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A new catalyst test setup on miniplant‐scale was planned and built. The setup enables the use of real process gases in the environment of a steel mill or related application and the utilization of synthetic gases with a wide range of gas compositions including trace compounds to investigate the operational limits of gas cleaning catalysts. First investigations focus on oxygen removal from real coke oven gas (COG). The concept not only addresses effects of scale and heat management but also emphasizes the use of real process gases for application‐oriented catalyst development in industrial settings. [ABSTRACT FROM AUTHOR]

The Carbon2Chem® project utilizes steel production gases to synthesize methanol, urea, and other commodity chemicals. The complex process involves CO2 capture and hydrogen production and synthesis, requiring precise analysis due to the diverse components in steel mill flue gases. As some of these components could harm the employed catalysts, the analytics needs to ensure the quality of the purification unit and enhance the understanding of transportation effects and performance in gas cleaning and methanol synthesis. An already established method, proton transfer reaction‐mass spectrometry (PTR‐MS), was employed to assess the gas quality. [ABSTRACT FROM AUTHOR]

The paper presents the results of industrial testing and using of reagents for circulation water clarification for gas cleaning systems at ferroalloy making plants. The process of treatment involving the combination of liquid composite coagulant AS-C2001 and powder anionic flocculant AS-FL7003 was shown to remove successfully suspended material from circulation water for gas cleaning and to reliably provide the specified amount of suspended material (less than 150 mg/L) in cold water used in gas cleaning. The proposed process of treatment with the mentioned reagents has been employed for more than 6 years at the section of water preparation for the gas cleaning installation of the reduction furnace at one of the ferroalloy plants in Kazakhstan. [ABSTRACT FROM AUTHOR]

Observations of a delegation of VUKhIN specialists regarding China's coke plants are noted. The processes and equipment employed are described, and some aspects of coke plant operation are considered. [ABSTRACT FROM AUTHOR]

Pyrolysis of waste tyres produces harmful hydrogen sulfide and other mercaptan compounds as by-products. The current study is concerned with the purification of hydrogen-rich pyrolysis gas from hydrogen sulfide gas that is present in a great amount (up to 5.1% mol at 420 °C), and mercaptans that are also problematic impurities. The method proposed is absorption by alkanolamines which is one of the most economical methods applied in natural gas sweetening. However, it has not been adopted in waste tyre pyrolysis gas purification yet. Two organic absorbents were tested, diethanolamine (DEA), N-methyldiethanolamine (MDEA) as well as theirs blends, at various concentrations. The application of 30 wt% DEA in water reduced H 2 S emission by 98%. In turn, 40 wt% MDEA aqueous solutions reduced H 2 S emission by 97%. The best results were produced when 30 wt% DEA was mixed with 40 wt% of MDEA (1:1 vol ratio) which allowed a removal of 99% of H 2 S from the pyrolysis gas. Moreover, the maximum H 2 S emission was 7 ppm, and a level below 5 ppm was kept for 99% of experiments duration. Finally, the application of this mixture also reduced significantly the concentrations of other sulfur-containing compounds such as methyl mercaptan and carbonyl sulfide (a minimum of 98%), ethyl mercaptan (∼90%), and carbon disulphide (by more than 99%). Thus, aqueous solvent mixture of 30 wt% DEA with 40 wt% of MDEA (1:1 v/v) can be recommended as a potential desulfurization method for waste tyres pyrolysis gas. • Pyrolysis gas is a valuable fuel, but it needs pre-treatment focused on desulfurization. • Raw pyrolysis gas contains high concentrations of H 2 S (up to 5.1%) and mercaptans. • Solutions of alkanolamines can be applied in desulfurization of pyrolysis gas. • DEA, MDEA and as their blends are effective in cleaning pyrolytic gas from H 2 S (>97%). • Blends of DEA/MDEA can also remove other sulfur containing compounds. [ABSTRACT FROM AUTHOR]

