Since we got started digging in the USDOE's garden, we've been able to turn up some root crops, growing just below the surface, that weren't easy to find and everyone seems to have overlooked.
In addition to the NETL's survey of coal liquefaction technologies we earlier posted, we've discovered the DOE has been looking into another subject; now a controversial one among some of us it seems, but still one that all in US Coal Country should be talking about.
We've documented that the US Department of Defense holds patents on CO2 recycling, and the Department of Energy, as per the enclosed, seems interested in following suit, albeit along a different path.
As we've reported, there is interest in, and research being done on, the use of algae, cultivated in "bioreactors", to capture Carbon Dioxide that might be emitted from point sources, such as power generation plants, and using waste heat generated by those sources to support more rapid growth of the algae.
The algae can then be processed, as we've earlier documented, to yield products as varied as jet fuel and farm animal feed.
Not only that, but: The USDOE posits herein that Carbon Dioxide not consumed by algae can then be reacted with the fly ash by-product of coal combustion, and thereby form stable carbonate minerals which can be safely disposed of as solid waste near their point of production - even as mine backfill.
And, according to the DOE, that solves a problem we've previously pointed out, because it would: "eliminate the expense of locating suitable underground storage areas and costs of pumping stack gas over long distances" to nearly-depleted petroleum reservoirs, one supposes.
Carbon recycling through the farming of algae, and the chemical fixation of Carbon Dioxide with Coal Combustion Products, it turns out, are both topics of synergistic research and development within the US Department of Energy, as the following excerpt from the enclosed link attests:
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| United States Department of Energy | |
| Office of Fossil Energy | |
| Project Fact Sheet | |
| | |
| Project Information | |
| Project ID: | DE-FC26-00NT40933 |
| Project Title: | Chemical Fixation of CO2 in Coal Combustion Products and Recycling Through Algal Biosystems |
| FE Program: | Adv. Power - Supporting Research and Environmental Technology |
| Research Type: | Basic Research |
| Funding Memorandum: | Cooperative Agree't (nonCCT) - Tech R&D |
| Project Performer | |
| Performer Type: | U.S. Government Agency |
| Performer: | Tennessee Valley Authority 3J Lookout Place 1101 Market Street |
| Project Team Members: | |
| Project Location | |
| City: | Chattanooga |
| State: | Tennessee |
| Zip Code: | 37402-2801 |
| Congressional District: | 03 |
| Responsible FE Site: | NETL |
| Project Point of Contact | |
| Name: | Copeland, Robert |
| Telephone: | (303) 940-2323 |
| Fax Number: | |
| Email Address: | copeland@tda.com |
| Fossil Energy Point of Contact | |
| Name: | Figueroa, Jose D. |
| Telephone: | (412) 386-4966 ext. 4966 |
| Location: | NETL |
| Email Address: | jose.figueroa@netl.doe.gov |
| Project Dates | |
| Start Date: | 10/01/2000 |
| End Date: | 09/30/2003 |
| Contract Specialist | |
| Name: | Pearse, Mary Beth J. |
| Telephone: | (412) 386-4949 |
| Cost & Funding Information | |
| Total Est. Cost: | $755,291 |
| DOE Share: | $604,233 |
| Non DOE Share: | $151,058 |
| Project Description | |
| The overall objective is to develop basic methods for use of coal combustion products (CCP) produced at fossil fuel power plants as a sequestering medium for CO2 in stack gas from gas turbine plants, with subsequent production of methane and other recyclable carbon-containing products from the system. | |
| Project Background | |
| A research area under consideration by DOE to address carbon sequestration is pumping of CO2 to underground geologic formations, such as coal beds, to displace and recover methane. A more effective and economical alternative may be the use of coal combustion products (CCP) produced at fossil fuel power plants as a sequestering medium for CO2, with subsequent production of methane and other recyclable carbon-containing products from this system. Each year in the U.S., about 22 million metric tons of fly ash and flue gas desulfurization products (FGD) are stored on power plant sites in vast ponds or other disposal areas. Such CCP may serve as a sink for CO2 and eliminate the expense of locating suitable underground storage areas and costs of pumping stack gas over long distances. Conceptually, these impoundments may function as large reaction vessels wherein the fly ash and FGD, due to their large surface area and the presence of a surface electrical charge, might serve as highly reactive media for sequestration of the CO2 