The Experts below are selected from a list of 1734 Experts worldwide ranked by ideXlab platform
Karlheinz Schaber - One of the best experts on this subject based on the ideXlab platform.
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collection and generation of sulfuric Acid aerosols in a wet electrostatic precipitator
Aerosol Science and Technology, 2015Co-Authors: Christopher Anderlohr, Jan Mertens, L Brachert, Karlheinz SchaberAbstract:Wet electrostatic precipitators (WESPs) are considered to be a possible technology for the control of sulfuric Acid Mist. The performance of a lab-scale WESP was investigated as a precipitator for sulfuric Acid aerosol droplets produced under controlled conditions in a pilot plant. It was found that for higher levels of residual SO2 in the flue gas, WESP collection efficiencies were greatly reduced due to aerosol formation inside the WESP. Investigations showed a strong correlation of aerosol emission from the WESP with incoming SO2 concentration and operating voltage. It is suspected that the reactive species produced in the nonthermal plasma of the corona discharge oxidize the SO2 to SO3 which forms sulfuric Acid. This causes supersaturation with subsequent homogeneous nucleation and thus aerosol formation.Copyright 2015 American Association for Aerosol Research
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characterization of sulphuric Acid and ammonium sulphate aerosols in wet flue gas cleaning processes
Chemical Engineering and Processing, 2008Co-Authors: S Sinanis, Karlheinz SchaberAbstract:Abstract Sulphuric Acid aerosols can be formed in wet flue gas cleaning processes by spontaneous condensation initiated mainly by homogeneous nucleation. Even at low gas inlet concentrations of SO 3 (2 mg/m 3 (STP)) aerosol formation can be observed. For the design of absorption processes and sulphuric Acid Mist precipitators the aerosol characteristic data like mean diameter and number concentration are required for different process conditions and raw gas concentrations. In the present contribution, a combination of an experimental method with the simulation tool AerCode is described, which permits the determination of the diameter and the number concentration of sulphuric Acid aerosols formed in wet flue gas cleaning processes. As a result of the extreme azeotropic phase behaviour of the H 2 SO 4 –H 2 O system the mechanism of homogeneous nucleation is predominant for aerosol formation in absorption processes. Furthermore, the influence of soluble and insoluble particles on homogeneous nucleation in the system H 2 SO 4 –H 2 O is shown. The investigation of the influence of insoluble foreign nuclei shows that at high SO 3 raw gas concentrations >30 mg/m 3 (STP), the mechanism of homogeneous nucleation is predominant. At lower raw gas concentrations between 2 and 10 mg/m 3 (STP) SO 3 heterogeneous nucleation is the major reason for aerosol formation. Solid (NH 4 ) 2 SO 4 particles that are formed by the reaction between H 2 SO 4 and NH 3 in the gas phase are used as soluble foreign nuclei. The studies show that aerosol formation is determined by the reaction component whose concentration is below the stoichiometric ratio. It was observed that in the case of an excess of sulphuric Acid a decrease of the amount of ammonia leads to an increase of the particle size combined with a decrease in the number concentration. If ammonia is in excess, the decrease in the concentration of ammonia changes neither the particle size nor the number concentration of the aerosol significantly.
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characterization of sulphuric Acid and ammonium sulphate aerosols in wet flue gas cleaning processes
Chemical Engineering and Processing, 2008Co-Authors: S Sinanis, Karlheinz SchaberAbstract:Abstract Sulphuric Acid aerosols can be formed in wet flue gas cleaning processes by spontaneous condensation initiated mainly by homogeneous nucleation. Even at low gas inlet concentrations of SO 3 (2 mg/m 3 (STP)) aerosol formation can be observed. For the design of absorption processes and sulphuric Acid Mist precipitators the aerosol characteristic data like mean diameter and number concentration are required for different process conditions and raw gas concentrations. In the present contribution, a combination of an experimental method with the simulation tool AerCode is described, which permits the determination of the diameter and the number concentration of sulphuric Acid aerosols formed in wet flue gas cleaning processes. As a result of the extreme azeotropic phase behaviour of the H 2 SO 4 –H 2 O system the mechanism of homogeneous nucleation is predominant for aerosol formation in absorption processes. Furthermore, the influence of soluble and insoluble particles on homogeneous nucleation in the system H 2 SO 4 –H 2 O is shown. The investigation of the influence of insoluble foreign nuclei shows that at high SO 3 raw gas concentrations >30 mg/m 3 (STP), the mechanism of homogeneous nucleation is predominant. At lower raw gas concentrations between 2 and 10 mg/m 3 (STP) SO 3 heterogeneous nucleation is the major reason for aerosol formation. Solid (NH 4 ) 2 SO 4 particles that are formed by the reaction between H 2 SO 4 and NH 3 in the gas phase are used as soluble foreign nuclei. The studies show that aerosol formation is determined by the reaction component whose concentration is below the stoichiometric ratio. It was observed that in the case of an excess of sulphuric Acid a decrease of the amount of ammonia leads to an increase of the particle size combined with a decrease in the number concentration. If ammonia is in excess, the decrease in the concentration of ammonia changes neither the particle size nor the number concentration of the aerosol significantly.
