Belma B Demirel

US Patent:

7303731, Dec 4, 2007

Filed:

Dec 7, 2004

Appl. No.:

11/005873

Inventors:

Belma Demirel - Longmont CO, US
Mark S. Bohn - Golden CO, US
Charles B. Benham - Littleton CO, US
James E. Siebarth - Lakewood CO, US
Mark D. Ibsen - Highlands Ranch CO, US

Assignee:

Rentech, Inc. - Los Angeles CA

International Classification:

B01J 8/00
B01J 38/48

US Classification:

422223, 422212, 422213, 422140, 422144, 422145, 422147, 518710, 502 22

Abstract:

Solvent extraction is used to remove wax and contaminants from an iron-based Fischer-Tropsch catalyst in a natural circulation continuous-flow system. The wax-free catalyst is then subjected to controlled oxidation to convert the iron to its initial oxidized state, FeO. Reactivation of the oxide catalyst precursor is carried out by addition of synthesis gas.

US Patent:

7644587, Jan 12, 2010

Filed:

Dec 21, 2005

Appl. No.:

11/316455

Inventors:

Dennis L. Yakobson - Arvada CO, US
Charles B. Benham - Arvada CO, US
Belma Demirel - Longmont CO, US
Peter S. Pedersen - Boulder CO, US

Assignee:

Rentech, Inc. - Los Angeles CA

International Classification:

F02C 3/28
F02C 6/14

US Classification:

60780, 60 3912, 60 39464

Abstract:

A method for meeting both base-load and peak-load demand in a power production facility. By integrating a Fischer-Tropsch (FT) hydrocarbon production facility with an electrical power generating facility, peak-load power demand can be met by reducing the temperature of the FT reactor thereby increasing the quantity of tail gases and using FT tail gases to fuel a gas turbine generator set. The method enables rapid power response and allows the synthesis gas generating units and the FT units to operate with constant flow rates.

US Patent:

7879756, Feb 1, 2011

Filed:

Aug 11, 2008

Appl. No.:

12/189424

Inventors:

Belma Demirel - Longmont CO, US
Charles B. Benham - Arvada CO, US
Jesse W. Taylor - Westminister CO, US
Pandurang V. Nikrad - Boulder CO, US
Sara L. Rolfe - Loveland CO, US
Olga P. Ionkina - Boulder CO, US
Dawid J. Duvenhage - Evergreen CO, US
Harold A. Wright - Longmont CO, US

Assignee:

Rentech, Inc. - Los Angeles CA

International Classification:

B01J 23/00
B01J 21/00
B01J 20/00

US Classification:

502331, 502330, 502338

Abstract:

A method of producing an iron catalyst for catalyzing the hydrogenation of carbon monoxide is disclosed. The method comprises using a reduced amount of acid for iron dissolution compared to certain previous methods. The resulting acidic iron mixture is heated without boiling to obtain a nitrate solution having a Fe:Fe ratio in the range of about 0. 01%:99. 99% to about 100%:0% (wt:wt). Iron phases are precipitated at a lower temperature compared to certain previous methods. The recovered catalyst precursor is dried and sized to form particles having a size distribution between 10 microns and 100 microns. In embodiments, the Fe:Fe ratio in the nitric acid solution may be in the range of from about 3%:97% to about 30%:70% (wt:wt) and the calcined catalyst may comprise a maghemite:hematite ratio of about 1%:99% to about 70%:30%.

US Patent:

7915193, Mar 29, 2011

Filed:

Nov 18, 2008

Appl. No.:

12/272960

Inventors:

Belma Demirel - Longmont CO, US
Charles B. Benham - Arvada CO, US
Dan Fraenkel - Boulder CO, US
Richard Bley - Longmont CO, US
Jesse W. Taylor - Westminster CO, US
Bahman Rejai - Littleton CO, US
Sara Rolfe - Loveland CO, US
Harold A. Wright - Longmont CO, US

Assignee:

Rentech, Inc. - Los Angeles CA

International Classification:

B01J 23/42

US Classification:

502158, 502336, 502327, 502326, 502302, 518715, 518700

Abstract:

A method of activating an iron Fischer-Tropsch catalyst by introducing an inert gas into a reactor comprising a slurry of the catalyst at a first temperature, increasing the reactor temperature from the first temperature to a second temperature at a first ramp rate, wherein the second temperature is in the range of from about 150 C. to 250 C. , introducing synthesis gas having a ratio of H:CO to the reactor at a space velocity, and increasing the reactor temperature from the second temperature to a third temperature at a second ramp rate, wherein the third temperature is in the range of from about 270 C. to 300 C. The iron Fischer-Tropsch catalyst may be a precipitated unsupported iron catalyst, production of which is also provided.

