Ninth Year Annual Report:
Carbon Capture: Future Plans
The Williams Group will continue work on coal-biomass co-production with CCS, extend their models to examine strategies for natural gas-biomass co-production with CCS, study dispatch competition among various sources of low-carbon electricity, and study algae systems and other technologies for producing liquid fuels. The Arnold Group will lay the groundwork for developing numerical models and experimental prototypes of hybrid energy storage systems. The Law Group will expand its new focus on biofuel combustion.
Modeling FTL and MTG Systems
Tom Kreutz, Eric Larson, Liu Guangian, and Zhou Zhe (a Tsinghua University student visiting Princeton through September) will extend FTL and MTG modeling of coal/biomass co-processing systems to low-rank coals, giving focused attention to systems that co-produce liquid fuels and electricity. The analysis will include a comparison of coal gasification systems based on dry-feed entrained flow and fluidized bed gasifiers.
Williams and Larson will analyze applications of systems using low-rank coals to the Rocky Mountain/Upper Great Plains region of the United States - including consideration of use of biomass hauled in via coal unit trains returning (otherwise empty) to the Powder River Basin from Eastern coal markets and picked up en route in the Southeast or Midwest.
Larson, Williams, Liu, and Zhou will analyze applications of systems using low-rank coals to Shandong Province and Inner Mongolia in China, building on preliminary research carried out by Cathy Kunkel during her one-year visit to Tsinghua University in 2006/2007 (hosted by Li Zheng) during which she carried out considerable research on biomass supply logistics for coprocessing with coal crop residues in Shandong Province and mixed prairie grasses in Inner Mongolia.
Williams, Larson, Liu, and Chen Haiping (a visitor during 2010 from North China Electric Power University) will compare two CCS strategies for coal in China: (i) via coproduction of electricity and transportation fuels from coal and from coal/biomass, and (ii) via post-combustion capture at supercritical coal steam-electric power plants with regard to energy penalties, water penalties, CO2 storage requirements and costs evaluated for Chinese conditions.
Kreutz, Liu, and Williams will extend the coal/biomass/CCS concept for the co-production of liquid fuels and electricity to natural gas/biomass co-processing with CCS (including both stranded gas and shale gas applications) as a strategy for simultaneously decarbonizing both liquid fuels and electricity. Detailed Aspen Plus and economic modeling will be carried out and comparisons will be made as to how such systems compare to similar coal/biomass co-processing systems, considered in the context of the new bullishness about the potential abundance and ubiquity of shale gas and giving particular attention to the trade-off between the lower capital costs (but likely higher feedstock costs) for typical natural gas systems.
Larson, Liu, and Dr. Guo Xiangbo (a visitor during 2010 from SINOPEC's Research Institute of Petroleum Processing) will improve models for upgrading raw Fischer-Tropsch liquids into final diesel and gasoline products and explore opportunities for integrating F-T synthesis plants into crude oil refineries.
Liu and Larson will develop performance and cost models for Fischer–Tropsch synthesis based on cobalt catalyst and make comparisons to models currently used that involve iron catalyst.
Dispatch Competition Among Low-Carbon Power Sources
Kreutz and Williams will carry out modeling of economic dispatch competition among alternative low-carbon power sources [e.g., co-production plants with CCS that convert coal/biomass and natural gas/biomass to liquid transportation fuels and power; large wind farms with compressed air energy storage (wind/CAES); PC plants that have been retrofitted for CCS; natural gas combined cycles (NGCC, with and without CCS); CIGCC-CCS; and nuclear power] for a single independent system operator such as PJM (but considered without security or transmission constraints). The researchers will focus on market conditions that would favor the replacement of old pulverized coal plants that vent CO2 with some mix of these alternative lowcarbon power sources.
Alternative Biomass Technologies for Liquid Fuels
Kreutz, Larson, Williams, and Liu will analyze and compare in a self-consistent manner several alternative technologies using biomass not grown on good cropland that offer promise in reducing GHG emissions for transportation fuels (including aviation fuels). The researchers will investigate the fuels' technical suitability for replacing crude oil products, potential liquid fuel yields (GJ per hectare per year), overall production potential, potential for reducing GHG emissions, adverse impacts, and (in those instances where plausible cost data are available in the peer-reviewed literature) production costs. Much of this effort will be focused on analysis of algae grown in appropriately designed ponds from relatively concentrated streams of fossil CO2 (plus sunlight, water, and nutrients), extraction of the algae's natural oils, and their processing into liquid transportation fuels such as biodiesel. However, attention will also be given to biodiesel derived from camelina and jatropha, and a deeper analysis of cellulosic ethanol technologies will be pursued. Comparisons will be made to the low-carbon synthetic fuels derived via gasification already analyzed (low-carbon FTL and MTG technologies).
Expand "Master Framework" for Energy Modelling
Kreutz, Larson, and Liu will add to the evolving "Master Framework" both new plant models developed at Princeton as they become available (e.g. coal/biomass-to-SNG and natural gas/biomass coproduction systems) as well as data on other critical energy technologies such as nuclear power and renewable energy that were researched by others (including other groups involved with the NRC's America's Energy Future study). The Williams Group thereby hopes to gain a better understanding under this self-consistent framework of how a wide range of alternative energy technologies interrelate and compete in a future with rising GHG emission prices and uncertain oil and feedstock prices.
Solid Oxide Fuel Cells
Kreutz will take the lead in developing new analyses of potential roles for use of solid oxide fuel cells in systems that co-produce electricity and liquid transportation fuels from coal/biomass and/or natural gas/biomass with CCS. Particular emphasis will be given to exploring implications of the strategic advantages offered by these fuel cells in such systems—including their high energy conversion efficiency and the opportunities they offer for low-cost CO2 capture compared to today's technologies. Comparisons will be made to co-production systems that instead use gas turbine/steam turbine power systems for making co-product electric power; this research will be pursued in collaboration with Andrea Lanzini, a graduate student at Politecnico di Torino (Italy) who has applied for a Fulbright scholarship to carry out such research at Princeton over a 6- month period beginning in the fall of 2010 (if Lanzini does not win this Fulbright award, this research will not be pursued during 2010).
Energy Storage Technologies
In the year ahead, Craig Arnold and colleagues will be continuing their work on assessment and optimization by examining how the regime of optimal storage efficiency differs among the various available chemistries and how they can be integrate together to form hybrid systems. In addition, they will continue to study the interrelated effects of mechanics and electrochemistry in order to improve the lifetimes in these electrochemistry systems. These combined results will form the input for numerical modeling of hybrid systems that will inform experimental prototype systems that exhibit significant lifetime, capacity and power capabilities for real-world energy storage needs.
Alternative Fuel Combustion
A comprehensive experimental and modeling research program on the combustion of biofuels has been initiated by the Law Group and will form the major thrust of the program going forward. In addition to studying the combustion chemistry of bio-butanols, the researchers will also initiate studies on its soot chemistry.
In addition, collaboration with the simulation group at the Sandia National Laboratory will be initiated for HCCI (homogeneous charge compression ignition) engines, again using the highly efficient reaction mechanisms that the team has developed. The Sandia group under the direction of Dr. Jackie Chen is world renowned in performing high-fidelity direct numerical simulations (DNS) of combustion processes in engines.