Oil & Natural Gas Projects
Exploration and Production Technologies
Developing Enzyme and Biomimetic Catalysts for Upgrading Heavy Crudes via
Biological Hydrogenation and Hydrodesulfurization
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 research, development, and demonstration of advanced technologies
for improved natural gas and oil recovery.
The project goal was to develop a hydrogenation catalyst capable of operation
at moderate or mild conditions.
Argonne National Laboratory (ANL)
Oak Ridge National Laboratory (ORNL)
Oak Ridge, TN
Selected enzyme catalysts were subjected to kinetic testing and thermal stability
tests. EXAFS technology allowed improvement of the catalysts for operation under
In order to make biological enzymes work with compounds in crude oil, it is
necessary to create favorable binding interactions between the oil substrates
and enzymes. The difficulty in coupling enzymes with the hydrophobic substrates
in oil can be overcome by reducing the polarity or increasing the hydrophobicity
of the enzyme's substrate docking site. This modification was done at ORNL.
The approach was based on understanding the enzyme-substrate interaction and
then modifying the enzyme to improve its activity.
The improvements are to be partly assessed using EXAFS technology in collaboration
with ANL. Selected enzyme catalysts were subjected to kinetic testing and thermal
stability tests. Industrial input will be sought in catalyst development as
well as in performing preliminary economic analysis.
Ultimately, the work is expected to benefit U.S. refiners by developing an
environmentally friendly technology that provides a less-severe method of processing
heavy crude oils than conventional upgrading techniques while helping to reduce
corrosion in process units.
The processing of heavy oils is currently plagued by two major problems: dealing
with the presence of asphaltenes, which increases oil viscosity, and with the
heteroatom content, which poses corrosion and complex-refining problems. Technology
is needed to process heavy crudes in such a way as to reduce viscosity and heteroatom
content under mild conditions. Additions of hydrogen to aromatic and heteroatom
molecules via a biological route can be a potentially attractive alternative
to upgrading heavy crudes. However, hydrogen addition to molecules existing
in petroleum by using natural enzymes is difficult.
The laboratory set-up was updated to carry out anaerobic microbiology and enzymology
work for the modification of hydrogenase enzymes to be developed into desulfurization
biocatalysts. A collaboration was set up with Dr. Mike Adams at the University
of Georgia, Athens, GA, to obtain the thermophilic hydrogenase enzyme and to
study its activity against organosulfur compounds.
A Cooperative Research and Development Agreement was developed with Texaco (now
part of Chevron) and ANL to facilitate further testing and to allow protection
of the resulting proprietary property.
At ANL, catalyst-testing units were modified for testing of catalyst samples
received from ORNL. These units include a plug flow unit that can study supported
enzymes and a stirred autoclave for studying unsupported enzymes. The plug flow
unit also has a back-mixed reactor cell for studying long-term deactivation
patterns for the most promising catalyst systems. In-situ EXAFS cells have been
modified and tested for on-stream collectiong of data for promising catalyst
leads. With this equipment, researchers hope to be able to tell the coordination
sphere and oxidation state of the active metals in time slices as small as one
minute under reaction conditions.
Current Status (October 2005)
The project is complete.
Project Start: April 11, 2001
Project End: April 11, 2004
Anticipated DOE Contribution: $259,000
Performer Contribution: $151,000 (36 % of Total)
NETL - Kathleen Stirling (firstname.lastname@example.org or 918-699-2008)
ANL - Richard Baker (email@example.com or 708-252-2647)