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At least 271 records · Page 15

Strategies for Achieving the DOE Hydrogen Shot Goal: Thermal Conversion Approaches

In July 2021 the United States (U.S.) Department of Energy (DOE) launched the first of a series of Department-wide Energy Earthshot goals designed to accelerate breakthroughs of more abundant, affordable, and reliable clean energy solutions within the decade. The Hydrogen Shot goal seeks to reduce the cost of clean hydrogen to $\$$1 per 1 kilogram in 1 decade ("1 1 1"). Today, thermal conversion of fossil fuels represents the predominant, lowest cost method of hydrogen production. In 2020 approximately 75 percent of global, dedicated hydrogen production was produced via fossil fuels using thermal conversion approaches such as steam reforming and gasification. However, carbon management techniques such as CO 2 capture and sequestration (CCS) and pyrolysis are not widely represented in the current fossil-based hydrogen production fleet. Lowering the cost of clean hydrogen production from commercial and advanced thermal conversion-based technologies is critical for successfully achieving the Hydrogen Shot goal. This report presents the findings from an initial screening analysis of several scenarios that explore cost drivers related to clean hydrogen production. The screening encompasses commercially available and developing thermal conversion technology alternatives as well as factors exogenous to the plant such as feedstock/byproduct pricing, CO 2 pipeline and storage infrastructure costs, and scale to assess potential pathways towards meeting the Hydrogen Shot goal. Additionally, this report presents initial Research and Development (R&D) strategies to advance thermal conversion technology towards meeting the Hydrogen Shot goal.

08 HYDROGEN↗

Hydrogen Shot Technology Assessment: Thermal Conversion Approaches

In July 2021 the United States (U.S.) Department of Energy (DOE) launched the first of a series of Department-wide Energy Earthshot™ goals designed to accelerate breakthroughs of more abundant, affordable, and reliable clean energy solutions within the decade. The Hydrogen Shot goal seeks to reduce the cost of clean hydrogen to $\$$1 per 1 kilogram in 1 decade ("1 1 1"). Today, thermal conversion of fossil fuels represents the predominant, lowest cost method of hydrogen production. In 2020 approximately 75 percent of global, dedicated hydrogen production was produced via fossil fuels using thermal conversion approaches such as steam reforming and gasification. However, carbon management techniques such as CO 2 capture and sequestration (CCS) and pyrolysis are not widely represented in the current fossil-based hydrogen production fleet. Lowering the cost of clean hydrogen production from commercial and advanced thermal conversion-based technologies is critical for successfully achieving the Hydrogen Shot goal. This report presents the findings from an initial screening analysis of several scenarios that explore cost drivers related to clean hydrogen production. The screening encompasses commercially available and developing thermal conversion technology alternatives as well as factors exogenous to the plant such as feedstock/byproduct pricing, CO 2 pipeline and storage infrastructure costs, and scale to assess potential pathways towards meeting the Hydrogen Shot goal. Additionally, this report presents initial Research and Development (R&D) strategies to advance thermal conversion technology towards meeting the Hydrogen Shot™ goal.

08 HYDROGEN↗

Policy implications of net-zero emissions: A multi-model analysis of United States emissions and energy system impacts

Many countries, subnational jurisdictions, and companies are setting net-zero emissions goals; however, questions remain about strategies to reach these targets, policy measures, technology gaps, and economic impacts. Here, we investigate the potential policy implications of reaching economy-wide net-zero CO 2 emissions across the United States by 2050 using results from a multi-model comparison with 14 energy-economic models. Model results suggest that achieving net-zero CO 2 targets depends on policies that accelerate deployment of zero- and low-emitting technologies that have seen rapid cost reductions in recent years (including wind, solar, battery storage, and electric vehicles) as well as relatively nascent options (including carbon capture and storage, advanced biofuels, low-carbon hydrogen, advanced nuclear, and long-duration energy storage). While net-zero policies are likely to lower fossil fuel consumption, including considerable coal and petroleum reductions, achieving net-zero emissions does not necessarily mean phasing out all fossil fuels. Model results indicate that the Inflation Reduction Act’s energy and climate provisions amplify near-term decarbonization but that net-zero policies have larger impacts on long-run outcomes. Stringent climate policy can have large fiscal impacts on tax revenue and government spending—revenues from carbon pricing and subsidies for carbon removal range from 0.1 % to 3.7 % of GDP in 2050 across models. Each dollar per metric ton carbon price leads to a 0.06 % to 0.31 % reduction in economy-wide CO 2 emissions relative to a reference scenario with current policies. Spending on energy across the economy decreases relative to today for many models under reference and net-zero policies, especially as a share of GDP, due primarily to end-use electrification and energy efficiency.

