The Experts below are selected from a list of 1575 Experts worldwide ranked by ideXlab platform

Trubetskaya Anna - One of the best experts on this subject based on the ideXlab platform.

  • One way of representing the size and shape of biomass particles in combustion modeling
    'Elsevier BV', 2018
    Co-Authors: Trubetskaya Anna, Beckmann Gert, Wadenbäck Johan, Holm, Jens Kai, Velaga, Sitaram P., Weber Roman
    Abstract:

    This study aims to provide a geometrical description of biomass particles that can be used in combustion models. The particle size of wood and herbaceous biomass was compared using light microscope, 2D dynamic imaging, laser diffraction, sieve analysis and focused beam reflectance measurement. The results from light microscope and 2D dynamic imaging analysis were compared and it showed that the data on particle width, measured by these two techniques, were identical. Indeed, 2D dynamic imaging was found to be the most convenient particle characterization method, providing information on both the shape and the external surface area. Importantly, a way to quantify all three dimensions of biomass particles has been established. It was recommended to represent a biomass particle in combustion models as an infinite cylinder with the volume-to-surface ratio (V/A) measured using 2D dynamic imaging.The authors would like to acknowledge the financial support received from the Danish Strategic Research Council (Grant Nr. DSF-10-093956), Kempestiftelse, Dong Energy, Vattenfall and HOFOR. We would like also to thank Ian Haley and Brian O’Sullivan from Mettler Toledo for assisting with FBRM measurements. The authors thank DTU Combustion and Harmful Emission Control group for the fruitful discussions. Erika Christ is acknowledged for the article proof reading.peer-reviewed2019-06-2

  • One way of representing the size and shape of biomass particles in combustion modeling
    'Elsevier BV', 2018
    Co-Authors: Trubetskaya Anna, Beckmann Gert, Wadenbäck Johan, Holm, Jens Kai, Velaga, Sitaram P., Weber Roman
    Abstract:

    This study aims to provide a geometrical description of biomass particles that can be used in combustion models. The particle size of wood and herbaceous biomass was compared using light microscope, 2D dynamic imaging, laser diffraction, sieve analysis and focused beam reflectance measurement. The results from light microscope and 2D dynamic imaging analysis were compared and it showed that the data on particle width, measured by these two techniques, were identical. Indeed, 2D dynamic imaging was found to be the most convenient particle characterization method, providing information on both the shape and the external surface area. Importantly, a way to quantify all three dimensions of biomass particles has been established. It was recommended to represent a biomass particle in combustion models as an infinite cylinder with the volume-to-surface ratio (V/A) measured using 2D dynamic imaging.The authors would like to acknowledge the financial support received from the Danish Strategic Research Council (Grant Nr. DSF-10-093956), Kempestiftelse, Dong Energy, Vattenfall and HOFOR. We would like also to thank Ian Haley and Brian O’Sullivan from Mettler Toledo for assisting with FBRM measurements. The authors thank DTU Combustion and Harmful Emission Control group for the fruitful discussions. Erika Christ is acknowledged for the article proof reading.2019-06-2

  • Secondary comminution of wood pellets in power plant and laboratory-scale mills
    'Elsevier BV', 2018
    Co-Authors: Trubetskaya Anna, Weber Roman, Poyraz Yunus, Wadenbäck Johan
    Abstract:

    This study aims to determine the influence of mill type and pellet wood composition on particle size and shape of milled wood. The size and shape characteristics of pellets comminuted using power plant roller mills were compared with those obtained by using laboratory-scale roller- and hammer mills. A 2D dynamic imaging device was used for particle characterization. It was shown that mill type has a significant impact on particle size but an almost negligible effect on the shape of milled wood. Comminution in the pilot plant using a Loesche roller mill requires less Energy than using a hammer mill, but generates a larger fraction of coarse particles. The laboratory-scale roller mill provides comparable results with the power plant roller mill with respect to particle size and shape.The authors would like to acknowledge the financial support received from the Danish Strategic Research Council (Grant Nr. DSF-10-093956), Dong Energy, Vattenfall and HOFOR. We would also like to thank the Wood Sciences Laboratory at Technical University of Munich for the help with the pellets comminution in the laboratory-scale hammer mill to test the repeatability of our results. Jarl Wallden from LatGran and Kalju Erras from Heatlets are acknowledged for helping with the preparation of wood material before pelletization. The authors thank DTU Combustion and Harmful Emission Control group for fruitful discussions. Jayme Currie and Associate Professor Sunkyu Park are acknowledged for the article proof reading.peer-reviewed2019-03-1

  • Effect of fast pyrolysis conditions on biomass solid residues at high temperatures
    'Elsevier BV', 2018
    Co-Authors: Trubetskaya Anna, Jensen, Peter Arendt, Jensen, Anker Degn, Garcia Llamas, Angel David, Umeki Kentaro, Glarborg Peter
    Abstract:

    Fast pyrolysis of wood and straw was conducted in a drop tube furnace (DTF) and compared with corresponding data from a wire mesh reactor (WMR) to study the influence of temperature (1000–1400)°C, biomass origin (pinewood, beechwood, wheat straw, alfalfa straw), and heating rate (103 °C/s, 104 °C/s) on the char yield and morphology. Scanning electron microscopy (SEM), elemental analysis, and ash compositional analysis were applied to characterize the effect of operational conditions on the solid residues (char, soot) and gaseous products. The char yield from fast pyrolysis in the DTF setup was 3 to 7% (daf) points lower than in the WMR. During fast pyrolysis pinewood underwent drastic morphological transformations, whereas beechwood and straw samples retained the original porous structure of the parental fuel with slight melting on the surface. The particle size of Danish wheat straw char decreased in its half-width with respect to the parental fuel, whereas the alfalfa straw char particle size remained unaltered at higher temperatures. Soot particles in a range from 60 to 300 nm were obtained during fast pyrolysis. The soot yield from herbaceous fuels was lower than from wood samples, possibly due to differences in the content of lignin and resin acids.The authors from DTU would like to acknowledge the financial support that they received for this project from Danish Strategic Research Council (Contract 0603-00429B), Dong Energy, and Vattenfall. We also thank DTU CEN, Gert Beckmann (Retsch Company) and Kawnish Kirtania (LTU) for assisting with TEM/SEM microscopy and CAMSIZER XT measurements and micro GC measurements.peer-reviewe

