4. ADVANCED COAL RESEARCH

 

For the foreseeable future, the energy needed to reduce our dependence on imported foreign oil and sustain economic growth will continue to come largely from fossil fuels.  However, in supplying this energy need, the Nation must address growing global and regional environmental concerns, supply issues, and energy prices. Maintaining low-cost energy in the face of growing demand, diminishing supply, and increasing environmental pressure requires new technologies and diversified energy supplies.  These technologies must allow the Nation to use all of its indigenous resources more wisely, cleanly, and efficiently.  These resources include the Nation’s most abundant and lowest cost resource, coal. 

 

Grant applications are sought only in the following subtopics:

 

 

a. Coal and Biomass-to-Liquids (CBTL) Catalyst Development—As oil prices continue to rise, the production of fuels from sources such as biomass or coal once again appear attractive.  Feedstocks composed of mixed biomass and coal could result in neutral or negative carbon emissions, reducing the impact on global warming.  In particular, fuels produced from Fischer-Tropsch synthesis (FTS) are premium products with low aromaticity, zero sulfur, and high energy content, resulting in ultra-clean transportation fuels with minimum tailpipe emissions.  In this process, catalysts are used to hasten CO hydrogenation reactions for the desired products; avoid wide varieties of competing reactions; lower the temperature and pressure; maintain activity and selectivity in stable operation for long periods of time; and in some cases, accelerate the water gas reaction. 

 

Bio-catalysis also may find application in the conversion of syngas to fuels.  A preliminary evaluation indicated that microorganisms could produce alcohols (up to C3), acetic/propionic acid, and acetone from syngas.  For some strains, the preliminary results showed slow CO conversion (40%) to alcohols, predominately ethanol.  The current emphasis has shifted towards maximizing the yield of high-cetane (C10-C20) products from Fischer-Tropsch synthesis.

 

Grant applications are sought for novel and innovative catalytic improvements that could contribute significantly to more economical manufacturing of synthetic liquid fuels from coal/biomass-derived syngas.  One possible approach involves the development of catalysts with higher selectivity to molecular species, which would be useful in the production of high performance fuels.  For hydrocarbons, this means conversion (preferably in one step) to high octane gasoline components, diesel fractions, or olefins, which in turn can be converted to liquid fuels.  For oxygenates, this means the production of octane-enhancing ethanol or higher mixed alcohols.  Other approaches of interest include:  (1) catalysts that eliminate or greatly reduce methane formation, particularly in FT processes or in higher alcohol manufacture; (2) catalysts that provide for operation of process modes, which are engineered to improve plant investment and operating costs (e.g., a catalytic slurry system that can control heat release and decrease the requirements for syngas recycle); (3) catalysts with higher stability, thereby providing resistance to attrition or to deactivation by carbon deposition, sulfur, or halides; and (4) catalyst systems capable of providing better efficiency through process integration.

 

Proposed approaches must be novel and innovative, and show clear economic advantages over the existing state of the art.

 

Questions - contact Doug Archer (douglas.archer@hq.doe.gov)    

 

 

b. Development of New and Novel CO2 Monitoring Devices/Sensor for Detection of Low Levels of CO2 in the Surface and Subsurface—Carbon sequestration has emerged as a key potential technology pathway for the reduction of greenhouse gas emissions associated with fossil fuel power plants.  Because potential reservoir leakage paths are not known, monitoring will be required over large areas above and around the reservoirs.  In addition, many of the injection sites could be miles from the power plant, requiring miles of above-ground or buried pipe.  The relative background levels of CO2 present in the atmosphere and soil make detection of small levels of CO2 leaks difficult.  Therefore, grant applications are sought to accelerate the development of low-cost sensors for the detection of low levels of CO2 in the surface and subsurface.  Proposed approaches must:  (1) address the practical problem of deployment, (2) address practical and low cost methods to monitoring and maintain the sensors along the CO2 stream and reservoir, (3) address risk, safety, and economic considerations with respect to the type of geological sequestration reservoirs, and (4) recommend at least one candidate site for viability of commercial-scale testing of the sensors and sensor arrays by industry.

 

Questions – contact Regis Conrad (regis.conrad@hq.doe.gov)

 

 

c. Sealing Systems for High Temperature Solid Oxide Fuel Cells—High temperature (650C to 850C) solid oxide fuel cell (SOFC) stacks involve the formation of alternating fuel and air chambers, which are sealed from each other and connected to gas flow delivery manifolds.  The planar walls of the chambers are the cells and interconnect plates.  A common stack configuration utilizes the material at the edges of the plates to define the gas delivery path from one cell to the next.  While specific proprietary stack geometries accomplish gas flow management in unique ways, they all require seals that maintain the separation of the air and fuel along the various joints of the planar configuration. 