54 ENVIRONMENTAL SCIENCES↗

Net-Zero Carbon Microgrids

The microgrid concept has been effective in creating aggregations of distributed energy resources—generation, storage and loads—for resiliency, in the form of energy security. The success of microgrids in bringing energy security to a wide range of customers—from individual residences to commercial and industrial installations to military bases—has been exemplified during power disruptions and extended outages due to extreme weather events, cybersecurity attacks, and equipment failures. Now microgrids have an opportunity to meet the challenges of climate change and contribute to a carbon-free power delivery system. The transition to net-zero starts within microgrids themselves. In fact, today’s microgrids are largely dominated by generators using fossil fuels, natural gas and diesel, with high greenhouse gas emissions. In short, the transition to net-zero means replacing fossil fueled generators with renewable generation in microgrids. This transition is extended by including new dispatchable generation technologies that are 100% carbon-free and that offer additional advantage of a more-dependable and sustainable source of energy and power. Basically, the decarbonization of microgrids requires three elements: 1) maximizing generation from renewable energy resources, 2) management of storage and flexible loads to balance the variability and intermittency of renewable energy resources, and 3) introducing new clean power sources, including hydrogen-based generation and small modular reactors. This report affirms a need for specific focus by governmental agencies at national, regional, and local levels to establish technology, policy, and investment in this area. The intention of the Net-Zero Microgrid (NZM) Program is to inform these constituencies with cross-cutting research and tools for the reduction of GHG in microgrids – to net-zero in the near term eventually to zero in the longer term. The NZM Program is committed to achieving decarbonization for resiliency and for providing clean energy at the local or distribution level, from remote communities to underserved communities, and large industrial and military facilities. The NZM Planning and Design Platform is a core tool to be developed as an early deliverable of the NZM Program because only a fully integrated microgrid-design approach will ensure maximum carbon reduction in energy production.

13 HYDRO ENERGY↗

Implications of Sustainability for the United States Light-Duty Transportation Sector

Climate change is a problem that must be solved. The primary cause of this problem is burning of fossil fuels to generate energy. A dramatic reduction in carbon emissions must happen soon, and a significant fraction of this reduction must come from the transportation sector. This paper reviews existing literature to assess the consensus of the scientific and engineering communities concerning the potential for the United States' light-duty transportation sector to meet a goal of 80 percent reduction in vehicle emissions and examine what it will take to meet this target. It is unlikely that reducing energy consumption in just vehicles with gasoline-based internal combustion drivetrains will be sufficient to meet GHG emission-reduction targets. This paper explores what additional benefits are possible through the adoption of alternative energy sources, looking at three possible on-vehicle energy carriers: carbon-based fuels, hydrogen, and batteries. potential for the United States' light-duty transportation sector to meet a goal of 80 percent reduction in vehicle emissions and examine what it will take to meet this target. It is unlikely that reducing energy consumption in just vehicles with gasoline-based internal combustion drivetrains will be sufficient to meet GHG emission-reduction targets. This paper explores what additional benefits are possible through the adoption of alternative energy sources, looking at three possible on-vehicle energy carriers: carbon-based fuels, hydrogen, and batteries.

