Improving the Efficiency of the Wet Gas Cleaning Process  in a Venturi Tube by Superposition of Ultrasonic Fields

This paper outlines the system used by the authorities in Zurich to treat and recycle waste in an environmentally acceptable way. The waste incineration system produces power and incorporates a district heating system as well as a wet gas-cleaning process.

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Efficiency Increase of Wet Gas Cleaning from Dispersed Admixtures by the Application of Ultrasonic Fields

Archives of Acoustics ◽

10.1515/aoa-2016-0073 ◽

2016 ◽

Vol 41 (4) ◽

pp. 757-771 ◽

Cited By ~ 15

Author(s):

Vladimir N. Khmelev ◽

Andrey V. Shalunov ◽

Roman N. Golykh ◽

Roman S. Dorovskikh ◽

Viktor A. Nesterov ◽

...

Keyword(s):

Sound Pressure Level ◽

Sound Pressure ◽

Ultrasonic Field ◽

Pressure Level ◽

Venturi Tube ◽

Dust Extraction ◽

Ultrasonic Action ◽

Gas Cleaning ◽

Wet Gas ◽

Ultrasonic Influence

Abstract The article presents the results of research aimed at increase of the efficiency of gas cleaning equipment based on the Venturi tube using high-intensity ultrasound. The model based on known laws of hydrodynamics of multiphase mediums of dust-extraction in Venturi scrubbers was proposed. Modification of this model taking into account ultrasonic field allows evaluating optimum modes (sound pressure level) and conditions (direction of ultrasonic field, square and number of ultrasonic sources) of ultrasonic influence. It is evaluated that optimum for efficient gas cleaning is the mode of ultrasonic action at the frequency of 22 kHz with sound pressure level of 145. . . 155 dB at the installation of two radiators with area of 0.14 m2, four radiators with area of 0.11 m2 or six radiators with area of 0.08 m2 at the angle of 45 degrees to the axis of Venturi tube. Numerical calculations showed that realization of ultrasonic action is the most efficient for the reduction (up to 15 times) of the content of fine-dispersed fraction (2 μm and less), which is impossible to extract without ultrasonic action. The received theoretical results were confirmed by industrial testing by typical dust-extraction plant and used as foundations of development of apparatuses with the radiators of various sizes.

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Improving the efficiency of cleaning gas emissions from foundry

Ventilation, Illumination and Heat Gas Supply ◽

10.32347/2409-2606.2020.35.21-25 ◽

2020 ◽

Vol 35 ◽

pp. 21-25

Author(s):

Y. Burda ◽

A. Cherednik ◽

I. Redko ◽

Y. Pivnenko

Keyword(s):

Carbon Dioxide ◽

Direct Action ◽

Carbon Dioxide Concentration ◽

Coke Oven ◽

Measurement Range ◽

Cleaning Process ◽

Gas Cleaning ◽

Term Operation ◽

Carbon Dioxide Gas ◽

Wet Gas

The work is devoted to the topical problem of increasing the efficiency of cleaning process of gases in packed-type scrubbers in order to reduce emissions of harmful substances and solid impurities into the atmosphere and improve the technical and economic indicators of wet gas cleaning systems. For this, a triangular cross-cut packing has been developed. Due to the size of the holes and their specific shape, the triangular packing provides longer contact of the packaging with water, which reduces water consumption. The packing is made of alloy steel AISI 316, so it can be used even in the most aggressive environment. In the work, the efficiency of cleaning with a scrubber with this packing is experimentally determined. The tests were performed at an ambient temperature of 23 °C. Several measurements were made for each type of packing, in a typical scrubber design. To conduct these industrial tests, a thermohygrometer-carbon dioxide gas analyzerAZ-7797 was used with high-precision NDIR (infrared) sensor, automatic background calibration (W/ABC), and compensation for deviations during long-term operation. The concentration measurement range is 0-9999 ppm with an error of ± 5 %. The gases were cooled in two stages. At first, they were cooled with ammonia water from 750 to 80 °C. Then they were fed to a primary gas refrigerator (basic type) of direct action, where its temperature were falled to 15 °C. Carbon dioxide concentration was measured after the first stage of cooling, after the final cooling, and after the cleaning process. The comparison is carried out with the most effective types of packing for wet gas cleaning today – chordal wood and Raschig rings. It is shown that the developed triangular packing with cross-shaped notches during the purification of coke oven gas from carbon dioxide improves the purification by 25 % in comparison with the wooden chord one, and by 15 % - with Raschig rings. This allows us to recommend it for widespread implementation.

