Oliver Lindqvist - Academia.edu (original) (raw)
Papers by Oliver Lindqvist
Fuel, May 1, 2004
Alkali metals, mainly potassium, together with other ash forming inorganic components in biomass ... more Alkali metals, mainly potassium, together with other ash forming inorganic components in biomass are believed to be responsible for bed agglomeration in fluidized bed boilers burning biomass. A solution to the problem is to capture alkali vapor released from the fuel during ...
Science of the Total Environment, Mar 20, 2003
The mechanism and kinetics of the formation of methylmercury from an experimental solution contai... more The mechanism and kinetics of the formation of methylmercury from an experimental solution containing divalent mercury and acetic acid has been investigated. The experiments were performed in a 2-dm Teflon reactor. The 3 organic mercury was measured with time resolutions varying between minutes and hours, after derivatisation, gas chromatography separation and Cold vapour atomic fluorescence detection. (GC)-CVAFS. CVAFS technique was used for determination of inorganic mercury in the aqueous phase using an automated mercury analyser. The experiments were carried out in concentrations relevant for natural waters. Our result shows that the reaction proceeds via mercury acetate complexes. A first order reaction coefficient has been calculated at various pH values, and was found to be (9.0"0.9)=10 s at pH 3.6-3.7. The rate was not found to be enhanced by UV-light when taking y7 y1 into account the photolytical degradation of methylmercury. The reaction rate at various pH values, the influences of some other relevant reaction parameters, and implications for atmospheric and terrestrial waters are discussed. ᮊ
Atmospheric Environment, Nov 1, 2008
Mercury species samples for gaseous elemental mercury (GEM) with a temporal resolution of 5 min, ... more Mercury species samples for gaseous elemental mercury (GEM) with a temporal resolution of 5 min, 5 h and 20 min integrated measurements of reactive gaseous mercury (RGM), and 24-h sampling of particulate mercury (HgP) at urban Femman and total gaseous mercury (TGM) at rural Rö rvik were conducted during the measurement campaign GÖ TE-2005 in Gö teborg, Sweden. Results showed that average concentrations for GEM, RGM, HgP and TGM were 1.96 AE 0.38 ng m À3 , 2.53 AE 4.09 pg m À3 , 12.50 AE 5.88 pg m À3 and 1.63 AE 0.19 ng m À3 , respectively. A reverse diurnal distribution pattern between GEM and RGM was observed, and early morning GEM concentration was elevated compared to daytime values which was likely due to activation of fossil fuel combustion, electric utilities, etc., by the formation of a nighttime inversion layer, less activity of GEM and reduced mixing. The subsequent decline and afternoon minimum were likely related to increase vertical mixing, photochemical reaction, and coupling with the coal combustion. However, the photochemical conversion from GEM during daytime and nocturnal behavior of ''sticky'' gases under higher relative humidity may result in strong diurnal cycles for RGM. Sampling site was heavily affected by anthropogenic sources from two distinguished wind sectors. One was ESE-SSW sector which was likely impacted by long distance transport from south highly industrialized region; the other was likely tied with local sources from N-NE sector.
Aerosol Science and Technology, Oct 1, 2004
A novel particle trap impactor has been developed for use with the gas-quenching probe in order t... more A novel particle trap impactor has been developed for use with the gas-quenching probe in order to exclude solid particles from entering into the probe during sampling of gaseous metallic species in fluidized bed combustion conditions. The impactor must be small in size (Ø impactor ≤ Ø probe = 45 mm) but capable of collecting a relatively large amount of particles at elevated temperatures. As the first step, the impactor was designed, constructed, and tested at room temperature for KCl aerosol particles. The impactor with a nozzle of 0.95 mm in diameter, in combination with the orifice-tojet diameter ratio of 1.5 and the ratio of the jet-to-plate spacing to jet diameter at 1.4 yielded a sharp cutoff curve with a maximum collection efficiency of about 0.9 and a √ Stk 50 value of about 0.22. In addition, the collection efficiency of the impactor was compared with the particle removal efficiency of a filter of the same type as the filter previously used with the gas-quenching probe. The difference from the comparison is very small, indicating that the impactor can be used to replace the filter to prevent fly ash particles from entering the gas-quenching probe in fluidized bed combustion conditions.