33 ADVANCED PROPULSION SYSTEMS↗

AREVA Steam Cycle High Temperature Gas-Cooled Reactor Development and Deployment Plan - 18684

The development and deployment timeline for the AREVA SC-HTGR is among the shortest of all Generation IV reactor technologies. Once demonstrated, the SC-HTGR enters an expanding marketplace beyond electricity generation. This enables industrial growth that is today solely captive to fossil fuels, primarily natural gas supply. The SC-HTGR plant will be a hedge that insulates a wide range of process industries from fossil fuel price and supply volatility in coming decades when the SC-HTGR plant design is ready for deployment. Similar to existing light water reactors, the SC-HTGR is largely immune to fuel price swings for its expected 60 year operating life cycle. Approximately 70% of the SCHTGR plant energy cost is driven by the initial capital investment with fuel being less than 20%. This is entirely the opposite of natural gas fueled power plants where about 70% of the energy cost is directly tied to the cost and availability of fuel and the potential volatility this brings with it over a plant life cycle that could span several decades. This paper details the development and deployment strategy envisioned by AREVA for the SC-HTGR plant. The development phase includes completion of the full scale reactor module design and licensing, build and demonstrate the first commercial scale module, get design certification, and launch the commercial fleet deployment. The development plan takes full advantage of a) a large body of successful pre-application licensing interactions with the NRC under the DOE NGNP project, b) ongoing experiments and test results accumulated through the TRISO particle fuel qualification and nuclear grade graphite characterization R and D activities conducted in the U.S. and internationally, and c) operation of several small scale technology demonstration facilities and large scale commercial design projects. The abundance of the historic HTGR reactor technology demonstration projects provides a high degree of confidence that sufficient technical information is available to begin FOAK plant engineering and licensing followed by commercial demonstration of the first reactor module within a next decade. (authors)

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗

Dynamic optimization with flexible heat integration of a solar parabolic trough collector plant with thermal energy storage used for industrial process heat

There is an increasing need to reduce fossil fuel consumption used for industrial process heat to slow the effects of climate change. Using solar thermal heat is a viable way to replace fossil fuel use, but solar industrial process heat plants have limited implementation due to large upfront costs and inefficiencies from the inherent variability from solar energy. Having more flexible and optimized control over these plants can enable them to be more efficient. Here in this work, a solar industrial process heat plant with thermal energy storage that can flexibly collect and deliver heat to two industrial processes (flexible heat integration) is dynamically modeled with control setpoints found by a dynamic optimization method. The optimized case can increase the solar efficiency of the plant by 7.5% on average relative to a base case. The results show that it is best to collect heat at lower temperatures for all but ideal solar conditions, only medium to high quality heat should be stored in large quantities, and exchanging heat with a lower temperature heat sink is generally more efficient. The optimized case is able to reduce the levelized cost of heat of the plant to $31.83/MWh th compared to a base case value of $34.10/MWh th . The optimized case can reduce emissions by 22.2% compared to a plant which uses only natural gas. This work shows that dynamic optimization with flexible heat integration can be a cost-effective way to increase efficiency so that more of these types of plants can be implemented.

14 SOLAR ENERGY↗

CO 2 and Renewable Electricity into Chemicals: Formic Acid Production from Coal Flue Gas

Formic acid (FA) is an industrial chemical. It is used as a preservative for silage, as a digestive aid for animals, as a fluid for fracking, as a pharmaceutical intermediate and in leather tanning. The global formic acid market is valued at 777.4 million USD in 2020 and is expected to reach 851.8 million USD by the end of 2026. A new major formic acid application is the use of formic acid as a key feedstock for the bioprocessing industry. It has the potential to grow tremendously if we can lower the cost of formic acid production compared with the current fossil-fuel one. Recently, Dioxide Materials has developed a technology that can directly convert CO 2 to pure formic acid with a three-compartment CO 2 electrolyzer. However, the electrolyzer performance needs further improvement for the technology to be commercially viable. The major objective of this project is to develop the electrolyzer technology to enable formic acid as a feedstock for the bioprocessing industry to be economically manufactured from flue gas from a coal fired pilot plant. In particular, the project is to understand how to run the electrolyzer for the conversion of CO 2 into formic acid using flue gas from a coal fired power plant as a source of CO 2 . The work will include characterizing how the performance of the electrolyzer changes with low CO 2 concentration and impurities, developing new cell designs that can still operate with feedstocks with low CO 2 concentrations, testing simulated flue gas in the electrolyzer system and developing filters to remove any impurities that arise.