  • Effect of fast pyrolysis conditions on biomass solid residues at high temperatures
    Elsevier, 2018
    Co-Authors: Trubetskaya Anna, Jensen, Peter Arendt, Jensen, Anker Degn, Garcia Llamas, Angel David, Umeki Kentaro, Glarborg Peter
    Abstract:

    Fast pyrolysis of wood and straw was conducted in a drop tube furnace (DTF) and compared with corresponding data from a wire mesh reactor (WMR) to study the influence of temperature (1000–1400)°C, biomass origin (pinewood, beechwood, wheat straw, alfalfa straw), and heating rate (103 °C/s, 104 °C/s) on the char yield and morphology. Scanning electron microscopy (SEM), elemental analysis, and ash compositional analysis were applied to characterize the effect of operational conditions on the solid residues (char, soot) and gaseous products. The char yield from fast pyrolysis in the DTF setup was 3 to 7% (daf) points lower than in the WMR. During fast pyrolysis pinewood underwent drastic morphological transformations, whereas beechwood and straw samples retained the original porous structure of the parental fuel with slight melting on the surface. The particle size of Danish wheat straw char decreased in its half-width with respect to the parental fuel, whereas the alfalfa straw char particle size remained unaltered at higher temperatures. Soot particles in a range from 60 to 300 nm were obtained during fast pyrolysis. The soot yield from herbaceous fuels was lower than from wood samples, possibly due to differences in the content of lignin and resin acids.The authors from DTU would like to acknowledge the financial support that they received for this project from Danish Strategic Research Council (Contract 0603-00429B), Dong Energy, and Vattenfall. We also thank DTU CEN, Gert Beckmann (Retsch Company) and Kawnish Kirtania (LTU) for assisting with TEM/SEM microscopy and CAMSIZER XT measurements and micro GC measurements

Glarborg Peter - One of the best experts on this subject based on the ideXlab platform.

  • Effect of fast pyrolysis conditions on biomass solid residues at high temperatures
    'Elsevier BV', 2018
    Co-Authors: Trubetskaya Anna, Jensen, Peter Arendt, Jensen, Anker Degn, Garcia Llamas, Angel David, Umeki Kentaro, Glarborg Peter
    Abstract:

    Fast pyrolysis of wood and straw was conducted in a drop tube furnace (DTF) and compared with corresponding data from a wire mesh reactor (WMR) to study the influence of temperature (1000–1400)°C, biomass origin (pinewood, beechwood, wheat straw, alfalfa straw), and heating rate (103 °C/s, 104 °C/s) on the char yield and morphology. Scanning electron microscopy (SEM), elemental analysis, and ash compositional analysis were applied to characterize the effect of operational conditions on the solid residues (char, soot) and gaseous products. The char yield from fast pyrolysis in the DTF setup was 3 to 7% (daf) points lower than in the WMR. During fast pyrolysis pinewood underwent drastic morphological transformations, whereas beechwood and straw samples retained the original porous structure of the parental fuel with slight melting on the surface. The particle size of Danish wheat straw char decreased in its half-width with respect to the parental fuel, whereas the alfalfa straw char particle size remained unaltered at higher temperatures. Soot particles in a range from 60 to 300 nm were obtained during fast pyrolysis. The soot yield from herbaceous fuels was lower than from wood samples, possibly due to differences in the content of lignin and resin acids.The authors from DTU would like to acknowledge the financial support that they received for this project from Danish Strategic Research Council (Contract 0603-00429B), Dong Energy, and Vattenfall. We also thank DTU CEN, Gert Beckmann (Retsch Company) and Kawnish Kirtania (LTU) for assisting with TEM/SEM microscopy and CAMSIZER XT measurements and micro GC measurements.peer-reviewe

  • Effect of fast pyrolysis conditions on biomass solid residues at high temperatures
    Elsevier, 2018
    Co-Authors: Trubetskaya Anna, Jensen, Peter Arendt, Jensen, Anker Degn, Garcia Llamas, Angel David, Umeki Kentaro, Glarborg Peter
    Abstract:

    Fast pyrolysis of wood and straw was conducted in a drop tube furnace (DTF) and compared with corresponding data from a wire mesh reactor (WMR) to study the influence of temperature (1000–1400)°C, biomass origin (pinewood, beechwood, wheat straw, alfalfa straw), and heating rate (103 °C/s, 104 °C/s) on the char yield and morphology. Scanning electron microscopy (SEM), elemental analysis, and ash compositional analysis were applied to characterize the effect of operational conditions on the solid residues (char, soot) and gaseous products. The char yield from fast pyrolysis in the DTF setup was 3 to 7% (daf) points lower than in the WMR. During fast pyrolysis pinewood underwent drastic morphological transformations, whereas beechwood and straw samples retained the original porous structure of the parental fuel with slight melting on the surface. The particle size of Danish wheat straw char decreased in its half-width with respect to the parental fuel, whereas the alfalfa straw char particle size remained unaltered at higher temperatures. Soot particles in a range from 60 to 300 nm were obtained during fast pyrolysis. The soot yield from herbaceous fuels was lower than from wood samples, possibly due to differences in the content of lignin and resin acids.The authors from DTU would like to acknowledge the financial support that they received for this project from Danish Strategic Research Council (Contract 0603-00429B), Dong Energy, and Vattenfall. We also thank DTU CEN, Gert Beckmann (Retsch Company) and Kawnish Kirtania (LTU) for assisting with TEM/SEM microscopy and CAMSIZER XT measurements and micro GC measurements

