Alan E. Bland

Pressurized fluidized bed combustion ash 2. Soil and mine spoil amendment use options

Abstract The commercial introduction of pressurized fluidized bed combustion (PFBC) has spurred evaluation of ash management options for this technology. ashes used in this study were produced in the Foster Wheeler Energia Oys circulating PFBC pilot facility in Karhula, Finland and the American Electric Power Tidd PFBC facility in Ohio. The fly ashes contain numerous compounds, including calcite (CaCO 3 ), anhydrite (CaSO 4 ) and, in the Tidd fly ash, dolomite [CaMg(CO 3 ) 2 ], that have the potential to be a nutrient source and a soil amendment for the reclamation of acid and sodic soils (soils influenced by high levels of sodium). The objective of this research was to determine if the PFBC ash could be used as soil amendments for acid and sodic soils. The research effort consisted of three separate tests: (1) a laboratory equilibration study to determine the influence of fly ash amendments on pH and EC (electrical conductivity) of actively oxidizing, acid-forming, mine spoil material; (2) a greenhouse study to determine the influence of fly ash on plant growth; and (3) a hydraulic conductivity evaluation of sodic soils treated with the PFBC fly ash materials. The study showed that the PFBC fly ashes were effective acid spoil amendments. In a comparison with ag-lime, the fly ash reacted with the spoil at a slower rate and the final pH of the treated material was slightly lower (∼7 versus ∼8). In addition, the EC of the fly-ash-treated spoil was ∼1 mS cm −1 higher than that associated with the ag-lime-treated materials. The greenhouse study demonstrated that the fly ash was an effective amendment for the remediation of acid spoil materials. In fact, the soils amended with fly ash supported higher plant production than those amended with ag-lime. These findings are possibly due to pH and nutritional effects. The hydraulic conductivity study demonstrated that the application of fly ash to sodic soils resulted in enhanced permeability of the treated soil.

Pressurized fluidized bed combustion ash 1. Construction-related use options

Ash collected from the low-sulfur subbituminous coal-fired Foster Wheeler Energia Oy pilot-scale circulating PFBC tests in Karhula, Finland, and from AEPs high-sulfur bituminous coal-fired bubbling PFBC in Brilliant, Ohio, were evaluated in laboratory and pilot-scale ash use tests. Options evaluated for these ashes were construction-related applications, such as cement production, fills and embankment, soil stabilization and synthetic aggregate production, as well as an amendment for acidic and sodic soil and mine spoil as described in Part 2 of this paper. The tests related to construction applications, described herein, led to the following conclusions. (1) PFBC ash does not meet the ASTM chemical requirements as a pozzolan for cement replacement (ASTM C618). However, there is potential for its use as a pozzolan and as a set-retardant (gypsum replacement) in type-IP Portland cement production. (2) PFBC ash shows relatively high strength development ( > 2.75 MPa), low expansion ( 27.5 MPa), manageable early expansion, and whet-dry and freeze-thaw cycle durability ( 135 kg), resistance to Los Angeles (LA) abrasion resistance (10-30 wt% loss) and soundness resistance (< 5%), making the ash an excellent material for synthetic aggregate production for construction applications. In summary, PFBC ash appears to be a viable material for use in a number of construction-related applications.

MARKET ASSESSMENT AND TECHNICAL FEASIBILITY STUDY OF PRESSURIZED FLUIDIZED BED COMBUSTION ASH USE

Western Research Institute, in conjunction with the Electric Power Research Institute, Foster Wheeler International, Inc. and the US Department of Energy, has undertaken a research and demonstration program designed to examine the market potential and the technical feasibility of ash use options for PFBC ashes. Ashes from the Foster Wheeler Energia Oy pilot-scale circulating PFBC tests in Karhula, Finland, combusting (1) low-sulfur subbituminous and (2) high-sulfur bituminous coal, and ash from the AEPs high-sulfur bituminous coal-fired bubbling PFBC in Brilliant, Ohio, were evaluated in laboratory and pilot-scale ash use testing at WR1. The technical feasibility study examined the use of PFBC ash in construction-related applications, including its use as a cementing material in concrete and use in cement manufacturing, fill and embankment materials, soil stabilization agent, and use in synthetic aggregate production. Testing was also conducted to determine the technical feasibility of PFBC ash as a soil amendment for acidic and sodic problem soils and spoils encountered in agricultural and reclamation applications. The results of the technical feasibility testing indicated the following conclusions. PFBC ash does not meet the chemical requirements as a pozzolan for cement replacement. However, it does appear that potential may exist for its use in cement production as a pozzolan and/or as a set retardant. PFBC ash shows relatively high strength development, low expansion, and low permeability properties that make its use in fills and embankments promising. Testing has also indicated that PFBC ash, when mixed with low amounts of lime, develops high strengths, suitable for soil stabilization applications and synthetic aggregate production. Synthetic aggregate produced from PFBC ash is capable of meeting ASTM/AASHTO specifications for many construction applications. The residual calcium carbonate and calcium sulfate in the PFE3C ash has been shown to be of value in making PFBC ash a suitable soil amendment for acidic and sodic problem soils and mine spoils. In conclusion, PFBC ash represents a viable material for use in currently established applications for conventional coal combustion ashes. As such, PFBC ash should be viewed as a valuable resource, and commercial opportunities for these materials should be explored for planned PFBC installations.

