The Experts below are selected from a list of 105 Experts worldwide ranked by ideXlab platform
Martin Van Sint Annaland - One of the best experts on this subject based on the ideXlab platform.
-
Chemical looping reforming in packed-bed reactors: Modelling, experimental validation and large-scale reactor design
Fuel Processing Technology, 2017Co-Authors: Vincenzo Spallina, B. Marinello, M C Romano, Fausto Gallucci, Martin Van Sint AnnalandAbstract:This paper addresses the experimental demonstration and model validation of chemical looping reforming in dynamically operated packed-bed reactors for the production of H2or CH3OH with integrated CO2capture. This process is a combination of auto-thermal and steam methane reforming and is carried out at high pressure, as typical for reforming processes, and at relatively Low to intermediate temperatures (ranging from 600 to 900 °C). The oxidation of the oxygen carrier is performed with air and the hot depleted air stream is fed to a gas turbine, which contributes to reduce the electricity demand. After oxidation, a Low-Grade Fuel is used for the reduction of the oxygen carrier, e.g. off-gas from a PSA unit or non-condensable species from methanol synthesis and, when the bed is completely reduced, natural gas diluted with H2O and CO2is reformed while the reactor is cooled down. An experimental campaign has been carried out in a 2 kWthpacked-bed reactor using 500 g of NiO supported on CaAl2O4as reforming catalyst and oxygen carrier. This material has demonstrated very high stability over > 400 h of consecutive redox and reforming cycles. Due to the flexibility of the process, dry, wet and steam reforming compositions have been tested during the reforming phase. A 1D reactor model has been validated with the obtained experimental results, including also a detailed thermal model to account for the inevitable heat losses of the system. The experimental and model results are in good agreement in terms of breakthrough curves and temperature profiles. The experimental campaign during reforming also confirmed the possibility to carry out the heat removal phase by means of endothermic methane reforming. The validated reactor model has subsequently been used for the simulation of different configurations in terms of heat management in which the different phases (oxidation, reduction and reforming) are simulated in series. In these analyses, the reactor design and performance have been compared for two plant configurations based on H2and CH3OH production integrated with CO2capture. For the case of H2production, the CH4conversion is 92% and all the CO2is captured from the plant, while for CH3OH production the CH4conversion reaches 90% and all carbon species, except CH3OH, are converted into CO2, which is separated with high purity.
Ronald W Thring - One of the best experts on this subject based on the ideXlab platform.
-
pyrolysis of lignins experimental and kinetics studies
Energy & Fuels, 2002Co-Authors: D Ferdous, Ajay K Dalai, Shyamal K Bej, Ronald W ThringAbstract:Lignins are generally used as a Low Grade Fuel in the pulp and paper industry. In this work, pyrolysis of Alcell and Kraft lignins obtained from the Alcell process and Westvaco, respectively, was carried out in a fixed-bed reactor and in a thermogravimetric analyzer (TGA) using helium (13.4 mL/min/g of lignin) and nitrogen (50 mL/min/g of lignin), respectively. The reaction temperature was increased from 300 to 1073 K, while the heating rates were varied from 5 to 15 K/min. The gaseous products mainly consisted of H2, CO, CO2, CH4, and C2+. With increase in heating rate from 5 to 15 K/min both lignin conversion and hydrogen production increased from 56 to 65 wt % and from 25 to 31 mol %, respectively for fixed-bed pyrolysis reaction of Alcell lignin at 1073 K, whereas at the same condition the conversion and hydrogen production increased from 52 to 57 wt % and from 30 to 43 mol % for Kraft lignin. The distributed activation energy model (DAEM) was used to analyze complex reactions involved in the lignin p...
-
production of h2 and medium btu gas via pyrolysis of lignins in a fixed bed reactor
Fuel Processing Technology, 2001Co-Authors: D Ferdous, Ajay K Dalai, Shyamal K Bej, Ronald W Thring, N N BakhshiAbstract:Lignins are generally used as a Low-Grade Fuel in the pulp and paper industry. In this work, pyrolysis of Alcell and Kraft lignins obtained from Alcell process and Westvaco, respectively, was carried out in a fixed-bed reactor to produce hydrogen and gas with medium heating value. The effects of carrier gas (helium) fLow rate (13.4–33 ml/min/g of lignin), heating rate (5–15°C/min) and temperature (350–800°C) on the lignin conversion, product composition, and gas yield have been studied. The gaseous products mainly consisted of H2, CO, CO2, CH4 and C2+. The carrier gas fLow rate did not have any significant effect on the conversion. However, at 800°C and at a constant heating rate of 15°C/min with increase in carrier gas fLow rate from 13.4 to 33 ml/min/g of lignin, the volume of product gas decreased from 820 to 736 ml/g for Kraft and from 820 to 762 ml/g for Alcell lignin and the production of hydrogen increased from 43 to 66 mol% for Kraft lignin and from 31 to 46 mol% for Alcell lignin. At a Lower carrier gas fLow rate of 13.4 ml/min/g of lignin, the gas had a maximum heating value of 437 Btu/scf. At this fLow rate and at 800°C, with increase in heating rate from 5 to 15°C/min both lignin conversion and hydrogen production increased from 56 to 65 wt.% and 24 to 31 mol%, respectively, for Alcell lignin. With decrease in temperature from 800°C to 350°C, the conversion of Alcell and Kraft lignins were decreased from 65 to 28 wt.% and from 57 to 25 wt.%, respectively. Also, with decrease in temperature, production of hydrogen was decreased. Maximum heating value of gas (491 Btu/scf) was obtained at 450°C for Alcell lignin.
