Thermogravimetric analysis (TGA) combined with X-ray diffraction (XRD) was used to identify miner... more Thermogravimetric analysis (TGA) combined with X-ray diffraction (XRD) was used to identify mineral phases and determine corrosion rates of granular iron samples from a 2-yr field column study. Similar to other studies, goethite, magnetite, aragonite, and calcite were found to be the major precipitated minerals, with Fe 2 (OH) 2 CO 3 and green rust as minor phases. Based on TGA-mass spectrometry (MS) analysis, Fe 0 corrodes at rates of 0.5-6.1 mmol kg -1 d -1 in the high NO 3 -(up to 13.5 mM) groundwater; this rate is significantly higher than previously reported. Porosity reduction was 40.6%-45.1% for the inlet sand/Fe 0 interface and 7.4%-25.6% for effluent samples of two test columns. Normalized for treatment volumes, porosity loss values are consistent with studies that use high levels of SO 4 2but are higher than those using low levels of corrosive species. Aqueous mass balance calculations yield corrosion rates similar to the TGA-MS method, providing an alternative to coring and mineralogical analysis. A severely corroded iron sample from the column simulating a 17-yr treatment throughput showed >75% porosity loss. Extensive porosity loss due to high levels of corrosive species in groundwater will have significant impact on long-term performance of permeable reactive barriers.
Through the use of a metal catalyst, gasification of wet biomass can be accomplished with high le... more Through the use of a metal catalyst, gasification of wet biomass can be accomplished with high levels of carbon conversion to gas at relatively low temperature (350°C). In a pressurized-water environment (20 MPa), near-total conversion of the organic structure of biomass to gases has been achieved in the presence of a ruthenium metal catalyst. The process is essentially steam reforming, as there is no added oxidizer or reagent other than water. In addition, the gas produced is a medium heating value gas due to the synthesis of high levels of methane, as dictated by thermodynamic equilibrium. While good gas production was demonstrated, biomass trace components caused some processing difficulties in the fixed catalyst bed tubular reactor system used for the catalytic gasification process. Results are described for tests using both benchscale and scaled-up reactor systems.
Through the use of a metal catalyst, gasification of wet biomass can be accomplished with high le... more Through the use of a metal catalyst, gasification of wet biomass can be accomplished with high levels of carbon conversion to gas at relatively low temperature (350 degrees Celsius). In the pressurized-water environment (3000 psig) near-total conversion of the organic structure of biomass to gases has been accomplished in the presence of a ruthenium metal catalyst. The process is essentially
ABSTRACT Wet macroalgal slurries have been converted into a biocrude by hydrothermal liquefaction... more ABSTRACT Wet macroalgal slurries have been converted into a biocrude by hydrothermal liquefaction (HTL) in a bench-scale continuous-flow reactor system. Carbon conversion to a gravity-separable oil product of 58.8% was accomplished at relatively low temperature (350 °C) in a pressurized (subcritical liquid water) environment (20 MPa) when using feedstock slurries with a 21.7% concentration of dry solids. As opposed to earlier work in batch reactors reported by others, direct oil recovery was achieved without the use of a solvent, and biomass trace mineral components were removed by processing steps so that they did not cause processing difficulties. In addition, catalytic hydrothermal gasification (CHG) was effectively applied for HTL byproduct water cleanup and fuel gas production from water-soluble organics. Conversion of 99.2% of the carbon left in the aqueous phase was demonstrated. As a result, high conversion of macroalgae to liquid and gas fuel products was found with low levels of residual organic contamination in byproduct water. Both process steps were accomplished in continuous-flow reactor systems such that design data for process scale-up was generated.
... 2. Development of Catalysts for Gasification Douglas C. Elliott,' L. John Sealock, Jr., ... more ... 2. Development of Catalysts for Gasification Douglas C. Elliott,' L. John Sealock, Jr., and Eddie G. Baker Pacific Northwest Laboratory,? ... In this paper, experiments are described which were used to evaluate a wide range of catalyst materials and support compositions. ...
