Oil & Natural Gas Projects
Exploration and Production Technologies
Proton Exchange Reactive Membranes for Conversion of Light Alkanes to Clean
This project was funded through DOE's Natural Gas and Oil Technology Partnership
Program. The program establishes alliances that combine the resources and experience
of the Nation's petroleum industry with the capabilities of the National Laboratories
to expedite RD&D of advanced technologies for improved natural gas and oil
production and processing.
The project goal is to investigate the moderate-temperature conversion of light
alkanes to non-aromatic liquid hydrocarbons by employing the equilibrium-shifting
potential of catalytic membranes.
Idaho National Laboratory
Idaho Falls, ID
Salt Lake City, UT
BP Products North America
The project looked at the direct conversion of C1 through C5 alkanes to low
vapor-pressure, low-sulfur, non-aromatic gasoline and diesel fuels by exploring
proton- exchange reactive membranes (PERM) for the homologation reaction. Coupling
the catalytic homologation reaction with proton-exchange membranes is an innovative,
multi-functional technology for enhanced alkane dehydrogenation, hydrogen separation,
Since processed light alkanes contain low levels of sulfur, and the reaction
products are low vapor-pressure alkanes and cyclo-alkanes, this process has
a high potential for producing clean liquid transportation fuels.
Modern refinery processes produce significant quantities of light alkane byproducts
that have limited potential for blending in liquid transportation fuels. These
byproducts, which contain low levels of sulfur, are typically burned as low-value
fuel gas or flared, representation a significant economic loss.
This experimental research project will explore the catalytic homologation
of light alkanes to liquid fuels via a PERM. Catalytic homologation reaction
has a high potential for success, since the reaction can be manipulated to produce
primarily low vapor-pressure, non-aromatic hydrocarbons. The PERM reactor can
be a net hydrogen producer or could be coupled with a fuel cell to produce power
from the hydrogen byproduct.
Equilibrium shifting of catalytic membranes was tested for conversion of light
alkanes to non-aromatic, liquid hydrocarbons.
The non-oxidative homologation catalytic reaction has been shown to be a unique
and promising technology for upgrading light alkanes. Run isothermally, the
reaction has a positive Gibbs free energy of reaction, limiting conversion and
yields. Researchers have found that this reaction can be split into two steps,
significantly improving the thermodynamic constraints. In the first step, a
flowing hydrocarbon chemisorbs and dehydrogenates on the catalyst surface. The
flow is switched to hydrogen in the second step, forming re-hydrogenated higher
hydrocarbons that are released from the catalyst.
Technical issues explored in the project were:
- Obtaining high hydrogen-flux rates across the membrane, such that the alkane
upgrading reaction is promoted.
- Achieving rapid catalyst kinetics that promote the chemisoption/dehydrogenation
and rehydrogenation/higher-hydrocarbon formation reaction.
- Determining optimum process conditions that positively affect both the catalytic
reaction and the membrane performance.
- Avoiding negative catalyst-membrane interactions.
- Exploring material stability in the reaction environment.
The developed PERM was tested in an automated flowing reactor system. The alkane/hydrogen
reactor affluent stream was analyzed to determine alkane conversion, product
yield, selectivity, and production rate as a function of process variables.
The goal of this effort was to increase reaction kinetics to the point that
a continuous steady-state process can be established.
Current Status (October 2005)
Additional funding for this project was received in August 2004. The Cooperative
Research and Development Agreement with Ceramatec Inc. was modified to cover
a new scope of work under this project. This included a scale-up of the process
to a pilot by Ceramatec. Positive results from the pilot study will lead to
full-scale development and demonstration of the PERM alkane upgrading process.
Project Start: March 27, 2002
Project End: March 26, 2005
Anticipate DOE Contribution: $ 440,000
Performer Contribution: $55,000 (11% of total)
NETL - Kathy Stirling (Kathy.Stirling@netl.doe.gov or 918-699-2008)
INL - Daniel M. Ginosar (Daniel.Ginosar@inl.gov or 208-526-9049)