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Fehmi Akgün - One of the best experts on this subject based on the ideXlab platform.

  • experimental results of gasification of cotton stalk and hazelnut shell in a bubbling Fluidized Bed Gasifier under air and steam atmospheres
    Fuel, 2013
    Co-Authors: Hakan Karatas, Hayati Olgun, Fehmi Akgün
    Abstract:

    Abstract Gasification converts solid fuel into product gas which can be used in various applications. The product gas can be combusted to generate heat and electricity. It can also be used as a feedstock for the production of synthesis gas, liquid fuel and chemicals. This paper presents the experimental results of gasification of cotton stalk (C.S.) and hazelnut shell (H.S.) in a laboratory scale bubbling Fluidized Bed Gasifier under air and steam atmospheres. The effects of equivalence ratio (ER) and steam to fuel ratio on the quality of the product gas are investigated for the air and steam atmospheres, respectively. Identical tests are conducted to investigate the repeatability of experimental results. The composition of the product gas is determined with an online gas analyzer which measures CO, CO 2 , CH 4 , H 2 and O 2 components. The lower heating value (LHV) of the product gas is calculated by using the gas composition measurements. The LHV is obtained in the range of 2.49–11.28 MJ/Nm 3 . In the case of air gasification, the ER is varied in the range of 0.71–0.36 and 0.68–0.25 for the cotton stalk and hazelnut shell cases, respectively. The ER significantly affects the LHV for hazelnut shell. In the case of steam gasification, the steam to fuel ratio is changed in the range of 1.69–0.52 and 2.26–0.33 for the cotton stalk and hazelnut shell cases, respectively. The steam feeding rate can be maintained at minimum because it slightly changes the LHV.

  • coal and coal and calcined dolomite gasification experiments in a bubbling Fluidized Bed Gasifier under air atmosphere
    Fuel Processing Technology, 2013
    Co-Authors: Hakan Karatas, Hayati Olgun, Fehmi Akgün
    Abstract:

    Abstract Among different kinds of parameters, the fuel input plays a principal role on the quality of the product gas generated by gasification. Turkish coals have high ash and sulfur contents along with low carbon content and low heating value. The present study investigates the gasification characteristics of four different Turkish coals and also the effects of addition of calcined dolomite on the quality of the product gas. A laboratory scale bubbling Fluidized Bed Gasifier is used to perform gasification tests. Within this frame, air is used as a gasification agent, quartz sand is used as a Bed material and the effects of equivalence ratio (ER), coal type and calcined dolomite on gas properties are investigated. The LHV is calculated by using the measured gas compositions. Comparing the gasification performances of four Turkish coals at a fixed ER value, the present study reveals that the ranking is, from the highest to the lowest, Orhaneli, Kale-2, Kale-1 and Goynuk. For Kale-1, the LHV is obtained in the range of 4.36 to 6.16 MJ/Nm 3 for the ER range of 0.44 to 0.17, respectively. The dolomite decreases the tar, H 2 S and NH 3 contents, as well as the LHV of the product gas.

  • Experimental results of gasification of waste tire with air&CO2, air&steam and steam in a bubbling Fluidized Bed Gasifier
    Fuel Processing Technology, 2012
    Co-Authors: Hakan Karatas, Hayati Olgun, Fehmi Akgün
    Abstract:

    Gasification is one of the thermochemical conversion methods to produce both product gas and solid char. The quality of the product gas widely differs depending on the type of the gasification agent used in the gasification process. Therefore, one of the important parameters in the design phase of the gasification system is the gasification agent. In the present study, a laboratory scale bubbling Fluidized Bed Gasifier was used to gasify the waste tire with the gasification agents of air&CO2, air&steam and steam. Within this frame, the effects of gasification agents, Bed material particle size, CO2 to air ratio, steam to air ratio, steam temperature and steam to fuel ratio on the quality of the product gas were investigated. In order to determine the composition of the product gas, an online gas analyzer, which can measure CO, CO2, CH4, H2 and O2 components, was used. By using the measured gas compositions, the lower heating value (LHV) was calculated to represent the quality of the product gas. Comparing the gasification agents of air&CO2, air&steam and steam, the LHV of the product gas was obtained 9.59, 7.34 and 15.21 MJ/Nm3, respectively. The repetition and uncertainty calculation of the tests were performed.

