The Experts below are selected from a list of 315 Experts worldwide ranked by ideXlab platform

Chi-hwa Wang - One of the best experts on this subject based on the ideXlab platform.

  • nitrogen removal and energy recovery from sewage sludge by combined hydrothermal pretreatment and co2 gasification
    ACS Sustainable Chemistry & Engineering, 2018
    Co-Authors: Ye Shen, Xiaoping Chen, Alexei A. Lapkin, Wende Xiao, Chi-hwa Wang
    Abstract:

    Disposal of nitrogen-containing sewage sludge (SS) via gasification leads to the formation of NOx precursors and NOx and ammonia emissions. Pretreatment of SS via hydrothermal carbonization (HTC) was shown to improve coalification, desulfurization, and deamination. In this study, we propose a combined hydrothermal pretreatment and CO2 gasification process for removal of nitrogen from SS and production of energy via the gasification of the pretreated SS. In the HTC process, around 50% of nitrogen contained in the sludge was removed. The derived hydrochar (HC) was subsequently fed for gasification using CO2 as a gasifying agent, which was characterized by the expected reduction in the formation of ammonia. We further improved the process by establishing Cogasification of hydrochar with waste leaves. The improvement is believed to be due to the catalytic effect of Ca, present in plant leaves, on the gasification. Cold gas efficiency of the Cogasification process of a 1/1 hydrochar/leaves blend by mass was en...

  • Nitrogen Removal and Energy Recovery from Sewage Sludge by Combined Hydrothermal Pretreatment and CO2 Gasification
    2018
    Co-Authors: Ye Shen, Xiaoping Chen, Alexei A. Lapkin, Wende Xiao, Chi-hwa Wang
    Abstract:

    Disposal of nitrogen-containing sewage sludge (SS) via gasification leads to the formation of NOx precursors and NOx and ammonia emissions. Pretreatment of SS via hydrothermal carbonization (HTC) was shown to improve coalification, desulfurization, and deamination. In this study, we propose a combined hydrothermal pretreatment and CO2 gasification process for removal of nitrogen from SS and production of energy via the gasification of the pretreated SS. In the HTC process, around 50% of nitrogen contained in the sludge was removed. The derived hydrochar (HC) was subsequently fed for gasification using CO2 as a gasifying agent, which was characterized by the expected reduction in the formation of ammonia. We further improved the process by establishing Cogasification of hydrochar with waste leaves. The improvement is believed to be due to the catalytic effect of Ca, present in plant leaves, on the gasification. Cold gas efficiency of the Cogasification process of a 1/1 hydrochar/leaves blend by mass was enhanced to 66%. The combination of hydrothermal conversion of sewage sludge with CO2 Cogasification of hydrochar and waste leaves was shown to be a clean and efficient method for SS management and energy recovery

  • co gasification of woody biomass and sewage sludge in a fixed bed downdraft gasifier
    Aiche Journal, 2015
    Co-Authors: Yongpan Cheng, Thawatchai Maneerung, Yen Wah Tong, Chi-hwa Wang
    Abstract:

    Experimental and numerical studies of Cogasification of woody biomass and sewage sludge have been carried out. The gasification experiments were performed in a fixed-bed downdraft gasifier and the experimental results show that 20 wt % dried sewage sludge in the feedstock was effectively gasified to generate producer gas comprising over 30 vol % of syngas with an average lower heating value of 4.5 MJ/Nm3. Further increasing sewage sludge content to 33 wt % leads to the blockage of gasifier, which is resulted from the formation of agglomerated ash. The numerical models were then developed to simulate the reactions taking place in four different zones of the gasifier (i.e., drying, pyrolysis, combustion, and reduction zones) and to predict the producer gas composition and cold gas efficiency. The deviation between the numerical and experimental results obtained was lower than 10%. © 2015 American Institute of Chemical Engineers AIChE J, 61: 2508–2521, 2015