A. Cruz - One of the best experts on this subject based on the ideXlab platform.
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Use of quillaja saponins (Quillaja saponaria Molina) to control Acid Mist in copper electrowinning processes: Part 1. Laboratory scale evaluation
Hydrometallurgy, 2005Co-Authors: R.m. San Martin, A.f. Otero, M. Figueroa, V. Escobar, A. CruzAbstract:Abstract This work describes the use of extracts of the Chilean quillaja tree (Quillaja saponaria Molina) as alternative low cost surfactants for the control of Acid Mist in copper electrowinning (EW). Quillaja extracts contain triterpenoid saponins, which are natural surfactants traditionally used as foaming agents in food and beverages. Two commercial products with different degrees of purification were tested: QL 1000® (non-refined product, 8.4% saponin content) and Mistop® (refined product, 16% saponin content). Laboratory experiments determined the effects of both products on electrolyte surface tension (ST), solvent extraction process (SX), current efficiency (CE) and cathode quality. A surface tension of 55 dyn/cm was attained with 10 ppm of Mistop® and 25 ppm of QL 1000®, respectively. This corresponded to similar saponin levels for both products (1.6–2.1 ppm saponins). At these concentrations, Mistop® had little negative impact on the SX process, and no effect on CE and cathode quality. However, QL 1000® had a negative impact on phase disengagement time and extraction efficiency. Based on this, Mistop® was recommended for further testing at pilot plant and industrial scale in the facilities of Radomiro Tomic copper mine (Calama, Chile), at a dose of 8 to 12 ppm.
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use of quillaja saponins quillaja saponaria molina to control Acid Mist in copper electrowinning processes part 2 pilot plant and industrial scale evaluation
Hydrometallurgy, 2005Co-Authors: San R Martin, A.f. Otero, A. CruzAbstract:Abstract This work describes the use of Mistop®, a novel surfactant of natural origin that contains primarily triterpenoid saponins (active ingredient), to control Acid Mist in copper electrowinning (EW). Previous laboratory tests indicated that Mistop® has no negative effects on cathode quality, current efficiency, and overall solvent extraction (SX) process conditions (e.g. phase disengagement time, extraction/stripping kinetics, maximum charge/discharge, etc.). In this work Mistop® was tested at pilot plant, semi-industrial and industrial scale. The work was performed in the facilities of Radomiro Tomic (RT), which produces approximately 900 tons copper/day. Pilot plant tests were performed during 6 months with product dosages in the electrolyte entering the EW cells within 0 and 32 ppm. The tests indicated that total Acid aerosols could be significantly decreased at Mistop® dosages within 6 and 8 ppm in the electrolyte entering the EW cells. At these dosages no operational problems in the SX/EW process were encountered. The semi-industrial tests indicated that with 6 ppm of Mistop® in the electrolyte entering the EW system, Acid Mist aerosols decreased significantly with no negative impact on EW operational parameters (e.g. cathode quality, current efficiency). Industrial scale implementation showed that the addition of 8–9 ppm of Mistop® to the total electrolyte inventory (24,000 m 3 ) every 24 h, decreased total Acid Mist aerosols in the tankhouse below present Chilean environmental regulatory requirements (e.g. 0.58 mg/m 3 ). Under the operational conditions tested (e.g. electrolyte average temperature 45 °C, average current density 280 A/m 2 ) the specific product consumption was approximately 0.21 kg Mistop®/ton copper cathodes, resulting in Mistop® usage costs significantly lower than that of alternative chemical surfactants.
S Sinanis - One of the best experts on this subject based on the ideXlab platform.