  • Influence of fast pyrolysis conditions on yield and structural transformation of biomass chars
    'Elsevier BV', 2018
    Co-Authors: Trubetskaya Anna, Jensen, Peter Arendt, Jensen, Anker Degn, Steibel Markus, Spliethoff Hartmut, Glarborg Peter
    Abstract:

    Fast pyrolysis of biomass (wood, straw, rice husk) and its major components (cellulose, hemicellulose, lignin) was conducted in a wire mesh reactor. The aim of this study was to understand the influence of temperature (350–1400 ∘ C), heating rate (10–3000 ∘ C/s), particle size (0.05–2 mm) and holding time (1–4 s) on the char morphology and char yield. Scanning electron microscopy (SEM) and elemental analysis were conducted to determine the effect of operating conditions on char softening and melting during pyrolysis. The char yield decreased with heating rate for rates ≤ 600 ∘ C/s; above this value a similar biomass char yield was obtained. The potassium content affected the char yield stronger than other minerals, while the distribution of the three major biomass constituents (cellulose, hemicellulose, lignin) affected the char yield only to a minor degree. Moreover, it was found that the heat treatment temperature had a larger influence on the char yield than the heating rate. Scanning electron microscopy indicated different types of biomass char plasticization influenced by the applied temperatures, heating rates, particle sizes and holding times, except for the rice husk char that formed chars with a structure similar to the parental fuel at all conditions. The less severe morphological changes of rice husk char were attributed to a high silica content.The authors would like to acknowledge the financial support that they received for this project from Danish Strategic Research Council, Dong Energy and Vattenfall. We also thank DTU Danish Polymer Center, DTU CEN, and Jesper Harholt (University of Copenhagen) for assisting with hemicellulose purification, microscopy measurements, and biomass compositional analysis

  • Comparison of high temperature chars of wheat straw and rice husk with respect to chemistry, morphology and reactivity
    'Elsevier BV', 2018
    Co-Authors: Trubetskaya Anna, Jensen, Peter Arendt, Jensen, Anker Degn, Glarborg Peter, Steibel Markus, Spliethoff Hartmut, Larsen, Flemming Hofmann
    Abstract:

    Fast pyrolysis of wheat straw and rice husk was carried out in an entrained flow reactor at high-temperatures (1000–1500) °C. The collected char was analyzed using X-ray diffractometry, N2-adsorption, scanning electron microscopy, particle size analysis with CAMSIZER XT, 29Si and 13C solid-state nuclear magnetic resonance spectroscopy and thermogravimetric analysis to investigate the effect of inorganic matter on the char morphology and oxygen reactivity. The silicon compounds were dispersed throughout the turbostratic structure of rice husk char in an amorphous phase with a low melting temperature (≈730 °C), which led to the formation of a glassy char shell, resulting in a preserved particle size and shape of chars. The high alkali content in the wheat straw resulted in higher char reactivity, whereas the lower silicon content caused variations in the char shape from cylindrical to near-spherical char particles. The reactivities of pinewood and rice husk chars were similar with respect to oxidation, indicating less influence of silicon oxides on the char reactivity.The authors would like to acknowledge the financial support that they received for this project from Danish Strategic Research Council (Grant DSF-10-093956), Dong Energy and Vattenfall. We also thank Gert Beckmann (Retsch Company) for assisting with the reproducibility tests on CAMSIZER XT, Professor Kenny Ståhl (DTU Chemistry) and Sunday Chukwudi Okoro (DTU, Chemical Engineering) for support with the XRD measurements and data processing, Dr. Martin Høj (DTU, Chemical Engineering) for assisting with N2-adsorption analysis and Andrea Hartung (TU Munich) for the careful ash compositional analysis. We emphasize special thank you to Andreas Geißler, Simon Schatzmann and Benedikt Schels for their support during measurements on the entrained flow reactor

  • Comparison of high temperature chars of wheat straw and rice husk with respect to chemistry, morphology and reactivity
    'Elsevier BV', 2018
    Co-Authors: Trubetskaya Anna, Jensen, Peter Arendt, Jensen, Anker Degn, Glarborg Peter, Steibel Markus, Spliethoff Hartmut, Larsen, Flemming Hofmann
    Abstract:

    Fast pyrolysis of wheat straw and rice husk was carried out in an entrained flow reactor at high-temperatures (1000–1500) °C. The collected char was analyzed using X-ray diffractometry, N2-adsorption, scanning electron microscopy, particle size analysis with CAMSIZER XT, 29Si and 13C solid-state nuclear magnetic resonance spectroscopy and thermogravimetric analysis to investigate the effect of inorganic matter on the char morphology and oxygen reactivity. The silicon compounds were dispersed throughout the turbostratic structure of rice husk char in an amorphous phase with a low melting temperature (≈730 °C), which led to the formation of a glassy char shell, resulting in a preserved particle size and shape of chars. The high alkali content in the wheat straw resulted in higher char reactivity, whereas the lower silicon content caused variations in the char shape from cylindrical to near-spherical char particles. The reactivities of pinewood and rice husk chars were similar with respect to oxidation, indicating less influence of silicon oxides on the char reactivity.The authors would like to acknowledge the financial support that they received for this project from Danish Strategic Research Council (Grant DSF-10-093956), Dong Energy and Vattenfall. We also thank Gert Beckmann (Retsch Company) for assisting with the reproducibility tests on CAMSIZER XT, Professor Kenny Ståhl (DTU Chemistry) and Sunday Chukwudi Okoro (DTU, Chemical Engineering) for support with the XRD measurements and data processing, Dr. Martin Høj (DTU, Chemical Engineering) for assisting with N2-adsorption analysis and Andrea Hartung (TU Munich) for the careful ash compositional analysis. We emphasize special thank you to Andreas Geißler, Simon Schatzmann and Benedikt Schels for their support during measurements on the entrained flow reactor.peer-reviewe

Jensen, Anker Degn - One of the best experts on this subject based on the ideXlab platform.

