The Experts below are selected from a list of 13608 Experts worldwide ranked by ideXlab platform

María Encarnación Rodríguez - One of the best experts on this subject based on the ideXlab platform.

  • air and air steam gasification of sewage sludge the influence of dolomite and throughput in Tar Production and composition
    Fuel, 2014
    Co-Authors: Elena Roche, Juan Manuel De Andrés, Adolfo Narros, María Encarnación Rodríguez
    Abstract:

    Abstract The influence of throughput (TR), steam and the use of dolomite (as primary catalyst) over the sewage sludge gasification products was investigated. For this purpose, experiments were conducted in an atmospheric fluidised bed reactor using air and air + steam as gasifying agents. The analysis of the results was mainly focussed on the gas composition, the gravimetric Tar Production, and the GC-detectable Tar composition (and dew point estimations). According to the obtained results, higher TRs decreased the H2 content of the produced gas and clearly increased the gravimetric Tar Production. The use of air + steam, especially in the presence of dolomite, increased the H2 content (between 20% and 36%) and decreased the gravimetric Tar Production over all the tested TR, reaching Tar removal efficiencies of up to 71%. Regarding the GC-detectable Tar, higher TRs increased the heavy polyaromatic hydrocarbons Production, steam slightly increased the water soluble Tar content while the use of dolomite decreased the yield of all the Tar classes except light aromatic hydrocarbons. Under the tested gasification conditions, the gas dew point never dropped below 110 °C, value far above the recommended temperature when the syngas is to be used for engine applications.

  • behaviour of dolomite olivine and alumina as primary catalysts in air steam gasification of sewage sludge
    Fuel, 2011
    Co-Authors: Juan Manuel De Andrés, Adolfo Narros, María Encarnación Rodríguez
    Abstract:

    Abstract Sewage sludge gasification assays were performed in an atmospheric fluidised bed reactor using air and air–steam mixtures as the gasifying agents. Dolomite, olivine and alumina are three well known Tar removal catalysts used in biomass gasification processing. However, little information is available regarding their performance in sewage sludge gasification. The aim of the current study was to learn about the influence of these three catalysts in the product distribution and Tar Production during sewage sludge gasification. To this end, a set of assays was performed in which the temperature (750–850 °C), the in-bed catalyst content (0, 10 and 15 wt.%) and the steam–biomass ratio (SB) in the range of 0–1 were varied with a constant equivalence ratio (ER) of 0.3. The results were compared to the results from gasification without a catalyst. We show that dolomite has the highest activity in Tar elimination, followed by alumina and olivine. In addition to improving Tar removal, the presence of water vapour and the catalysts increased the content of H 2 in the gases by nearly 60%.

  • Air-steam gasification of sewage sludge in a bubbling bed reactor: Effect of alumina as a primary catalyst
    Fuel Processing Technology, 2011
    Co-Authors: Juan Manuel De Andrés, Adolfo Narros, María Encarnación Rodríguez
    Abstract:

    Abstract Numerous references can be found in scientific literature regarding biomass gasification. However, there are few works related to sludge gasification. A study of sewage sludge gasification process in a bubbling fluidised bed gasifier on a laboratory scale is here reported. The aim was to find the optimum conditions for reducing the Production of Tars and gain more information on the influx of different operating variables in the products resulting from the gasification of this waste. The variables studied were the equivalence ratio (ER), the steam-biomass ratio (SB) and temperature. Specifically, the ER was varied from 0.2 to 0.4, the SB from 0 to 1 and the temperature from 750 °C (1023 K) to 850 °C (1123 K). Although it was observed that Tar Production could be considerably reduced (up to 72%) by optimising the gasification conditions, the effect of using alumina (aluminium oxide, of proven efficacy in destroying the Tar produced in biomass gasification) as primary catalyst in air and air-steam mixture tests was also verified. The results show that by adding small quantities of alumina to the bed (10% by weight of fed sludge) considerable reductions in Tar Production can be obtained (up to 42%) improving, at the same time, the lower heating value (LHV) of the gas and carbon conversion.