produced by gas turbine generators. After suitable adjustments to system pH, adsorption and exchange reactions of CO2 in the sterile CCP medium, followed by precipitation as carbonates, would maintain carbon in an inorganic, stable form and prevent reintroduction into the carbon cycle for an indefinite period. When economically feasible, the CCP might be used as flowable fill material for construction or could be back-hauled and used to fill underground mine voids. The carbon-enriched CCP media may also be used to create an algae biosystem, which is expected to extract and utilize carbon compounds sequestered in the CCP. Stack gas diverted into the biosystem will expose the algae to additional CO2. The CCP will provide a nutrient growth matrix for the algae, and more importantly, should provide the critical mechanism needed to increase the available CO2 in solution above the limits that are achievable with the dissolved gas alone. This would most likely increase algal growth beyond what is normally attainable. Carbon in the algal biomass can then be extracted and converted to hydrogen gas with a gasifier or converted to liquid CO2. An anaerobic digestor in the system may be used to convert the biomass into methane for on-site use in a gas turbine generator. The solid biomass residue from the digestor may be re-cycled as additional fuel stock for the gasifier. The liquid residue from the digestor may be re-cycled to provide nutrients to perpetuate the algal biosystem. The system provides for continued cycling of sequestered carbon within the system. Being solar driven, the CCP biosystem requires minimal inputs of energy and materials, and solves the energy storage problems associated with the photovoltaic cells of a solar collection system. The turnaround time for biomass production in the system is short, since it is not limited by transpiration or sunlight exposure, as would be terrestrial plants. A reasonable estimate for the area of algal biomass required to generate methane to support a 1000 MW gas turbine plant would be in the range of 2.5 - 25km2. The primary limiting factor for biosystem output would be the time required for the system to reach steady-state production of algae, methane, hydrogen, and liquid CO2. | |
| Project Milestones | |
| This information is currently unavailable. | |
| Project Accomplishments | |
| Title: | Technical Assessment |
| Date: | 10/17/2002 |
| Description | Conversion of CO2 to bicarbonate using fly ash as a catalyst. The rate of uptake of CO2 in a fly ash column id 5 to 9 times the rate of uptake in the control column containing glass beads. At 1.5 hours the fly ash column ph was 6.5 while the glass bead column was 5.6. This indicates the fly ash has a capacity to buffer the solution. At a ph of 6.5 the bicarbonate using the fly ash column was double that of the glass beads. The ph and higher bicarbonate level from the fly ash column are more suitable for biological systems than the glass bead column. Signifcantly increases in biomass production can be obtained by supplementing the algae growth medium with additional bicarbonate. The annual production of biomass from an algae facility could be in excess of 150 metric tons per hectare (74 metric tons per year)" |
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Now, in honesty, we don't know how promising "150 metric tons (of biomass) per hectare", per year presumably, might be. But, we suppose they are talking about open ponds, as opposed to more compact columns, as other researchers have proposed. And, it is still a big step in the right direction. Algae farming could be another piece of the complete puzzle of supplying our United States liquid fuel needs, through the liquefaction of coal and the direct recycling of Carbon Dioxide. By combining algal recycling and, perhaps, direct Sabatier or Carnol conversion of CO2 into methane and methanol, along with reacting any excess CO2 with Coal Combustion Products to form stable carbonate minerals for disposal in nearby, exhausted, underground mine works, we might not have to pump CO2 through any more than a few hundred feet of pipeline - certainly not across a state, or a state line, to get it into some leaky oil field that might not, as research from the Colorado School of Mines we've reported suggests, hold the gas underground, anyway.
But, one point that shouldn't be missed is the concept of: "Conversion of CO2 to bicarbonate using fly ash as a catalyst". In other words, one coal combustion by-product, fly ash, can improve the efficiency of capturing another coal combustion by-product, CO2, and turning it into a solid chemical that can be more easily handled, doesn't have to be transported over long distances for storage, and which might have some commercial uses.
The synergies are everywhere.