The article presents research on the purification process of pyrolysis gas from hydrogen sulfide. To our best knowledge, similar studies have not been performed yet on a real pyrolysis gas obtained from waste tyres, which contains huge amounts of hydrogen sulfide - average 3.6% (up to 5.1% at 420 °C). Different sorbents were tested, among them sodium hydroxide, zinc oxide, and manganese oxide. NaOH in concentration 0.05 M appeared to be the most efficient, showing ∼94% H 2 S removal efficiency under the conditions studied. ZnO features a better efficiency of H 2 S removal from hot gas (∼55%) than MnO. Furthermore, the combination of ZnO and a 0.05 M solution of NaOH was studied. The detailed composition of the pyrolysis gas was performed, too. The main components and sulfur-containing compounds, such as methyl mercaptan, carbonyl sulfide, and ethyl mercaptan, concentrations were measured. Predominantly, the gas consists of methane, hydrogen, ethane, ethene, carbon dioxide, iso-butane, and hydrogen sulfide. Aggregated concentrations of the above-mentioned exceed 80% of the gas, which makes it a very promising gaseous fuel. • Pyrolysis gas with a high heating value – approx. 34 MJ/m3 – contains significant amounts of hydrocarbons and hydrogen. • Pyrolysis gas features high concentrations of sulfur-containing compounds, mainly hydrogen sulfide with average conc. 3.6%. • Pyrolysis gas is as a valuable gaseous fuel, but it needs pre-treatment focused on desulfurization. • Tested metal oxides can significantly reduce the concentration of hydrogen sulfide in the gases (∼55% - ZnO; 38% - MnO). • Sodium hydroxide (NaOH) features the best potential for hydrogen sulfide removal, reaching about 94% removal efficiency. [ABSTRACT FROM AUTHOR]

This research argues that countries should adopt unified regulations regarding the release of the wash water from the Exhaust Gas Cleaning Systems in their port, territorial, and Exclusive Economic Zone (EEZ). Ships use scrubbers to decrease their greenhouse gases emission in order to comply with the International Maritime Organization sulphur content of ships' fuel limit. In January 2020, the global upper limit reached 0.5%. Ships release scrubbers' wash water (SWW) into the sea. The SWW includes toxic materials. The 2008 and 2015 Guidelines for the Exhaust Gas Cleaning Systems regulates the level of the SWW. However, there is uncertainty related to the SWW harm to the marine environment and human health. This uncertainty reflects as well on the national level. Currently, countries fall under one of three main categories. The first is countries that adopt a complete ban against using scrubbers in their territorial water, such as Egypt and Qatar. The second is countries that partially ban the use of scrubbers. The second form is a ban against the type of the discharge/disposal from open loop discharge (Argentina, China, and France). The third type is countries that do not regulate the discharge of scrubbers. Hence, this research is divided into three Parts. After a brief Introduction, Part II tackles who bears the responsibility to investigate environmental harm, especially the transboundary harm of the scrubbers' wash water. Part III deals with the legal models that are adopted by the national regulations related to SWW. These models are (1) limited ban, versus unlimited ban, (2) specific regulations, versus general regulations, and finally (3) binding, versus non-binding regulations. Part IV deals with the solution to the uncertainty. [ABSTRACT FROM AUTHOR]

Theoretical substantiation of the physical principle of increasing the efficiency of ultrasonic agglomeration of submicron particles is proposed, which is based on the creation of resonant conditions for forming vortex flows in gas gaps. The generated vortex flows lead to a local increase in the concentration of particles, which increases the frequency of collisions and, consequently, the efficiency of agglomeration. A numerical model of this process is proposed. The results of calculations carried out on the basis of the numerical model made it possible to ascertain that the efficiency of agglomeration when creating vibrations by a flexurally oscillating radiator (a collection of vortex flows is formed) is more than four times higher than in the case of creating vibrations using a piston radiator (one little-effective vortex flow is generated). [ABSTRACT FROM AUTHOR]

Analytical dependencies for calculating the economically optimal value of the conditional gas velocity in a cyclone are identified taking into account both technical and economic parameters that affect the gas cleaning cost. A method for determining the optimal cyclone diameter and the number of cyclones corresponding to the minimum cost of gas cleaning taking into account the required dust collection efficiency is proposed. Based on the dependencies identified, it has been established that the recommended fixed values of the conditional gas velocity used today when selecting a cyclone are overestimated in most cases. [ABSTRACT FROM AUTHOR]