Bishnu Acharya - One of the best experts on this subject based on the ideXlab platform.

  • cao based chemical looping gasification of biomass for hydrogen enriched gas Production with in situ co2 capture and Tar reduction
    Fuel Processing Technology, 2014
    Co-Authors: Jakkapong Udomsirichakorn, Prabir Basu, Abdul P Salam, Bishnu Acharya
    Abstract:

    Abstract Steam gasification of biomass undergoes the problem of undesirable CO 2 and Tar formation. Calcium oxide (CaO), when added to the gasification, could play the dual role of Tar reforming catalyst and CO 2 sorbent, and thereby produce more hydrogen. However, the deactivation of CaO after carbonation reaction is challenging for continuous hydrogen Production and economical perspective. The concept of CaO-based chemical looping gasification (CaO-CLG) plays a key role in overcoming such a challenge. This work primarily aims at studying steam gasification of biomass with the presence of CaO in a uniquely designed chemical looping gasification (CLG) system for hydrogen Production with in situ CO 2 capture and Tar reduction. The effect of solid circulation rates on gas and Tar Production is studied. A comparison of CaO-CLG, sand-based chemical looping gasification (Sand-CLG) and CaO-based bubbling fluidized bed gasification (CaO-BFBG) is presented mainly focusing on gas and Tar Production. The maximum H 2 and minimum CO 2 concentrations as well as maximum H 2 yields of 78%, 4.98% and 451.11 ml (STP)/g of biomass, respectively, are obtained at the solid circulation rate of 1.04 kg/m 2 s. At the same point, the maximum total gas yield was 578.38 ml (STP)/g of biomass and the Tar content of 2.48 g/Nm 3 was the lowest. 30% higher concentration of H 2 and triple yield of H 2 were found in CaO-CLG compared to Sand-CLG. Compared to CaO-BFBG, CaO-CLG resulted in 15% higher concentration of H 2 and almost double yield of H 2 . Moreover, the lowest Tar content of 2.48 g/Nm 3 was obtained for CaO-CLG while the Tar content was 68.5 g/Nm 3 for Sand-CLG and 26.71 g/Nm 3 for CaO-BFBG. CO 2 concentration obtained for CaO-CLG also significantly reduced by 13–17% as compared to both Sand-CLG and CaO-BFBG.

  • effect of cao on Tar reforming to hydrogen enriched gas with in process co2 capture in a bubbling fluidized bed biomass steam gasifier
    International Journal of Hydrogen Energy, 2013
    Co-Authors: Jakkapong Udomsirichakorn, Prabir Basu, Abdul P Salam, Bishnu Acharya
    Abstract:

    Abstract Previous studies showed that calcium oxide (CaO), when added to a biomass steam gasifier, could play the role of both CO 2 sorbent and Tar reforming catalyst, and thereby produce more hydrogen. However, most of these works focused on the former role with little attention to Tar reforming aspect of CaO. Therefore, this work aims primarily at studying the Tar reforming effect of in-bed CaO. To this end, an in-depth analysis of the effect of CaO on Tar yield and composition is presented. The present work also studies the role of CaO as a CO 2 sorbent to enhance hydrogen Production from steam gasification of biomass in a bubbling fluidized bed. The influence of different operating parameters, temperature ( T ) and steam to biomass ( S / B ) ratio, as well as the effect of using in-bed CaO on gas and Tar Production is investigated. Results show that the maximum H 2 and minimum CO 2 concentration of 63.07% and 18.68%, respectively are obtained at T  = 650 °C and S / B  = 3.41. The maximum H 2 yield of 256.81 ml g −1 -biomass was obtained at T  = 700 °C and S / B  = 3.41, at which the minimum Tar content of 6.45 g N m −3 was also received. Compared to a bed of sand alone, a 20% higher H 2 concentration, an almost double H 2 yield and a 67% reduction in Tar content were obtained when a bed of CaO was used. Moreover, shifting the Tar species from higher to fewer ring structures as a result of in-bed CaO can reduce Tar dew point by 11 °C and Tar carcinogenic potential by almost 60%.