01 COAL, LIGNITE, AND PEAT↗

Modeling and Optimal Design of Absorbent Enhanced Ammonia Synthesis

Synthetic ammonia produced from fossil fuels is essential for agriculture. However, the emissions-intensive nature of the Haber–Bosch process, as well as a depleting supply of these fossil fuels have motivated the production of ammonia using renewable sources of energy. Small-scale, distributed processes may better enable the use of renewables, but also result in a loss of economies of scale, so the high capital cost of the Haber–Bosch process may inhibit this paradigm shift. A process that operates at lower pressure and uses absorption rather than condensation to remove ammonia from unreacted nitrogen and hydrogen has been proposed as an alternative. In this work, a dynamic model of this absorbent-enhanced process is proposed and implemented in gPROMS ModelBuilder. This dynamic model is used to determine optimal designs of this process that minimize the 20-year net present cost at small scales of 100 kg/h to 10,000 kg/h when powered by wind energy. The capital cost of this process scales with a 0.77 capacity exponent, and at production scales below 6075 kg/h, it is less expensive than the conventional Haber–Bosch process.

10 SYNTHETIC FUELS↗

Modular Designed Protein Constructions for Solar Generated H 2 From Water (Final Report)

As the title of the grant clearly states, this project has explored a unique way that makes use of manmade proteins to turn solar energy into chemical fuels. A major impetus to the work is that there is growing support for the view that two related forces will impact on future livability of Earth. The first is the finite supply of fossil fuels to power the Earth making it prudent to save this resource for the creation of useful chemicals. The second is that burning fossil fuels to generate power releases “greenhouse” gases into the atmosphere. There is mounting evidence that this is a major contribution to the warming trend in the Earth’s atmosphere and biosphere.

08 HYDROGEN↗

Adoption of Biofuels for Marine Shipping

Biomass-derived fuels can undoubtedly play an essential role in a future of marine fuel that is more renewable and offers potential synergistic benefits when blended with petroleum fuels. Biomass-derived marine fuel would reduce sulfur content, as well as improve overall emission profiles and ultimately environmental sustainability (including decarbonization) for marine transport. For example, biofuel derived from biomass such as forest residues is expected to deliver possibly up to 90% of life cycle (or well-to-propeller) greenhouse gas reduction versus fossil equivalents, and virtually eliminate SOx emissions - potentially without any requirement for engine modifications. For the benefits of biofuels to be realized and to be impactful, a significant fraction of marine fossil fuel will need to be displaced with biofuel. The direct replacement of marine fossil fuel with a biofuel necessitates that the production volume of biofuel will be high enough to meet the demand. Furthermore, the potential of biofuel adoption also depends on the future biofuel price. Hence, the long-term price and availability of marine biofuel are two critical factors for establishing the feasibility of marine biofuel adoption for operating vessels. This study will shed light on the prospect of biofuel to be adopted for the maritime shipping sector.

air emissions↗

Hyperlight Energy 7342 10-26-19 (Final Report)