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characterization of sulphuric Acid and ammonium sulphate aerosols in wet flue gas cleaning processes
Chemical Engineering and Processing, 2008Co-Authors: S Sinanis, Karlheinz SchaberAbstract:Abstract Sulphuric Acid aerosols can be formed in wet flue gas cleaning processes by spontaneous condensation initiated mainly by homogeneous nucleation. Even at low gas inlet concentrations of SO 3 (2 mg/m 3 (STP)) aerosol formation can be observed. For the design of absorption processes and sulphuric Acid Mist precipitators the aerosol characteristic data like mean diameter and number concentration are required for different process conditions and raw gas concentrations. In the present contribution, a combination of an experimental method with the simulation tool AerCode is described, which permits the determination of the diameter and the number concentration of sulphuric Acid aerosols formed in wet flue gas cleaning processes. As a result of the extreme azeotropic phase behaviour of the H 2 SO 4 –H 2 O system the mechanism of homogeneous nucleation is predominant for aerosol formation in absorption processes. Furthermore, the influence of soluble and insoluble particles on homogeneous nucleation in the system H 2 SO 4 –H 2 O is shown. The investigation of the influence of insoluble foreign nuclei shows that at high SO 3 raw gas concentrations >30 mg/m 3 (STP), the mechanism of homogeneous nucleation is predominant. At lower raw gas concentrations between 2 and 10 mg/m 3 (STP) SO 3 heterogeneous nucleation is the major reason for aerosol formation. Solid (NH 4 ) 2 SO 4 particles that are formed by the reaction between H 2 SO 4 and NH 3 in the gas phase are used as soluble foreign nuclei. The studies show that aerosol formation is determined by the reaction component whose concentration is below the stoichiometric ratio. It was observed that in the case of an excess of sulphuric Acid a decrease of the amount of ammonia leads to an increase of the particle size combined with a decrease in the number concentration. If ammonia is in excess, the decrease in the concentration of ammonia changes neither the particle size nor the number concentration of the aerosol significantly.
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characterization of sulphuric Acid and ammonium sulphate aerosols in wet flue gas cleaning processes
Chemical Engineering and Processing, 2008Co-Authors: S Sinanis, Karlheinz SchaberAbstract:Abstract Sulphuric Acid aerosols can be formed in wet flue gas cleaning processes by spontaneous condensation initiated mainly by homogeneous nucleation. Even at low gas inlet concentrations of SO 3 (2 mg/m 3 (STP)) aerosol formation can be observed. For the design of absorption processes and sulphuric Acid Mist precipitators the aerosol characteristic data like mean diameter and number concentration are required for different process conditions and raw gas concentrations. In the present contribution, a combination of an experimental method with the simulation tool AerCode is described, which permits the determination of the diameter and the number concentration of sulphuric Acid aerosols formed in wet flue gas cleaning processes. As a result of the extreme azeotropic phase behaviour of the H 2 SO 4 –H 2 O system the mechanism of homogeneous nucleation is predominant for aerosol formation in absorption processes. Furthermore, the influence of soluble and insoluble particles on homogeneous nucleation in the system H 2 SO 4 –H 2 O is shown. The investigation of the influence of insoluble foreign nuclei shows that at high SO 3 raw gas concentrations >30 mg/m 3 (STP), the mechanism of homogeneous nucleation is predominant. At lower raw gas concentrations between 2 and 10 mg/m 3 (STP) SO 3 heterogeneous nucleation is the major reason for aerosol formation. Solid (NH 4 ) 2 SO 4 particles that are formed by the reaction between H 2 SO 4 and NH 3 in the gas phase are used as soluble foreign nuclei. The studies show that aerosol formation is determined by the reaction component whose concentration is below the stoichiometric ratio. It was observed that in the case of an excess of sulphuric Acid a decrease of the amount of ammonia leads to an increase of the particle size combined with a decrease in the number concentration. If ammonia is in excess, the decrease in the concentration of ammonia changes neither the particle size nor the number concentration of the aerosol significantly.
Yaping Zhang - One of the best experts on this subject based on the ideXlab platform.