  • experimental results of gasification of waste tire with air co2 air steam and steam in a bubbling Fluidized Bed Gasifier
    Fuel Processing Technology, 2012
    Co-Authors: Hakan Karatas, Hayati Olgun, Fehmi Akgün
    Abstract:

    Gasification is one of the thermochemical conversion methods to produce both product gas and solid char. The quality of the product gas widely differs depending on the type of the gasification agent used in the gasification process. Therefore, one of the important parameters in the design phase of the gasification system is the gasification agent. In the present study, a laboratory scale bubbling Fluidized Bed Gasifier was used to gasify the waste tire with the gasification agents of air&CO2, air&steam and steam. Within this frame, the effects of gasification agents, Bed material particle size, CO2 to air ratio, steam to air ratio, steam temperature and steam to fuel ratio on the quality of the product gas were investigated. In order to determine the composition of the product gas, an online gas analyzer, which can measure CO, CO2, CH4, H2 and O2 components, was used. By using the measured gas compositions, the lower heating value (LHV) was calculated to represent the quality of the product gas. Comparing the gasification agents of air&CO2, air&steam and steam, the LHV of the product gas was obtained 9.59, 7.34 and 15.21 MJ/Nm3, respectively. The repetition and uncertainty calculation of the tests were performed.

Gul Zarren - One of the best experts on this subject based on the ideXlab platform.

  • experimental investigation of tar arresting techniques and their evaluation for product syngas cleaning from bubbling Fluidized Bed Gasifier
    Journal of Cleaner Production, 2019
    Co-Authors: Farooq Sher, Gul Zarren
    Abstract:

    Abstract Hazardous waste products along with the syngas produced from biomass gasification are one of the major problems of today world. Tar and other solid contaminants removal from syngas are necessary as it is widely used for the production of energy in thermal and power sectors. The raw syngas can be clean up by directly controlling the operating parameters and applying cleaning units. This study aimed to analyze bubbling Fluidized Bed Gasifier and focuses on investigating the novel tar reducing techniques. Different cleaning units; char Bed, woodchip Bed and mop fan were used to arrest tar directly from producer gas. For the first time, a novel strategical technique of mop fan based on water spray was evaluated. Results showed that tar arrest with bio-char is unsuccessful due to the burning of Bed while the average concentration of tar captured by woodchips and mop fan with or without water spray was 0.459 mg/L, 0.987 mg/L and 0.617 mg/L respectively. Furthermore, the concentration of naphthalene and phenanthrene reduced significantly by 96.46% and 99.27% with water spray based mop fan. Overall tar arresting percentage efficiency with small woodchip, large woodchip, mop fan without water and mop fan with water spray was 22.5%

Hakan Karatas - One of the best experts on this subject based on the ideXlab platform.

  • experimental results of gasification of cotton stalk and hazelnut shell in a bubbling Fluidized Bed Gasifier under air and steam atmospheres
    Fuel, 2013
    Co-Authors: Hakan Karatas, Hayati Olgun, Fehmi Akgün
    Abstract:

    Abstract Gasification converts solid fuel into product gas which can be used in various applications. The product gas can be combusted to generate heat and electricity. It can also be used as a feedstock for the production of synthesis gas, liquid fuel and chemicals. This paper presents the experimental results of gasification of cotton stalk (C.S.) and hazelnut shell (H.S.) in a laboratory scale bubbling Fluidized Bed Gasifier under air and steam atmospheres. The effects of equivalence ratio (ER) and steam to fuel ratio on the quality of the product gas are investigated for the air and steam atmospheres, respectively. Identical tests are conducted to investigate the repeatability of experimental results. The composition of the product gas is determined with an online gas analyzer which measures CO, CO 2 , CH 4 , H 2 and O 2 components. The lower heating value (LHV) of the product gas is calculated by using the gas composition measurements. The LHV is obtained in the range of 2.49–11.28 MJ/Nm 3 . In the case of air gasification, the ER is varied in the range of 0.71–0.36 and 0.68–0.25 for the cotton stalk and hazelnut shell cases, respectively. The ER significantly affects the LHV for hazelnut shell. In the case of steam gasification, the steam to fuel ratio is changed in the range of 1.69–0.52 and 2.26–0.33 for the cotton stalk and hazelnut shell cases, respectively. The steam feeding rate can be maintained at minimum because it slightly changes the LHV.