One of the principal issues preventing the widescale deployment of Concentrating Solar Power (CSP) technologies for power and process heat generation is the high cost per unit energy produced. While the operating expenses of a solar plant are often far less than those of a comparable natural gas plant due to zero fuel costs, the increased capital costs of the system, and the collector field in particular, are a significant barrier to project feasibility. Hyperlight Energy has been funded under the DOE COLLECTS program to further develop its novel Linear Fresnel Reflector (LFR) design to meet the DOE’s programmatic goal of creating a solar collector that has an installed cost of less than $\$$99/m2 with a pathway towards a future price of $\$$50/m2. Hyperlight Energy has a unique, inexpensive design featuring four-inch-wide mirror slats mounted on 48 ft long extruded plastic D-profile tubes. By removing the steel and concrete of a traditional collectors Hyperlight is able to drastically decrease the materials and fabrication costs of the primary reflectors. The goal of this project was to prove the manufacturability of these reflectors, install a half-acre system of the collector, and test the performance of the field to determine the actual cost of the energy produced by the solar field. During the course of the project the half-acre system was successfully manufactured and deployed at the company’s demonstration site in Brawley, CA. The total collector cost came in under the desired $\$$99/m2 goal and proved the feasibility of this new type of solar field. With further planned cost reductions the DOE’s ultimate goal of $\$$50/m2 appears to be achievable. The data generated from this project has already been sufficient to secure Hyperlight Energy’s first commercial project, and continued operations will help to validate the product’s lifespan and performance over time. This will provide invaluable support for future installations. Hyperlight Energy has won a contract for a three-acre commercial project, but the company plans to aggressively pursue multiple similar and larger-scale projects in the near future. At present, these projects will serve to replace natural gas fired boilers in industrial processes, reducing the emissions of the associated plants. In the future, potential project sites will expand to include enhanced oil recovery (EOR) and other uses in the transportation fuel pathway, leading to fuels with a lower carbon intensity (CI). This path will allow renewable energy to begin to make an impact on the industrial process heat sector, which is one the primary consumers of natural gas and other fossil fuels in the country, and which is beyond the scope of other existing renewable technologies that exclusively generate electricity. Only by replacing the fossil fuels burned in industrial processes will the DOE’s emissions goals be achieved.

14 SOLAR ENERGY↗

Accounting for radiative forcing from albedo change in future global land-use scenarios

We demonstrate the effectiveness of a new method for quantifying radiative forcing from land use and land cover change (LULCC) within an integrated assessment model, the Global Change Assessment Model (GCAM). The method relies on geographically differentiated estimates of radiative forcing from albedo change associated with major land cover transitions derived from the Community Earth System Model. We find that conversion of 1 km² of woody vegetation (forest and shrublands) to non-woody vegetation (crops and grassland) yields between 0 and –0.71 nW/m² of globally averaged radiative forcing determined by the vegetation characteristics, snow dynamics, and atmospheric radiation environment characteristic within each of 151 regions we consider globally. Across a set of scenarios designed to span a range of potential future LULCC, we find LULCC forcing ranging from –0.06 to –0.29 W/m² by 2070 depending on assumptions regarding future crop yield growth and whether climate policy favors afforestation or bioenergy crops. Inclusion of this previously uncounted forcing in the policy targets driving future climate mitigation efforts leads to changes in fossil fuel emissions on the order of 1.5 PgC/yr by 2070 for a climate forcing limit of 4.5 Wm –2 , corresponding to a 12–67 % change in fossil fuel emissions depending on the scenario. Scenarios with significant afforestation must compensate for albedo-induced warming through additional emissions reductions, and scenarios with significant deforestation need not mitigate as aggressively due to albedo-induced cooling. In all scenarios considered, inclusion of albedo forcing in policy targets increases forest and shrub cover globally.

Jones, Andrew D.↗

Implications of Zero-Carbon Nuclear Renewable Economy: Equity, Economics, and Social Costs

