In Washington, the DOE is making up to $15 million available to demonstrate biomass-based oil supplements that can be blended with petroleum. These “bio-oil” precursors for renewable transportation fuels could be integrated into the oil refining processes that make conventional gasoline, diesel and jet fuels without requiring modifications to existing fuel distribution networks or engines.
The Department expects to fully fund between five to ten projects in fiscal year 2012 to produce bio-oil prototypes that can be tested in oil refineries and used to develop comprehensive technical and economic analyses of how bio-oils could work. The prototype bio-oils will be produced from a range of feedstocks that could include algae, corn and wheat stovers, dedicated energy crops or wood residues. Domestic industry, universities and laboratories are all eligible to apply at eere-exchange.energy.gov, under Reference Number DE-FOA-0000686.
The DOE highlighted the R&D challenges, thus:
Overarching R&D Challenges
• There is no standard definition of what constitutes an acceptable bio-oil feedstock product. This includes physical properties (density, viscosity, etc.) as well as chemical properties (hydrocarbon range, stability, etc.). The current slate of intermediates depends strongly on both the feedstock and process.
• The community lacks a clear understanding of the tradeoff between optimizing yield and product quality. This partially stems from the lack of a clear definition of what constitutes product quality.
• The fundamental thermochemical mechanisms of biomass decomposition are not well understood. Thorough characterization of process streams (including the product) is difficult.
• Current biomass catalysts have a short lifespan and are prone to deactivation by impurities. Catalyst stability and selectivity are problematic.
• Solvent recovery and recycle is difficult (and expensive) in many liquefaction processes. Better technologies are needed to improve cost-competitiveness; wastewater treatment suffers from similar challenges.
• Process sustainability and economics are strongly influenced by the amount of hydrogen that is needed to simultaneously achieve high carbon yields and low GHG emissions. Low-cost, non-fossil hydrogen sources are needed.
Overarching R&D Needs
• Process modeling with comprehensive techno-economic analyses to guide the selection of feasible intermediate products. Clearly defined properties and insertion points for intermediate products.
• Better analytical techniques to characterize oxygenated hydrocarbon mixtures. In situ, non-intrusive analyses are of particular interest and can improve process monitoring and control.
• A database of well-defined “benchmark” processes, feeds, and catalysts to provide a common measure to compare emerging technologies.
• Biomass-specific heat and mass transfer correlations for common reactor systems.
• Innovative processes for oxygen removal, including catalytic and electrochemical routes that limit the production of COX species.
• Parametric testing to evaluate catalyst performance using real biomass feedstocks, as synthetic feeds are not sufficiently representative for large-scale process design.
• Pilot-scale R&D operations to study integrated heat transfer, internal recycle (e.g., solvent and dense-phase recovery), and continuous runs; evaluation of product quality and contaminant buildup over long-term testing.
Barriers in Catalysis
• Effectively designing catalysts for long term upgrading.
• Understanding the mechanistic basis for catalyst fouling and deactivation.
• Developing protocols and operating parameters for suitable upgrading / hydroprocessing catalysts in the presence of destabilizing components and contaminants.
• Developing poison and corrosion tolerant catalysts that can achieve high levels of deoxygenation while maintaining high carbon yields.
• Demonstrating techniques/methodologies for >1000 hours continuous operation on a catalyst.
• Developing effective catalysts that combine both chemical activity and mechanical strength (attrition resistant, highly active catalyst development).
• Understanding vapor phase interaction of organic compounds with catalysts, especially oxygenated species.
• Optimizing carbon distribution for C10-C18 length molecules.
• Developing multi-functional heterogeneous catalysts to balance hydrodeoxygenation, decarboxylation, and decarbonylation pathways for minimizing oxygenate and water production while increasing carbon efficiency.
Barriers in Separations
• Designing holistic trace contaminant removal process technology (P, Si, Cl, metals and other inorganics).
• Comparing and contrasting separation technologies (fractionation, solvent extraction, etc.) in terms of a cost benefit analysis for specific liquefaction processes and technologies.
• Optimizing char removal filters and membranes.
• Determining the effect of bio-oil chemical properties on membranes (particle fouling, acidic nature) for improved vapor and liquid separations.
• Staged condensation of bio-oil fractions.
• Upfront removal of volatile (vapor) mineral compounds along with entrained char.
• Understanding relative heating/cooling rates vs. temperature impact on product distributions.
• Improving hot gas particulate filtration without severely decreasing vapor phase carbon yield.
• Defining char particle size distributions and the effects on cyclone efficiency.
• Agglomeration or flocculation of entrained particles.
• Characterizing the impact of residence time in hot gas filtration.
• Understanding the reactivity of char/filter material on vapor phase chemistry.
• Vapor phase separation of water from desired bio-oil components.
Barriers in Process Integration and Analysis
• Establishing minimum requirements for acceptable refinery inputs at specific points of integration (increasing involvement and collaboration with the off take partners).
• Generating extensive techno-economic data on thermochemical biomass liquefaction processes for targeted refinery off take (a lack of robust data to convince refineries that bio-oil is compatible with their infrastructure).
• Defining quality traits for a suite of refineries and refinery insertion points.
• Analyzing the impact of finished fuels on the prospect for ASTM certification.
• Generating a database of bio-oil chemical composition based on such variables as feedstock, type of process and process conditions.
• Evaluating applicability of petroleum standards for bio-oils, and modifying where needed (e.g., CCR (Continuous Catalytic Regeneration), Simulated Distillation, Boiling ranges, TAN (Total Acid Number), oxygen content, oxygen functionality, phenolics, aromatics, cetane).
• Determine what specifications of the end products are performance related and what specifications are flexible (i.e., does composition matter so long as the fuel meets the performance specifications in the engine testing).
• Petroleum refining processes are not optimized for hydrocarbon liquids with high oxygen content, like bio-oils (optimizing carbon efficiency during bio-oil deoxygenation).
More background on the story from the Digest
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