  • Effect of fast pyrolysis conditions on biomass solid residues at high temperatures
    'Elsevier BV', 2018
    Co-Authors: Trubetskaya Anna, Jensen, Peter Arendt, Jensen, Anker Degn, Garcia Llamas, Angel David, Umeki Kentaro, Glarborg Peter
    Abstract:

    Fast pyrolysis of wood and straw was conducted in a drop tube furnace (DTF) and compared with corresponding data from a wire mesh reactor (WMR) to study the influence of temperature (1000–1400)°C, biomass origin (pinewood, beechwood, wheat straw, alfalfa straw), and heating rate (103 °C/s, 104 °C/s) on the char yield and morphology. Scanning electron microscopy (SEM), elemental analysis, and ash compositional analysis were applied to characterize the effect of operational conditions on the solid residues (char, soot) and gaseous products. The char yield from fast pyrolysis in the DTF setup was 3 to 7% (daf) points lower than in the WMR. During fast pyrolysis pinewood underwent drastic morphological transformations, whereas beechwood and straw samples retained the original porous structure of the parental fuel with slight melting on the surface. The particle size of Danish wheat straw char decreased in its half-width with respect to the parental fuel, whereas the alfalfa straw char particle size remained unaltered at higher temperatures. Soot particles in a range from 60 to 300 nm were obtained during fast pyrolysis. The soot yield from herbaceous fuels was lower than from wood samples, possibly due to differences in the content of lignin and resin acids.The authors from DTU would like to acknowledge the financial support that they received for this project from Danish Strategic Research Council (Contract 0603-00429B), Dong Energy, and Vattenfall. We also thank DTU CEN, Gert Beckmann (Retsch Company) and Kawnish Kirtania (LTU) for assisting with TEM/SEM microscopy and CAMSIZER XT measurements and micro GC measurements.peer-reviewe

  • Effect of fast pyrolysis conditions on biomass solid residues at high temperatures
    Elsevier, 2018
    Co-Authors: Trubetskaya Anna, Jensen, Peter Arendt, Jensen, Anker Degn, Garcia Llamas, Angel David, Umeki Kentaro, Glarborg Peter
    Abstract:

    Fast pyrolysis of wood and straw was conducted in a drop tube furnace (DTF) and compared with corresponding data from a wire mesh reactor (WMR) to study the influence of temperature (1000–1400)°C, biomass origin (pinewood, beechwood, wheat straw, alfalfa straw), and heating rate (103 °C/s, 104 °C/s) on the char yield and morphology. Scanning electron microscopy (SEM), elemental analysis, and ash compositional analysis were applied to characterize the effect of operational conditions on the solid residues (char, soot) and gaseous products. The char yield from fast pyrolysis in the DTF setup was 3 to 7% (daf) points lower than in the WMR. During fast pyrolysis pinewood underwent drastic morphological transformations, whereas beechwood and straw samples retained the original porous structure of the parental fuel with slight melting on the surface. The particle size of Danish wheat straw char decreased in its half-width with respect to the parental fuel, whereas the alfalfa straw char particle size remained unaltered at higher temperatures. Soot particles in a range from 60 to 300 nm were obtained during fast pyrolysis. The soot yield from herbaceous fuels was lower than from wood samples, possibly due to differences in the content of lignin and resin acids.The authors from DTU would like to acknowledge the financial support that they received for this project from Danish Strategic Research Council (Contract 0603-00429B), Dong Energy, and Vattenfall. We also thank DTU CEN, Gert Beckmann (Retsch Company) and Kawnish Kirtania (LTU) for assisting with TEM/SEM microscopy and CAMSIZER XT measurements and micro GC measurements

  • Influence of fast pyrolysis conditions on yield and structural transformation of biomass chars
    'Elsevier BV', 2018
    Co-Authors: Trubetskaya Anna, Jensen, Peter Arendt, Jensen, Anker Degn, Steibel Markus, Spliethoff Hartmut, Glarborg Peter
    Abstract:

    Fast pyrolysis of biomass (wood, straw, rice husk) and its major components (cellulose, hemicellulose, lignin) was conducted in a wire mesh reactor. The aim of this study was to understand the influence of temperature (350–1400 ∘ C), heating rate (10–3000 ∘ C/s), particle size (0.05–2 mm) and holding time (1–4 s) on the char morphology and char yield. Scanning electron microscopy (SEM) and elemental analysis were conducted to determine the effect of operating conditions on char softening and melting during pyrolysis. The char yield decreased with heating rate for rates ≤ 600 ∘ C/s; above this value a similar biomass char yield was obtained. The potassium content affected the char yield stronger than other minerals, while the distribution of the three major biomass constituents (cellulose, hemicellulose, lignin) affected the char yield only to a minor degree. Moreover, it was found that the heat treatment temperature had a larger influence on the char yield than the heating rate. Scanning electron microscopy indicated different types of biomass char plasticization influenced by the applied temperatures, heating rates, particle sizes and holding times, except for the rice husk char that formed chars with a structure similar to the parental fuel at all conditions. The less severe morphological changes of rice husk char were attributed to a high silica content.The authors would like to acknowledge the financial support that they received for this project from Danish Strategic Research Council, Dong Energy and Vattenfall. We also thank DTU Danish Polymer Center, DTU CEN, and Jesper Harholt (University of Copenhagen) for assisting with hemicellulose purification, microscopy measurements, and biomass compositional analysis

