Robert Luther Moser

US Patent:

52600459, Nov 9, 1993

Filed:

Nov 22, 1991

Appl. No.:

7/796603

Inventors:

Robert E. Moser - Palo Alto CA
James H. Wilhelm - Sandy UT
John Burke - Chamblee GA
Sterling Gray - Louisville KY

Assignee:

Electric Power Research Institute - Palo Alto CA

International Classification:

C01B 1700
C01B 1722

US Classification:

42324309

Abstract:

An improved wet magnesium-enhanced lime flue gas desulfurization system and process are provided. The magnesium-enhanced lime slurry process for removing sulfur dioxide from flue gas to produce gas that is substantially free from sulfur dioxide and calcium and sulfite-containing waste solids is modified to include the addition of process reagents to a separate premix slurry tank which has a controlled, high pH. The addition of slurry formed from the scrubber effluent to the premix slurry tank is controlled to maintain the pH above 10. The premix slurry tank mixture is circulated to a reaction tank for reaction with the scrubber effluent to produce large crystal, easily dewatered waste solids.

US Patent:

52137821, May 25, 1993

Filed:

Nov 22, 1991

Appl. No.:

7/796613

Inventors:

Robert E. Moser - Palo Alto CA
James H. Wilhelm - Sandy UT
John Burke - Chamblee GA
Sterling Gray - Louisville KY

Assignee:

Electric Power Research Institute - Palo Alto CA

International Classification:

C01B 1700

US Classification:

4232431

Abstract:

An improved magnesium-enhanced lime flue gas desulfurization system and process are provided which produce the high sulfur dioxide removal level of previous magnesium-enhanced lime flue gas desulfurization systems and additionally produce waste solids that have significantly better properties and are more easily dewatered than the solids produced by known systems. The magnesium-enhanced lime flue gas desulfurization system of the present invention includes a crystallizer-clarifier reaction tank (CCRT) which receives scrubber effluent and functions as a combined reaction tank and thickener. Clear liquor from the CCRT is sent to a scrubber to scrub the flue gas, and a portion of the CCRT-thickened solids are directed to a high pH premix slurry tank (PMST) where the crystallization environment can be controlled by reagent addition and pH. The PMST contents are circulated to the CCRT and are separated to produce a waste solids fraction that is easily dewatered. A fines removal system may also be employed to reduce the presence of fine solids and promote large crystal solids.

US Patent:

55588484, Sep 24, 1996

Filed:

May 30, 1995

Appl. No.:

8/453897

Inventors:

Robert E. Moser - Palo Alto CA
David R. Owens - Mountain View CA
James H. Wilhelm - Sandy UT
James D. Colley - Anchorage KY
Oliver W. Hargrove - Austin TX

International Classification:

B01D 5350

US Classification:

42324301

Abstract:

An efficient and cost-effective flue gas desulfurization process for removing sulfur dioxide from waste gases is provided. The process employs a substantially solids-free clear liquor scrubbing liquid and an organic acid additive capable of maintaining a process pH of 4. 5 to 6. 0 under inhibited oxidation conditions in the absorber to accomplish sulfur dioxide removal while avoiding scale formation and encrustation. Calcium sulfite relative saturation is controlled to a desired low optimum level by maintaining the circulating calcium ion concentration at a corresponding optimum low level. A smaller thickener unit area is required to produce calcium sulfite crystals with optimum settling and dewatering characteristics. A reactor system that promotes the formation of small, efficiently dewatered calcium sulfite solids is also provided.