The article considers the methods for choosing an economically optimal standard size of a cyclone-dust collector: choosing the optimal type, diameter and number of cyclones. The results of calculating the most profitable options (for given cleaning conditions), as well as economic and energy losses that may occur with an arbitrary choice of the cyclone type and the use of a simplified calculation method used today based on the recommended fixed values of the conventional gas velocity, are presented. Based on the technical and economic calculations, an analysis of the manufactured range of the most common NIIOGAZ cyclones has been performed; a number of missing options for cyclone standard sizes that would reduce the cost of cyclone gas cleaning have been detected. [ABSTRACT FROM AUTHOR]

[Display omitted] Garnet-type Ta-doped Li 7 La 3 Zr 2 O 12 (LLZTO) electrolyte suffers from unstable chemical passivation under air exposure, responsible for the poor interfacial wettability and conductivity with Li metal. Instead of conventional methods to remove surface contaminants by mechanical polishing, acid etching and high temperature reduction, herein we propose a simple strategy of interfacial gas release and detergency to smartly convert Li 2 CO 3 passivation layer into ion-conductive Li 3 PO 4 domains at mild temperature (∼200 ℃). The in-situ formation of PH 3 vapor and its phosphorization enables a dramatic decrease of Li/garnet interfacial resistance down to 2 Ω cm2 at room temperature (RT). The improved interfacial wettability and conductivity endow the symmetric cells with ultra-stable galvanostatic cycling over 1500 h and high critical current density of 2.6 mA/cm2. The high coulombic efficiency of Li plating enables a high reversibility of solid-state NCM811/Li cells even under a low N/P ratio (∼4) and high cut-off voltage of 4.5 V at RT. The prototype of fluoride-garnet solid-state batteries are successfully driven as rechargeable system (rather than widely known primary battery) with high conversion capacity (400 ∼ 500 mAh/g) and high-rate performance (251.2 mAh/g at 3 C). This interface infiltration-detergency approach provides a practical solution to the achievement of high-energy solid-state Li metal batteries. [ABSTRACT FROM AUTHOR]

This article provides time standards and calculation methods for the purpose of studying air pollution from industrial facilities. Calculations of technological equipment and the efficiency of the dust and gas treatment plant. The results of inventory, regulation of emissions of pollutants entering the atmosphere are considered. Questions on the study of equipment for cleaning dust - gas, methods for improving and improving the efficiency of the equipment are highlighted. The methods for determining the composition and quantity of pollutants in the off - gas flows are given: theoretical (balance), computational and analytical (experimental), and reporting and static. The procedure for conducting an inventory of sources of emissions on the territory of the enterprise, the number and composition of emissions of pollutants. Analyses of harmful substances entering the atmosphere from the production of asphalt concrete, measures to improve the efficiency of dust and gas treatment plants were performed. The process of asphalt mixing and production capacity of the enterprise are studied Samarkand asphalt concrete production. [ABSTRACT FROM AUTHOR]

Within the Carbon2Chem® network, basic research is mandatory for a successful implementation and realization of sustainable technologies for CO2 emission reduction. For this purpose, the exchange of knowledge between the project partners in the individual subareas is as essential as obtaining precise data on the fundamental parameters on a laboratory scale in order to transfer them later to large‐scale plants. Therefore, the Carbon2Chem® laboratory offers a platform to gain detailed insights into the individual sub‐processes and to then apply these findings at the technical center in Duisburg. [ABSTRACT FROM AUTHOR]

Biomass gasification is a versatile thermochemical process that can be used for direct energy applications and the production of advanced liquid and gaseous energy carriers. In the present work, the results are presented concerning the H2 production at a high purity grade from biomass feedstocks via steam/oxygen gasification. The data demonstrating such a process chain were collected at an innovative gasification prototype plant coupled to a portable purification system (PPS). The overall integration was designed for gas conditioning and purification to hydrogen. By using almond shells as the biomass feedstock, from a product gas with an average and stable composition of 40%-v H2, 21%-v CO, 35%-v CO2, 2.5%-v CH4, the PPS unit provided a hydrogen stream, with a final concentration of 99.99%-v and a gas yield of 66.4%. [ABSTRACT FROM AUTHOR]