  • Comparison of high temperature chars of wheat straw and rice husk with respect to chemistry, morphology and reactivity
    'Elsevier BV', 2018
    Co-Authors: Trubetskaya Anna, Jensen, Peter Arendt, Jensen, Anker Degn, Glarborg Peter, Steibel Markus, Spliethoff Hartmut, Larsen, Flemming Hofmann
    Abstract:

    Fast pyrolysis of wheat straw and rice husk was carried out in an entrained flow reactor at high-temperatures (1000–1500) °C. The collected char was analyzed using X-ray diffractometry, N2-adsorption, scanning electron microscopy, particle size analysis with CAMSIZER XT, 29Si and 13C solid-state nuclear magnetic resonance spectroscopy and thermogravimetric analysis to investigate the effect of inorganic matter on the char morphology and oxygen reactivity. The silicon compounds were dispersed throughout the turbostratic structure of rice husk char in an amorphous phase with a low melting temperature (≈730 °C), which led to the formation of a glassy char shell, resulting in a preserved particle size and shape of chars. The high alkali content in the wheat straw resulted in higher char reactivity, whereas the lower silicon content caused variations in the char shape from cylindrical to near-spherical char particles. The reactivities of pinewood and rice husk chars were similar with respect to oxidation, indicating less influence of silicon oxides on the char reactivity.The authors would like to acknowledge the financial support that they received for this project from Danish Strategic Research Council (Grant DSF-10-093956), Dong Energy and Vattenfall. We also thank Gert Beckmann (Retsch Company) for assisting with the reproducibility tests on CAMSIZER XT, Professor Kenny Ståhl (DTU Chemistry) and Sunday Chukwudi Okoro (DTU, Chemical Engineering) for support with the XRD measurements and data processing, Dr. Martin Høj (DTU, Chemical Engineering) for assisting with N2-adsorption analysis and Andrea Hartung (TU Munich) for the careful ash compositional analysis. We emphasize special thank you to Andreas Geißler, Simon Schatzmann and Benedikt Schels for their support during measurements on the entrained flow reactor

  • Comparison of high temperature chars of wheat straw and rice husk with respect to chemistry, morphology and reactivity
    'Elsevier BV', 2018
    Co-Authors: Trubetskaya Anna, Jensen, Peter Arendt, Jensen, Anker Degn, Glarborg Peter, Steibel Markus, Spliethoff Hartmut, Larsen, Flemming Hofmann
    Abstract:

    Fast pyrolysis of wheat straw and rice husk was carried out in an entrained flow reactor at high-temperatures (1000–1500) °C. The collected char was analyzed using X-ray diffractometry, N2-adsorption, scanning electron microscopy, particle size analysis with CAMSIZER XT, 29Si and 13C solid-state nuclear magnetic resonance spectroscopy and thermogravimetric analysis to investigate the effect of inorganic matter on the char morphology and oxygen reactivity. The silicon compounds were dispersed throughout the turbostratic structure of rice husk char in an amorphous phase with a low melting temperature (≈730 °C), which led to the formation of a glassy char shell, resulting in a preserved particle size and shape of chars. The high alkali content in the wheat straw resulted in higher char reactivity, whereas the lower silicon content caused variations in the char shape from cylindrical to near-spherical char particles. The reactivities of pinewood and rice husk chars were similar with respect to oxidation, indicating less influence of silicon oxides on the char reactivity.The authors would like to acknowledge the financial support that they received for this project from Danish Strategic Research Council (Grant DSF-10-093956), Dong Energy and Vattenfall. We also thank Gert Beckmann (Retsch Company) for assisting with the reproducibility tests on CAMSIZER XT, Professor Kenny Ståhl (DTU Chemistry) and Sunday Chukwudi Okoro (DTU, Chemical Engineering) for support with the XRD measurements and data processing, Dr. Martin Høj (DTU, Chemical Engineering) for assisting with N2-adsorption analysis and Andrea Hartung (TU Munich) for the careful ash compositional analysis. We emphasize special thank you to Andreas Geißler, Simon Schatzmann and Benedikt Schels for their support during measurements on the entrained flow reactor.peer-reviewe

Jensen, Peter Arendt - One of the best experts on this subject based on the ideXlab platform.

  • Effect of fast pyrolysis conditions on biomass solid residues at high temperatures
    'Elsevier BV', 2018
    Co-Authors: Trubetskaya Anna, Jensen, Peter Arendt, Jensen, Anker Degn, Garcia Llamas, Angel David, Umeki Kentaro, Glarborg Peter
    Abstract:

    Fast pyrolysis of wood and straw was conducted in a drop tube furnace (DTF) and compared with corresponding data from a wire mesh reactor (WMR) to study the influence of temperature (1000–1400)°C, biomass origin (pinewood, beechwood, wheat straw, alfalfa straw), and heating rate (103 °C/s, 104 °C/s) on the char yield and morphology. Scanning electron microscopy (SEM), elemental analysis, and ash compositional analysis were applied to characterize the effect of operational conditions on the solid residues (char, soot) and gaseous products. The char yield from fast pyrolysis in the DTF setup was 3 to 7% (daf) points lower than in the WMR. During fast pyrolysis pinewood underwent drastic morphological transformations, whereas beechwood and straw samples retained the original porous structure of the parental fuel with slight melting on the surface. The particle size of Danish wheat straw char decreased in its half-width with respect to the parental fuel, whereas the alfalfa straw char particle size remained unaltered at higher temperatures. Soot particles in a range from 60 to 300 nm were obtained during fast pyrolysis. The soot yield from herbaceous fuels was lower than from wood samples, possibly due to differences in the content of lignin and resin acids.The authors from DTU would like to acknowledge the financial support that they received for this project from Danish Strategic Research Council (Contract 0603-00429B), Dong Energy, and Vattenfall. We also thank DTU CEN, Gert Beckmann (Retsch Company) and Kawnish Kirtania (LTU) for assisting with TEM/SEM microscopy and CAMSIZER XT measurements and micro GC measurements.peer-reviewe

