Integrated bio-refinery in Colorado complete

Nov. 9, 2011, Los Angeles, CA – Rentech Inc. announced today that all systems required
to start up a new integrated bio-refinery (IBF) in Commerce
City, Colorado are mechanically complete.

Commissioning, validation and
start-up of the renewable energy demonstration facility are underway.
The project has reached this milestone within the original budget and
schedule.

The IBR project was co-funded by a $23 million grant from the U.S.
Department of Energy, to manufacture and install at the Rentech Energy
Technology Center a 20 ton-per-day Rentech-ClearFuels biomass gasifier.
The gasifier is designed to produce bio-synthesis gas from various high
impact wood waste and sugar cane bagasse feedstocks. The gasifier has
been integrated with Rentech's existing Product Demonstration Unit (PDU)
at the site, which uses the Rentech Process and UOP's upgrading
technologies to produce renewable drop-in synthetic jet and diesel fuels
at demonstration scale. Rentech expects the integrated facility, which
will have the flexibility to produce renewable syngas, hydrogen, and
steam as well as biofuels, will be used to evaluate additional
technology integration opportunities. Rentech funded the balance of the
project's total cost of approximately $36 million, which includes the
cost of building the gasifier, feedstock handling equipment, integration
with Rentech's synthetic fuels plant, and operation of the facility for
a period of 6 months to collect 2,000 hours of operating data. The
project team responsible for meeting this important milestone for
mechanical completion included URS Corporation, Linde Group/Hydro-Chem,
Piper Electric Corporation and Ames Construction, Inc.

The IBR is anticipated to produce certified renewable fuels in late
2011. This demonstration-scale project is expected to lead to the final
design basis for commercial-scale facilities using the combined
technologies, including for potential biomass-to-energy projects that
are contemplated in the southeastern United States, Hawaii and Canada.

Dr. Harold Wright, Rentech's Chief Technology Officer, commented,
"Achieving mechanical completion of the IBR demonstration facility
on-time and on-budget leads the way for cellulosic fuels production at
the PDU with the Rentech-ClearFuels gasifier and Rentech Process." Dr.
Wright continued, "We're pleased to have a successful collaboration with
the DOE, whose funding helped make this demonstration possible."

About Rentech, Inc.

Rentech, Inc. (www.rentechinc.com),
incorporated in 1981, provides clean energy solutions. The Company's
Rentech-SilvaGas and Rentech-ClearFuels biomass gasification processes
can convert multiple cellulosic biomass feedstocks into synthesis gas
(syngas) for production of renewable fuels and power. Combining the
gasification processes with Rentech's unique application of syngas
conditioning and clean-up technology and the patented Rentech Process
based on Fischer-Tropsch chemistry, Rentech offers an integrated
solution for production of synthetic fuels from cellulosic biomass. The
Rentech Process can also convert syngas from fossil resources into
ultra-clean synthetic jet and diesel fuels, specialty waxes, and
chemicals. Final product upgrading and acid gas removal technologies are
provided under an alliance with UOP, a Honeywell company. Rentech
develops projects and offers licenses for these technologies for
application in synthetic fuels and power facilities worldwide. Rentech,
Inc. owns a majority interest and serves as general partner of Rentech
Nitrogen Partners, L.P., a nitrogen fertilizer limited partnership.
Rentech Nitrogen Partners, L.P. manufactures and sells nitrogen
fertilizer products including ammonia, urea ammonia nitrate, urea
granule and urea solution in the Mid Corn Belt region of the United
States.

Safe Harbor Statement

This press release contains forward-looking statements as defined in the
Private Securities Litigation Reform Act of 1995 about matters such as
the timing of the completion of the demonstration, the characteristics
of the renewable fuels to be produced from the technologies, and the
proposed development projects using integrated technologies. These
statements are based on management's current expectations and actual
results may differ materially as a result of various risks and
uncertainties. Other factors that could cause actual results to differ
from those reflected in the forward-looking statements include the
ability of the parties to create and successfully market a combined
technology offering, the financial means of Rentech and ClearFuels to
build their proposed projects, fluctuations in commodities prices
including the price of oil and the materials necessary to construct a
project, the impact of changing government regulations on the project
permitting process and the qualification of renewable fuels and factors
set forth in the Company's press releases and periodic public filings
with the Securities and Exchange Commission, which are available via
Rentech's web site at
www.rentechinc.com.
The forward-looking statements in this press release are made as of the
date of this release, and Rentech does not undertake to revise or update
these forward-looking statements, except to the extent that it is
required to do so under applicable law.