A gasification system is under development at Pacific Northwest Laboratory that can be used with ... more A gasification system is under development at Pacific Northwest Laboratory that can be used with high-moisture biomass feedstocks. The system operates at 350 C and 205 atm using a liquid water phase as the processing medium. Since a pressurized system is used, the wet biomass can be fed as a slurry to the reactor without drying. Through the development of
A low-temperature (300 C to 375 C) hydrothermal organic destruction process is being evaluated to... more A low-temperature (300 C to 375 C) hydrothermal organic destruction process is being evaluated to help facilitate the removal of complexed radioactive species from bulk liquid components in Hanford tank waste. The work focuses on hydrothermal processing to destroy organic compounds that contribute to waste safety issues and organic complexants that promote the solubility of radioactive constituents such as {sup
The objective of this work is to evaluate and develop a low temperature hydrothermal process (HTP... more The objective of this work is to evaluate and develop a low temperature hydrothermal process (HTP) for the destruction of organics that are present wastes temporarily stored in underground tanks at the Hanford Site. Organic compounds contribute to tank waste safety issues, such as hydrogen generation. Some organic compounds act as complexants, promoting the solubility of radioactive constituents such as
A catalytic gasification system operating in a pressurized water environment has been developed a... more A catalytic gasification system operating in a pressurized water environment has been developed and refined at Pacific Northwest Laboratory (PNL) for over 12 years. Initial experiments were aimed at developing kinetics information for steam gasification of biomass in the presence of catalysts. The combined use of alkali and metal catalysts was reported for gasification of biomass and its components at
ABSTRACT Wet algae slurries can be converted into an upgradeable biocrude by hydrothermal liquefa... more ABSTRACT Wet algae slurries can be converted into an upgradeable biocrude by hydrothermal liquefaction (HTL). High levels of carbon conversion to gravity separable biocrude product were accomplished at relatively low temperature (350 °C) in a continuous-flow, pressurized (sub-critical liquid water) environment (20 MPa). As opposed to earlier work in batch reactors reported by others, direct oil recovery was achieved without the use of a solvent and biomass trace components were removed by processing steps so that they did not cause process difficulties. High conversions were obtained even with high slurry concentrations of up to 35 wt.% of dry solids. Catalytic hydrotreating was effectively applied for hydrodeoxygenation, hydrodenitrogenation, and hydrodesulfurization of the biocrude to form liquid hydrocarbon fuel. Catalytic hydrothermal gasification was effectively applied for HTL byproduct water cleanup and fuel gas production from water soluble organics, allowing the water to be considered for recycle of nutrients to the algae growth ponds. As a result, high conversion of algae to liquid hydrocarbon and gas products was found with low levels of organic contamination in the byproduct water. All three process steps were accomplished in bench-scale, continuous-flow reactor systems such that design data for process scale-up was generated.
Small‐scale tests (∼20 mL) were conducted with samples from Hanford underground storage tanks AN‐... more Small‐scale tests (∼20 mL) were conducted with samples from Hanford underground storage tanks AN‐102 and AN‐107 to assess the mechanisms for removing Sr‐90 and transuranics (TRU) from the liquid (supernatant) portion of the waste. The Sr‐90 and TRU must be removed (decontaminated), in addition to Cs‐137 and the entrained solids, before the supernatant can be disposed of as low‐activity waste. Experiments
Water Quality Research Journal of Canada - WATER QUAL RES J CAN, 2006
Activated carbon (AC) has been extensively used to remove trace metals, particularly arsenic, fro... more Activated carbon (AC) has been extensively used to remove trace metals, particularly arsenic, from water for a number of years. To date, attempts to quantify directly the concentration of arsenic in activated carbon using non-destructive methods have been limited. High-energy ion beam based particle induced X-ray emission (PIXE) is ideally suited to investigate the issues regarding the quantification of trace metals in solids. In this study, after the adsorption of arsenic on activated carbon, arsenic concentration in granular activated carbon (GAC) and powder activated carbon (PAC) were quantified using PIXE. The PIXE results were compared with atomic absorption spectrometry (AAS) and inductively coupled plasma (ICP) measurements. Some differences are observed between these measurements. The differences are greater in the case of GAC compared to PAC. These differences are mainly due to inhomogeneous structure of GAC and PAC, which includes the variable surface properties such as su...
... 2. Development of Catalysts for Gasification Douglas C. Elliott,' L. John Sealock, Jr., ... more ... 2. Development of Catalysts for Gasification Douglas C. Elliott,' L. John Sealock, Jr., and Eddie G. Baker Pacific Northwest Laboratory,? ... In this paper, experiments are described which were used to evaluate a wide range of catalyst materials and support compositions. ...