  • Effect of fast pyrolysis conditions on biomass solid residues at high temperatures
    Elsevier, 2018
    Co-Authors: Trubetskaya Anna, Jensen, Peter Arendt, Jensen, Anker Degn, Garcia Llamas, Angel David, Umeki Kentaro, Glarborg Peter
    Abstract:

    Fast pyrolysis of wood and straw was conducted in a drop tube furnace (DTF) and compared with corresponding data from a wire mesh reactor (WMR) to study the influence of temperature (1000–1400)°C, biomass origin (pinewood, beechwood, wheat straw, alfalfa straw), and heating rate (103 °C/s, 104 °C/s) on the char yield and morphology. Scanning electron microscopy (SEM), elemental analysis, and ash compositional analysis were applied to characterize the effect of operational conditions on the solid residues (char, soot) and gaseous products. The char yield from fast pyrolysis in the DTF setup was 3 to 7% (daf) points lower than in the WMR. During fast pyrolysis pinewood underwent drastic morphological transformations, whereas beechwood and straw samples retained the original porous structure of the parental fuel with slight melting on the surface. The particle size of Danish wheat straw char decreased in its half-width with respect to the parental fuel, whereas the alfalfa straw char particle size remained unaltered at higher temperatures. Soot particles in a range from 60 to 300 nm were obtained during fast pyrolysis. The soot yield from herbaceous fuels was lower than from wood samples, possibly due to differences in the content of lignin and resin acids.The authors from DTU would like to acknowledge the financial support that they received for this project from Danish Strategic Research Council (Contract 0603-00429B), Dong Energy, and Vattenfall. We also thank DTU CEN, Gert Beckmann (Retsch Company) and Kawnish Kirtania (LTU) for assisting with TEM/SEM microscopy and CAMSIZER XT measurements and micro GC measurements

  • Influence of fast pyrolysis conditions on yield and structural transformation of biomass chars
    'Elsevier BV', 2018
    Co-Authors: Trubetskaya Anna, Jensen, Peter Arendt, Jensen, Anker Degn, Steibel Markus, Spliethoff Hartmut, Glarborg Peter
    Abstract:

    Fast pyrolysis of biomass (wood, straw, rice husk) and its major components (cellulose, hemicellulose, lignin) was conducted in a wire mesh reactor. The aim of this study was to understand the influence of temperature (350–1400 ∘ C), heating rate (10–3000 ∘ C/s), particle size (0.05–2 mm) and holding time (1–4 s) on the char morphology and char yield. Scanning electron microscopy (SEM) and elemental analysis were conducted to determine the effect of operating conditions on char softening and melting during pyrolysis. The char yield decreased with heating rate for rates ≤ 600 ∘ C/s; above this value a similar biomass char yield was obtained. The potassium content affected the char yield stronger than other minerals, while the distribution of the three major biomass constituents (cellulose, hemicellulose, lignin) affected the char yield only to a minor degree. Moreover, it was found that the heat treatment temperature had a larger influence on the char yield than the heating rate. Scanning electron microscopy indicated different types of biomass char plasticization influenced by the applied temperatures, heating rates, particle sizes and holding times, except for the rice husk char that formed chars with a structure similar to the parental fuel at all conditions. The less severe morphological changes of rice husk char were attributed to a high silica content.The authors would like to acknowledge the financial support that they received for this project from Danish Strategic Research Council, Dong Energy and Vattenfall. We also thank DTU Danish Polymer Center, DTU CEN, and Jesper Harholt (University of Copenhagen) for assisting with hemicellulose purification, microscopy measurements, and biomass compositional analysis

  • Comparison of high temperature chars of wheat straw and rice husk with respect to chemistry, morphology and reactivity
    'Elsevier BV', 2018
    Co-Authors: Trubetskaya Anna, Jensen, Peter Arendt, Jensen, Anker Degn, Glarborg Peter, Steibel Markus, Spliethoff Hartmut, Larsen, Flemming Hofmann
    Abstract:

    Fast pyrolysis of wheat straw and rice husk was carried out in an entrained flow reactor at high-temperatures (1000–1500) °C. The collected char was analyzed using X-ray diffractometry, N2-adsorption, scanning electron microscopy, particle size analysis with CAMSIZER XT, 29Si and 13C solid-state nuclear magnetic resonance spectroscopy and thermogravimetric analysis to investigate the effect of inorganic matter on the char morphology and oxygen reactivity. The silicon compounds were dispersed throughout the turbostratic structure of rice husk char in an amorphous phase with a low melting temperature (≈730 °C), which led to the formation of a glassy char shell, resulting in a preserved particle size and shape of chars. The high alkali content in the wheat straw resulted in higher char reactivity, whereas the lower silicon content caused variations in the char shape from cylindrical to near-spherical char particles. The reactivities of pinewood and rice husk chars were similar with respect to oxidation, indicating less influence of silicon oxides on the char reactivity.The authors would like to acknowledge the financial support that they received for this project from Danish Strategic Research Council (Grant DSF-10-093956), Dong Energy and Vattenfall. We also thank Gert Beckmann (Retsch Company) for assisting with the reproducibility tests on CAMSIZER XT, Professor Kenny Ståhl (DTU Chemistry) and Sunday Chukwudi Okoro (DTU, Chemical Engineering) for support with the XRD measurements and data processing, Dr. Martin Høj (DTU, Chemical Engineering) for assisting with N2-adsorption analysis and Andrea Hartung (TU Munich) for the careful ash compositional analysis. We emphasize special thank you to Andreas Geißler, Simon Schatzmann and Benedikt Schels for their support during measurements on the entrained flow reactor