The aim of this paper is to define and select stable zones in the off-gas duct of an ore-thermal furnace using a mathematical model. This is needed to increase the effectiveness of exhaust gas composition control in metallurgical silicon production. Methods. The goals of this study were achieved by means of computational fluid dynamics. A model with a water-cooled furnace roof as well as a model comprising steel gas passes with a sliding shutter was developed using ANSYS Fluent software. Both models were symmetrical to ensure a uniform gas-dust distribution, which allowed us to test the adequacy of the obtained models. The models were based on the Navier–Stokes equations system as well as on a discrete phase model (DPM) that was developed using the Euler–Lagrange method. Results. As a result of the modelling, a transition flow mode (Re 0-7437) was revealed behind the sliding shutter. As such, it can be assumed that the most suitable place for measuring equipment to be installed is directly behind the closed part of the sliding shutter. [ABSTRACT FROM AUTHOR]

The work contains a numerical solution of the scientific and technical problem of the determination of the efficiency of packed scrubbers during condensation cooling and purification of the dispersed phase of gases in the process of a stationary film liquid flow through regular and chaotic contact devices. A system of differential equations with partial derivatives of the conjugate transfer of heat, the mass of water vapor, and the dispersed phase in the packing layer is written. The heat and mass transfer and the transfer of dispersed particles between the gas and liquid phases are taken into account with volume source terms of the interfacial transfer, averaged over the local volume of the layer. Expressions are given to determine the source parameters. The results of the numerical solution of the system of equations in terms of the temperature and moisture content fields and comparison with known experimental data are presented. The dependence of the efficiency of gas purification from a finely dispersed phase on the gas velocity is shown. Comparative characteristics of packings, as well as scientific and technical solutions for the modernization of scrubbers introduced in the industry, are given. [ABSTRACT FROM AUTHOR]

[Display omitted] • Packed-bed adsorbers with randomly packed spheres or cylinders at same porosity. • Characterization of how the particle shape determines the bed microstructure. • Numerical evaluations of permeability, dispersion, conversion and liquid transport. • Interstitial liquid affects bed performance by filling of smaller pores. • Intermittent interstitial liquid influences parameters in reduced-order models. Several industrial applications use packed-bed reactors for heterogeneous processes with intermittent presence of interstitial liquid. One such example is steam-regenerated adsorption systems. Here, we computationally generate two randomly packed beds of the same voidage – one with spheres and one with cylinders – to study the role of particle shape in such a process. We analyze the geometrical characteristics and determine the flow, transport and reaction properties at the same driving pressure difference. We also establish the effect of liquid on these characteristics. The bed of spheres exhibits 69% higher permeability due to differences in microstructure, and its shorter retention time and lower specific surface yields lower conversion in a first-order heterogeneous reaction. However, at the same flow rate, the spheres could be expected to outperform the cylinders. The bed of cylinders exhibits more pronounced local concentration variations due to a dominance of smaller pores, which are not as readily accessible to the flow. The presence of interstitial liquid reduces the permeability and significantly changes the streamwise velocity distributions inside both beds, effectively homogenizing the geometries by filling up the smaller pores. The implications of the present findings for reduced-order modelling of packed-bed adsorbers are discussed. [ABSTRACT FROM AUTHOR]

A method is proposed for the implementation of acoustic monitoring of the state of valves in gas cleaning equipment using a step-by-step model for recognizing acoustic events. In addition, the main features of typical valve malfunctions have been identified and a system for their recognition has been developed. The use of the developed model makes it possible to ameliorate 15% of equipment failures with 5.1% of cases of false-positive predictions. [ABSTRACT FROM AUTHOR]