Journal of the European Ceramic Society, 1991
Various possible rate-controlling processes in the o.vidation 0[" HIPped Si3N4 with 4 wt% Y20 3 a... more Various possible rate-controlling processes in the o.vidation 0[" HIPped Si3N4 with 4 wt% Y20 3 and without shitering additives have been studied ush~g TGA. XRD. FTIR, SEM and TEM/STEM methods. It is proposed that, h7 the temperature range 1000 to 1450 C, the oxidation kinetics of the studied Si3N ~ materials is main O' determined by 0 2 d(ffusivio' in the heterogeneous oxide scales and possibly also by the chemical reactivi O' o['Si3N4 materials with 0 2. It is shown that the effective 02 d(ffhsion coefficient in the glas~s3' oxide scales decreases with an increasing volume q/ devitrified phases and changes with the structural form q['the oxMe scales. This may explain why experimental oxidation kinetic curves usually deviate Ji'om the conventional parabolic' growth law. Die bei der OxMation yon he(/3isostatisch gepreJ3tem Si3N 4 mit 4 Gew.% Y203 bzw. ohne Sinteradditive miJglichen diskreten geschwindigkeitsbestimmenden Mechanismen
SwePub titelinformation: From Here to Sustainability Is the Lisbon/Göteborg agenda delivering?
Atmos Environ, 2008
Mercury species samples for gaseous elemental mercury (GEM) with a temporal resolution of 5 min, ... more Mercury species samples for gaseous elemental mercury (GEM) with a temporal resolution of 5 min, 5 h and 20 min integrated measurements of reactive gaseous mercury (RGM), and 24-h sampling of particulate mercury (HgP) at urban Femman and total gaseous mercury (TGM) at rural Rörvik were conducted during the measurement campaign GÖTE-2005 in Göteborg, Sweden. Results showed that average concentrations for GEM, RGM, HgP and TGM were 1.96 ± 0.38 ng m−3, 2.53 ± 4.09 pg m−3, 12.50 ± 5.88 pg m−3 and 1.63 ± 0.19 ng m−3, respectively. A reverse diurnal distribution pattern between GEM and RGM was observed, and early morning GEM concentration was elevated compared to daytime values which was likely due to activation of fossil fuel combustion, electric utilities, etc., by the formation of a nighttime inversion layer, less activity of GEM and reduced mixing. The subsequent decline and afternoon minimum were likely related to increase vertical mixing, photochemical reaction, and coupling with the coal combustion. However, the photochemical conversion from GEM during daytime and nocturnal behavior of “sticky” gases under higher relative humidity may result in strong diurnal cycles for RGM. Sampling site was heavily affected by anthropogenic sources from two distinguished wind sectors. One was ESE-SSW sector which was likely impacted by long distance transport from south highly industrialized region; the other was likely tied with local sources from N–NE sector.
Atmospheric Environment, Jun 1, 2001
This study includes five intensive field measurement campaigns. Four of the campaigns were perfor... more This study includes five intensive field measurement campaigns. Four of the campaigns were performed over seawater surface during the summer and winter of 1997 and the summer of 1998 at Kristineberg Marine Research Station (KMRS). The fifth campaign was conducted over a river surface during the summer of 1999 at Knobesholm in southwestern Sweden. The major purpose of these campaigns was to determine emissions of mercury from natural waters in northern Europe. The influence of some physical parameters, i.e. temperature in water and air, relative humidity and solar radiation were also examined. Dynamic flux chamber technique coupled with automatic mercury vapour-phase analysers (Gardis 1A or Tekran 2357) was used. Both sites show net evasion during summer season, however, the surficial evasion rate of the river is more than one order of magnitude higher than that of the seawater. The high content of organic matter in the river in conjunction with strong insolation and subsequent water temperature variations may explain the high mercury evasion measured at the river site. An average evasion of þ11 ng m À2 h À1 (varying from À2:5 to þ88:9 ng m À2 h À1 ) was obtained during the course of the river measurement. At the sea site, mercury evasion was found in the interval between À2:72 and þ8:84 ng m À2 h À1 with an average evasion of þ0:61 ng m À2 h À1 . Mercury evasion measured over both river and seawater surfaces exhibits a consistently diurnal pattern with maximum evasion during the daytime period and minimum evasion during the nighttime period. At the freshwater site, mercury evasion is strongly correlated with the intensity of net insolation, and negatively correlated with relative humidity. An exponential relationship between mercury evasion and water temperature was also observed at the freshwater measurement site. At the seawater site, a strong correlation between mercury evasion and intensity of UV A part of insolation was obtained. Insolation is speculated to play an important role in the formation of dissolved gaseous mercury in both river and seawater. #
Acta Crystallographica Section B Structural Science, Oct 1, 1991
To whom correspondence should be addressed. 0108-7681/91/050672-07503.00 room temperature under v... more To whom correspondence should be addressed. 0108-7681/91/050672-07503.00 room temperature under vacuum (< 10 -4 Pa). Final RI values (for intensities) vary from 0.038 to 0-070 and Rp values (for profile) from 0.045 to 0.086. Only the (Si,AI)--O(2) bond length is significantly influenced by the change in composition, whereas the Si--O(2)--(Si,AI) bond angles, connecting the puckered layers of Si,A1 and N,O(1), remains unchanged. The change in (Si,AI)--O(2) bond length is related to the change in occupancies of Si and A1 in the tetrahedral site, i.e. to the change in x, and is in agreement with the expression (1-x/2)1.62/~+ (x/2)1.77 ~,, which has been determined for layered silicates. No ordering of the replacing atoms has been observed for the range of O'-sialons studied.