US Patent:

57701644, Jun 23, 1998

Filed:

May 9, 1996

Appl. No.:

8/647053

Inventors:

Robert E. Moser - Palo Alto CA
David R. Owens - Mountain View CA
James H. Wilhelm - Sandy UT
James D. Colley - Anchorage KY
Oliver W. Hargrove - Austin TX

Assignee:

Electric Power Research Institute - Palo Alto CA

International Classification:

B01D 5000
B01J 804
C10B 1720

US Classification:

422171

Abstract:

An efficient and cost-effective flue gas desulfurization apparatus for removing sulfur dioxide from waste gases is provided. The apparatus employs a substantially solids-free clear liquor scrubbing liquid and an, organic acid additive capable of maintaining a process pH of 4. 5 to 6. 0 under inhibited oxidation conditions in the absorber to accomplish sulfur dioxide removal while avoiding scale formation and encrustation. Calcium sulfite relative saturation is controlled to a desired low optimum level by maintaining the circulating calcium ion concentration at a corresponding, optimum low level. A smaller thickener unit area is required to produced calcium sulfite crystals with optimum settling and dewatering characteristics. A reactor system that promotes the formation of small, efficiently dewatered calcium sulfite solids is also provided.

US Patent:

54863422, Jan 23, 1996

Filed:

Jun 13, 1994

Appl. No.:

8/258921

Inventors:

Robert E. Moser - Palo Alto CA
David R. Owens - Mountain View CA
James H. Wilhelm - Sandy UT
Miriam Stohs - Austin TX
James D. Colley - Anchorage KY
Oliver W. Hargrove - Austin TX

Assignee:

Electric Power Research Institute - Palo Alto CA

International Classification:

B01D 5350

US Classification:

42324301

Abstract:

A flue gas desulfurization process and system employing a clear scrubbing liquor and an organic acid buffer conducted under forced oxidation conditions to produce a usable gypsum by-product without scrubber scaling and abrasion is provided. Calcium ion concentration and chloride concentration are suppressed to improve limestone utilization, reduce the consumption of organic acids and improve crystal growth. The FGD system includes a limestone reactor for precipitating gypsum separate from the scrubber system which allows the recovery of pure carbon dioxide and a clarifier/softener tank which allows the production of gypsum-free clear scrubbing liquor and a drier gypsum filter cake.

US Patent:

53405471, Aug 23, 1994

Filed:

Jan 19, 1993

Appl. No.:

7/986068

Inventors:

Robert E. Moser - Palo Alto CA
James H. Wilhelm - Sandy UT
John Burke - Chamblee GA
Sterling Gray - Louisville KY

Assignee:

Electric Power Research Institute - Palo Alto CA

International Classification:

G05D 700
B01D 5334
F01N 300

US Classification:

422177

Abstract:

An improved magnesium-enhanced lime flue gas desulfurization system is provided which produces the high sulfur dioxide removal level of previous magnesium-enhanced lime flue gas desulfurization systems and additionally produce waste solids that have significantly better properties and are more easily dewatered than the solids produced by known systems. The magnesium-enhanced lime flue gas desulfurization system of the present invention includes a crystallizer-clarifier reaction tank (CCRT) which receives scrubber effluent and functions as a combined reaction tank and thickener. Clear liquor from the CCRT is sent to a scrubber to scrub the flue gas, and a portion of the CCRT--thickened solids are directed to a high pH premix slurry tank (PMST) where the crystallization environment can be controlled by reagent addition and pH. The PMST contents are circulated to the CCRT and are separated to produce a waste solids fraction that is easily dewatered. A fines removal system may also be employed to reduce the presence of fine solids and promote large crystal solids.

US Patent:

50342045, Jul 23, 1991

Filed:

Dec 22, 1989

Appl. No.:

7/454855

Inventors:

Robert E. Moser - Palo Alto CA
John M. Burke - Austin TX
David R. Owens - Lockport NY

Assignee:

Electric Power Research Institute - Palo Alto CA

International Classification:

C01B 1700
B01D 800

US Classification:

423243

Abstract:

A wet, calcium-based, flue gas desulfurization process for reliably and cost effectively removing sulfur dioxide from the flue gas generated by the combustion of fossil flues containing sulfur includes the step of contacting the combustion flue gas preferably as a part of the scrubbing liquor, with an aqueous solution containing formate ions and a dissolved calcium concentration reduction agent. The latter reduces the dissolved calcium concentration present in the flue gas which, in turn reduces the coprecipitation and loss of formate within and from the system. Also, by contacting the flue gas with an aqueous solution comprising formate and thiosulfate ions, the formate coprecipitation within the system is reduced independent of the calcium concentration level within the system.