of lycopene

Abstract The impact of fermentation (Saccharomyces cerevisiae ATCC 9763) on the bioaccessibility of lycopene in a model tomato juice was examined. The physicochemical and structural properties of the tomato tissue were determined after fermentation and the bioaccessibility of lycopene was monitored using a simulated gastrointestinal tract. A lycopene concentration of 45.1 mg/100 g was obtained under optimal fermentation conditions. The cell walls of the tomato cells were hydrolyzed and disrupted by fermentation. Cell disruption decreased the pectin content and reduced the tissue fragment size, thereby reducing gravitational separation and facilitating lycopene release. The lycopene bioaccessibility in the tomato juices increased in the following order: unfermented (8.5%)

Simulating age of air and the distribution of SF<sub>6</sub> in the stratosphere with the SILAM model

Abstract. The paper presents a comparative study of age of air (AoA) derived from several approaches: a widely used passive-tracer accumulation method, the SF6 accumulation, and a direct calculation of an ideal-age tracer. The simulations were performed with the Eulerian chemistry transport model SILAM driven with the ERA-Interim reanalysis for 1980–2018. The Eulerian environment allowed for simultaneous application of several approaches within the same simulation and interpretation of the obtained differences. A series of sensitivity simulations revealed the role of the vertical profile of turbulent diffusion in the stratosphere, destruction of SF6 in the mesosphere, and the effect of gravitational separation of gases with strongly different molar masses. The simulations reproduced well the main features of the SF6 distribution in the atmosphere observed by the MIPAS (Michelson Interferometer for Passive Atmospheric Sounding) satellite instrument. It was shown that the apparent very old air in the upper stratosphere derived from the SF6 profile observations is a result of destruction and gravitational separation of this gas in the upper stratosphere and the mesosphere. These processes make the apparent SF6 AoA in the stratosphere several years older than the ideal-age AoA, which, according to our calculations, does not exceed 6–6.5 years. The destruction of SF6 and the varying rate of emission make SF6 unsuitable for reliably deriving AoA or its trends. However, observations of SF6 provide a very useful dataset for validation of the stratospheric circulation in a model with the properly implemented SF6 loss.