  • coal and coal and calcined dolomite gasification experiments in a bubbling Fluidized Bed Gasifier under air atmosphere
    Fuel Processing Technology, 2013
    Co-Authors: Hakan Karatas, Hayati Olgun, Fehmi Akgün
    Abstract:

    Abstract Among different kinds of parameters, the fuel input plays a principal role on the quality of the product gas generated by gasification. Turkish coals have high ash and sulfur contents along with low carbon content and low heating value. The present study investigates the gasification characteristics of four different Turkish coals and also the effects of addition of calcined dolomite on the quality of the product gas. A laboratory scale bubbling Fluidized Bed Gasifier is used to perform gasification tests. Within this frame, air is used as a gasification agent, quartz sand is used as a Bed material and the effects of equivalence ratio (ER), coal type and calcined dolomite on gas properties are investigated. The LHV is calculated by using the measured gas compositions. Comparing the gasification performances of four Turkish coals at a fixed ER value, the present study reveals that the ranking is, from the highest to the lowest, Orhaneli, Kale-2, Kale-1 and Goynuk. For Kale-1, the LHV is obtained in the range of 4.36 to 6.16 MJ/Nm 3 for the ER range of 0.44 to 0.17, respectively. The dolomite decreases the tar, H 2 S and NH 3 contents, as well as the LHV of the product gas.

  • Experimental results of gasification of waste tire with air&CO2, air&steam and steam in a bubbling Fluidized Bed Gasifier
    Fuel Processing Technology, 2012
    Co-Authors: Hakan Karatas, Hayati Olgun, Fehmi Akgün
    Abstract:

    Gasification is one of the thermochemical conversion methods to produce both product gas and solid char. The quality of the product gas widely differs depending on the type of the gasification agent used in the gasification process. Therefore, one of the important parameters in the design phase of the gasification system is the gasification agent. In the present study, a laboratory scale bubbling Fluidized Bed Gasifier was used to gasify the waste tire with the gasification agents of air&CO2, air&steam and steam. Within this frame, the effects of gasification agents, Bed material particle size, CO2 to air ratio, steam to air ratio, steam temperature and steam to fuel ratio on the quality of the product gas were investigated. In order to determine the composition of the product gas, an online gas analyzer, which can measure CO, CO2, CH4, H2 and O2 components, was used. By using the measured gas compositions, the lower heating value (LHV) was calculated to represent the quality of the product gas. Comparing the gasification agents of air&CO2, air&steam and steam, the LHV of the product gas was obtained 9.59, 7.34 and 15.21 MJ/Nm3, respectively. The repetition and uncertainty calculation of the tests were performed.

  • experimental results of gasification of waste tire with air co2 air steam and steam in a bubbling Fluidized Bed Gasifier
    Fuel Processing Technology, 2012
    Co-Authors: Hakan Karatas, Hayati Olgun, Fehmi Akgün
    Abstract:

    Gasification is one of the thermochemical conversion methods to produce both product gas and solid char. The quality of the product gas widely differs depending on the type of the gasification agent used in the gasification process. Therefore, one of the important parameters in the design phase of the gasification system is the gasification agent. In the present study, a laboratory scale bubbling Fluidized Bed Gasifier was used to gasify the waste tire with the gasification agents of air&CO2, air&steam and steam. Within this frame, the effects of gasification agents, Bed material particle size, CO2 to air ratio, steam to air ratio, steam temperature and steam to fuel ratio on the quality of the product gas were investigated. In order to determine the composition of the product gas, an online gas analyzer, which can measure CO, CO2, CH4, H2 and O2 components, was used. By using the measured gas compositions, the lower heating value (LHV) was calculated to represent the quality of the product gas. Comparing the gasification agents of air&CO2, air&steam and steam, the LHV of the product gas was obtained 9.59, 7.34 and 15.21 MJ/Nm3, respectively. The repetition and uncertainty calculation of the tests were performed.

Hayati Olgun - One of the best experts on this subject based on the ideXlab platform.