  • Comparison of high temperature chars of wheat straw and rice husk with respect to chemistry, morphology and reactivity
    'Elsevier BV', 2018
    Co-Authors: Trubetskaya Anna, Jensen, Peter Arendt, Jensen, Anker Degn, Glarborg Peter, Steibel Markus, Spliethoff Hartmut, Larsen, Flemming Hofmann
    Abstract:

    Fast pyrolysis of wheat straw and rice husk was carried out in an entrained flow reactor at high-temperatures (1000–1500) °C. The collected char was analyzed using X-ray diffractometry, N2-adsorption, scanning electron microscopy, particle size analysis with CAMSIZER XT, 29Si and 13C solid-state nuclear magnetic resonance spectroscopy and thermogravimetric analysis to investigate the effect of inorganic matter on the char morphology and oxygen reactivity. The silicon compounds were dispersed throughout the turbostratic structure of rice husk char in an amorphous phase with a low melting temperature (≈730 °C), which led to the formation of a glassy char shell, resulting in a preserved particle size and shape of chars. The high alkali content in the wheat straw resulted in higher char reactivity, whereas the lower silicon content caused variations in the char shape from cylindrical to near-spherical char particles. The reactivities of pinewood and rice husk chars were similar with respect to oxidation, indicating less influence of silicon oxides on the char reactivity.The authors would like to acknowledge the financial support that they received for this project from Danish Strategic Research Council (Grant DSF-10-093956), Dong Energy and Vattenfall. We also thank Gert Beckmann (Retsch Company) for assisting with the reproducibility tests on CAMSIZER XT, Professor Kenny Ståhl (DTU Chemistry) and Sunday Chukwudi Okoro (DTU, Chemical Engineering) for support with the XRD measurements and data processing, Dr. Martin Høj (DTU, Chemical Engineering) for assisting with N2-adsorption analysis and Andrea Hartung (TU Munich) for the careful ash compositional analysis. We emphasize special thank you to Andreas Geißler, Simon Schatzmann and Benedikt Schels for their support during measurements on the entrained flow reactor.peer-reviewe

Larsen, Flemming Hofmann - One of the best experts on this subject based on the ideXlab platform.

  • Comparison of high temperature chars of wheat straw and rice husk with respect to chemistry, morphology and reactivity
    'Elsevier BV', 2018
    Co-Authors: Trubetskaya Anna, Jensen, Peter Arendt, Jensen, Anker Degn, Glarborg Peter, Steibel Markus, Spliethoff Hartmut, Larsen, Flemming Hofmann
    Abstract:

    Fast pyrolysis of wheat straw and rice husk was carried out in an entrained flow reactor at high-temperatures (1000–1500) °C. The collected char was analyzed using X-ray diffractometry, N2-adsorption, scanning electron microscopy, particle size analysis with CAMSIZER XT, 29Si and 13C solid-state nuclear magnetic resonance spectroscopy and thermogravimetric analysis to investigate the effect of inorganic matter on the char morphology and oxygen reactivity. The silicon compounds were dispersed throughout the turbostratic structure of rice husk char in an amorphous phase with a low melting temperature (≈730 °C), which led to the formation of a glassy char shell, resulting in a preserved particle size and shape of chars. The high alkali content in the wheat straw resulted in higher char reactivity, whereas the lower silicon content caused variations in the char shape from cylindrical to near-spherical char particles. The reactivities of pinewood and rice husk chars were similar with respect to oxidation, indicating less influence of silicon oxides on the char reactivity.The authors would like to acknowledge the financial support that they received for this project from Danish Strategic Research Council (Grant DSF-10-093956), Dong Energy and Vattenfall. We also thank Gert Beckmann (Retsch Company) for assisting with the reproducibility tests on CAMSIZER XT, Professor Kenny Ståhl (DTU Chemistry) and Sunday Chukwudi Okoro (DTU, Chemical Engineering) for support with the XRD measurements and data processing, Dr. Martin Høj (DTU, Chemical Engineering) for assisting with N2-adsorption analysis and Andrea Hartung (TU Munich) for the careful ash compositional analysis. We emphasize special thank you to Andreas Geißler, Simon Schatzmann and Benedikt Schels for their support during measurements on the entrained flow reactor

  • Comparison of high temperature chars of wheat straw and rice husk with respect to chemistry, morphology and reactivity
    'Elsevier BV', 2018
    Co-Authors: Trubetskaya Anna, Jensen, Peter Arendt, Jensen, Anker Degn, Glarborg Peter, Steibel Markus, Spliethoff Hartmut, Larsen, Flemming Hofmann
    Abstract:

