Thermochemical Conversion Techno-Economic Analysis

NREL's Thermochemical Conversion Analysis team focuses on the conceptual process design and techno-economic analysis (TEA) for the thermochemical conversion of biomass to fuels and products via direct liquefaction pathways, using pyrolysis or bio-oil intermediates, and indirect liquefaction pathways, using gasification or gaseous intermediates, from lignocellulosic biomass.

Illustration of a simplified process flow diagram of NREL's catalytic fast pyrolysis reactor with vapor phase upgrading. Starting in the upper left is an illustration of a Feeder showing Biomass going into a Fast Pyrolysis Reactor (for ex situ)/Catalytic Fast Pyrolysis Reactor (for in situ) that also has Fluidizing Gases (includes H2) entering the reactor. The Feedstock breaks down to Ash, Char, Sand/Catalyst (in situ) and goes into the Char Combustor (for ex situ)/Catalyst Regenerator (for in situ). Air goes into the Combustor/Regenerator and some Sand/Catalyst (in situ) converts back to the Reactor; in addition Flue Gas and Ash & Fines are released. Pyrolysis Vapor (ex situ)/Upgraded Vapor (in situ) next go into the Ex Situ Upgrade Reactor; Upgraded Pyrolysis Vapors leave this reactor and go into Coolers (process heat recovery). Used Catalyst goes into the Catalysts Regenerator, as does Air/Regenerative Gases, and Regenerative Catalyst reverts back the Ex Situ Upgrade Reactor; Fines and Flue Gas are released from the Catalyst Regenerator. The Ex Situ Upgrade Reactor and Catalyst Regenerator section is labeled: "Reactor not used for in situ configuration." After the Coolers comes the High Temperature Absorber Condenser, which for one pathway leads to additional Coolers (including chilled water) then to the Low Temperature Absorber Condenser that also has two pathways: one leads to either Purge (fuel gas/to reformer), Fluidizing Gas to Fast Pyrolysis/In Situ Reactor (with the addition of Makeup Hydrogen), or to a Water Gas Shift, then Cooler then PSA that releases Hydrogen or Purge (fuel gas/to reformer). A second pathway from the Low Temperature Absorber Condenser leads to a Decanter, which can travel one of four ways: (1) out to the Aqueous Phase (to wastewater section), (2) to Organic Liquid that goes through another Cooler (chilled water) and back into the Low Temperature Absorber Condenser, (3) to Light Organic Liquid and back into the High Temperature Absorber Condenser, or (4) to the Hydrotreater. Heavy Organic Liquids that also leave the High Temperature Absorber Condenser go through a Cooler and on to the Hydrotreater section as well. The Organic Phase that goes into the Hydrotreater goes either into a Furnace then the Hydrotreater that recirculates the Organic Phase and Hydrogen into the Furnace repeatedly, or to a Cooler than Flash where it is either, (1) released as Purge Gas (to PSA), (2) goes to the Aqueous Phase (to wastewater section), (3) the Hydrogen gets recycled with Makeup Hydrogen back to the start of the Organic Phase, or (4) it moves on to become Purge Gas and Gasoline Range Product or moves on to become Diesel Range Product or goes to the Hydrocracker section. The Hydrocracker section is a circuitous loop showing Recycled Hydrogen, Makeup Hydrogen, and Hydrogen going from the Hydrotreater section into either the Furnace or the Hydrocracker. Some Recycled Hydrogen, Makeup Hydrogen, and Hydrogen goes on to the Cooler where it then goes into the Flash and is either released as Purge Gas (to PSA) or Aqueous Phase (to wastewater section) or gets recycled into the Hydrocracker loop. In the lower right of the diagram are four sections that are not part of the flow chart, and are labeled: Hydrogen Production (Reformer, Water Gas Shift and PSA), Steam System (On-Site Electricity Generation), Cooling Water System and Other Utilities, and Wastewater Utilization and Treatment.

The primary objective of the Thermochemical Conversion Analysis effort is to support the Department of Energy Bioenergy Technologies Office's goal to help research technologies that will enable the production of cost-competitive hydrocarbon fuels from biomass. The conceptual process designs, detailed process models, and TEA developed under this project provide insights into the potential economic viability of biomass conversion process technologies currently in the research and development stage.