Very small particles dispersed in the atmosphere display complex dynamics, due to their characteristics of Brownian motion and low sedimentation rate, while chemical and physical transformations in the air can lead to the formation of compounds that present greater risk. In this context, one of the most efficient gas-solid separators is the electrostatic precipitator (ESP), based on electrical charging of the particles and their attraction to collection electrodes. Therefore, this work summarizes the technological strategies employing ESPs to collect nanoparticles and submicron particles. The physical phenomena involved in particle charging and collection are described, together with discussion of the geometrical and operating differences between industrial-scale ESPs and small-scale devices. Studies and innovations involving strategies of design and operation are presented. Aspects of the electro-fluid dynamics in the device are described, as well as methods used to mitigate ozone production in this process. [ABSTRACT FROM AUTHOR]

Fluidized bed gasification technology offers an attractive way to use inhomogeneous biomass residues and various waste-derived feedstocks in power and heat production as well as in various circular economy concepts based on the synthesis gas route. A fluidized bed gasification process development (PDU) plant of 200 kW capacity was operated with Solid Recovered Fuels (SRFs) and demolition wood. In part of the tests carried out with SRF, deposits were formed in the gas lines, and the pressure drop of the filter increased as well. However, optimal combination of gasification, gas cooling and filtration conditions were found to achieve a stable pressure drop, avoid deposit formation and to achieve efficient removal of gas contaminants. The effects of the operating conditions on the achieved carbon conversion and formation of tars and other gas contaminants were studied. The produced gas was filtered at 370-500 °C using two alternative filtration systems applying ceramic bag filters or ceramic fiber filters. The removal efficiency of waste-derived trace metals and chlorine was determined at different filtration temperatures. [ABSTRACT FROM AUTHOR]

The work is devoted to the numerical study of the process of downdraft fixed-bed gasification of woody biomass. Such processes are used to produce combustible gases at lowcapacity power plants. To improve the quality of the produced gas, it is proposed to use a mixture of wood fuel with a non-combustible material that can exhibit catalytic activity in the decomposition of undesired tary products. Adding a non-combustible material leads to lower heat value of fuel mixture, but contributes to a deeper gas purification. The aim of the study is to select the optimal "active material / wood fuel" ratio and to determine the minimum material activity at which its addition to the fuel becomes effective.

To predict the behavior of gas-cleaning filters during real-world operation, it is essential to understand their response to ambient conditions. The temporary presence of water droplets in gas-cleaning filtration systems due to fog, spray rain, or condensation, as examples of irregular events, has an impact on the filters’ operating performance, especially when soluble particles are present. In this work, surface filters were loaded with mixtures of water-soluble salt particles and insoluble glass spheres. These were, subsequently, exposed to water mist and dried by a particle-free gas stream. A novel approach to analyze the drainage of solution on filters with soluble filter cakes is presented, which allows the detection of solubles on the clean gas side of the filter. As a result, this work, for the first time, presents a sighting of the penetration of soluble filter cake material through gas-cleaning filters. Furthermore, filter performance, in terms of differential pressure and fractional separation efficiency, was determined and a characteristic differential pressure evolution for hydrophilic filters during exposure to water mist was also identified. The fractional separation efficiency of gas-cleaning filters decreases due to exposure to water mist. The findings are supported by scanning electron microscopy (SEM) images, energy-dispersive X-ray (EDX), and X-ray microtomography (µ-CT analysis) images.

Biomass gasification is a versatile thermochemical process that can be used for direct energy applications and the production of advanced liquid and gaseous energy carriers. In the present work, the results are presented concerning the H2 production at a high purity grade from biomass feedstocks via steam/oxygen gasification. The data demonstrating such a process chain were collected at an innovative gasification prototype plant coupled to a portable purification system (PPS). The overall integration was designed for gas conditioning and purification to hydrogen. By using almond shells as the biomass feedstock, from a product gas with an average and stable composition of 40%-v H2, 21%-v CO, 35%-v CO2, 2.5%-v CH4, the PPS unit provided a hydrogen stream, with a final concentration of 99.99%-v and a gas yield of 66.4%.

