Inventing modern invention: the professionalization of technological progress in the US

Summary:

• Focus: energy generation using renewable resources

• Many options and choices:

  • Electrify vs liquid field

  • Biofuel pathway options

  • Solar power via electricity, liquid fuels, etc.

• Optimization-based process synthesis

  • Traditional process synthesis

    • Hiearchical design

      • Reaction

      • Separation & recycle

      • Heat recovery network

      • Industrial utilities

    • Sequential decisions, optimized one at a time

  • Optimization-based design / network design

    • Solving constraint system that related different industrial components

  • Aiming to provide feedback to experimental chemists/process engineers to identify regions of design space that are most/least fruitful

  • Simulation

    • Input chemicals/economics

    • Model of chemistry

    • Design

    • ->Output

  • Optimization: find design that optimizes the target “reward” function

  • Their approach: solve system of equations where design is embedded

• BECCS: Bioenergy with Carbon Capture and Storage

  • Use biomass to generate energy / liquid fuels for energy storage, long distance energy transport

  • Emits CO2 in the process

  • Can capture at different points in the industrial process

    • Upto 75% can be captured with sufficient work to capture

  • Emissions due to transporting biomass to facility

  • Tradeoff

    • Larger facilities are more efficient at producing energy/fuels but transportation costs/emissions are higher

    • Smaller facilities have lower transport costs but are less efficient

    • Hybrid: intermediate facilities that densify feedstock

  • Can optimize system design around industrial constraints and revenues 

    • Carbon credits due to capture

    • Ethanol price

    • Biomaterial sources (they focused on switchgrass grown on marginal lands but can expand to agricultural residue, forests, etc.)

  • Range of technological options

    • Gasification -> Electricity or H2

    • Fermentation

    • Pyrolysis

    • Capture in Flue, Biogas

    • Key to document the supply chain: 

      • Emissions: harvesting, transportation, etc. 

      • Capture: soils

      • Impacts of outputs:

        • Liquid fuels are burned: emissions

        • Electricity output can displace CO2 emitting power

• Integrated Spatially Explicit Network model

  • Typically supply chain analyses focus on point solutions that ignore geography

  • Biomaterial availability varies both spatially and temporally

    • Different types of lands where different amounts of material can be grown

    • Biomaterial harvest varies over the year and yields vary across years

  • Optimizing facility design in a spatially-explicit way

  • A field-to-product analysis

    • Bioenergy lands

    • High quality land appropriate for food crops

    • Low quality lands best for grazing

    • Middle-quality lands good for bioenergy crops

    • ML and drone tech being used to identify marginal lands in the US

      • atlas.glbrc.org

      • Intermittent and recently abandoned land

      • Formerly irrigated land

    • Estimate the productivity of various lands: 

      • SALUS model: https://www.cibotechnologies.com/salus-model/

      • Yield maps for different crops

      • Distribution of yields for a given crop/land

      • 10 weather/yield samples

    • Focus on switchgrass in US Midwest

  • Can analyse operating efficiency of biorefineries at any location, given material availability in any given location

  • Large-scale optimization of deployment of refineries across a large area

    • Stochastic Mixed-integer Program

    • Can do single-state analysis that places a biorefinery and densification sites

• Investigation of Economic and Environmental Tradeoffs

  • Larger-scale analysis of 8 US Midwest states

  • Choosing from among a fixed set of sites for biorefineries, sequestration, depots

    • Constrained by geological structure, availability of rail transport

    • Accounting for price and emissions of electricity from regional grid

      • Need electricity for some types of sequestration (where heat biorefinery is not enough)

  • Goal is to compute optimal design, which informs decision makers about the regions of design space where more detailed investments should be explored

  • Optimal configuration depends on the types of emissions for which carbon credits are paid

    • If emissions in transport, harvest, electricity displacement are accounted, explicitly optimize location to be close to biomass, located in high emission grids