Pathways
- Pyrolysis and gasification
- Fermentation and catalysis
- Separation and upgrading
MODULE 02
Conversion & Circular Valorization
How do resources become fuels, chemicals, materials and services?
Compare biological, thermochemical and catalytic routes through mass, carbon and energy balances—not technology labels alone.
Open lesson →
MODULE 02Performance
- Mass and energy balances
- Carbon and process efficiency
- Integration and co-products
CURRICULUM
6 lessons
182 min
01Conversion pathways, mass and energy balancesBeginner · 26 minA pathway is credible when every input, product, coproduct, emission and loss is accounted for on a common basis.02Pyrolysis, gasification and thermochemical routesIntermediate · 30 minHow temperature, heating, atmosphere and residence time distribute carbon among solids, liquids and gases.03Fermentation, catalysis and upgradingIntermediate · 30 minBiological selectivity and catalytic transformation are both powerful, but they impose different feed purity, operating and separation demands.04Biorefineries and process integrationIntermediate · 30 minA biorefinery coordinates multiple feed fractions, products, utilities and recycles to create more value than isolated unit operations.05Sustainable aviation fuel pathwaysAdvanced · 34 minSAF is a specification- and certification-constrained system connecting feedstocks, molecules, hydrogen, refineries, airports and life-cycle accounting.06Renewable carbon materials, hard carbon and plastic upcyclingIntermediate · 32 minMaterial pathways preserve carbon in products but must align molecular transformation, separation, performance, markets and end-of-life.
EVIDENCE LIBRARY
Research, models & tools
A curated starting shelf for this teaching area.
TOOLS
Related tools
BioSTEAM project
BioSTEAM
An open-source process simulation framework with integrated TEA, LCA and uncertainty workflows.
- Use it when
- How do unit operations combine into material, energy, cost and impact results?
- Limits
- Outputs are only as credible as property methods, scale-up rules and input evidence.
Inputs, outputs & scope
- Inputs
- Thermodynamics, streams, reactions, unit operations, design and economic assumptions.
- Outputs
- Flowsheets, mass and energy balances, equipment sizes, costs and life-cycle indicators.
- Typical applications
- Biorefineries, separation trains, plastic upcycling and early-stage process comparison.
Argonne National Laboratory
GREET
A life-cycle model for energy use, emissions, fuels, vehicles and material pathways.
- Use it when
- How do fuel and vehicle pathways compare on a consistent life-cycle basis?
- Limits
- Results depend on pathway version, geography, allocation and counterfactual assumptions.
Inputs, outputs & scope
- Inputs
- Feedstocks, process energy, transport, conversion efficiencies and pathway assumptions.
- Outputs
- Life-cycle energy use, greenhouse gases and regulated air emissions.
- Typical applications
- Transport fuels, SAF, hydrogen, biofuels and materials comparisons.
CASE STUDIES
Examples from Wang Group
2024Conversion
A novel three-stage ex-situ catalytic pyrolysis process for improved bio-oil yield and quality from lignocellulosic biomass
Illustrates how staged catalytic process design can trade equipment complexity against product yield and quality.
2021Conversion
Synergistic effects in the copyrolysis of municipal sewage sludge digestate and salix: Reaction mechanism, product characterization and char stability
Shows why co-pyrolysis synergy must be read together with product characterization and char stability.
2025Conversion
Breaking the yield–selectivity trade-off in polystyrene waste valorization via tandem depolymerization and hydrogenolysis
Provides a clear conversion example of a yield–selectivity trade-off and the value of tandem process design.
2022Outcomes
Novel carbon-negative methane production via integrating anaerobic digestion and pyrolysis of organic fraction of municipal solid waste
Illustrates an integrated organic-waste pathway where process coupling and the counterfactual waste fate determine the carbon claim.
2026Conversion
Ambient-pressure conversion of plastic waste to jet fuel cycloalkanes by tandem hydropyrolysis and vapour-phase hydrogenation
A plastic-to-jet-fuel conversion case for separating molecular feasibility from feedstock supply, hydrogen, certification and deployment questions.