    Fast pyrolysis of wheat straw and rice husk was carried out in an entrained flow reactor at high-temperatures (1000–1500) °C. The collected char was analyzed using X-ray diffractometry, N2-adsorption, scanning electron microscopy, particle size analysis with CAMSIZER XT, 29Si and 13C solid-state nuclear magnetic resonance spectroscopy and thermogravimetric analysis to investigate the effect of inorganic matter on the char morphology and oxygen reactivity. The silicon compounds were dispersed throughout the turbostratic structure of rice husk char in an amorphous phase with a low melting temperature (≈730 °C), which led to the formation of a glassy char shell, resulting in a preserved particle size and shape of chars. The high alkali content in the wheat straw resulted in higher char reactivity, whereas the lower silicon content caused variations in the char shape from cylindrical to near-spherical char particles. The reactivities of pinewood and rice husk chars were similar with respect to oxidation, indicating less influence of silicon oxides on the char reactivity.The authors would like to acknowledge the financial support that they received for this project from Danish Strategic Research Council (Grant DSF-10-093956), Dong Energy and Vattenfall. We also thank Gert Beckmann (Retsch Company) for assisting with the reproducibility tests on CAMSIZER XT, Professor Kenny Ståhl (DTU Chemistry) and Sunday Chukwudi Okoro (DTU, Chemical Engineering) for support with the XRD measurements and data processing, Dr. Martin Høj (DTU, Chemical Engineering) for assisting with N2-adsorption analysis and Andrea Hartung (TU Munich) for the careful ash compositional analysis. We emphasize special thank you to Andreas Geißler, Simon Schatzmann and Benedikt Schels for their support during measurements on the entrained flow reactor.peer-reviewe

  • Characterization of free radicals by electron spin resonance spectroscopy in biochars from pyrolysis at high heating rates and at high temperatures
    'Elsevier BV', 2018
    Co-Authors: Trubetskaya Anna, Jensen, Peter Arendt, Jensen, Anker Degn, Glarborg Peter, Larsen, Flemming Hofmann, Andersen, Mogens Larsen
    Abstract:

    The concentration and type of free radicals from the decay (termination stage) of pyrolysis at slow and fast heating rates and at high temperatures (above 1000°C) in biomass char have been studied. A room-temperature electron spin resonance spectroscopy study was conducted on original wood, herbaceous biomass, holocelluloses, lignin and their chars, prepared at high temperatures in a wire mesh reactor, an entrained flow reactor, and a tubular reactor. The radical concentrations in the chars from the decay stage range up between 7·1016 and 1.5·1018 spins g−1. The results indicated that the biomass major constituents (cellulose, hemicellulose, lignin) had a minor effect on remaining radical concentrations compared to potassium and silica contents. The higher radical concentrations in the wheat straw chars from the decay stage of pyrolysis in the entrained flow reactor compared to the wood chars were related to the decreased mobility of potassium in the char matrix, leading to the less efficient catalytic effects of potassium on the bond-breaking and radical re-attachments. The high Si levels in the rice husk caused an increase in the char radical concentration compared to the wheat straw because the free radicals were trapped in a char consisting of a molten amorphous silica at heating rates of 103–104 K s−1. The experimental electron spin resonance spectroscopy spectra were analyzed by fitting to simulated data in order to identify radical types, based on g-values and line widths. The results show that at high temperatures, mostly aliphatic radicals (g = 2.0026–2.0028) and PAH radicals (g = 2.0027–2.0031) were formed.The authors would like to acknowledge the financial support that they received for this project from Danish Strategic Research Council (Grant Nr. DSF-10-093956), Dong Energy and Vattenfall. We also thank Professor Spliethoff and Markus Steibel (TU Munich) for the support with the entrained flow reactor experiments, Jesper Harholt (Carlsberg Laboratory) and Søren Talbro Barsberg (University of Copenhagen, Department of Geosciences and Natural Resource Management) for assisting with the biomass compositional analysis and for the fruitful discussions.peer-reviewed2018-09-0

  • Characterization of free radicals by electron spin resonance spectroscopy in biochars from pyrolysis at high heating rates and at high temperatures
    'Elsevier BV', 2018
    Co-Authors: Trubetskaya Anna, Jensen, Peter Arendt, Jensen, Anker Degn, Glarborg Peter, Larsen, Flemming Hofmann, Andersen, Mogens Larsen
    Abstract:

    The concentration and type of free radicals from the decay (termination stage) of pyrolysis at slow and fast heating rates and at high temperatures (above 1000°C) in biomass char have been studied. A room-temperature electron spin resonance spectroscopy study was conducted on original wood, herbaceous biomass, holocelluloses, lignin and their chars, prepared at high temperatures in a wire mesh reactor, an entrained flow reactor, and a tubular reactor. The radical concentrations in the chars from the decay stage range up between 7·1016 and 1.5·1018 spins g−1. The results indicated that the biomass major constituents (cellulose, hemicellulose, lignin) had a minor effect on remaining radical concentrations compared to potassium and silica contents. The higher radical concentrations in the wheat straw chars from the decay stage of pyrolysis in the entrained flow reactor compared to the wood chars were related to the decreased mobility of potassium in the char matrix, leading to the less efficient catalytic effects of potassium on the bond-breaking and radical re-attachments. The high Si levels in the rice husk caused an increase in the char radical concentration compared to the wheat straw because the free radicals were trapped in a char consisting of a molten amorphous silica at heating rates of 103–104 K s−1. The experimental electron spin resonance spectroscopy spectra were analyzed by fitting to simulated data in order to identify radical types, based on g-values and line widths. The results show that at high temperatures, mostly aliphatic radicals (g = 2.0026–2.0028) and PAH radicals (g = 2.0027–2.0031) were formed.The authors would like to acknowledge the financial support that they received for this project from Danish Strategic Research Council (Grant Nr. DSF-10-093956), Dong Energy and Vattenfall. We also thank Professor Spliethoff and Markus Steibel (TU Munich) for the support with the entrained flow reactor experiments, Jesper Harholt (Carlsberg Laboratory) and Søren Talbro Barsberg (University of Copenhagen, Department of Geosciences and Natural Resource Management) for assisting with the biomass compositional analysis and for the fruitful discussions.2018-09-0