H2S Removal and Sulfur Recovery Technologies for CO2 Streams:
Old and New Approaches
Kenneth E. McIntush, P.E.
CrystaTech, Inc.
Austin, Texas, USA
Robert N. MacCallum, Ph.D., P.E.
Occidental Permian Ltd
Houston, Texas, USA
Curtis O. Rueter, P.E.
CrystaTech, Inc.
Denver, Colorado, USA
David W. DeBerry, Ph.D.
CrystaTech, Inc.
Austin, Texas, USA
Presented at:
Seventh Annual CO2 Conference
Center for Energy and Economic Diversification (CEED)
University of Texas of the Permian Basin (UTPB)
Midland, Texas, December 4th & 5th, 2001
ABSTRACT
CrystaTech and Oxy Permian have been working together to demonstrate the use
of CrystaSulf, a nonaqueous approach for H2S removal and sulfur recovery, at a large
pilot facility located at Oxy Permian’s Denver Unit CO2 Recovery Plant (DUCRP) in
Denver City, Texas. CrystaSulf uses nonaqueous components that do not react with CO2.
As a result, CrystaSulf can selectively remove H2S in the presence of extremely high CO2
partial pressures without the complications that accompany aqueous approaches. The
work at DUCRP has been very successful at demonstrating the benefits of using this
approach to H2S removal and sulfur recovery.
Oxy Permian has direct experience with several different H2S removal and sulfur
recovery approaches for CO2 streams: refrigerated aqueous amine systems combined
with modified Claus technology, aqueous redox sulfur recovery systems, and the
nonaqueous CrystaSulf process. The aqueous approaches use alkaline aqueous solution
to scrub H2S. As a result, the aqueous approaches must contend with the reaction of CO2
with the scrubbing solution. In addition, some of the aqueous processes form elemental
sulfur particles within the absorber; the presence of these solids and the surfactants that
must also be added to wet the solids further complicates use of these systems for
scrubbing CO2 streams. This paper discusses and compares several approaches for H2S
removal and sulfur recovery from CO2 streams.