REFERENCES
References & further reading
- U.S. Department of Energy (2024). Feedstock-Conversion Interface Consortium: Crosscutting Analysis Research.Open source ↗
- Préat et al. (2020). Identification of microalgae biorefinery scenarios and development of mass and energy balance flowsheets.https://doi.org/10.1016/j.algal.2019.101737 ↗
- Cortes-Peña et al. (2020). BioSTEAM: A Fast and Flexible Platform for the Design, Simulation, and Techno-Economic Analysis of Biorefineries under Uncertainty.https://doi.org/10.1021/acssuschemeng.9b07040 ↗
- Sahoo and Remya (2020). Influence of operating parameters on the microwave pyrolysis of rice husk: biochar yield, energy yield, and property of biochar.https://doi.org/10.1007/s13399-020-00914-8 ↗
- Kundu et al. (2024). Obtaining high H2-rich syngas yield and carbon conversion efficiency from biomass gasification: From characterization to process optimization using machine learning with experimental validation.https://doi.org/10.1016/j.fuel.2024.132931 ↗
- Intergovernmental Panel on Climate Change (2022). Climate Change 2022: Mitigation of Climate Change — Chapter 6, Energy Systems.Open source ↗
- Wyman, Spindler and Grohmann (1992). Simultaneous saccharification and fermentation of several lignocellulosic feedstocks to fuel ethanol.https://doi.org/10.1016/0961-9534(92)90001-7 ↗
- Oliveira et al. (2018). Process integration of a multiperiod sugarcane biorefinery.https://doi.org/10.1016/j.apenergy.2017.11.020 ↗
- BioSTEAM project (2026). BioSTEAM process simulation, TEA and LCA documentation.Open source ↗
- U.S. Department of Energy, U.S. Department of Transportation and U.S. Department of Agriculture (2022). Sustainable Aviation Fuel Grand Challenge Roadmap.Open source ↗
- Yao, Staples, Malina and Tyner (2017). Stochastic techno-economic analysis of alcohol-to-jet fuel production.https://doi.org/10.1186/s13068-017-0702-7 ↗
- Batten, Karanjikar and Spatari (2024). A sustainable aviation fuel pathway from biomass: life cycle environmental and cost evaluation for dimethylcyclooctane jet fuel.https://doi.org/10.1039/d3se01470c ↗
- Argonne National Laboratory (2026). GREET Model.Open source ↗
- Yoo, Lee and Wang (2022). Life-Cycle Greenhouse Gas Emissions of Sustainable Aviation Fuel through a Net-Zero Carbon Biofuel Plant Design.https://doi.org/10.1021/acssuschemeng.2c00977 ↗
- Yanghao Jin, Sirui Liu, Ziyi Shi, Shule Wang, Ilman Nuran Zaini, Chuchu Tang, Sibudjing Kawi, Chi-Hwa Wang, Mikael Hedenqvist, Xincheng Lu, Yuming Wen, Jianchun Jiang, Pär Göran Jönsson, Weihong Yang (2024). A novel three-stage ex-situ catalytic pyrolysis process for improved bio-oil yield and quality from lignocellulosic biomass.https://doi.org/10.1016/j.energy.2024.131029 ↗
- Shule Wang, Per Mandfloen, Pär Jönsson, Weihong Yang (2021). Synergistic effects in the copyrolysis of municipal sewage sludge digestate and salix: Reaction mechanism, product characterization and char stability.https://doi.org/10.1016/j.apenergy.2021.116687 ↗
- Jia Wang, Zedong Zhang, Yan Zhang, Dongxian Li, Zechao Zhuang, Wei Liao, Tong Han, Lin Dong, Shule Wang, Dingsheng Wang, Jianchun Jiang (2025). Breaking the yield–selectivity trade-off in polystyrene waste valorization via tandem depolymerization and hydrogenolysis.https://doi.org/10.1038/s41565-025-02069-x ↗
- Shule Wang, Yuming Wen, Ziyi Shi, Ilman Nuran Zaini, Pär Göran Jönsson, Weihong Yang (2022). Novel carbon-negative methane production via integrating anaerobic digestion and pyrolysis of organic fraction of municipal solid waste.https://doi.org/10.1016/j.enconman.2021.115042 ↗
- Jia Wang, Zedong Zhang, Shule Wang, Ya-Fei Jiang, He Zhou, Wenhui Zhong, Yiyun Zhang, Dongxian Li, Wenjun Zhong, Shiyao Li, Daniel Sanchez, Dingsheng Wang, Jun Li, Jianchun Jiang, Yadong Li (2026). Ambient-pressure conversion of plastic waste to jet fuel cycloalkanes by tandem hydropyrolysis and vapour-phase hydrogenation.https://doi.org/10.1038/s41560-026-02078-7 ↗