US Patent:

7964156, Jun 21, 2011

Filed:

Oct 18, 2007

Appl. No.:

11/874661

Inventors:

Belma Demirel - Longmont CO, US
Mark S. Bohn - Golden CO, US
Charles B. Benham - Arvada CO, US
James E. Siebarth - Lakewood CO, US
Mark D. Ibsen - Highlands Ranch CO, US

Assignee:

Rentech, Inc. - Los Angeles CA

International Classification:

B01J 8/20
B01J 8/22
B01J 38/48

US Classification:

422223, 422234, 422140, 422144, 422145, 422147, 518709, 518710, 502 22

Abstract:

Solvent extraction is used to remove wax and contaminants from an iron-based Fischer-Tropsch catalyst in a natural circulation continuous-flow system. The wax-free catalyst is then subjected to controlled oxidation to convert the iron to its initial oxidized state, Fe0. Reactivation of the oxide catalyst precursor is carried out by addition of synthesis gas.

US Patent:

7968611, Jun 28, 2011

Filed:

Feb 26, 2010

Appl. No.:

12/713807

Inventors:

Belma Demirel - Longmont CO, US
Charles B. Benham - Arvada CO, US
Jesse W. Taylor - Westminister CO, US
Pandurang V. Nikrad - Boulder CO, US
Sara L. Rolfe - Loveland CO, US
Olga P. Ionkina - Boulder CO, US
Dawid J. Duvenhage - Evergreen CO, US
Harold A. Wright - Longmont CO, US

Assignee:

Rentech, Inc. - Los Angeles CA

International Classification:

C07C 27/00
B01J 23/00
B01J 21/00
B01J 20/00

US Classification:

518713, 502330, 502331, 502338

Abstract:

A method of producing an iron catalyst for catalyzing the hydrogenation of carbon monoxide is disclosed. The method comprises using a reduced amount of acid for iron dissolution compared to certain previous methods. The resulting acidic iron mixture is heated without boiling to obtain a nitrate solution having a Fe:Fe ratio in the range of about 0. 01%: 99. 99% to about 100%:0% (wt:wt). Iron phases are precipitated at a lower temperature compared to certain previous methods. The recovered catalyst precursor is dried and sized to form particles having a size distribution between 10 microns and 100 microns. In embodiments, the Fe:Fe ratio in the nitric acid solution may be in the range of from about 3%:97% to about 30%:70% (wt:wt) and the calcined catalyst may comprise a maghemite:hematite ratio of about 1%:99% to about 70%:30%.

US Patent:

8138115, Mar 20, 2012

Filed:

Feb 26, 2010

Appl. No.:

12/713358

Inventors:

Belma Demirel - Longmont CO, US
Charles B. Benham - Arvada CO, US
Jesse W. Taylor - Westminister CO, US
Pandurang V. Nikrad - Boulder CO, US
Sara L. Rolfe - Loveland CO, US
Olga P. Ionkina - Boulder CO, US
Dawid J. Duvenhage - Evergreen CO, US
Harold A. Wright - Longmont CO, US

Assignee:

Rentech, Inc. - Los Angeles CA

International Classification:

B01J 23/00

US Classification:

502331, 502338, 502345

Abstract:

A method of producing an iron catalyst for catalyzing the hydrogenation of carbon monoxide is disclosed. The method comprises using a reduced amount of acid for iron dissolution compared to certain previous methods. The resulting acidic iron mixture is heated without boiling to obtain a nitrate solution having a Fe:Fe ratio in the range of about 0. 01%:99. 99% to about 100%:0% (wt:wt). Iron phases are precipitated at a lower temperature compared to certain previous methods. The recovered catalyst precursor is dried and sized to form particles having a size distribution between 10 microns and 100 microns. In embodiments, the Fe:Fe ratio in the nitric acid solution may be in the range of from about 3%:97% to about 30%:70% (wt:wt) and the calcined catalyst may comprise a maghemite:hematite ratio of about 1%:99% to about 70%:30%.

US Patent:

8146368, Apr 3, 2012

Filed:

Dec 1, 2009

Appl. No.:

12/628975

Inventors:

Dennis L. Yakobson - Arvada CO, US
Charles B. Benham - Arvada CO, US
Belma Demirel - Longmont CO, US
Peter S. Pedersen - Boulder CO, US

Assignee:

Rentech, Inc. - Los Angeles CA

International Classification:

F02C 3/28
F02C 6/14

US Classification:

60781, 60780

Abstract:

A method for meeting both base-load and peak-load demand in a power production facility. By integrating a Fischer-Tropsch (FT) hydrocarbon production facility with an electrical power generating facility, peak-load power demand can be met by reducing the temperature of the FT reactor thereby increasing the quantity of tail gases and using FT tail gases to fuel a gas turbine generator set. The method enables rapid power response and allows the synthesis gas generating units and the FT units to operate with constant flow rates.