Featured Publications

Conceptual Process Design and Techno-Economic Assessment of Ex Situ Catalytic Fast Pyrolysis of Biomass: A Fixed Bed Reactor Implementation Scenario for Future Feasibility, Topics in Catalysis (2015)

Conceptual Process Design and Economics for the Production of High-Octane Gasoline Blendstock via Indirect Liquefaction of Biomass through Methanol/Dimethyl Ether Intermediates, Biofuels, Bioproducts and Biorefining (2015)

Process Design and Economics for the Conversion of Lignocellulosic Biomass to Hydrocarbon Fuels: Thermochemical Research Pathways with In Situ and Ex Situ Upgrading of Fast Pyrolysis Vapors, NREL/PNNL Technical Report (2015)

Process Design and Economics for the Conversion of Lignocellulosic Biomass to Hydrocarbons via Indirect Liquefaction: Thermochemical Research Pathway to High-Octane Gasoline Blendstock Through Methanol/Dimethyl Ether Intermediates, NREL/PNNL Technical Report (2015)

View all NREL thermochemical conversion techno-economic analysis publications.

Capabilities

Techno-economic analyses are performed to determine the potential economic viability of process technologies in the research and development stage. Evaluating the production costs of a given process technology, based on current performance and targets established for process improvements though research efforts, allows the analysis team to assess the potential economic feasibility of a process configuration. Results of these analyses are useful in determining which emerging technologies have the highest potential for near-, mid-, and long-term deployment success.

Conceptual process designs and detailed process models developed for TEA under this project allow the analysis team to evaluate aspects of process technology development like production costs, product qualities, heat integration, process optimization, and scale-up. The analysis team also assists the research efforts by helping establish technical targets for the research programs and quantifying the economic impact from research achievements. This helps direct research in the most impactful directions, with a goal of maturing towards commercial deployment. Sustainability metrics associated with the conversion processes are also tracked.

Within the Thermochemical Conversion Analysis project, there are currently two primary integrated conversion platforms under development, one based on pyrolysis of biomass to produce an oxygenated bio-oil intermediate (pyrolysis pathway analysis) and one based on the gasification of biomass to synthesis gas intermediate (indirect liquefaction pathway analysis).

Flow diagram of the pyrolysis conversion pathway, starting at Feedstock Logistics and moving through Feedstock Processing and Handling, Fast Pyrolysis and Vapor Upgrading, Bio-Oil Recovery, Processing to Fuel Blendstocks, and finally to Biofuels Distribution.

Pyrolysis Pathway Analysis

Pyrolysis, direct liquefaction or bio-oil intermediate pathways R&D focuses on developing commercially viable technologies for converting biomass into energy-dense, fungible finished liquid fuels, such as renewable gasoline, jet, and diesel, as well as bioproducts and bioenergy. Current areas of research and analysis at NREL focus on catalyst development, bio-oil yield improvements, hydrodeoxygenation, maximizing production of diesel-range products, product quality relative to target fuels, process integration and optimization, and scale-up from bench to pilot scale.

Flow diagram of the indirect liquefaction conversion pathway, starting at Feedstock Logistics and moving through Feedstock Processing and Handling, Gasification and Gas Cleanup, Fuel Synthesis, Product Recovery and Finishing, and finally to Biofuels Distribution.

Indirect Liquefaction Pathway Analysis

Gasification, indirect liquefaction or gaseous intermediates/syngas pathways R&D focuses on developing technology that converts biomass to a gaseous intermediate (e.g., synthesis gas, synthetic natural gas, or other mixed oxygenates) for the production of fuels, chemicals, and power. Current areas of research and analysis at NREL focus on catalyst development, increasing selectivity to desired products, coupling of olefins to produce jet- and/or diesel-range products, generating premium fuel blendstocks, process integration and optimization, and scale-up from bench to pilot scale.

Research Team

Principal Investigators

Abhijit Dutta

Abhijit Dutta

Biorefinery Analysis Section Supervisor

Abhijit.Dutta@nrel.gov
Eric Tan

Eric Tan

Senior Research Engineer, Biorefinery Analysis Team

Eric.Tan@nrel.gov

Engineers

Arpit Bhatt

Yanan Zhang

Related and Integrated Programs

Bioenergy Sustainability Analysis

Biomass Feedstocks

Computational Modeling

Heterogeneous Catalysis for Thermochemical Conversion

Strategic and Market Analysis

Thermochemical Process Integration, Scale-up, and Piloting

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