Biopropane Production For Natural Gas Processors

BioPropane Production for Natural Gas Processors

Previously, I described three opportunities for generating BioPropane from BioGas.  Each opportunity has the potential to generate RIN credits.  There is commercial interest in BioPropane as an alternative transportation fuel.  In this blog post, I describe two opportunities that use novel autotrophic microbes for BioPropane Production for Natural Gas Processors.

Natural Gas Processor Opportunities

Natural Gas Processors could generate BioPropane with two different configurations. Both configurations use a 2-bioreactor system that converts methane to ethane and then propane.  The first configuration utilizes biogas as the input, while the second configuration utilizes raw natural gas.  Let’s learn more about each configuration.

BioPropane using Biogas, Hydrogen, and Unprocessed Natural Gas

Anaerobic digesters and landfills generate biogas that could be processed by a natural gas processor to generate BioPropane and valuable RIN credits.   Many biogas generators cannot generate RNG due to the high cost of connecting to available natural gas lines.  Alternatively, the raw biogas could be collected and transported to a nearby natural gas collection network for downstream processing.  Discounted RNG (raw methane) priced at 67% may be attractive for both biogas producer and Natural Gas Processor.  A two step process converts biogas and supplemental hydrogen into bioethane and biopropane.  Biogas processing of the biopropane reactor headspace recovers Biopropane.

BioPropane Option 3 Natural Gas Processor with BioGas H2 and CO2
BioPropane Production for Natural Gas Processor using BioGas and H2

BioPropane using Hydrogen, Carbon Dioxide, and Unprocessed Natural Gas

A simpler bioreactor system could be used by natural gas processors to generate BioPropane using carbon dioxide and hydrogen, purchased or generated on-site.  A 2-step process converts biogas and hydrogen into bioethane and biopropane.  Processing of the biopropane reactor headspace recovers Biopropane for injection into the unprocessed natural gas line for downstream separation.

BioPropane Option 4 Natural Gas Processor with H2 and CO2 only
BioPropane Production for Natural Gas Processors using H2 and CO2

The CO2 emission factor for propane was used for calculating the percent reduction in CO2, which is necessary for classifying the RIN type.  I used the GREET model to estimate the CO2 reduction in the new pathway for generating BioPropane from Unprocessed Natural Gas.  I assumed that hydrogen would be generated by electrolysis using solar or windmill power.  Captured CO2 at or near the Natural Gas Processor have very low CO2 emissions.  Carbon dioxide used in the bioreactor system offset CO2 emissions for a net reduction of more than 20%, which qualifies for D6 RIN credit.  The generation of RIN credit for BioPropane requires a petition to U.S. EPA’s Renewable Fuel Standard Program.

Revenue Comparison for BioPropane Using Unprocessed Natural Gas

The table below provides the revenue potential of BioPropane for the two bioreactor systems.  Both scenarios suggest high revenues when compared to the value of the raw methane.  Natural Gas Processors purchase biogas methane at a 67% discount with respect to RIN credit.  I used Spot Prices of $2.10/MMBtu and $6.50/MMBtu for Natural Gas (and biogas methane) and BioPropane, respectively.  I used the same costs for hydrogen ($1.80/kg) and carbon dioxide ($0.10/kg) used for biogas conversion to BioPropane.  The CO2 is assumed to be captured CO2, which is renewable, which is incorporated into BioPropane making it renewable.  I added costs of $0.10 per gallon of BioPropane for bioreactor generation and recovery for a total of $0.20/gallon.  Calculations used RIN credit values from December 2022 of $2.76  and $1.64 for D3 and D6, respectively.  Both opportunities have large revenue multiples of 4.02 and 7.87 for biogas and UNG, respectively.

Revenue Comparison for BioPropane Production From BioGas and UNG for Natural Gas Processors
Revenue Comparison for BioPropane Production From BioGas and UNG for Natural Gas Processors


The BioPropane production opportunities warrant a deeper dive into the cost estimates, which I’ll provide in a future blog post focused on BioNGL opportunities.  I will explore the various options available to Natural Gas Processors for generating several transportation biofuels including BioPropane, BioButane, and BioPentane from all of the alkanes available in Natural Gas.

Commercialization Pathway for Natural Gas Processors

If there’s interest in this approach to generating BioPropane, then follow the four step plan for commercialization.

Isolate and Characterize Ethanogens and Propanogens

This commercialization plan requires two novel alkanogens, Ethanogens and Propanogens.  Thermodynamic analysis predicts these alkanogens and other novel autotrophic microbes.  The combination of a proper anaerobic, autotrophic microbiology laboratory and a skilled microbiologist should suffice.  The laboratory will require gas chromatography for gas characterization.  Growth rate information for isolates will be necessary for bioreactor design.  I’m available to assist in this effort.

Demonstrate Bioreactor System for Generating BioPropane

With both alkanogens properly characterized, design a simple bioreactor system for a simple demonstration using biogas or unprocessed natural gas.  A successful demonstration provides a good estimate of the potential profitability of the bioreactor system.

Petition US EPA for Advanced BioFuel Pathway

In order to qualify for the valuable RIN credits, the US EPA requires a petition describing the novel approach for generating a biofuel.

Secure License for Patents

License the patents for the bioreactor system from the University of South Florida (USF).  Send me an email for USF contact information.

More Information Available

I provided a video that describes multiple business opportunities that could impact Agriculture, Environmental Remediation, Water and Wastewater Treatment, Metals Recovery, BioEnergy, and Health markets.  In the future, I’ll provide new blog posts that describe opportunities for generating BioButanol and novel autotrophic probiotics for ruminants that reduce methane emissions.

Send Me Your Questions About BioPropane Production

Send me your questions about generating BioPropane to pete@glixin.com.


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