• Novel combination between electrostatic precipitator and falling film absorber. • Primary experimental data on electrohydrodynamically enhanced mass transfer. • Electrohydrodynamically enhanced mass transfer for industrial gas cleaning units. • Electrode design and polarity significantly influence enhanced turbulent transport. • Evaluation of industrial feasibility dependent on power input considerations. Intensified heat and mass transfer due to electrohydrodynamically (EHD) induced turbulence in wet electrostatic precipitators allows for versatile new opportunities and applications in the process industry. In order to demonstrate its feasibility and provide primary experimental data, a combination of a wetted- wall column and an electrostatic precipitator was tested experimentally. This investigation includes the variation over a multitude of different operating and design parameters, such as the magnitude and polarity of operating voltage, shape of the discharge electrode, flow velocity and flow configuration, i.e. counter-current vs. parallel flow. The results are presented as mass transfer coefficients, determined by measuring concentration changes of two different substance systems, i.e. the evaporation of water in air and the absorption of vaporized acetic acid in a highly alkaline aqueous solution. The study has shown that mass transfer can be enhanced significantly by EHD effects in the gas phase. The enhancement factor ranges between three to eight, depending on the operating conditions and the choice of discharge electrode design. These findings are complemented by a feasibility assessment based on the energy consumption, showing that this technique will work best when using non-symmetrical discharge electrode designs. [ABSTRACT FROM AUTHOR]

Biomass has the potential to make a major contribution to a renewable future economy. If biomass is gasified, a wide variety of products (e.g., bulk chemicals, hydrogen, methane, alcohols, diesel) can be produced. In each of these processes, gas cleaning is crucial. Impurities in the gas can cause catalyst poisoning, pipe plugging, unstable or poisoned end products, or harm the environment. Aromatic compounds (e.g., benzene, naphthalene, pyrene), in particular, have a huge impact on stable operation of syngas processes. The removal of these compounds can be accomplished by wet, dry, or hot gas cleaning methods. Wet gas cleaning methods tend to produce huge amounts of wastewater, which needs to be treated separately. Hot gas cleaning methods provide a clean gas but are often cost intensive due to the high operating temperatures and catalysts used in the system. Another approach is dry or semi-dry gas cleaning methods, including absorption and adsorption on solid matter. In this work, special focus was laid on adsorption-based gas cleaning for syngas applications. Adsorption and desorption test runs were carried out under laboratory conditions using a model gas with aromatic impurities. Adsorption isotherms, as well as dynamics, were measured with a multi-compound model gas. Based on these results, a temperature swing adsorption process was designed and tested under laboratory conditions, showing the possibility of replacing conventional wet gas cleaning with a semi-dry gas cleaning approach. [ABSTRACT FROM AUTHOR]

The direct methanation of biogas using hydrogen from electrolysis is a promising pathway for seasonal storage of renewables in the natural gas network. It offers particular advantages over the methanation of carbon dioxide separated from biogas, as it eliminates a costly and unnecessary carbon dioxide separation step. The key implementation challenges facing direct methanation of biogas are reviewed here: 1) treatment of biogas impurities; 2) competing reactor concepts for methanation; and 3) competing process concepts for final upgrading. For each of these three aspects, the state of the art is reviewed, focusing especially on results which have been validated at a high Technology Readiness Level (TRL) at recent long-duration demonstrations. The different technology solutions have advantages and disadvantages which may fit best to different technical and economic boundary conditions, which are discussed. As a final outlook, TRL 8 demo plants will be necessary to show the full potential of these systems, and to obtain consistent operation data to allow a cost comparison.

The capacity of adsorber beds used in industrial-scale temperature-swing adsorption diminishes over time due to bed aging. Here, we present industrial data on the temperature signals from fixed-bed adsorbers using activated carbon designed to remove benzene and other impurities from the gas produced in biomass gasification. The aging of the adsorber beds proceeds due to irreversible adsorption of trace species and manifests itself via two simultaneous effects: a decrease in the availability of active adsorption sites over time and an increase in the overall thermal mass of the bed. Both effects tend to dampen the temperature response of the beds during operation, implying that they are easily confounded. Model descriptions of bed aging should account for both effects.