D Ferdous - One of the best experts on this subject based on the ideXlab platform.
-
pyrolysis of lignins experimental and kinetics studies
Energy & Fuels, 2002Co-Authors: D Ferdous, Ajay K Dalai, Shyamal K Bej, Ronald W ThringAbstract:Lignins are generally used as a Low Grade Fuel in the pulp and paper industry. In this work, pyrolysis of Alcell and Kraft lignins obtained from the Alcell process and Westvaco, respectively, was carried out in a fixed-bed reactor and in a thermogravimetric analyzer (TGA) using helium (13.4 mL/min/g of lignin) and nitrogen (50 mL/min/g of lignin), respectively. The reaction temperature was increased from 300 to 1073 K, while the heating rates were varied from 5 to 15 K/min. The gaseous products mainly consisted of H2, CO, CO2, CH4, and C2+. With increase in heating rate from 5 to 15 K/min both lignin conversion and hydrogen production increased from 56 to 65 wt % and from 25 to 31 mol %, respectively for fixed-bed pyrolysis reaction of Alcell lignin at 1073 K, whereas at the same condition the conversion and hydrogen production increased from 52 to 57 wt % and from 30 to 43 mol % for Kraft lignin. The distributed activation energy model (DAEM) was used to analyze complex reactions involved in the lignin p...
-
production of h2 and medium btu gas via pyrolysis of lignins in a fixed bed reactor
Fuel Processing Technology, 2001Co-Authors: D Ferdous, Ajay K Dalai, Shyamal K Bej, Ronald W Thring, N N BakhshiAbstract:Lignins are generally used as a Low-Grade Fuel in the pulp and paper industry. In this work, pyrolysis of Alcell and Kraft lignins obtained from Alcell process and Westvaco, respectively, was carried out in a fixed-bed reactor to produce hydrogen and gas with medium heating value. The effects of carrier gas (helium) fLow rate (13.4–33 ml/min/g of lignin), heating rate (5–15°C/min) and temperature (350–800°C) on the lignin conversion, product composition, and gas yield have been studied. The gaseous products mainly consisted of H2, CO, CO2, CH4 and C2+. The carrier gas fLow rate did not have any significant effect on the conversion. However, at 800°C and at a constant heating rate of 15°C/min with increase in carrier gas fLow rate from 13.4 to 33 ml/min/g of lignin, the volume of product gas decreased from 820 to 736 ml/g for Kraft and from 820 to 762 ml/g for Alcell lignin and the production of hydrogen increased from 43 to 66 mol% for Kraft lignin and from 31 to 46 mol% for Alcell lignin. At a Lower carrier gas fLow rate of 13.4 ml/min/g of lignin, the gas had a maximum heating value of 437 Btu/scf. At this fLow rate and at 800°C, with increase in heating rate from 5 to 15°C/min both lignin conversion and hydrogen production increased from 56 to 65 wt.% and 24 to 31 mol%, respectively, for Alcell lignin. With decrease in temperature from 800°C to 350°C, the conversion of Alcell and Kraft lignins were decreased from 65 to 28 wt.% and from 57 to 25 wt.%, respectively. Also, with decrease in temperature, production of hydrogen was decreased. Maximum heating value of gas (491 Btu/scf) was obtained at 450°C for Alcell lignin.
Vincenzo Spallina - One of the best experts on this subject based on the ideXlab platform.