Fresenius J Anal Chem, 2000
The Semtech Hg 2000 analyzer continuously monitors the Hg 0 content in flue gas. An on-line measu... more The Semtech Hg 2000 analyzer continuously monitors the Hg 0 content in flue gas. An on-line measurement method of total gaseous mercury in flue gas developed in our laboratory is described, which uses the absorption cell of the Semtech Hg Analyzer connected to a converter that is located in a furnace heated up to 650°C. The converter can be heated up to 800°C by both the furnace and an extra heating of a Ni-Cr alloy heating wire. Both the absorption cell and the converter are made of quartz. All gaseous Hg 2+ species in flue gas are thermally reduced to Hg 0 by the converter and detected by the Semtech Hg 2000 analyzer. The thermal reduction efficiencies of different conversion materials, which were filled in the converter, such as quartz chips, granular MgO, Ni and CoO powder, were tested using different flue gas conditions. Studies have shown that HCl is the major factor to inhibit the thermal reduction of Hg 2+ to Hg 0 , and in the converter and the absorption cell Hg 0 will react readily with HCl to form HgCl 2 . Both MgO and Ni could be used in the converter to absorb HCl in the flue gas, but Ni has better absorption efficiency. By using an original Semtech and a modified one, both Hg 0 and total gaseous Hg contents in flue gas could be monitored simultaneously and continuously.
Zeitschrift für anorganische Chemie
ABSTRACT
Fuel, May 1, 2004
Alkali metals, mainly potassium, together with other ash forming inorganic components in biomass ... more Alkali metals, mainly potassium, together with other ash forming inorganic components in biomass are believed to be responsible for bed agglomeration in fluidized bed boilers burning biomass. A solution to the problem is to capture alkali vapor released from the fuel during ...
Science of the Total Environment, Mar 20, 2003
The mechanism and kinetics of the formation of methylmercury from an experimental solution contai... more The mechanism and kinetics of the formation of methylmercury from an experimental solution containing divalent mercury and acetic acid has been investigated. The experiments were performed in a 2-dm Teflon reactor. The 3 organic mercury was measured with time resolutions varying between minutes and hours, after derivatisation, gas chromatography separation and Cold vapour atomic fluorescence detection. (GC)-CVAFS. CVAFS technique was used for determination of inorganic mercury in the aqueous phase using an automated mercury analyser. The experiments were carried out in concentrations relevant for natural waters. Our result shows that the reaction proceeds via mercury acetate complexes. A first order reaction coefficient has been calculated at various pH values, and was found to be (9.0"0.9)=10 s at pH 3.6-3.7. The rate was not found to be enhanced by UV-light when taking y7 y1 into account the photolytical degradation of methylmercury. The reaction rate at various pH values, the influences of some other relevant reaction parameters, and implications for atmospheric and terrestrial waters are discussed. ᮊ
Atmospheric Environment, Nov 1, 2008
Mercury species samples for gaseous elemental mercury (GEM) with a temporal resolution of 5 min, ... more Mercury species samples for gaseous elemental mercury (GEM) with a temporal resolution of 5 min, 5 h and 20 min integrated measurements of reactive gaseous mercury (RGM), and 24-h sampling of particulate mercury (HgP) at urban Femman and total gaseous mercury (TGM) at rural Rö rvik were conducted during the measurement campaign GÖ TE-2005 in Gö teborg, Sweden. Results showed that average concentrations for GEM, RGM, HgP and TGM were 1.96 AE 0.38 ng m À3 , 2.53 AE 4.09 pg m À3 , 12.50 AE 5.88 pg m À3 and 1.63 AE 0.19 ng m À3 , respectively. A reverse diurnal distribution pattern between GEM and RGM was observed, and early morning GEM concentration was elevated compared to daytime values which was likely due to activation of fossil fuel combustion, electric utilities, etc., by the formation of a nighttime inversion layer, less activity of GEM and reduced mixing. The subsequent decline and afternoon minimum were likely related to increase vertical mixing, photochemical reaction, and coupling with the coal combustion. However, the photochemical conversion from GEM during daytime and nocturnal behavior of ''sticky'' gases under higher relative humidity may result in strong diurnal cycles for RGM. Sampling site was heavily affected by anthropogenic sources from two distinguished wind sectors. One was ESE-SSW sector which was likely impacted by long distance transport from south highly industrialized region; the other was likely tied with local sources from N-NE sector.
