scholarly journals Low-level waste treatment laboratory studies: evaporation of simulated ion- exchange eluates

1974 ◽  
Author(s):  
J. G. Moore
Keyword(s):  
Ion Exchange ◽  
Waste Treatment ◽  
Laboratory Studies ◽  
Low Level

Low-Level Liquid Waste Treatment System Technical Design in China

2013 ◽  
Author(s):  
Juan Zhao
Keyword(s):  
Ion Exchange ◽  
Radioactive Waste ◽  
Waste Treatment ◽  
Fuel Cycle ◽  
Liquid Radioactive Waste ◽  
Liquid Waste ◽  
Spent Fuel ◽  
Nuclear Facilities ◽  
High Concentration ◽  
Low Level

Radioactive wastes are produced within the nuclear fuel cycle operations (uranium conversion and enrichment, fuel fabrication and spent fuel reprocessing). Evaporation is a proven method for the treatment of liquid radioactive waste providing both good decontamination and high concentration. Two technical designs of nuclear facilities for low-level liquid radioactive waste treatment are presented in the paper and the evaluation of both methods, as well. One method is two-stage evaporation, widely used in the People’s Republic of China’s nuclear facilities; another is two evaporator units and subsequently ion exchange, which is based on the experience gained from TIANWAN nuclear power plant. Primary evaporation and ion exchange ensure the treated waste water discharged to environment by controlling the condensate radioactivity, and secondary evaporation is to control concentrates in a limited salt concentration.

Compositional Effects on Displacement Mechanisms of the Micellar Fluid Injected in the Sloss Field Test

1984 ◽  
Vol 24 (01) ◽  
pp. 38-48 ◽  
Author(s):  
Surendra P. Gupta
Keyword(s):  
Ion Exchange ◽  
Oil Recovery ◽  
Mobility Control ◽  
Laboratory Studies ◽  
Pilot Performance ◽  
Time Effects ◽  
Oil Saturation ◽  
Compositional Effects ◽  
Mechanistic Understanding ◽  
Composition Changes

Abstract The performance of the micellar/polymer flood conducted in the Sloss reservoir did not follow predictions by a streamtube model. The model assumed that micellar flood displaces oil and water in a piston-type miscible manner with a final oil saturation of 5 % PV, and sulfonate retention based on short-term laboratory adsorption tests. This paper, in conjunction with a complementary paper,1 describes process mechanisms needed to model the flood performance. The results of laboratory studies show higher sulfonate retention caused by ion-exchange effects, which result in partitioning of sulfonate into the oil phase and higher adsorption caused by long contact times. Long-term aging of the Sloss micellar fluid at the high reservoir temperature (93.3°C [200°F]) does not reduce oil recovery. The results of laboratory studies also show that the final oil saturation after micellar flooding is capillary-number dependent. A higher final oil saturation can be the result of reduced injectivity /productivity, increased interfacial tension (1FT), and/or decreased viscosity. This paper demonstrates that ion exchange, hardness, and sulfonate partitioning can significantly affect micellar-flood performance. The paper presents an experimental plan that provides information for optimizing the design of micellar/polymer floods. This plan, when applied to a specific flood, allows an investigator to examine effects of adsorption, ion exchange, hardness, and partitioning on flood performance. Specifically, phase studies and sulfonate requirements must encompass effects of in-situ-generated calcium ions as a result of sodium/calcium ion exchange. Sulfonate itself can increase the calcium content of the fluids because of a calcium/micelle association. High calcium concentrations can increase sulfonate requirements. Sulfonate adsorption requirements for micellar flood design are sensitive to the experimental procedures employed. The paper outlines improved procedures encompassing ion exchange and time effects and demonstrates that a favorable ion-exchange process can be used to reduce adsorption requirements. Introduction Interpretation of micellar-flooding pilots is essential to the development of a predictive model for commercial demonstration and fieldwide micellar floods. To interpret field micellar-flood performance, process variables (e.g., compositional effects) must be separated from field variables (e.g., reservoir description and operational difficulties), and the process mechanisms must be identified. This paper describes experimental procedures for use by industry to identify effects of composition changes during micellar flooding. The paper describes application of these procedures to determine the effects of composition changes on the displacement mechanisms of the micellar/polymer fluids injected in the Sloss field, Kimball County, NE.2 The results enhanced our mechanistic understanding of the micellar-flooding process. This understanding is required for interpretation of pilot performance. This paper discusses the first portion of the mechanism studies for the micellar/polymer system used in the Sloss reservoir. Results of the second portion of the mechanism research were published in 1982.1 A separate paper discussed results of the Sloss pilot posttest evaluation well.3 Pilot Performance The streamtube model with classical miscible-immiscible displacements was used to obtain preflood predictions.1 This model assumed sulfonate retention (by adsorption) of 3.42 kg active Mahogany AA sulfonate/m3 contacted PV [1.20 lbm/bbl PV], a final oil saturation of 5 % PV in the micellar swept zone, and mobility control. The preflood predictions and pilot performance were in excellent agreement during the early stages of the project.2 However, the observed performance later deviated from the preflood predicted performance.2,4 Postflood predictions by the same model more closely matched total pilot performance by assuming an increased sulfonate retention and a higher final oil saturation. Process Mechanism Studies Detailed laboratory studies were initiated to enhance our mechanistic understanding of the process. These studies needed for interpretation of the pilot performance included:phase behavior,compositional effects on oil displacement,propagation of the oil and micellar banks,ion-exchange behavior,sulfonate retention,time effects on sulfonate adsorption, andeffect of micellar fluid aging on oil recovery.

scholarly journals On the Formation of COS from H2S and CO2 in the Presence of Zeolite/Salt Compounds

1998 ◽  
Vol 16 (7) ◽  
pp. 577-581 ◽  
Author(s):  
Wolfgang Lutz ◽  
Andreas Seidel ◽  
Bruno Boddenberg
Keyword(s):  
Carbon Dioxide ◽  
Ion Exchange ◽  
Hydrogen Sulphide ◽  
Calcium Ions ◽  
Gaseous Mixture ◽  
Degree Of Conversion ◽  
Low Level ◽  
Sodium Cations

A gaseous mixture of hydrogen sulphide and carbon dioxide (20% H2S, 80% CO2) was brought into contact at 25°C with NaY and NaX zeolites in an as-synthesized form as well as after modification by the inclusion of salts (NaCl, NaBr) in the small cages of the aluminosilicate framework and ion exchange with aqueous CaCl2 solution. At small contact times (5 h), the degree of conversion of H2S according to the reaction H2S + CO2 → COS + H2O by the various samples was found to follow the sequence NaY/NaCl ≈ NaY/NaBr ≈ NaX/NaCl(CaCl2) < NaY « NaX/NaCl ≈ NaX. Long-term runs with NaY and NaY/NaBr revealed that the latter zeolite retained a very low level of H2S conversion for contact times as long as 250 h. It is concluded that such low H2S conversion requires the absence of low-coordinated sodium cations in the supercages or their replacement by calcium ions, and blocking of the β-cages with salt anions.

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