-
Chemical looping reforming in packed-bed reactors: Modelling, experimental validation and large-scale reactor design
Fuel Processing Technology, 2017Co-Authors: Vincenzo Spallina, B. Marinello, M C Romano, Fausto Gallucci, Martin Van Sint AnnalandAbstract:This paper addresses the experimental demonstration and model validation of chemical looping reforming in dynamically operated packed-bed reactors for the production of H2or CH3OH with integrated CO2capture. This process is a combination of auto-thermal and steam methane reforming and is carried out at high pressure, as typical for reforming processes, and at relatively Low to intermediate temperatures (ranging from 600 to 900 °C). The oxidation of the oxygen carrier is performed with air and the hot depleted air stream is fed to a gas turbine, which contributes to reduce the electricity demand. After oxidation, a Low-Grade Fuel is used for the reduction of the oxygen carrier, e.g. off-gas from a PSA unit or non-condensable species from methanol synthesis and, when the bed is completely reduced, natural gas diluted with H2O and CO2is reformed while the reactor is cooled down. An experimental campaign has been carried out in a 2 kWthpacked-bed reactor using 500 g of NiO supported on CaAl2O4as reforming catalyst and oxygen carrier. This material has demonstrated very high stability over > 400 h of consecutive redox and reforming cycles. Due to the flexibility of the process, dry, wet and steam reforming compositions have been tested during the reforming phase. A 1D reactor model has been validated with the obtained experimental results, including also a detailed thermal model to account for the inevitable heat losses of the system. The experimental and model results are in good agreement in terms of breakthrough curves and temperature profiles. The experimental campaign during reforming also confirmed the possibility to carry out the heat removal phase by means of endothermic methane reforming. The validated reactor model has subsequently been used for the simulation of different configurations in terms of heat management in which the different phases (oxidation, reduction and reforming) are simulated in series. In these analyses, the reactor design and performance have been compared for two plant configurations based on H2and CH3OH production integrated with CO2capture. For the case of H2production, the CH4conversion is 92% and all the CO2is captured from the plant, while for CH3OH production the CH4conversion reaches 90% and all carbon species, except CH3OH, are converted into CO2, which is separated with high purity.
Shyamal K Bej - One of the best experts on this subject based on the ideXlab platform.
-
pyrolysis of lignins experimental and kinetics studies
Energy & Fuels, 2002Co-Authors: D Ferdous, Ajay K Dalai, Shyamal K Bej, Ronald W ThringAbstract:Lignins are generally used as a Low Grade Fuel in the pulp and paper industry. In this work, pyrolysis of Alcell and Kraft lignins obtained from the Alcell process and Westvaco, respectively, was carried out in a fixed-bed reactor and in a thermogravimetric analyzer (TGA) using helium (13.4 mL/min/g of lignin) and nitrogen (50 mL/min/g of lignin), respectively. The reaction temperature was increased from 300 to 1073 K, while the heating rates were varied from 5 to 15 K/min. The gaseous products mainly consisted of H2, CO, CO2, CH4, and C2+. With increase in heating rate from 5 to 15 K/min both lignin conversion and hydrogen production increased from 56 to 65 wt % and from 25 to 31 mol %, respectively for fixed-bed pyrolysis reaction of Alcell lignin at 1073 K, whereas at the same condition the conversion and hydrogen production increased from 52 to 57 wt % and from 30 to 43 mol % for Kraft lignin. The distributed activation energy model (DAEM) was used to analyze complex reactions involved in the lignin p...
-
production of h2 and medium btu gas via pyrolysis of lignins in a fixed bed reactor
Fuel Processing Technology, 2001Co-Authors: D Ferdous, Ajay K Dalai, Shyamal K Bej, Ronald W Thring, N N BakhshiAbstract:Lignins are generally used as a Low-Grade Fuel in the pulp and paper industry. In this work, pyrolysis of Alcell and Kraft lignins obtained from Alcell process and Westvaco, respectively, was carried out in a fixed-bed reactor to produce hydrogen and gas with medium heating value. The effects of carrier gas (helium) fLow rate (13.4–33 ml/min/g of lignin), heating rate (5–15°C/min) and temperature (350–800°C) on the lignin conversion, product composition, and gas yield have been studied. The gaseous products mainly consisted of H2, CO, CO2, CH4 and C2+. The carrier gas fLow rate did not have any significant effect on the conversion. However, at 800°C and at a constant heating rate of 15°C/min with increase in carrier gas fLow rate from 13.4 to 33 ml/min/g of lignin, the volume of product gas decreased from 820 to 736 ml/g for Kraft and from 820 to 762 ml/g for Alcell lignin and the production of hydrogen increased from 43 to 66 mol% for Kraft lignin and from 31 to 46 mol% for Alcell lignin. At a Lower carrier gas fLow rate of 13.4 ml/min/g of lignin, the gas had a maximum heating value of 437 Btu/scf. At this fLow rate and at 800°C, with increase in heating rate from 5 to 15°C/min both lignin conversion and hydrogen production increased from 56 to 65 wt.% and 24 to 31 mol%, respectively, for Alcell lignin. With decrease in temperature from 800°C to 350°C, the conversion of Alcell and Kraft lignins were decreased from 65 to 28 wt.% and from 57 to 25 wt.%, respectively. Also, with decrease in temperature, production of hydrogen was decreased. Maximum heating value of gas (491 Btu/scf) was obtained at 450°C for Alcell lignin.