Aerosol Science and Technology, Oct 1, 2004
A novel particle trap impactor has been developed for use with the gas-quenching probe in order t... more A novel particle trap impactor has been developed for use with the gas-quenching probe in order to exclude solid particles from entering into the probe during sampling of gaseous metallic species in fluidized bed combustion conditions. The impactor must be small in size (Ø impactor ≤ Ø probe = 45 mm) but capable of collecting a relatively large amount of particles at elevated temperatures. As the first step, the impactor was designed, constructed, and tested at room temperature for KCl aerosol particles. The impactor with a nozzle of 0.95 mm in diameter, in combination with the orifice-tojet diameter ratio of 1.5 and the ratio of the jet-to-plate spacing to jet diameter at 1.4 yielded a sharp cutoff curve with a maximum collection efficiency of about 0.9 and a √ Stk 50 value of about 0.22. In addition, the collection efficiency of the impactor was compared with the particle removal efficiency of a filter of the same type as the filter previously used with the gas-quenching probe. The difference from the comparison is very small, indicating that the impactor can be used to replace the filter to prevent fly ash particles from entering the gas-quenching probe in fluidized bed combustion conditions.
Journal of the European Ceramic Society, 1991
Various possible rate-controlling processes in the o.vidation 0[" HIPped Si3N4 with 4 wt% Y20 3 a... more Various possible rate-controlling processes in the o.vidation 0[" HIPped Si3N4 with 4 wt% Y20 3 and without shitering additives have been studied ush~g TGA. XRD. FTIR, SEM and TEM/STEM methods. It is proposed that, h7 the temperature range 1000 to 1450 C, the oxidation kinetics of the studied Si3N ~ materials is main O' determined by 0 2 d(ffusivio' in the heterogeneous oxide scales and possibly also by the chemical reactivi O' o['Si3N4 materials with 0 2. It is shown that the effective 02 d(ffhsion coefficient in the glas~s3' oxide scales decreases with an increasing volume q/ devitrified phases and changes with the structural form q['the oxMe scales. This may explain why experimental oxidation kinetic curves usually deviate Ji'om the conventional parabolic' growth law. Die bei der OxMation yon he(/3isostatisch gepreJ3tem Si3N 4 mit 4 Gew.% Y203 bzw. ohne Sinteradditive miJglichen diskreten geschwindigkeitsbestimmenden Mechanismen
SwePub titelinformation: From Here to Sustainability Is the Lisbon/Göteborg agenda delivering?
Atmos Environ, 2008
Mercury species samples for gaseous elemental mercury (GEM) with a temporal resolution of 5 min, ... more Mercury species samples for gaseous elemental mercury (GEM) with a temporal resolution of 5 min, 5 h and 20 min integrated measurements of reactive gaseous mercury (RGM), and 24-h sampling of particulate mercury (HgP) at urban Femman and total gaseous mercury (TGM) at rural Rörvik were conducted during the measurement campaign GÖTE-2005 in Göteborg, Sweden. Results showed that average concentrations for GEM, RGM, HgP and TGM were 1.96 ± 0.38 ng m−3, 2.53 ± 4.09 pg m−3, 12.50 ± 5.88 pg m−3 and 1.63 ± 0.19 ng m−3, respectively. A reverse diurnal distribution pattern between GEM and RGM was observed, and early morning GEM concentration was elevated compared to daytime values which was likely due to activation of fossil fuel combustion, electric utilities, etc., by the formation of a nighttime inversion layer, less activity of GEM and reduced mixing. The subsequent decline and afternoon minimum were likely related to increase vertical mixing, photochemical reaction, and coupling with the coal combustion. However, the photochemical conversion from GEM during daytime and nocturnal behavior of “sticky” gases under higher relative humidity may result in strong diurnal cycles for RGM. Sampling site was heavily affected by anthropogenic sources from two distinguished wind sectors. One was ESE-SSW sector which was likely impacted by long distance transport from south highly industrialized region; the other was likely tied with local sources from N–NE sector.