Thermogravimetric analysis (TGA) combined with X-ray diffraction (XRD) was used to identify miner... more Thermogravimetric analysis (TGA) combined with X-ray diffraction (XRD) was used to identify mineral phases and determine corrosion rates of granular iron samples from a 2-yr field column study. Similar to other studies, goethite, magnetite, aragonite, and calcite were found to be the major precipitated minerals, with Fe 2 (OH) 2 CO 3 and green rust as minor phases. Based on TGA-mass spectrometry (MS) analysis, Fe 0 corrodes at rates of 0.5-6.1 mmol kg -1 d -1 in the high NO 3 -(up to 13.5 mM) groundwater; this rate is significantly higher than previously reported. Porosity reduction was 40.6%-45.1% for the inlet sand/Fe 0 interface and 7.4%-25.6% for effluent samples of two test columns. Normalized for treatment volumes, porosity loss values are consistent with studies that use high levels of SO 4 2but are higher than those using low levels of corrosive species. Aqueous mass balance calculations yield corrosion rates similar to the TGA-MS method, providing an alternative to coring and mineralogical analysis. A severely corroded iron sample from the column simulating a 17-yr treatment throughput showed >75% porosity loss. Extensive porosity loss due to high levels of corrosive species in groundwater will have significant impact on long-term performance of permeable reactive barriers.
Through the use of a metal catalyst, gasification of wet biomass can be accomplished with high le... more Through the use of a metal catalyst, gasification of wet biomass can be accomplished with high levels of carbon conversion to gas at relatively low temperature (350°C). In a pressurized-water environment (20 MPa), near-total conversion of the organic structure of biomass to gases has been achieved in the presence of a ruthenium metal catalyst. The process is essentially steam reforming, as there is no added oxidizer or reagent other than water. In addition, the gas produced is a medium heating value gas due to the synthesis of high levels of methane, as dictated by thermodynamic equilibrium. While good gas production was demonstrated, biomass trace components caused some processing difficulties in the fixed catalyst bed tubular reactor system used for the catalytic gasification process. Results are described for tests using both benchscale and scaled-up reactor systems.
Through the use of a metal catalyst, gasification of wet biomass can be accomplished with high le... more Through the use of a metal catalyst, gasification of wet biomass can be accomplished with high levels of carbon conversion to gas at relatively low temperature (350 degrees Celsius). In the pressurized-water environment (3000 psig) near-total conversion of the organic structure of biomass to gases has been accomplished in the presence of a ruthenium metal catalyst. The process is essentially
ABSTRACT Wet macroalgal slurries have been converted into a biocrude by hydrothermal liquefaction... more ABSTRACT Wet macroalgal slurries have been converted into a biocrude by hydrothermal liquefaction (HTL) in a bench-scale continuous-flow reactor system. Carbon conversion to a gravity-separable oil product of 58.8% was accomplished at relatively low temperature (350 °C) in a pressurized (subcritical liquid water) environment (20 MPa) when using feedstock slurries with a 21.7% concentration of dry solids. As opposed to earlier work in batch reactors reported by others, direct oil recovery was achieved without the use of a solvent, and biomass trace mineral components were removed by processing steps so that they did not cause processing difficulties. In addition, catalytic hydrothermal gasification (CHG) was effectively applied for HTL byproduct water cleanup and fuel gas production from water-soluble organics. Conversion of 99.2% of the carbon left in the aqueous phase was demonstrated. As a result, high conversion of macroalgae to liquid and gas fuel products was found with low levels of residual organic contamination in byproduct water. Both process steps were accomplished in continuous-flow reactor systems such that design data for process scale-up was generated.
... 2. Development of Catalysts for Gasification Douglas C. Elliott,' L. John Sealock, Jr., ... more ... 2. Development of Catalysts for Gasification Douglas C. Elliott,' L. John Sealock, Jr., and Eddie G. Baker Pacific Northwest Laboratory,? ... In this paper, experiments are described which were used to evaluate a wide range of catalyst materials and support compositions. ...