  • Co‐gasification of woody biomass and sewage sludge in a fixed‐bed downdraft gasifier
    AIChE Journal, 2015
    Co-Authors: Zhehan Ong, Chi-hwa Wang, Yongpan Cheng, Thawatchai Maneerung, Yen Wah Tong, Zhiyi Yao, Yanjun Dai
    Abstract:

    Experimental and numerical studies of Cogasification of woody biomass and sewage sludge have been carried out. The gasification experiments were performed in a fixed-bed downdraft gasifier and the experimental results show that 20 wt % dried sewage sludge in the feedstock was effectively gasified to generate producer gas comprising over 30 vol % of syngas with an average lower heating value of 4.5 MJ/Nm3. Further increasing sewage sludge content to 33 wt % leads to the blockage of gasifier, which is resulted from the formation of agglomerated ash. The numerical models were then developed to simulate the reactions taking place in four different zones of the gasifier (i.e., drying, pyrolysis, combustion, and reduction zones) and to predict the producer gas composition and cold gas efficiency. The deviation between the numerical and experimental results obtained was lower than 10%. © 2015 American Institute of Chemical Engineers AIChE J, 61: 2508–2521, 2015

Baosheng Jin - One of the best experts on this subject based on the ideXlab platform.

  • Oxygen-Enriched Gasification of Dried Sewage Sludge, Refuse-Derived Fuel, and Their Cogasification in a Laboratory-Scale Fluidized Bed
    Industrial & Engineering Chemistry Research, 2018
    Co-Authors: Tianyu Chen, Jun Cao, Baosheng Jin
    Abstract:

    Oxygen-enriched gasification of single-feed refuse-derived fuel (RDF) and dry sewage sludge (DSS) in a laboratory-scale fluidized bed was investigated. The optimal temperature, equivalence ratio (ER), and oxygen concentration of RDF and DSS gasification were 800 °C, 0.292, 50% and 750 °C, 0.321, 44.7%, respectively. The low heating values (LHVs) and cold gas efficiency (η values) of syngases from RDF and DSS were 6.79 MJ/Nm3, 53.0% and 6.51 MJ/Nm3, 49.2%, respectively, under optimal conditions. To improve the quality of DSS syngas, the effect of the RDF mixing ratio on RDF and DSS Cogasification was investigated at 800 °C, with an ER of 0.321 and an OC of 44.7%. The gas yield increased continuously with increased RDF mixing ratio, and η rose to 55.0% with relatively high LHV of producer gas at a 25% mixing ratio of RDF.

  • Oxygen-Enriched Gasification of Dried Sewage Sludge, Refuse-Derived Fuel, and Their Cogasification in a Laboratory-Scale Fluidized Bed
    2018
    Co-Authors: Tianyu Chen, Jun Cao, Baosheng Jin
    Abstract:

    Oxygen-enriched gasification of single-feed refuse-derived fuel (RDF) and dry sewage sludge (DSS) in a laboratory-scale fluidized bed was investigated. The optimal temperature, equivalence ratio (ER), and oxygen concentration of RDF and DSS gasification were 800 °C, 0.292, 50% and 750 °C, 0.321, 44.7%, respectively. The low heating values (LHVs) and cold gas efficiency (η values) of syngases from RDF and DSS were 6.79 MJ/Nm3, 53.0% and 6.51 MJ/Nm3, 49.2%, respectively, under optimal conditions. To improve the quality of DSS syngas, the effect of the RDF mixing ratio on RDF and DSS Cogasification was investigated at 800 °C, with an ER of 0.321 and an OC of 44.7%. The gas yield increased continuously with increased RDF mixing ratio, and η rose to 55.0% with relatively high LHV of producer gas at a 25% mixing ratio of RDF

Xin Gong - One of the best experts on this subject based on the ideXlab platform.