Juan Manuel De Andrés - One of the best experts on this subject based on the ideXlab platform.

  • air and air steam gasification of sewage sludge the influence of dolomite and throughput in Tar Production and composition
    Fuel, 2014
    Co-Authors: Elena Roche, Juan Manuel De Andrés, Adolfo Narros, María Encarnación Rodríguez
    Abstract:

    Abstract The influence of throughput (TR), steam and the use of dolomite (as primary catalyst) over the sewage sludge gasification products was investigated. For this purpose, experiments were conducted in an atmospheric fluidised bed reactor using air and air + steam as gasifying agents. The analysis of the results was mainly focussed on the gas composition, the gravimetric Tar Production, and the GC-detectable Tar composition (and dew point estimations). According to the obtained results, higher TRs decreased the H2 content of the produced gas and clearly increased the gravimetric Tar Production. The use of air + steam, especially in the presence of dolomite, increased the H2 content (between 20% and 36%) and decreased the gravimetric Tar Production over all the tested TR, reaching Tar removal efficiencies of up to 71%. Regarding the GC-detectable Tar, higher TRs increased the heavy polyaromatic hydrocarbons Production, steam slightly increased the water soluble Tar content while the use of dolomite decreased the yield of all the Tar classes except light aromatic hydrocarbons. Under the tested gasification conditions, the gas dew point never dropped below 110 °C, value far above the recommended temperature when the syngas is to be used for engine applications.

  • behaviour of dolomite olivine and alumina as primary catalysts in air steam gasification of sewage sludge
    Fuel, 2011
    Co-Authors: Juan Manuel De Andrés, Adolfo Narros, María Encarnación Rodríguez
    Abstract:

    Abstract Sewage sludge gasification assays were performed in an atmospheric fluidised bed reactor using air and air–steam mixtures as the gasifying agents. Dolomite, olivine and alumina are three well known Tar removal catalysts used in biomass gasification processing. However, little information is available regarding their performance in sewage sludge gasification. The aim of the current study was to learn about the influence of these three catalysts in the product distribution and Tar Production during sewage sludge gasification. To this end, a set of assays was performed in which the temperature (750–850 °C), the in-bed catalyst content (0, 10 and 15 wt.%) and the steam–biomass ratio (SB) in the range of 0–1 were varied with a constant equivalence ratio (ER) of 0.3. The results were compared to the results from gasification without a catalyst. We show that dolomite has the highest activity in Tar elimination, followed by alumina and olivine. In addition to improving Tar removal, the presence of water vapour and the catalysts increased the content of H 2 in the gases by nearly 60%.

  • Air-steam gasification of sewage sludge in a bubbling bed reactor: Effect of alumina as a primary catalyst
    Fuel Processing Technology, 2011
    Co-Authors: Juan Manuel De Andrés, Adolfo Narros, María Encarnación Rodríguez
    Abstract:

    Abstract Numerous references can be found in scientific literature regarding biomass gasification. However, there are few works related to sludge gasification. A study of sewage sludge gasification process in a bubbling fluidised bed gasifier on a laboratory scale is here reported. The aim was to find the optimum conditions for reducing the Production of Tars and gain more information on the influx of different operating variables in the products resulting from the gasification of this waste. The variables studied were the equivalence ratio (ER), the steam-biomass ratio (SB) and temperature. Specifically, the ER was varied from 0.2 to 0.4, the SB from 0 to 1 and the temperature from 750 °C (1023 K) to 850 °C (1123 K). Although it was observed that Tar Production could be considerably reduced (up to 72%) by optimising the gasification conditions, the effect of using alumina (aluminium oxide, of proven efficacy in destroying the Tar produced in biomass gasification) as primary catalyst in air and air-steam mixture tests was also verified. The results show that by adding small quantities of alumina to the bed (10% by weight of fed sludge) considerable reductions in Tar Production can be obtained (up to 42%) improving, at the same time, the lower heating value (LHV) of the gas and carbon conversion.