The aim of this paper is to define and select stable zones in the off-gas duct of an ore-thermal furnace using a mathematical model. This is needed to increase the effectiveness of exhaust gas composition control in metallurgical silicon production. Methods. The goals of this study were achieved by means of computational fluid dynamics. A model with a water-cooled furnace roof as well as a model comprising steel gas passes with a sliding shutter was developed using ANSYS Fluent software. Both models were symmetrical to ensure a uniform gas-dust distribution, which allowed us to test the adequacy of the obtained models. The models were based on the Navier–Stokes equations system as well as on a discrete phase model (DPM) that was developed using the Euler–Lagrange method. Results. As a result of the modelling, a transition flow mode (Re 0-7437) was revealed behind the sliding shutter. As such, it can be assumed that the most suitable place for measuring equipment to be installed is directly behind the closed part of the sliding shutter.

The article presents the results of a research of the process of removing particles in range 2.5 µm that are most dangerous to human health using ultrasonic coagulation. The two-stage gas clearing system consisting of the agglomerator and the cyclone dust collector (supplemented by an ultrasonic radiator) was proposed and made. The carried out investigations have revealed the optimal conditions for the formation of a swirling flow, providing high efficiency coagulation of fine-dispersed particles. The formation of a swirling gas-dispersed flow in the conditions of ultrasonic exposure provides an increase in the average particle size 2.5 µm by 4.5 times due to particles convergence and the formation of local areas with high concentration. In this case, the ultrasonic effect on a rectilinear flow with 2.5-μm particles allows increasing particles size of only 1.6 times. The ultrasonic exposure has increasing 2.5-µm particle clearing efficiency from 46 to 85% by optimal conditions for gas-dispersed flow. [ABSTRACT FROM AUTHOR]

This paper reports a study into the influence of sodium carbonate concentration (10, 30, and 50 kg/m3) in the simultaneous presence of sodium thiosulfate (250 kg/m³) and quinhydrone (5 kg/m³) on the coefficient of the phase distribution of hydrogen sulfide in a quinhydrone absorbing solution. The research was carried out at the laboratory installation using chemical analysis methods of liquid and gas phases. It has been found that the coefficient of phase distribution increases dramatically with an increase in the degree of saturation of the quinhydrone solution with hydrogen sulfide. At the same time, in the presence of sodium thiosulfate in quinhydrone absorbing solutions, the coefficient of phase distribution increases compared to carbonate solutions of the same concentration. Thus, the partial hydrogen sulfide pressure over a quinhydrone solution at low degrees of hydrogen sulfide saturation (up to 3 %) is 5...10 times larger than that over soda solution, while at high degrees (60...80 %) it is almost the same. It can be argued that at the high concentrations of sodium carbonate and the degree of the saturation of quinhydrone solution with hydrogen sulfide the effect of sodium thiosulfate on the partial pressure of hydrogen sulfide decreases. An equation of the effect exerted by the NaНS concentration and the starting Na2CO3 concentration on the H2S partial pressure over quinhydrone solutions has been proposed. Based on the experimental studies’ results, the equilibrium constant values for a hydrogen sulfide chemisorption reaction involving a quinhydrone solution have been calculated. To ensure the high absorption capacity, the process of hydrogen sulfide chemisorption should be carried out using solutions with a maximum concentration of sodium carbonate, 40...50 kg/m3. The presence of ballast components (Na2S2O3, NaHCO3) slightly reduces the sorption capacity of an absorbing solution. The results obtained could be used in engineering calculations and when developing technology for purification of fuel gases from hydrogen sulfide by a quinhydrone method. [ABSTRACT FROM AUTHOR]

In order to help answering the question 'Which electrode design is the best?', the precipitation performance of a tubular electrostatic precipitator was determined for different electrode designs with special attention to specific energy consumption. Experiments were conducted in a wire–tube arrangement with a high loading of liquid submicron particles causing strong space charge effects, also known as corona quenching. The experiments are supplemented by numerical simulation results showing the effect of residence time and power consumption on separation efficiency. [ABSTRACT FROM AUTHOR]