Hydrogen Storage on Carbon Adsorbents

Publisher Summary Global energy demand and global warming due to greenhouse gas emissions have spurred intensive research for alternative fuel. Hydrogen (H 2 ), an ideal energy carrier, is obviously a promising candidate. Its use efficiency is high; for instance, it is 2.75 times greater than gasoline for the same weight. The onboard storage of H 2 is obviously one of the most, if not the most, critical issues in developing an H 2 -based energy system. H 2 can be produced indirectly from coal gasification and reforming processes for which advanced technologies are available; these processes, combined with carbon dioxide (CO 2 ) separation and sequestration, have the potential to manufacture substantial quantities of H 2 with minimum greenhouse gas emissions. Synthesized H 2 can be deployed to generate electricity from fuel cells; alternatively, it can be combusted for providing energy for space heating, replacing natural gas in industry, and fueling aircraft. The most promising method for H 2 storage appears to be through materials-based storage technologies, which are inherently safe and should be more energy efficient than pressurization or liquefaction.Publisher Summary Global energy demand and global warming due to greenhouse gas emissions have spurred intensive research for alternative fuel. Hydrogen (H2), an ideal energy carrier, is obviously a promising candidate. Its use efficiency is high; for instance, it is 2.75 times greater than gasoline for the same weight. The onboard storage of H2 is obviously one of the most, if not the most, critical issues in developing an H2-based energy system. H2 can be produced indirectly from coal gasification and reforming processes for which advanced technologies are available; these processes, combined with carbon dioxide (CO2) separation and sequestration, have the potential to manufacture substantial quantities of H2 with minimum greenhouse gas emissions. Synthesized H2 can be deployed to generate electricity from fuel cells; alternatively, it can be combusted for providing energy for space heating, replacing natural gas in industry, and fueling aircraft. The most promising method for H2 storage appears to be through materials-based storage technologies, which are inherently safe and should be more energy efficient than pressurization or liquefaction.

CHAPTER 7 – Hydrogen Storage on Carbon Adsorbents: A Review

Publisher Summary Global energy demand and global warming due to greenhouse gas emissions have spurred intensive research for alternative fuel. Hydrogen (H 2 ), an ideal energy carrier, is obviously a promising candidate. Its use efficiency is high; for instance, it is 2.75 times greater than gasoline for the same weight. The onboard storage of H 2 is obviously one of the most, if not the most, critical issues in developing an H 2 -based energy system. H 2 can be produced indirectly from coal gasification and reforming processes for which advanced technologies are available; these processes, combined with carbon dioxide (CO 2 ) separation and sequestration, have the potential to manufacture substantial quantities of H 2 with minimum greenhouse gas emissions. Synthesized H 2 can be deployed to generate electricity from fuel cells; alternatively, it can be combusted for providing energy for space heating, replacing natural gas in industry, and fueling aircraft. The most promising method for H 2 storage appears to be through materials-based storage technologies, which are inherently safe and should be more energy efficient than pressurization or liquefaction.Publisher Summary Global energy demand and global warming due to greenhouse gas emissions have spurred intensive research for alternative fuel. Hydrogen (H2), an ideal energy carrier, is obviously a promising candidate. Its use efficiency is high; for instance, it is 2.75 times greater than gasoline for the same weight. The onboard storage of H2 is obviously one of the most, if not the most, critical issues in developing an H2-based energy system. H2 can be produced indirectly from coal gasification and reforming processes for which advanced technologies are available; these processes, combined with carbon dioxide (CO2) separation and sequestration, have the potential to manufacture substantial quantities of H2 with minimum greenhouse gas emissions. Synthesized H2 can be deployed to generate electricity from fuel cells; alternatively, it can be combusted for providing energy for space heating, replacing natural gas in industry, and fueling aircraft. The most promising method for H2 storage appears to be through materials-based storage technologies, which are inherently safe and should be more energy efficient than pressurization or liquefaction.