Jakkapong Udomsirichakorn - One of the best experts on this subject based on the ideXlab platform.

  • cao based chemical looping gasification of biomass for hydrogen enriched gas Production with in situ co2 capture and Tar reduction
    Fuel Processing Technology, 2014
    Co-Authors: Jakkapong Udomsirichakorn, Prabir Basu, Abdul P Salam, Bishnu Acharya
    Abstract:

    Abstract Steam gasification of biomass undergoes the problem of undesirable CO 2 and Tar formation. Calcium oxide (CaO), when added to the gasification, could play the dual role of Tar reforming catalyst and CO 2 sorbent, and thereby produce more hydrogen. However, the deactivation of CaO after carbonation reaction is challenging for continuous hydrogen Production and economical perspective. The concept of CaO-based chemical looping gasification (CaO-CLG) plays a key role in overcoming such a challenge. This work primarily aims at studying steam gasification of biomass with the presence of CaO in a uniquely designed chemical looping gasification (CLG) system for hydrogen Production with in situ CO 2 capture and Tar reduction. The effect of solid circulation rates on gas and Tar Production is studied. A comparison of CaO-CLG, sand-based chemical looping gasification (Sand-CLG) and CaO-based bubbling fluidized bed gasification (CaO-BFBG) is presented mainly focusing on gas and Tar Production. The maximum H 2 and minimum CO 2 concentrations as well as maximum H 2 yields of 78%, 4.98% and 451.11 ml (STP)/g of biomass, respectively, are obtained at the solid circulation rate of 1.04 kg/m 2 s. At the same point, the maximum total gas yield was 578.38 ml (STP)/g of biomass and the Tar content of 2.48 g/Nm 3 was the lowest. 30% higher concentration of H 2 and triple yield of H 2 were found in CaO-CLG compared to Sand-CLG. Compared to CaO-BFBG, CaO-CLG resulted in 15% higher concentration of H 2 and almost double yield of H 2 . Moreover, the lowest Tar content of 2.48 g/Nm 3 was obtained for CaO-CLG while the Tar content was 68.5 g/Nm 3 for Sand-CLG and 26.71 g/Nm 3 for CaO-BFBG. CO 2 concentration obtained for CaO-CLG also significantly reduced by 13–17% as compared to both Sand-CLG and CaO-BFBG.

  • effect of cao on Tar reforming to hydrogen enriched gas with in process co2 capture in a bubbling fluidized bed biomass steam gasifier
    International Journal of Hydrogen Energy, 2013
    Co-Authors: Jakkapong Udomsirichakorn, Prabir Basu, Abdul P Salam, Bishnu Acharya
    Abstract:

    Abstract Previous studies showed that calcium oxide (CaO), when added to a biomass steam gasifier, could play the role of both CO 2 sorbent and Tar reforming catalyst, and thereby produce more hydrogen. However, most of these works focused on the former role with little attention to Tar reforming aspect of CaO. Therefore, this work aims primarily at studying the Tar reforming effect of in-bed CaO. To this end, an in-depth analysis of the effect of CaO on Tar yield and composition is presented. The present work also studies the role of CaO as a CO 2 sorbent to enhance hydrogen Production from steam gasification of biomass in a bubbling fluidized bed. The influence of different operating parameters, temperature ( T ) and steam to biomass ( S / B ) ratio, as well as the effect of using in-bed CaO on gas and Tar Production is investigated. Results show that the maximum H 2 and minimum CO 2 concentration of 63.07% and 18.68%, respectively are obtained at T  = 650 °C and S / B  = 3.41. The maximum H 2 yield of 256.81 ml g −1 -biomass was obtained at T  = 700 °C and S / B  = 3.41, at which the minimum Tar content of 6.45 g N m −3 was also received. Compared to a bed of sand alone, a 20% higher H 2 concentration, an almost double H 2 yield and a 67% reduction in Tar content were obtained when a bed of CaO was used. Moreover, shifting the Tar species from higher to fewer ring structures as a result of in-bed CaO can reduce Tar dew point by 11 °C and Tar carcinogenic potential by almost 60%.