Grant applications are sought to develop new concepts for SOFC seal systems.  The sealing procedure must be consistent with the manufacturing steps during stack assembly, and with the thermal and mechanical variations that are present during initial start-up.  Also, degradation resistance during thermal transients would be a beneficial feature of a robust seal system (despite the fact that there are relatively fewer and more benign thermal cycles in coal syn-gas power plant applications compared to other applications).  Other sealing system requirements include appropriate mechanical strength, reliability, gas tightness, and compatibility with the other functional and structural parts of the SOFC stack.  The seal material must exhibit appropriate interfacial chemical stability in contact with mating parts and must not emit gas contaminant species that would poison the electrochemically active electrode surfaces.  Lastly, grant applications should provide the complete context for appropriate seal configuration and testing.

 

It is impossible to describe in detail, in this limited space, the complexities of a SOFC seal system relevant to functional state-of-the-art stacks being developed as an element of a power plant.  Examples of seal systems currently being developed can be found in the SECA web site under the proceedings of the SECA Core Technology Program workshops (http://www.netl.doe.gov/technologies/coalpower/fuelcells/seca/workshop.html, http://www.netl.doe.gov/publications/proceedings/06/seca/index.htm).  The SOFC group at Pacific Northwest National Laboratory (PNNL) is presently constructing short stack test vehicles that encapsulate the environmental boundary conditions that would be placed on a candidate seal system.  Potential applicants can obtain more detail regarding the short stack configuration by contacting Dr. Prabhakar Singh (Prabhakar.Singh@pnl.gov (509-375-5945).

 

Questions - contact Ayyakkannu Manivannan (Ayyakkannu.Manivannan@netl.doe.gov)

 

 

d. Advanced R&D in Coal-to-Liquids Technology Improvement—Commercial production of CTL (coal-to-liquids) fuels has been in operation in South Africa since the 1970s, with a current capacity of 150,000 barrels per day. [1]  A recent  publication indicates that the erection of a CTL plant in U.S. would be feasible under the right circumstances. [2]  CTL technology includes a coal gasification step to produce syngas (mainly carbon monoxide and hydrogen), followed by a second step to remove impurities and then by the syngas conversion step to produce liquid hydrocarbon fuels.  The last step is known as Fischer-Tropsch (F-T) synthesis, which employs catalysts to facilitate the syngas conversions. 

 

In F-T synthesis, the reactor is preceded with a guard bed to remove the trace impurities left in the feed stream exiting the syngas cleanup step.  This is considered a “must” arrangement in order to maintain the robust performance of F-T catalysts.  The current technology uses zinc oxide as the sorbent, which is most effective in the temperature range of 800 – 1200°F range. [4]  However, these sorbents are not effective at temperatures representative of warm syngas cleanup [3], an emerging technology that can contribute to a more efficient system integration of the three steps in the CTL process.

 

Grant applications are sought for novel sorbents that can match the exit temperature (300-700°F) from the warm gas cleanup step.  The new sorbents must be able to remove nearly all the trace impurities left in the gas feed to F-T reactor, including sulfur, halides, mercury, and arsenic.  Grant applications must demonstrate familiarity with:  (1) the advanced warm syngas cleanup R&D underway, (2) the contamination mechanisms of  F-T catalysts by the trace impurities in coal-derived syngas, (3) analytic techniques needed to analyze the trace impurities at very low levels, and (4) published data in the literature with respect to sorbent developments for other gas cleanup applications.

 

Questions – contact John Shen (john.shen@hq.doe.gov)  

 

 

Subtopic a  References:

 

1        Hydrogen & Clean Fuels Research, U.S. Dept. of Energy, Office of Fossil Energy, Office of  Sequestration, Hydrogen & Clean Coal Fuels. (Available at: http://www.fe.doe.gov/programs/fuels/index.html)

 

2        Samuel, P., “GTL Technology – Challenges and Opportunities in Catalysis,” Central Fuel Research Institute, Dhanbad – 828108, Bulletin of the Catalysis Society of India 2 (2003) 82-99. (Full Text Available at http://203.199.213.48/183/1/254_P._Samuel.pdf)

 

3        Benham, C.B. & Bohn, M.S., “Maximization of Diesel Fuel Production from an Iron-Based Fischer-Tropsch Catalyst,” Rentech, Inc., AIChE Spring National Meeting, Houston, TX, March 14-18, 1999. (URL: http://www.rentechinc.com/dieselfuel.htm)

 

4        Nikolopoulos, A.A., Gangwal, S.K., and Spivey, J.J., “Effect of Periodic Pulsed Operation on Product Selectivity in Fischer-Tropsch Synthesis on Co-ZrO2/SiO2,”, in Studies in Surface Science and Catalysis 136: Natural Gas Conversion VI (E. Iglesia, J.J. Spivey, and T.H. Fleisch, eds., Elsevier Science) (2001) 351. (ISBN-10: 0-4445-22212) (ISBN-13: 9-7804-44522-214)

 