Atmospheric Environment, Jun 1, 2001
This study includes five intensive field measurement campaigns. Four of the campaigns were perfor... more This study includes five intensive field measurement campaigns. Four of the campaigns were performed over seawater surface during the summer and winter of 1997 and the summer of 1998 at Kristineberg Marine Research Station (KMRS). The fifth campaign was conducted over a river surface during the summer of 1999 at Knobesholm in southwestern Sweden. The major purpose of these campaigns was to determine emissions of mercury from natural waters in northern Europe. The influence of some physical parameters, i.e. temperature in water and air, relative humidity and solar radiation were also examined. Dynamic flux chamber technique coupled with automatic mercury vapour-phase analysers (Gardis 1A or Tekran 2357) was used. Both sites show net evasion during summer season, however, the surficial evasion rate of the river is more than one order of magnitude higher than that of the seawater. The high content of organic matter in the river in conjunction with strong insolation and subsequent water temperature variations may explain the high mercury evasion measured at the river site. An average evasion of þ11 ng m À2 h À1 (varying from À2:5 to þ88:9 ng m À2 h À1 ) was obtained during the course of the river measurement. At the sea site, mercury evasion was found in the interval between À2:72 and þ8:84 ng m À2 h À1 with an average evasion of þ0:61 ng m À2 h À1 . Mercury evasion measured over both river and seawater surfaces exhibits a consistently diurnal pattern with maximum evasion during the daytime period and minimum evasion during the nighttime period. At the freshwater site, mercury evasion is strongly correlated with the intensity of net insolation, and negatively correlated with relative humidity. An exponential relationship between mercury evasion and water temperature was also observed at the freshwater measurement site. At the seawater site, a strong correlation between mercury evasion and intensity of UV A part of insolation was obtained. Insolation is speculated to play an important role in the formation of dissolved gaseous mercury in both river and seawater. #
Acta Crystallographica Section B Structural Science, Oct 1, 1991
To whom correspondence should be addressed. 0108-7681/91/050672-07503.00 room temperature under v... more To whom correspondence should be addressed. 0108-7681/91/050672-07503.00 room temperature under vacuum (< 10 -4 Pa). Final RI values (for intensities) vary from 0.038 to 0-070 and Rp values (for profile) from 0.045 to 0.086. Only the (Si,AI)--O(2) bond length is significantly influenced by the change in composition, whereas the Si--O(2)--(Si,AI) bond angles, connecting the puckered layers of Si,A1 and N,O(1), remains unchanged. The change in (Si,AI)--O(2) bond length is related to the change in occupancies of Si and A1 in the tetrahedral site, i.e. to the change in x, and is in agreement with the expression (1-x/2)1.62/~+ (x/2)1.77 ~,, which has been determined for layered silicates. No ordering of the replacing atoms has been observed for the range of O'-sialons studied.
Fresenius J Anal Chem, 2000
The Semtech Hg 2000 analyzer continuously monitors the Hg 0 content in flue gas. An on-line measu... more The Semtech Hg 2000 analyzer continuously monitors the Hg 0 content in flue gas. An on-line measurement method of total gaseous mercury in flue gas developed in our laboratory is described, which uses the absorption cell of the Semtech Hg Analyzer connected to a converter that is located in a furnace heated up to 650°C. The converter can be heated up to 800°C by both the furnace and an extra heating of a Ni-Cr alloy heating wire. Both the absorption cell and the converter are made of quartz. All gaseous Hg 2+ species in flue gas are thermally reduced to Hg 0 by the converter and detected by the Semtech Hg 2000 analyzer. The thermal reduction efficiencies of different conversion materials, which were filled in the converter, such as quartz chips, granular MgO, Ni and CoO powder, were tested using different flue gas conditions. Studies have shown that HCl is the major factor to inhibit the thermal reduction of Hg 2+ to Hg 0 , and in the converter and the absorption cell Hg 0 will react readily with HCl to form HgCl 2 . Both MgO and Ni could be used in the converter to absorb HCl in the flue gas, but Ni has better absorption efficiency. By using an original Semtech and a modified one, both Hg 0 and total gaseous Hg contents in flue gas could be monitored simultaneously and continuously.
Zeitschrift für anorganische Chemie
ABSTRACT