Adolfo Narros - One of the best experts on this subject based on the ideXlab platform.

  • air and air steam gasification of sewage sludge the influence of dolomite and throughput in Tar Production and composition
    Fuel, 2014
    Co-Authors: Elena Roche, Juan Manuel De Andrés, Adolfo Narros, María Encarnación Rodríguez
    Abstract:

    Abstract The influence of throughput (TR), steam and the use of dolomite (as primary catalyst) over the sewage sludge gasification products was investigated. For this purpose, experiments were conducted in an atmospheric fluidised bed reactor using air and air + steam as gasifying agents. The analysis of the results was mainly focussed on the gas composition, the gravimetric Tar Production, and the GC-detectable Tar composition (and dew point estimations). According to the obtained results, higher TRs decreased the H2 content of the produced gas and clearly increased the gravimetric Tar Production. The use of air + steam, especially in the presence of dolomite, increased the H2 content (between 20% and 36%) and decreased the gravimetric Tar Production over all the tested TR, reaching Tar removal efficiencies of up to 71%. Regarding the GC-detectable Tar, higher TRs increased the heavy polyaromatic hydrocarbons Production, steam slightly increased the water soluble Tar content while the use of dolomite decreased the yield of all the Tar classes except light aromatic hydrocarbons. Under the tested gasification conditions, the gas dew point never dropped below 110 °C, value far above the recommended temperature when the syngas is to be used for engine applications.

  • behaviour of dolomite olivine and alumina as primary catalysts in air steam gasification of sewage sludge
    Fuel, 2011
    Co-Authors: Juan Manuel De Andrés, Adolfo Narros, María Encarnación Rodríguez
    Abstract:

    Abstract Sewage sludge gasification assays were performed in an atmospheric fluidised bed reactor using air and air–steam mixtures as the gasifying agents. Dolomite, olivine and alumina are three well known Tar removal catalysts used in biomass gasification processing. However, little information is available regarding their performance in sewage sludge gasification. The aim of the current study was to learn about the influence of these three catalysts in the product distribution and Tar Production during sewage sludge gasification. To this end, a set of assays was performed in which the temperature (750–850 °C), the in-bed catalyst content (0, 10 and 15 wt.%) and the steam–biomass ratio (SB) in the range of 0–1 were varied with a constant equivalence ratio (ER) of 0.3. The results were compared to the results from gasification without a catalyst. We show that dolomite has the highest activity in Tar elimination, followed by alumina and olivine. In addition to improving Tar removal, the presence of water vapour and the catalysts increased the content of H 2 in the gases by nearly 60%.

  • Air-steam gasification of sewage sludge in a bubbling bed reactor: Effect of alumina as a primary catalyst
    Fuel Processing Technology, 2011
    Co-Authors: Juan Manuel De Andrés, Adolfo Narros, María Encarnación Rodríguez
    Abstract:

    Abstract Numerous references can be found in scientific literature regarding biomass gasification. However, there are few works related to sludge gasification. A study of sewage sludge gasification process in a bubbling fluidised bed gasifier on a laboratory scale is here reported. The aim was to find the optimum conditions for reducing the Production of Tars and gain more information on the influx of different operating variables in the products resulting from the gasification of this waste. The variables studied were the equivalence ratio (ER), the steam-biomass ratio (SB) and temperature. Specifically, the ER was varied from 0.2 to 0.4, the SB from 0 to 1 and the temperature from 750 °C (1023 K) to 850 °C (1123 K). Although it was observed that Tar Production could be considerably reduced (up to 72%) by optimising the gasification conditions, the effect of using alumina (aluminium oxide, of proven efficacy in destroying the Tar produced in biomass gasification) as primary catalyst in air and air-steam mixture tests was also verified. The results show that by adding small quantities of alumina to the bed (10% by weight of fed sludge) considerable reductions in Tar Production can be obtained (up to 42%) improving, at the same time, the lower heating value (LHV) of the gas and carbon conversion.