  • experimental results of gasification of cotton stalk and hazelnut shell in a bubbling Fluidized Bed Gasifier under air and steam atmospheres
    Fuel, 2013
    Co-Authors: Hakan Karatas, Hayati Olgun, Fehmi Akgün
    Abstract:

    Abstract Gasification converts solid fuel into product gas which can be used in various applications. The product gas can be combusted to generate heat and electricity. It can also be used as a feedstock for the production of synthesis gas, liquid fuel and chemicals. This paper presents the experimental results of gasification of cotton stalk (C.S.) and hazelnut shell (H.S.) in a laboratory scale bubbling Fluidized Bed Gasifier under air and steam atmospheres. The effects of equivalence ratio (ER) and steam to fuel ratio on the quality of the product gas are investigated for the air and steam atmospheres, respectively. Identical tests are conducted to investigate the repeatability of experimental results. The composition of the product gas is determined with an online gas analyzer which measures CO, CO 2 , CH 4 , H 2 and O 2 components. The lower heating value (LHV) of the product gas is calculated by using the gas composition measurements. The LHV is obtained in the range of 2.49–11.28 MJ/Nm 3 . In the case of air gasification, the ER is varied in the range of 0.71–0.36 and 0.68–0.25 for the cotton stalk and hazelnut shell cases, respectively. The ER significantly affects the LHV for hazelnut shell. In the case of steam gasification, the steam to fuel ratio is changed in the range of 1.69–0.52 and 2.26–0.33 for the cotton stalk and hazelnut shell cases, respectively. The steam feeding rate can be maintained at minimum because it slightly changes the LHV.

  • coal and coal and calcined dolomite gasification experiments in a bubbling Fluidized Bed Gasifier under air atmosphere
    Fuel Processing Technology, 2013
    Co-Authors: Hakan Karatas, Hayati Olgun, Fehmi Akgün
    Abstract:

    Abstract Among different kinds of parameters, the fuel input plays a principal role on the quality of the product gas generated by gasification. Turkish coals have high ash and sulfur contents along with low carbon content and low heating value. The present study investigates the gasification characteristics of four different Turkish coals and also the effects of addition of calcined dolomite on the quality of the product gas. A laboratory scale bubbling Fluidized Bed Gasifier is used to perform gasification tests. Within this frame, air is used as a gasification agent, quartz sand is used as a Bed material and the effects of equivalence ratio (ER), coal type and calcined dolomite on gas properties are investigated. The LHV is calculated by using the measured gas compositions. Comparing the gasification performances of four Turkish coals at a fixed ER value, the present study reveals that the ranking is, from the highest to the lowest, Orhaneli, Kale-2, Kale-1 and Goynuk. For Kale-1, the LHV is obtained in the range of 4.36 to 6.16 MJ/Nm 3 for the ER range of 0.44 to 0.17, respectively. The dolomite decreases the tar, H 2 S and NH 3 contents, as well as the LHV of the product gas.

  • Experimental results of gasification of waste tire with air&CO2, air&steam and steam in a bubbling Fluidized Bed Gasifier
    Fuel Processing Technology, 2012
    Co-Authors: Hakan Karatas, Hayati Olgun, Fehmi Akgün
    Abstract:

    Gasification is one of the thermochemical conversion methods to produce both product gas and solid char. The quality of the product gas widely differs depending on the type of the gasification agent used in the gasification process. Therefore, one of the important parameters in the design phase of the gasification system is the gasification agent. In the present study, a laboratory scale bubbling Fluidized Bed Gasifier was used to gasify the waste tire with the gasification agents of air&CO2, air&steam and steam. Within this frame, the effects of gasification agents, Bed material particle size, CO2 to air ratio, steam to air ratio, steam temperature and steam to fuel ratio on the quality of the product gas were investigated. In order to determine the composition of the product gas, an online gas analyzer, which can measure CO, CO2, CH4, H2 and O2 components, was used. By using the measured gas compositions, the lower heating value (LHV) was calculated to represent the quality of the product gas. Comparing the gasification agents of air&CO2, air&steam and steam, the LHV of the product gas was obtained 9.59, 7.34 and 15.21 MJ/Nm3, respectively. The repetition and uncertainty calculation of the tests were performed.