A gasification system is under development at Pacific Northwest Laboratory that can be used with ... more A gasification system is under development at Pacific Northwest Laboratory that can be used with high-moisture biomass feedstocks. The system operates at 350 C and 205 atm using a liquid water phase as the processing medium. Since a pressurized system is used, the wet biomass can be fed as a slurry to the reactor without drying. Through the development of
A low-temperature (300 C to 375 C) hydrothermal organic destruction process is being evaluated to... more A low-temperature (300 C to 375 C) hydrothermal organic destruction process is being evaluated to help facilitate the removal of complexed radioactive species from bulk liquid components in Hanford tank waste. The work focuses on hydrothermal processing to destroy organic compounds that contribute to waste safety issues and organic complexants that promote the solubility of radioactive constituents such as {sup
The objective of this work is to evaluate and develop a low temperature hydrothermal process (HTP... more The objective of this work is to evaluate and develop a low temperature hydrothermal process (HTP) for the destruction of organics that are present wastes temporarily stored in underground tanks at the Hanford Site. Organic compounds contribute to tank waste safety issues, such as hydrogen generation. Some organic compounds act as complexants, promoting the solubility of radioactive constituents such as
A catalytic gasification system operating in a pressurized water environment has been developed a... more A catalytic gasification system operating in a pressurized water environment has been developed and refined at Pacific Northwest Laboratory (PNL) for over 12 years. Initial experiments were aimed at developing kinetics information for steam gasification of biomass in the presence of catalysts. The combined use of alkali and metal catalysts was reported for gasification of biomass and its components at
ABSTRACT Wet algae slurries can be converted into an upgradeable biocrude by hydrothermal liquefa... more ABSTRACT Wet algae slurries can be converted into an upgradeable biocrude by hydrothermal liquefaction (HTL). High levels of carbon conversion to gravity separable biocrude product were accomplished at relatively low temperature (350 °C) in a continuous-flow, pressurized (sub-critical liquid water) environment (20 MPa). As opposed to earlier work in batch reactors reported by others, direct oil recovery was achieved without the use of a solvent and biomass trace components were removed by processing steps so that they did not cause process difficulties. High conversions were obtained even with high slurry concentrations of up to 35 wt.% of dry solids. Catalytic hydrotreating was effectively applied for hydrodeoxygenation, hydrodenitrogenation, and hydrodesulfurization of the biocrude to form liquid hydrocarbon fuel. Catalytic hydrothermal gasification was effectively applied for HTL byproduct water cleanup and fuel gas production from water soluble organics, allowing the water to be considered for recycle of nutrients to the algae growth ponds. As a result, high conversion of algae to liquid hydrocarbon and gas products was found with low levels of organic contamination in the byproduct water. All three process steps were accomplished in bench-scale, continuous-flow reactor systems such that design data for process scale-up was generated.
Small‐scale tests (∼20 mL) were conducted with samples from Hanford underground storage tanks AN‐... more Small‐scale tests (∼20 mL) were conducted with samples from Hanford underground storage tanks AN‐102 and AN‐107 to assess the mechanisms for removing Sr‐90 and transuranics (TRU) from the liquid (supernatant) portion of the waste. The Sr‐90 and TRU must be removed (decontaminated), in addition to Cs‐137 and the entrained solids, before the supernatant can be disposed of as low‐activity waste. Experiments
Water Quality Research Journal of Canada - WATER QUAL RES J CAN, 2006
Activated carbon (AC) has been extensively used to remove trace metals, particularly arsenic, fro... more Activated carbon (AC) has been extensively used to remove trace metals, particularly arsenic, from water for a number of years. To date, attempts to quantify directly the concentration of arsenic in activated carbon using non-destructive methods have been limited. High-energy ion beam based particle induced X-ray emission (PIXE) is ideally suited to investigate the issues regarding the quantification of trace metals in solids. In this study, after the adsorption of arsenic on activated carbon, arsenic concentration in granular activated carbon (GAC) and powder activated carbon (PAC) were quantified using PIXE. The PIXE results were compared with atomic absorption spectrometry (AAS) and inductively coupled plasma (ICP) measurements. Some differences are observed between these measurements. The differences are greater in the case of GAC compared to PAC. These differences are mainly due to inhomogeneous structure of GAC and PAC, which includes the variable surface properties such as su...
... 2. Development of Catalysts for Gasification Douglas C. Elliott,' L. John Sealock, Jr., ... more ... 2. Development of Catalysts for Gasification Douglas C. Elliott,' L. John Sealock, Jr., and Eddie G. Baker Pacific Northwest Laboratory,? ... In this paper, experiments are described which were used to evaluate a wide range of catalyst materials and support compositions. ...
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