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formation and removal characteristics of sulfuric Acid Mist in a wet flue gas desulfurization system
Journal of Chemical Technology & Biotechnology, 2017Co-Authors: Linjun Yang, Hao Wu, Rongting Huang, Yaping ZhangAbstract:BACKGROUND Owing to the visible plume and secondary aerosol formation, the emissions of sulfuric Acid Mist from coal-fired power plants have attracted increasing attention. To provide more information for the control of sulfuric Acid Mist emission, investigations were made of the formation and removal characteristics of sulfuric Acid Mist in a wet flue gas desulfurization system. RESULTS The results showed that large numbers of sulfuric Acid droplets with sizes less than 0.1 µm were generated via homogenous nucleation. With higher inlet SO3 concentrations, the fine particle concentration after desulfurization was increased. Increases in the liquid–gas ratio and the inlet fly ash concentration and decreases in the inlet flue gas temperature improved the sulfuric Acid Mist removal efficiency. The wet flue gas desulfurization (WFGD) system with double scrubbers achieved higher sulfuric Acid Mist removal efficiency than the WFGD system with a single scrubber. CONCLUSION The sulfuric Acid Mist droplets created via homogenous nucleation were mainly in the submicron range, and their removal efficiencies in the WFGD system were influenced by the desulfurization operating parameters. The WFGD system with double scrubbers achieved higher removal efficiency. © 2016 Society of Chemical Industry
A.f. Otero - One of the best experts on this subject based on the ideXlab platform.
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Use of quillaja saponins (Quillaja saponaria Molina) to control Acid Mist in copper electrowinning processes: Part 1. Laboratory scale evaluation
Hydrometallurgy, 2005Co-Authors: R.m. San Martin, A.f. Otero, M. Figueroa, V. Escobar, A. CruzAbstract:Abstract This work describes the use of extracts of the Chilean quillaja tree (Quillaja saponaria Molina) as alternative low cost surfactants for the control of Acid Mist in copper electrowinning (EW). Quillaja extracts contain triterpenoid saponins, which are natural surfactants traditionally used as foaming agents in food and beverages. Two commercial products with different degrees of purification were tested: QL 1000® (non-refined product, 8.4% saponin content) and Mistop® (refined product, 16% saponin content). Laboratory experiments determined the effects of both products on electrolyte surface tension (ST), solvent extraction process (SX), current efficiency (CE) and cathode quality. A surface tension of 55 dyn/cm was attained with 10 ppm of Mistop® and 25 ppm of QL 1000®, respectively. This corresponded to similar saponin levels for both products (1.6–2.1 ppm saponins). At these concentrations, Mistop® had little negative impact on the SX process, and no effect on CE and cathode quality. However, QL 1000® had a negative impact on phase disengagement time and extraction efficiency. Based on this, Mistop® was recommended for further testing at pilot plant and industrial scale in the facilities of Radomiro Tomic copper mine (Calama, Chile), at a dose of 8 to 12 ppm.
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use of quillaja saponins quillaja saponaria molina to control Acid Mist in copper electrowinning processes part 2 pilot plant and industrial scale evaluation
Hydrometallurgy, 2005Co-Authors: San R Martin, A.f. Otero, A. CruzAbstract:Abstract This work describes the use of Mistop®, a novel surfactant of natural origin that contains primarily triterpenoid saponins (active ingredient), to control Acid Mist in copper electrowinning (EW). Previous laboratory tests indicated that Mistop® has no negative effects on cathode quality, current efficiency, and overall solvent extraction (SX) process conditions (e.g. phase disengagement time, extraction/stripping kinetics, maximum charge/discharge, etc.). In this work Mistop® was tested at pilot plant, semi-industrial and industrial scale. The work was performed in the facilities of Radomiro Tomic (RT), which produces approximately 900 tons copper/day. Pilot plant tests were performed during 6 months with product dosages in the electrolyte entering the EW cells within 0 and 32 ppm. The tests indicated that total Acid aerosols could be significantly decreased at Mistop® dosages within 6 and 8 ppm in the electrolyte entering the EW cells. At these dosages no operational problems in the SX/EW process were encountered. The semi-industrial tests indicated that with 6 ppm of Mistop® in the electrolyte entering the EW system, Acid Mist aerosols decreased significantly with no negative impact on EW operational parameters (e.g. cathode quality, current efficiency). Industrial scale implementation showed that the addition of 8–9 ppm of Mistop® to the total electrolyte inventory (24,000 m 3 ) every 24 h, decreased total Acid Mist aerosols in the tankhouse below present Chilean environmental regulatory requirements (e.g. 0.58 mg/m 3 ). Under the operational conditions tested (e.g. electrolyte average temperature 45 °C, average current density 280 A/m 2 ) the specific product consumption was approximately 0.21 kg Mistop®/ton copper cathodes, resulting in Mistop® usage costs significantly lower than that of alternative chemical surfactants.