5        Ma, W., Kugler, E.L., Wright, J., Dadyburjor, D.B., “Effect of Molybdenum Loading on Iron-Based Fischer-Tropsch Catalyst,” AIChE Annual Meeting, Cincinnati, OH, October 30, 2005. (Summary Available: http://aiche.confex.com/aiche/2005/techprogram/P15849.HTM)

 

6        Fischer-Tropsch Synthesis, Catalysts and Catalysis, eds., Davis, B.H., CAER, U.Ky., Lexington, KY., Occelli, M.L., MLO Consultants, Atlanta, GA., series ed., Centi, G., Studies in Surface Science and Catalysis, Vol. 163, Elsevier, 2007. (ISBN-10: 0-4445-22212) (ISBN-13: 9-7804-44522-214)

 

7        Agrawal, R., Singh, N.R., Ribeiro, F.H., Delgass, W.N., “Sustainable Fuel for the Transportation Sector,” PNAS, vol. 104, no. 12, March 20, 2007. (Available at www.pnas.org/cgi/doi/10.1073/pnas.0609921104)

 

 

Subtopic b References:

 

1.      Benson S & Myer L. “Monitoring to Ensure Safe and Effective Geologic Sequestration of Carbon Dioxide”, in IPCC workshop on carbon dioxide capture and storage, Regina, 2002. (Full text available at: http://arch.rivm.nl/env/int/ipcc/docs/css2002/ccs02-10.pdf)

 

2.      Wildenborg A. Scheffers B, Ribberink H and Schrover A, 2002, “Framework for the Safety and Monitoring of a Facility for Underground CO2 Sequestration”, Netherlands Institute of Applied Geoscience TNO – National Geological Survey, Utecht, 28. ( Full text available at: http://www.senternovem.nl/mmfiles/26245_tcm24-124147.pdf)

 

3.      “Carbon Sequestration Technology Roadmap and Program Plan-2005,” U.S. DOE Office of Fossil Energy/National Energy Technology Laboratory, May 2005. (Full text available at:  http://www.netl.doe.gov/publications/carbon_seq/project%20portfolio/2007/2007Roadmap.pdf)

 

4.      Gale J and Davison D., “Transmission of CO2: safety and economic considerations”,   Sixth International Conference on Greenhouse Gas Control Technologies Kyoto, Japan, vol 1. Gale J and Kaya Y, editors. Amsterdam:  Pergamon, 2003. p. 517-522 (http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V2S-4CB63P9-5&_user=10&_coverDate=08%2F31%2F2004&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=2cb18243a076922e34186d22179ef36b)

 

 

Subtopic c References:

 

1        Minh, N. Q. and Takahashi, T., Science and Technology of Ceramic Fuel Cells, Amsterdam, NE:  Elsevier, 1995.  (ISBN-10:  0-444-89568) (ISBN-13: 9-7804-44895-684)

 

2        Solid State Energy Conversion Alliance Website. (URL: http://www.seca.doe.gov/)

 

3        Bouwmeester, H. J. and Gellings, P. J., CRC Handbook of Solid State Electrochemistry, Boca Raton, CRC Press, 1997.  (ISBN:  0-8493-89569)

 

4        7th Annual SECA Workshop and Peer Review, September 12-14, 2006. (Available at: http://www.netl.doe.gov/publications/proceedings/06/seca/index.htm)

 

5        Fergus, J.W., “Sealants for Solid Oxide Fuel Cells,” Journal of Power Sources, 147, 46-57 (2005). (http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TH1-4GBD7XV-8&_user=10&_coverDate=09%2F09%2F2005&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=2c04217765dd672d57fa776c8cfeaeb2)

 

6        R.K. Brow, “Thermochemically Stable Sealing Materials for Solid Oxide Fuel Cells,” Solid State Energy Conversion Alliance 6th P Annual Workshop, Pacific Grove, CA, Apr. 18-21, 2005. (INVITED) (Full text available at: http://www.netl.doe.gov/publications/proceedings/05/SECA_Workshop/pdf/day2_3/UMR-Brow%204-20.pdf)

 

 

Subtopic d References:

 

1        Sichinga, J., “Coal-to-liquids: a business view”, paper presented at the EFI Members Conference, Charleston, SC, Feb. 6 -9, 2005 (Available at: http://goliath.ecnext.com/coms2/gi_0199-4311515/Coal-to-liquids.html)

 

2        “Baseline technical and economic assessment of a commercial scale Fischer-Tropsch liquids facility”, DOE/NETL-2007/1260, April 9,  2007 (Full text is available at: http://www.netl.doe.gov/energy-analyses/pubs/Baseline%20Technical%20and%20Economic%20Assessment%20of%20a%20Commercial%20S.pdf)

 

3        “Gasification – Gas Cleaning & Conditioning”, National Energy Technology Laboratory Website. (URL: http://www.netl.doe.gov/technologies/coalpower/gasification/gas-clean/index.html)

 

4        US Patent 5494880 (URL: http://www.patentstorm.us/patents/5494880.html)