Different energy systems have different impacts on equity, economics, and social costs of energy. This leads to alternative strategies for a zero-carbon economy from considering all options to a renewables-only strategy. We examine implications of different choices from a long-term perspective. This is coupled to but separate from the discussion of how to transition to a low-carbon energy system. If we are to stop greenhouse gas emissions with current goals, the transition must be fast. That requires a large nuclear contribution. Experiences in France and Sweden indicate that one can transition the electric grid from fossil fuels to nuclear in 20 to 25 years if it is a priority. Neither renewables with associated storage and transmission nor carbon capture and sequestration for fossil fuel use in electricity generation are available today at competitive costs to do that. The cost of energy has historically been a major factor in determining where industry and cities are built because it is a large fraction of the global economy. The development of low-cost methods to transport coal, oil, and natural gas partly broke that connection by enabling relatively uniform global energy costs. Nuclear energy because of the low-cost of fuel transport has the same characteristic. Renewables are location dependent. In a renewables-only future, the renewable resources distribution determines local energy costs that directly impacts where there is future economic growth and where there will be lower costs of living. In the U.S. today solar is generally uneconomic. Some Great Plains wind is competitive. Offshore wind is uneconomic. Based on projections of renewables costs, an all-renewable U.S. would see (1) movement of industry and people to between the Mississippi River (water and transportation) and the high plains (high wind velocities and low construction costs) and the southwest and (2) growing regional differences in standards of living. The costs of moving energy from renewables long distances is partly because of the high cost of transport systems (high-voltage lines with low capacity factors, hydrogen inter-conversion losses, etc.) and partly because of the non-dispatchability of renewables. A nuclear renewable world will have large variations in the relative amounts of nuclear, wind and solar with location-reflecting local cost of renewable resources. The deployment of wind and solar would be similar to hydro and geothermal-deployed where there is a concentrated resource. In the U.S. and globally this will likely be the norm because countries with limited access to low-cost renewables will not accept lower standards of living. The relative quantities of nuclear, wind and solar will change with relative advances in energy technologies. Energy is a large fraction of the economy; thus, energy choices have major economic, equity, and social implications. That, in turn, impacts standards of living and economic competitiveness. (authors)

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

A Streamlined Strategy for Biohydrogen Production with Halanaerobium hydrogeniformans , an Alkaliphilic Bacterium

Biofuels are anticipated to enable a shift from fossil fuels for renewable transportation and manufacturing fuels, with biohydrogen considered attractive since it could offer the largest reduction of global carbon budgets. Currently, lignocellulosic biohydrogen production remains inefficient with pretreatments that are heavily fossil fuel-dependent. However, bacteria using alkali-treated biomass could streamline biofuel production while reducing costs and fossil fuel needs. An alkaliphilic bacterium, Halanaerobium hydrogeniformans, is described that is capable of biohydrogen production at levels rivaling neutrophilic strains, but at pH 11 and hypersaline conditions. H. hydrogeniformans ferments a variety of 5- and 6-carbon sugars derived from hemicellulose and cellulose including cellobiose, and forms the end products hydrogen, acetate, and formate. Further, it can also produce biohydrogen from switchgrass and straw pretreated at temperatures far lower than any previously reported and in solutions compatible with growth. Hence, this bacterium can potentially increase the efficiency and efficacy of biohydrogen production from renewable biomass resources.

09 BIOMASS FUELS↗

Using Computer Simulations to Optimize Biofuel Production

The DOE strives to ensure America's security and prosperity by addressing energy challenges. NREL shares this goal and tries to achieve a clean energy world. Fossil fuels are problematic for both organizations. Using them endangers American security. Their supply is finite and burning them causes environmental damage. Biofuels are a good alternative to fossil fuels. They are renewably produced on American soil and can lower greenhouse gas emissions. Also, cars and planes need no costly mechanical adjustments to use biofuels. However, the fuels themselves are expensive. For my SULI project, I reduced the cost of biofuels by optimizing the production process through computer simulations. Existing simulations were accurate but slow. One simulation takes up to eight hours, and researchers must do hundreds. My solution reduces the computing time. I treated the biomass particles in the simulation as one-dimensional. That simplified the simulation equations, making them easier for the computer to solve. Still, biomass particles are three-dimensional. The 1D assumption was wrong and produced inaccurate results. To maintain accuracy while increasing speed, I developed a method to convert 1D simulation results into usable 3D data. I adjusted the 1D simulation until the output matched the 3D results for a specific environment. I found out how much the simulation changed when the environment changed. Machine learning algorithms defined a relationship between 1D and 3D data for all environments. This lets scientists convert fast 1D simulation results into valid 3D data.

