Server maintenance is scheduled for Saturday, December 21st between 6am-10am CST.

During that time, parts of our website will be affected until maintenance is completed. Thank you for your patience.

Menu
Search
Filters
Close
Menu

Kinetic and Morphological Investigation of Calcium Sulfate Dihydrate (gypsum) Scale Formation on Heat Exchanger Surfaces in the Presence of Inhibitors

Picture for Kinetic and Morphological Investigation of Calcium Sulfate Dihydrate (gypsum) Scale Formation on Hea
Available for download

Gypsum scale formation takes place directly on the surface of heat exchanger without  bulk or spontaneous precipitation in the reaction cell. Polymeric and non-polymeric inhibitors have been examined for their effects on the rate of scale formation.

Product Number: 51317--9020-SG
ISBN: 9020 2017 CP
Author: Zahid Amjad
Publication Date: 2017
Industries: Chemical Inhibitors , Process Industries
$0.00
$20.00
$20.00

The formation and adherence of calcium sulfate dihydrate (CaSO4.2H2O gypsum) hemihydrate (CaSO4.1/2 H2O plaster of Paris) and anhydrite (CaSO4) scales on heat exchanger and equipment surfaces poses serious challenge in the efficient operation of many industrial processes utilizing feed and/or recirculating waters containing high levels of calcium and sulfate ions. Industrial processes affected by the deposition of sulfate scales include boiler cooling desalination by evaporation and reverse osmosis methods gas scrubbers and oil recovery utilizing water flooding technique.In the present work the kinetics of gypsum scale formation on heat exchanger surfaces from aqueous solutions has been investigated by a highly reproducible technique. It has been found that gypsum scale formation takes place directly on the surface of heat exchanger without any bulk or spontaneous precipitation in the reaction cell. The kinetic data also suggest that the rate of scale formation is a function of solution supersaturation heat exchanger surface area and the metallurgy of the heat exchanger. A variety of polymeric (synthetic and natural) and non-polymeric inhibitors have been examined for their effects on the rate of scale formation. The results indicate that the amount of gypsum scale formed on heat exchanger surface is strongly affected by changing of functional group (type and ionic charge) molecular weight and the concentration of the inhibitor. Scanning electron microscopic investigations of the gypsum crystals grown in the presence of inhibitors show that structures of these crystals are highly modified. A mechanism based on the surface adsorption of inhibitors on the growing crystals will be presented.

Key words: calcium sulfate dihydrate, gypsum, scale, maleic acid polymers, brass heat exchanger, crystal morphology

The formation and adherence of calcium sulfate dihydrate (CaSO4.2H2O gypsum) hemihydrate (CaSO4.1/2 H2O plaster of Paris) and anhydrite (CaSO4) scales on heat exchanger and equipment surfaces poses serious challenge in the efficient operation of many industrial processes utilizing feed and/or recirculating waters containing high levels of calcium and sulfate ions. Industrial processes affected by the deposition of sulfate scales include boiler cooling desalination by evaporation and reverse osmosis methods gas scrubbers and oil recovery utilizing water flooding technique.In the present work the kinetics of gypsum scale formation on heat exchanger surfaces from aqueous solutions has been investigated by a highly reproducible technique. It has been found that gypsum scale formation takes place directly on the surface of heat exchanger without any bulk or spontaneous precipitation in the reaction cell. The kinetic data also suggest that the rate of scale formation is a function of solution supersaturation heat exchanger surface area and the metallurgy of the heat exchanger. A variety of polymeric (synthetic and natural) and non-polymeric inhibitors have been examined for their effects on the rate of scale formation. The results indicate that the amount of gypsum scale formed on heat exchanger surface is strongly affected by changing of functional group (type and ionic charge) molecular weight and the concentration of the inhibitor. Scanning electron microscopic investigations of the gypsum crystals grown in the presence of inhibitors show that structures of these crystals are highly modified. A mechanism based on the surface adsorption of inhibitors on the growing crystals will be presented.

Key words: calcium sulfate dihydrate, gypsum, scale, maleic acid polymers, brass heat exchanger, crystal morphology

Product tags
Also Purchased
Picture for Evaluation of 316L and 2205 Steels Under Flow Effects in Caustic Environments
Available for download

Evaluation of 316L and 2205 Steels Under Flow Effects in Caustic Environments

Product Number: 51317--9158-SG
ISBN: 9158 2017 CP
Author: Bedi Aydin Baykal
Publication Date: 2017
$20.00

To better understand the mechanism of erosion-corrosion, electrochemical tests were performed on UNS G10180, UNS S31603 and UNS S32205, used in the construction of pulp/paper machinery components exposed to caustic environments.
Picture for Impact of Pre-Corrosion on Corrosion Inhibitor Performance: Can We Protect Aged Pipelines?
Available for download

Impact of Pre-Corrosion on Corrosion Inhibitor Performance: Can We Protect Aged Pipelines?

Product Number: 51317--8919-SG
ISBN: 8919 2017 CP
Author: Yao Xiong
Publication Date: 2017
$20.00

Impact of pre-existing corrosion (pre-corrosion) on Corrosion Inhibitor (CI) performance was evaluated in conditions unfavorable of protective scale formation. CI protectiveness was significantly reduced after a 3-day pre-corrosion period.
Picture for Monitoring Evaluating and Control of Corrosion and Scaling in Higher Pressure Industrial Boilers
Available for download

Monitoring Evaluating and Control of Corrosion and Scaling in Higher Pressure Industrial Boilers

Product Number: 51317--8988-SG
ISBN: 8988 2017 CP
Author: John Kelly
Publication Date: 2017
$20.00

The author has utilized two types of instruments in conducting hydrogen studies. Hydrogen analyzers are used extensively in both the laboratory and in industrial steam generating plants.  This is a collection of five case studies.
Categories
Industry
Recently viewed
Popular tags
View all

Association for Materials Protection and Performance

© AMPP All Rights Reserved.
Membership Terms of Content Use
Contact Customer Support