An Economically Competitive and Environmentally Friendly Process for Producing Synthetic Liquid Fuel from Coal, Biomass and Natural Gas

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Princeton Docket # 12-2791/2859-1


The challenges to reduce dependence on petroleum as energy sources, coupled with efforts to reduce greenhouse gas (GHG) emissions, are exigent problems faced by the US transportation sector.  Researchers at Princeton University have developed a novel hybrid energy process that utilizes coal, biomass, and natural gas as feedstocks to produce any given volumetric capacity of gasoline, diesel, and kerosene.  The process will produce synthesis gas (syngas) from each of the three feedstocks and subsequently convert that syngas to liquid fuels via the Fischer-Tropsch reaction or through a methanol intermediate.  The raw hydrocarbons from the Fischer-Tropsch reaction can then be converted to the desired liquid fuels via know chemical reactions.  

Employing innovative combinations of unit operations, Princeton researchers have postulated a superstructure detailing a wide array of process topologies and developed a mixed-integer nonlinear optimization model to examine the trade-offs with each topology and chosen the solution with the best economic and environmental value.  The detailed topological superstructure of the proposed refinery provides remarkable advantages over current technologies that utilize a limited set of process units because it is capable of finding a more efficient design methodology based on the inclusion of additional process considerations.


Conversion of coal, biomass, and natural gas to gasoline, diesel, or kerosene


·        The mixture of feedstocks will inherently mitigate the risk involved with price and demand uncertainty associated with a single feedstock refinery.

·        The low cost of coal, the greenhouse gas reduction potential of biomass, and the high hydrogen content of natural gas will combine to help design the most economically robust refinery possible.

·        Significant reduction in GHG emission by utilization of biomass feedstock, a CO2 recycle loop, and CO2 sequestration

·        A simultaneous heat and power integration to recover waste heat and minimize utility consumption

·        The refinery integrates a comprehensive wastewater network to minimize wastewater contaminants and freshwater intake.

·        Applicable to 16 different types of biomass

·        Optimization based on both cost and emission


·        Elia, J. A.; Baliban, R. C.; Floudas, C. A. Nationwide Supply Chain Analysis for Hybrid Feedstock Energy Processes with Significant CO2 Emissions Reduction.  AIChE Journal 2012, Accepted for publication.

·        Baliban, R. C.; Elia, J. A.; Weekman, V.; Floudas, C. A. Process Synthesis of Hybrid Coal, Biomass, and Natural Gas to Liquids via Fischer-Tropsch Synthesis, ZSM-5 Catalytic Conversion, Methanol Synthesis, Methanol-to-Gasoline, and Methanol-to-Olefins/Distillate Technologies. Computers and Chemical Engineering 2012, Submitted for publication.

·        Floudas, C. A.; Elia, J. A.; Baliban, R. C.  Hybrid and Single Feedstock Energy Processes for Liquid Transportation Fuels: A Critical Review. Computers and Chemical Engineering 201241, 24-51. (DOI:10.1016/j.compchemeng.2012.02.008)

·        Baliban, R. C.; Elia, J. A.; Misener, R.; Floudas, C. A. Global Optimization of  a MINLP Process Synthesis Model for Thermochemical Based Conversion of Hybrid Coal, Biomass, and Natural Gas to Liquid Fuels. Computers and Chemical Engineering 2012, in press.  (DOI:10.1016/j.compchemeng.2012.03.008)

·        Baliban, R. C.; Elia, J. A.; Floudas, C. A. Simultaneous Process Synthesis, Heat, Power, and Water Integration of Thermochemical Hybrid Biomass, Coal, and Natural Gas Facilities. Computers and Chemical Engineering 201237, 297-327. (DOI: 10.1016/j.compchemeng.2011.10.002)

·        Baliban, R. C.; Elia, J. A.; Floudas, C. A. Optimization Framework for the Simultaneous Process Synthesis, Heat and Power Integration of a Thermochemical Hybrid Biomass, Coal, and Natural Gas Facility. Computers and Chemical Engineering 201135, 1647-1690. (DOI:10.1016/j.compchemeng.2011.01.041)

·        Elia, J. A.; Baliban, R. C.; Xiao, X.; Floudas, C. A. Optimal energy supply network determination and life cycle analysis for hybrid coal, biomass and natural gas to liquid (CBGTL) plants using carbon-based hydrogen production. Computers and Chemical Engineering 201135, 1399-1430. (DOI:10.1016/j.compchemeng.2011.01.019)

·        Baliban, R. C.; Elia, J. A.; Floudas, C. A. Toward novel hybrid biomass, coal, and natural gas processes for satisfying current transportation fuel demands, 1: Process alternatives, gasification modeling, process simulation, and economic analysis. Industrial & Engineering Chemistry Research 201049, 7343-7370. (DOI: 10.1021/ie100063y)

·        Elia, J. A.; Baliban, R, C.; Floudas, C. A. Toward novel hybrid biomass, coal, and natural gas processes for satisfying current transportation fuel demands, 2: Simultaneous heat and power integration. Industrial & Engineering Chemistry Research 201049, 7371-7388. (DOI:10.1021/ie100064q)


Christodoulos A. Floudas is Stephen C. Macaleer '63 Professor in Engineering and Applied Science and Professor of Chemical and Biological Engineering at Princeton University.  Professor Floudas is a world-renowned authority in mathematical modeling and optimization of complex systems at the macroscopic and microscopic level.  His research interests lie at the interface of chemical engineering, applied mathematics, and operations research, with principal areas of focus including chemical process synthesis and design, process control and operations, discrete-continuous nonlinear optimization, local and global optimization, and computational chemistry and molecular biology.  Among Prof. Floudas¿ numerous honors and awards are Member of National Academy of Engineering (2011), Princeton University Graduate Mentoring Award (2007), AIChE Computing in Chemical Engineering Award (2006) and AIChE Professional Progress Award for Outstanding Progress in Chemical Engineering (2001), to name a few.

Richard C. Baliban is a fifth-year graduate student in Prof. Floudas¿ lab.

Josephine A. Elia is a fourth-year graduate student in Prof. Floudas¿ lab.

Intellectual Property and Technology Status

A provisional application has been filed.  For all units and simulations in this invention mathematical models were developed which are available for evaluation.


Princeton is interested in identifying collaborators for the further development and commercialization of this technology.   




Laurie Tzodikov

Princeton University Office of Technology Licensing


Patent Information:
For Information, Contact:
Laurie Tzodikov
Licensing Associates
Princeton University
Christodoulos Floudas (DECEASED) See Fotini P. Baba
Richard Baliban
Josephine Elia
green tech
process optimization