1D↗

Integrating renewable energy into mining operations: Opportunities, challenges, and enabling approaches

Mining is one of the most energy-intensive industries worldwide. It also provides a critical source of raw materials for the manufacturing, transportation, construction, and energy sectors. Demand for raw materials is projected to increase as the world population grows and many low-income economies become middle-income countries. This growth in mineral demand, coupled with falling mineral ore grade, will likely increase the mining industry’s energy demand, used for activities across exploration, extraction, beneficiation and processing, and refining. At the time of this writing, mine operations are – due to their remoteness – dependent on fossil fuels such as diesel, heavy oils, and coal. In principle, mining could use energy recovery, renewable energy, and carbon capture to supplement, replace, or mitigate the impacts of fossil fuel use. However, a combination of renewable-energy technologies would be required. We explore challenges, opportunities, and enabling approaches to integrate renewable energy technologies into mining operations by examining the literature, including academic work, technical reports, and data produced by international agencies. Here, we find that despite numerous opportunities, technical issues still need to be considered, but solutions can tailor renewables to the mining industry. Further research should focus on identifying specific opportunities, technologies, and implementation strategies across the value chain of a variety of minerals with similar operational procedures.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

Catalytic Deoxydehydration of Carbohydrates and Polyols to Chemicals and Fuels

As the world's fossil fuel resources are being depleted and their costs increase, there is an urgent need to discover and develop new processes for the conversion of renewable, biomass resources into fuels and chemical feedstocks. Research and development in this area have been given high priority by both governmental agencies and industry. To increase the energy content and decrease the boiling points of biomass-derived carbohydrates and polyols to the useful liquid range it is necessary to chemically remove water (dehydrate) and, preferably, oxygen (deoxygenate/reduce). The poly-hydroxylic nature of carbohydrates is attractive for their use as functionalized chemical building blocks, but it presents a daunting challenge for their selective conversion to single product chemicals or fuels. The long term, practical objective of this project is to develop catalytic processes for the deoxydehydration (DODH) of biomass-derived carbohydrates and polyols to produce unsaturated alcohols and hydrocarbons of value as chemical feedstocks and fuels; DODH: polyol + reductant --(LMOx catalyst)--> unsaturate + oxidized reductant + H2O. Limited prior studies have established the viability of the DODH process with expensive phosphine reductants and rhenium-catalysts. Initial studies in the PI's laboratory have now demonstrated: 1) the moderately efficient conversion of glycols to olefins by the economical sulfite salts is catalyzed by MeReO3 and Z+ReO4-; 2) effective phosphine-based catalytic DODH of representative glycols to olefins by cheap LMoO2 complexes; and 3) computational studies (with K. Houk, UCLA) have identified several Mo-, W-, and V-oxo complexes that are likely to catalyze glycol DODH. Seeking practically useful DODH reactions of complex polyols and new understanding of the reactivity of polyoxo-metal species with biomass-oxygenates we will employ a two-pronged approach: 1) investigate experimentally the reactivity, both stoichiometric and catalytic, of polyoxo-complexes and practical reductants with representative polyols to establish structure/reactivity relationships and reaction mechanisms; and b) carry out parallel computational studies of these reactions and their mechanisms- both analytical and predictive. Our prioritized action plan is: (1) to optimize the catalytic efficiency, assess the substrate scope/selectivity, and address key mechanistic aspects of Re-catalyzed, sulfite-driven DODH reactions; (2) use the findings from (1), together with computational predictions, to discover new, effective non-precious metal catalysts for sulfite-driven DODH reactions; and 3) to initiate exploratory studies of CO- and H2-driven DODH. Successful execution of this research project will: 1) provide practical chemical processes for the conversion of biomass into useful chemicals and fuels: 2) bring fundamental new understanding of chemical reactions involving metal-oxo catalysts; and 3) provide educational and technical training of future energy scientists.

09 BIOMASS FUELS↗