  • experimental results of gasification of waste tire with air co2 air steam and steam in a bubbling Fluidized Bed Gasifier
    Fuel Processing Technology, 2012
    Co-Authors: Hakan Karatas, Hayati Olgun, Fehmi Akgün
    Abstract:

    Gasification is one of the thermochemical conversion methods to produce both product gas and solid char. The quality of the product gas widely differs depending on the type of the gasification agent used in the gasification process. Therefore, one of the important parameters in the design phase of the gasification system is the gasification agent. In the present study, a laboratory scale bubbling Fluidized Bed Gasifier was used to gasify the waste tire with the gasification agents of air&CO2, air&steam and steam. Within this frame, the effects of gasification agents, Bed material particle size, CO2 to air ratio, steam to air ratio, steam temperature and steam to fuel ratio on the quality of the product gas were investigated. In order to determine the composition of the product gas, an online gas analyzer, which can measure CO, CO2, CH4, H2 and O2 components, was used. By using the measured gas compositions, the lower heating value (LHV) was calculated to represent the quality of the product gas. Comparing the gasification agents of air&CO2, air&steam and steam, the LHV of the product gas was obtained 9.59, 7.34 and 15.21 MJ/Nm3, respectively. The repetition and uncertainty calculation of the tests were performed.

Yoshizo Suzuki - One of the best experts on this subject based on the ideXlab platform.

  • Heat balance of Fluidized Bed Gasifier with triple-Beds and dual circulation
    Advanced Powder Technology, 2011
    Co-Authors: Takahiro Murakami, Minoru Asai, Yoshizo Suzuki
    Abstract:

    Abstract A new type of circulating Fluidized Bed Gasifier has been proposed. The main features of this proposed Gasifier are the adoption of a triple-Beds structure (comprising pyrolyzer, Gasifier, and combustor), and a circulation path for tar-absorbing material that is separate from the circulation path for the fuel and silica sand. Independent circulation systems are employed for the fuel system and for the tar-absorbing particles, and the pyrolyzer and Gasifier each have a two-stage Fluidized Bed. This new Gasifier is called “a Fluidized Bed Gasifier with triple-Beds and dual circulation”. As the second stage towards development of the proposed new type Gasifier, based on the data of the fundamental experiments obtained in our previous study, the parameters for obtaining higher cold gas efficiency as well as the particle circulation rates capable of sustaining desired temperatures in each furnace were clarified by the heat balance. As a result, in the proposed circulating Fluidized Bed Gasifier with a capacity of 5 t/d, a particle circulation rate of 3.1 t/h in the upper stage, and that of 5.8 t/h in the lower stage respectively was required to maintain temperatures of 973 K in the pyrolyzer, 1073 K in the Gasifier, and 1173 K in the combustor. Under these conditions, obtaining a cold gas efficiency of more than 70% was possible.

  • development of Fluidized Bed Gasifier with triple Beds and dual circulation
    Advanced Powder Technology, 2011
    Co-Authors: Takahiro Murakami, Minoru Asai, Tao Yang, Yoshizo Suzuki
    Abstract:

    Abstract A new type of circulating Fluidized Bed Gasifier was proposed. The main features of this proposed Gasifier are the adoption of a triple-Beds structure (comprising pyrolyzer, Gasifier, and combustor), the separation of a circulation path for tar-absorbing material and that for the fuel and silica sand. Independent circulation systems are employed for the fuel system and for the tar-absorbing particles, and the pyrolyzer and Gasifier each have a two-stage Fluidized Bed: the lower stage is for the fuel system and the upper stage is for the tar-absorbing particle system. The two circulation systems each have an independent combustor. In the pyrolyzer, the tar formed together with the gas produced during the pyrolysis of the fuel in the lower stage is absorBed by tar-absorbing particles in the upper stage. By adopting this two-stage Fluidized Bed approach, mixing of the tar-absorbing particles, which is rather expensive, with the ash contained in the fuel can be avoided. Accordingly, accumulation of ash in the circulation path for tar-absorbing material can be avoided, and the quantity of the discharge of absorption particles can be reduced. Therefore, the quantity used can be greatly reduced. The quantity of costly tar-absorbing particles used can be further minimized by optimizing the quantity of particles with respect to the quantity of tar generated by the fuel. As the first stage towards development of the proposed new type Gasifier, the fundamental experiments that simulated a two-stage pyrolyzer and Gasifier were carried out. As a result, the amount of H 2 formed by pyrolysis resulted in a marked increase by using porous alumina as the tar-absorbing particles than the conventional conditions of using only silica sand. The amount of H 2 formed was more increased because the coke was not only cracked but also reformed by steam gasification.