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Development of a simplified gas ultracleaning process: experiments in biomass residue-based fixed-bed gasification syngas

Biomass Conversion and Biorefinery ◽

10.1007/s13399-021-01680-x ◽

2021 ◽

Author(s):

Christian Frilund ◽

Esa Kurkela ◽

Ilkka Hiltunen

Keyword(s):

Activated Carbons ◽

Low Cost ◽

Fixed Bed ◽

Carbonyl Sulfide ◽

Gas Analysis ◽

Small Scale ◽

Cleaning Process ◽

Medium Temperature ◽

Gas Cleaning ◽

Adsorption Affinity

AbstractFor the realization of small-scale biomass-to-liquid (BTL) processes, low-cost syngas cleaning remains a major obstacle, and for this reason a simplified gas ultracleaning process is being developed. In this study, a low- to medium-temperature final gas cleaning process based on adsorption and organic solvent-free scrubbing methods was coupled to a pilot-scale staged fixed-bed gasification facility including hot filtration and catalytic reforming steps for extended duration gas cleaning tests for the generation of ultraclean syngas. The final gas cleaning process purified syngas from woody and agricultural biomass origin to a degree suitable for catalytic synthesis. The gas contained up to 3000 ppm of ammonia, 1300 ppm of benzene, 200 ppm of hydrogen sulfide, 10 ppm of carbonyl sulfide, and 5 ppm of hydrogen cyanide. Post-run characterization displayed that the accumulation of impurities on the Cu-based deoxygenation catalyst (TOS 105 h) did not occur, demonstrating that effective main impurity removal was achieved in the first two steps: acidic water scrubbing (AWC) and adsorption by activated carbons (AR). In the final test campaign, a comprehensive multipoint gas analysis confirmed that ammonia was fully removed by the scrubbing step, and benzene and H2S were fully removed by the subsequent activated carbon beds. The activated carbons achieved > 90% removal of up to 100 ppm of COS and 5 ppm of HCN in the syngas. These results provide insights into the adsorption affinity of activated carbons in a complex impurity matrix, which would be arduous to replicate in laboratory conditions.

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Hydrodynamic characteristics and efficiency of contact elements of wet-gas-cleaning equipment

Journal of Engineering Physics ◽

10.1007/bf00871237 ◽

1985 ◽

Vol 49 (5) ◽

pp. 1267-1270

Author(s):

A. A. Andrizhievskii ◽

A. A. Mikhalevich ◽

A. G. Trifonov

Keyword(s):

Hydrodynamic Characteristics ◽

Gas Cleaning ◽

Wet Gas ◽

Cleaning Equipment

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Recent advances in selective catalytic reduction of NOx by carbon monoxide for flue gas cleaning process: a review

Catalysis Reviews ◽

10.1080/01614940.2020.1753972 ◽

2020 ◽

pp. 1-52 ◽

Cited By ~ 3

Author(s):

Zahra Gholami ◽

Guohua Luo ◽

Fatemeh Gholami ◽

Fan Yang

Keyword(s):

Carbon Monoxide ◽

Selective Catalytic Reduction ◽

Flue Gas ◽

Catalytic Reduction ◽

Cleaning Process ◽

Gas Cleaning ◽

Recent Advances ◽

Reduction Of Nox

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Waste Combustion Technology and Air Emission Control Developments by Fisia Babcock Environment

19th Annual North American Waste-to-Energy Conference ◽

10.1115/nawtec19-5418 ◽

2011 ◽

Author(s):

Jens Sohnemann ◽

Walter Scha¨fers ◽

Armin Main

Keyword(s):

Flue Gas ◽

Combustion Process ◽

Great Majority ◽

Optimum Process ◽

Cleaning Process ◽

Gas Temperature ◽

Flash Evaporation ◽

Limit Values ◽

Gas Cleaning ◽

Secondary Air

The efforts for reducing the emissions into the atmosphere start already in the furnace and are completed by an effective flue gas cleaning system. This implies the necessity for design developments of key components for a modern EfW plant. For the core component of the firing system — the grate — Fisia Babcock Environment (FBE) is using forward moving grates as well as roller grates. The moving grate, which is used in the great majority of all our plants, has specific characteristics for providing uniform combustion and optimal burnout. These include, amongst others: - Uniform air supply by means of specific grate bar geometry. - Two grate steps in direction of waste transport for optimum burnout. - Flexible adaptation of the combustion process to the respective conditions and requirements by zone-specific air distribution and transport velocity of waste on grate. - Combustion control adapted to the specific plant for ensuring a consistent combustion process and production of energy. In addition to these features influencing the emissions the moving grate exhibits also specific characteristics regarding the mechanical aspects allowing low-maintenance and reliable operation. For optimum flue gas burnout a good oxygen distribution after leaving the combustion zone is required. For ensuring this, the injection of secondary air is designed to produce a double-swirl, developed by FBE. Final reduction of the nitrogen constituents NO and NO2 to the stipulated emission value is achieved by the SNCR process. As well in this respect, there is a great amount of experience available. Besides these measures regarding the combustion process, this paper also reports about flue gas cleaning systems. In this field the FBE CIRCUSORB® process is presented and compared with the known dry absorption process. CIRCUSORB® is a lime-based flue gas cleaning process with continuous recirculation of the moistened reaction product and simultaneous addition of fresh hydrated lime. The flue gas temperature downstream of the economizer can be selected very low and permits in this way maximized utilization of the energy. The evaporation of the moisture from the reaction product (flash evaporation) effects final cooling down of the flue gas to optimum process temperature and improves at the same time SO2 separation. This reduces the technical investment required for the flue gas cleaning process. The total of all measures taken and the robust design of all components permit economical plant operation while complying with the stipulated emission limit values.

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