Vision 21 Fossil Fuel Options for the Future (2000) / Chapter Skim
Currently Skimming:
4 Supporting Technologies and Systems Integration
4 Supporting Technologies and Systems Integration
Pages 61-84
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 61... ...
As distinct from the development of "hardware" (i.e., enabling and support component technologies for Vision 21 energy plants) , the development of "software" involves using computer-based tools for designing and analyzing plant configurations.
|
From page 62... ...
Program projects, and the NETL facilities could be used for the sequential and concurrent development and testing of component technologies. Modifications and sidestream tests could be done at CCT plants, particularly IGCC plants, to test breakthroughs or evolve processes.
|
From page 63... ...
Although reasonably sophisticated mechanistic models may indeed become available for some Vision 21 components, the committee believes it very unlikely that the level of detail described in the plan will be possible for most of Vision 21's advanced technologies. Furthermore, integrating component models of this complexity into an overall systems model of a Vision 21 plant is likely to be extremely cumbersome and time consuming at best, and completely unworkable at worst.
|
From page 64... ...
In addition to models of specific Vision 21 plant designs, the program will need modeling capabilities to assess the market potential for these technologies in the context of the overall energy picture. Tools such as the National Energy Modeling System (NEMS)
|
From page 65... ...
should make facilities at the Power Systems Development Facility, all of the Clean Coal Technology (CCT) Program projects, and the National Energy Technology Laboratory facilities available for sequential and concurrent development and testing of Vision 21 component technologies.
|
From page 66... ...
materials and production technologies development of catalytic materials for gas purification Although the ATS is an integral part of the Vision 21 Program, work on the ATS is carried out in a separate DOE program for the development of advanced gas turbine materials that can withstand 1,500°C to 1,650°C firing temperatures. The goal of materials research for the ATS is to improve the performance and durability of thermal barrier coatings-substrate materials, as applied to turbine blades in advanced land-based gas turbines.
|
From page 67... ...
The separation of hydrogen from carbon dioxide is also critical because pure hydrogen is the preferred reactant for fuel cells. The focus of an R&D program on hydrogen separation would be to minimize the energy and capital costs of the separation process.
|
From page 68... ...
High-temperature heat exchangers will also be required in high-efficiency fuel cell power systems for preheating fuel and air reactant streams and/or to make use of the hot combustion-product exhaust stream. Heat exchangers will have to be able to tolerate top temperatures of 760°C to 870°C in either oxidizing or reducing conditions and pressure differences of 2 to 4 atmospheres over the surface.
|
From page 69... ...
. Therefore, the availability of low-cost materials for advanced solid-oxide fuel cells should be considered a critical element of the Vision 21 Program.
|
From page 70... ...
Recently developed ODS alloys should be evaluated and tested for high-strength requirements at or above 1,100°C because traditional ingot-processed alloys are not strong enough to perform at this temperature. ODS alloys could be used for high-temperature heat exchangers at potentially lower cost.
|
From page 71... ...
Although some work on materials-related R&D is being performed by private industries (with partial funding from DOE) , additional work will be necessary for materials development for next-generation solid-oxide fuel cells.
|
From page 72... ...
Balance in the Portfolio Environmental control techniques include reducing emissions of NOX, SOx, particulates, mercury, organics, and trace metals, as well as minimizing emissions of CO2 and solid waste. The timelines for implementing controls are not specified in detail.
|
From page 73... ...
The control of fine particulates, an area that has been widely studied and will play a critical role in the reduction of ozone levels and acid rain, will require a fresh and more fundamental approach than the one that can be inferred from the Vision 21 Program Plan. Based on the results of parallel programs in DOE currently addressing automotive-related emissions control, early Vision 21 research should focus on the fundamentals of catalytic reactions of NOx and SOx, which react and condense in the atmosphere to produce fine particulates.
|
From page 74... ...
In keeping with this trend, Vision 21 should concentrate its R&D on strategies that yield more concentrated carbon dioxide effluent streams and novel sequestration technologies. Vision 21 should clearly differentiate between improvements in current technologies for capturing carbon dioxide that are part of DOE's current baseline program and the breakthrough technologies that Vision 21 plants will require.
|
From page 75... ...
Effective Vision 21 management will be necessary for these advanced new concepts to be incorporated into Vision 21 technologies. Advances in emissions control technologies are likely to require the application of newly emerging theoretical and experimental methods to a greater extent than for past emissions control challenges.
|
From page 76... ...
Department of Energy's ongoing program. Vision 21 should focus on much larger and more fundamental issues, such as the removal of NOx, sulfur dioxide, metals, and other toxins from effluent streams, evolutionary and revolutionary technologies for capturing carbon dioxide, and other separation technologies.
|
From page 77... ...
Gas streams for the operation of water-gas shift, hydrogen membranes, and electrodes must have fewer impurities if the product will be used for fuel cells. If the focus of Vision 21 is on gasification as the committee recommends, gas-stream purification will require R&D on high-temperature particulate filters and contaminant-removal technologies.
|
From page 78... ...
Contaminant-Removal Technologies Contaminant removal (i.e., the removal of sulfur, ammonia, mercury, and trace metals) will be critical to the high-efficiency process concepts proposed in Vision 21.
|
From page 79... ...
R&D on cold-gas cleanup should be continued both as an alternative to hot-gas cleanup and as a way to satisfy the potentially more stringent constraints for systems with fuel cells as the power-generating system. The milestones in the current plan will have to be revised to include the temperatures of streams at which the intended separations must take place.
|
From page 80... ...
Vision 21 should establish clear milestones to measure progress and should frequently assess the economic feasibility of the new technologies. The current program plan addresses the following key technologies: · ceramic membranes for oxygen production · high-temperature membranes for hydrogen production · carbon dioxide-hydrate separation for hydrogen production · hydrogen production from water dissociation Ceramic Membranes for Oxygen Production In partnership with DOE, an industry-led team has been aggressively developing an ion-transport membrane for oxygen separation.
|
From page 81... ...
Pure hydrogen is not only the preferred reactant for fuel cells, it can also be used to increase the ratio of hydrogen to carbon monoxide, thus broadening the range of fuel and chemical products that can be made from synthesis gas (carbon monoxide and hydrogen)
|
From page 82... ...
selectivity, and lifetimes, Vision 21 should conduct an independent economic assessment of advanced hydrogen-separation membrane technology, including associated cost uncertainties and a comparison with conventional hydrogenrecovery technology, before initiating a major development program. Carbon Dioxide Hydrate-Based Technology Numerous commercial processes for capturing carbon dioxide from gas mixtures are widely used in the refining industry (EPRI, 1991~.
|
From page 83... ...
Subsequent process evaluations have indicated that the carbon dioxide hydrate removal process may be able to operate at very low temperature and remove more than 80 percent of the carbon dioxide from a syngas stream in an IGCC plant while consuming less energy and at lower capital cost than for a commercial amine process (Spencer and White, 1998~. Although these preliminary results are encouraging, the findings have not been verified independently by a third party.
|
From page 84... ...
Presentation by Robert Romanosky, Federal Energy Technology Center, to the Committee on R&D Opportunities for Advanced Fossilfueled Energy Complexes, National Research Council, Washington, D.C., May 30, 1999. Romanosky, R
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.