  • Study on Cogasification of Food Waste Char with Biomass/Coal Char and Their Interaction Mechanisms
    Energy & Fuels, 2018
    Co-Authors: Lu Ding, Xin Gong
    Abstract:

    In this paper, the effects of gasification temperature and blending ratios on Cogasification reactivity of food waste char with sawdust/Shenfu coal char were studied via a thermogravimetric analyzer. Moreover, the relationship between synergy and char physical–chemical structure evolution was further studied using scanning electron microscopy equipped with energy-dispersive X-ray analysis (SEM–EDS), N2 absorption, and Fourier transform (FT) Raman techniques. The results revealed a significant synergetic effect between food waste and Shenfu coal. The synergetic effect always occurred at the mid-later reaction stage and was enhanced with the increase in carbon conversion. However, no synergy was found between food waste and sawdust. In the food waste–Shenfu Cogasification process, ash present in food waste (rich in Ca) transferred to the surface of Shenfu char without blocking the pore structure of Shenfu char. Moreover, the FT-Raman analysis revealed that the food waste ash reacted with Shenfu char to form...

  • Study on Cogasification of Food Waste Char with Biomass/Coal Char and Their Interaction Mechanisms
    Energy & Fuels, 2018
    Co-Authors: Xiaopeng Zou, Lu Ding, Xin Gong
    Abstract:

    In this paper, the effects of gasification temperature and blending ratios on Cogasification reactivity of food waste char with sawdust/Shenfu coal char were studied via a thermogravimetric analyzer. Moreover, the relationship between synergy and char physical–chemical structure evolution was further studied using scanning electron microscopy equipped with energy-dispersive X-ray analysis (SEM–EDS), N2 absorption, and Fourier transform (FT) Raman techniques. The results revealed a significant synergetic effect between food waste and Shenfu coal. The synergetic effect always occurred at the mid-later reaction stage and was enhanced with the increase in carbon conversion. However, no synergy was found between food waste and sawdust. In the food waste–Shenfu Cogasification process, ash present in food waste (rich in Ca) transferred to the surface of Shenfu char without blocking the pore structure of Shenfu char. Moreover, the FT-Raman analysis revealed that the food waste ash reacted with Shenfu char to form...

  • study on Cogasification of food waste char with biomass coal char and their interaction mechanisms
    Energy & Fuels, 2018
    Co-Authors: Xiaopeng Zou, Lu Ding, Xin Gong
    Abstract:

    In this paper, the effects of gasification temperature and blending ratios on Cogasification reactivity of food waste char with sawdust/Shenfu coal char were studied via a thermogravimetric analyzer. Moreover, the relationship between synergy and char physical–chemical structure evolution was further studied using scanning electron microscopy equipped with energy-dispersive X-ray analysis (SEM–EDS), N2 absorption, and Fourier transform (FT) Raman techniques. The results revealed a significant synergetic effect between food waste and Shenfu coal. The synergetic effect always occurred at the mid-later reaction stage and was enhanced with the increase in carbon conversion. However, no synergy was found between food waste and sawdust. In the food waste–Shenfu Cogasification process, ash present in food waste (rich in Ca) transferred to the surface of Shenfu char without blocking the pore structure of Shenfu char. Moreover, the FT-Raman analysis revealed that the food waste ash reacted with Shenfu char to form...

Tana Levi - One of the best experts on this subject based on the ideXlab platform.

  • Cogasification of blended coal biomass in an air steam bfb gasifier experimental investigation and model validation
    Aiche Journal, 2015
    Co-Authors: Shusheng Pang, Tana Levi
    Abstract:

    A series of Cogasification experiments were performed at a 100 kW bubbling fluidized bed (BFB) gasifier to gasify the blended pellets made from two types of coals and woody biomass, with biomass-to-fuel mass ratios of 0–30%. In the Cogasification, a mixture of air and steam was fed from the BFB gasifier bottom as gasification agent and the blended biomass-coal pellets were fed into the bed layer. Impacts of biomass mass fraction in the binary pellets and gasification operation temperature on producer gas composition were experimentally investigated. The experimental results have been used to validate a mathematical model developed in this study. From both experimental observation and model prediction, it was found that adding biomass into coal has overall negative impact on producer gas quality in terms of combustible substance contents, and the extents of the blending effect were different among fuel types which have different properties. © 2015 American Institute of Chemical Engineers AIChE J, 61: 1639–1647, 2015