Sulfur, and in particular, H 2 S removal is of significant importance in gas cleaning processes in different applications, including biogas production and biomass gasification. H 2 S removal with metal oxides is one of the most viable alternatives to achieve deep desulfurization. This process is usually conducted in a packed bed configuration in order to provide a high solid surface area in contact with the gas stream per unit of volume. The operating temperature of the process could be as low as room temperature, which is the case in biogas production plants or as high as 900 ∘ C suitable for gasification processes. Depending on the operating temperature and the cleaning requirement, different metal oxides can be used including oxides of Ca, Fe, Cu, Mn and Zn. In this review, the criteria for the design and scale-up of a packed bed units are reviewed and simple relations allowing for quick assessment of process designs and experimental data are presented. Furthermore, modeling methods for the numerical simulation of a packed bed adsorber are discussed. [ABSTRACT FROM AUTHOR]

• Mg-Al-CO 3 was successfully prepared using the coprecipitation method. • Mg-Al-400 exhibited the best performance, with an avg. HCl removal rate of 90.11 %. • The reaction of Mg with Cl formed MgCl 2 , and Cl− served as a novel interlayer anion. • The PSO and Bangham models fit well with the HCl removal by Mg-Al-400. To achieve carbon neutrality, it is essential to remove HCl resulting from the extensive use of alternative fuel feedstock in thermochemical plants. In this work, the HCl removal performance of modified calcined Mg-Al hydrotalcite (Mg-Al-CO 3) on gaseous stream was investigated. The layered structure of Mg-Al-CO 3 intercalated with CO 3 2– was successfully prepared using the coprecipitation method with a molar ratio of Mg/Al equal to 3.1. The optimal performance of Mg-Al-CO 3 for HCl removal was observed at 300 °C, and the breakthrough chlorine capacity was 102.7 mg g−1. Among calcined Mg-Al samples, only Mg-Al-400 exhibited better HCl removal performance than Mg-Al-CO 3. The specific surface area of Mg-Al-400 was 183.73 m2 g−1, which was 2.8 times greater than that of Mg-Al-CO 3. The average HCl removal rate was 90.11 % within the first 120 min, which was 1.12 times higher than that of Mg-Al-CO 3. Moreover, the breakthrough chlorine capacity of Mg-Al-400 was increased by 16.9 %, reaching 120.1 mg g−1. Two reaction paths were identified for Mg-Al-400, first Mg2+ reacts with Cl− to generate MgCl 2 , and then Cl− acted as a new interlayer anion of hydrotalcite. According to the results of adsorption kinetics, the pseudo-second-order and the Bangham model were found to fit well with the HCl removal process of Mg-Al-400. [ABSTRACT FROM AUTHOR]

The article presents an analytical review of publications on oxide ceramic binders that are used to prepare porous silicon carbide materials. The most promising ceramic binders are determined and the properties of materials based on ceramic binder data are provided. Mechanisms of modifier action making it possible to reduce the heat treatment temperature by up to 100°C are considered. [ABSTRACT FROM AUTHOR]

Abstract The coupling of biomass gasification and solid oxide cell technologies is very intriguing due to its high efficiency and flexibility potential. One of the key challenges in order to realize such a system design is a clean quality gas that can meet the strict requirements of the SOFC. This study presents the result of an experimental campaign with the TwoStage Viking biomass gasifier and a Topsoe Fuel Cell SOFC stack connected via a carbon filter and a desulphurizer. The stack is operated with both air- and O 2 CO 2 -blown product gas, at 700 °C and 800 °C, and tests without any gas cleaning was conducted. The study found electric efficiencies up to 40% at 69% fuel utilization and an 8–11% increase in power when raising the SOFC temperature to 800 °C. The O 2 CO 2 -blown product gas showed lower efficiencies due to lower CO performance in the SOFC. A preliminary 2-h test with no gas cleaning between the gasifier and SOFC, and a ≈1.5–2.8 ppm sulphur concentration showed no change in operational voltage. Hence the study finds that gasifier design can greatly simplify the demand for gas cleaning equipment. Highlights • SOFC tests at 700–800 °C using product gas reached up to 40% efficiency. • Lower SOFC performance with O 2 -CO 2 -blown product gas compared to air-blown. • O 2 -CO 2 -blown product gas with 1.5–2.8 ppm sulphur was used directly in the SOFC. [ABSTRACT FROM AUTHOR]