  • Cogasification of blended coal‐biomass in an air/steam BFB gasifier: Experimental investigation and model validation
    AIChE Journal, 2015
    Co-Authors: Shusheng Pang, Tana Levi
    Abstract:

    A series of Cogasification experiments were performed at a 100 kW bubbling fluidized bed (BFB) gasifier to gasify the blended pellets made from two types of coals and woody biomass, with biomass-to-fuel mass ratios of 0–30%. In the Cogasification, a mixture of air and steam was fed from the BFB gasifier bottom as gasification agent and the blended biomass-coal pellets were fed into the bed layer. Impacts of biomass mass fraction in the binary pellets and gasification operation temperature on producer gas composition were experimentally investigated. The experimental results have been used to validate a mathematical model developed in this study. From both experimental observation and model prediction, it was found that adding biomass into coal has overall negative impact on producer gas quality in terms of combustible substance contents, and the extents of the blending effect were different among fuel types which have different properties. © 2015 American Institute of Chemical Engineers AIChE J, 61: 1639–1647, 2015

Tianyu Chen - One of the best experts on this subject based on the ideXlab platform.

  • Oxygen-Enriched Gasification of Dried Sewage Sludge, Refuse-Derived Fuel, and Their Cogasification in a Laboratory-Scale Fluidized Bed
    Industrial & Engineering Chemistry Research, 2018
    Co-Authors: Tianyu Chen, Jun Cao, Baosheng Jin
    Abstract:

    Oxygen-enriched gasification of single-feed refuse-derived fuel (RDF) and dry sewage sludge (DSS) in a laboratory-scale fluidized bed was investigated. The optimal temperature, equivalence ratio (ER), and oxygen concentration of RDF and DSS gasification were 800 °C, 0.292, 50% and 750 °C, 0.321, 44.7%, respectively. The low heating values (LHVs) and cold gas efficiency (η values) of syngases from RDF and DSS were 6.79 MJ/Nm3, 53.0% and 6.51 MJ/Nm3, 49.2%, respectively, under optimal conditions. To improve the quality of DSS syngas, the effect of the RDF mixing ratio on RDF and DSS Cogasification was investigated at 800 °C, with an ER of 0.321 and an OC of 44.7%. The gas yield increased continuously with increased RDF mixing ratio, and η rose to 55.0% with relatively high LHV of producer gas at a 25% mixing ratio of RDF.

  • Oxygen-Enriched Gasification of Dried Sewage Sludge, Refuse-Derived Fuel, and Their Cogasification in a Laboratory-Scale Fluidized Bed
    2018
    Co-Authors: Tianyu Chen, Jun Cao, Baosheng Jin
    Abstract:

    Oxygen-enriched gasification of single-feed refuse-derived fuel (RDF) and dry sewage sludge (DSS) in a laboratory-scale fluidized bed was investigated. The optimal temperature, equivalence ratio (ER), and oxygen concentration of RDF and DSS gasification were 800 °C, 0.292, 50% and 750 °C, 0.321, 44.7%, respectively. The low heating values (LHVs) and cold gas efficiency (η values) of syngases from RDF and DSS were 6.79 MJ/Nm3, 53.0% and 6.51 MJ/Nm3, 49.2%, respectively, under optimal conditions. To improve the quality of DSS syngas, the effect of the RDF mixing ratio on RDF and DSS Cogasification was investigated at 800 °C, with an ER of 0.321 and an OC of 44.7%. The gas yield increased continuously with increased RDF mixing ratio, and η rose to 55.0% with relatively high LHV of producer gas at a 25% mixing ratio of RDF