Development of pyrolytic monolithic carbon composites for the conditioning of spent ion exchange resins

2012 ◽  
Vol 1475 ◽  
Author(s):  
Pamela B. Ramos ◽  
Néstor O. Fuentes ◽  
Vittorio Luca

ABSTRACTThe pyrolysis of ion exchange resin beads that are used for the purification of water in reactor primary- and secondary-cooling circuits can result in stable and leach resistant carbonaceous products. However, free flowing beads are less desirable waste forms for disposal in sub-surface or surface repositories than monolithic masses of low porosity. We have investigated the pyrolysis of polymeric resin – cation exchange resin composites to give mechanically robust and chemically durable monolithic carbonaceous waste forms that are suitable for repository disposition. Also investigated was the dependence of product properties on various processing parameters (temperature ramp and final temperature). As a first approach, epoxy resins were used for the preparation of monoliths since such resins cure at room temperature and result in a relatively high carbon yield. Carbonaceous monolithic products were prepared at 400, 500, 600, 700 and 800 °C using a temperature ramp of 2°C/min. The products were maintained at the chosen temperatures for a period of one hour. Mass losses, volume reduction, hardness and compressive strength were measured and mathematical functions are proposed to describe the measured values of these properties. The carbon monoliths were observed to be mechanically robust.

2018 ◽  
Vol 8 (9) ◽  
pp. 1611 ◽  
Author(s):  
Hong Sui ◽  
Jingjing Zhou ◽  
Guoqiang Ma ◽  
Yaqi Niu ◽  
Jing Cheng ◽  
...  

Ionic liquids (ILs) have been reported to be good process aids for enhanced bitumen recovery from oil sands. However, after the extraction, some ionic liquids are left in the residual solids or solutions. Herein, a washing–ion exchange combined method has been designed for the removal of two imidazolium-based ILs, ([Bmim][BF4] and [Emim][BF4]), from residual sands after ILs-enhanced solvent extraction of oil sands. This process was conducted as two steps: water washing of the residual solids to remove ILs into aqueous solution; adsorption and desorption of ILs from the solution by the sulfonic acid cation-exchange resin (Amberlite IR 120Na). Surface characterization showed that the hydrophilic ionic liquids could be completely removed from the solid surfaces by 3 times of water washing. The ionic liquids solution was treated by the ion-exchange resin. Results showed that more than 95% of [Bmim][BF4] and 90% of [Emim][BF4] could be adsorbed by the resins at 20 °C with contact time of 30 min. The effects of some typical coexisted chemicals and minerals, such as salinity, kaolinite (Al4[Si4O10](OH)8), and silica (SiO2), in the solution on the adsorption of ionic liquids have also been investigated. Results showed that both kaolinite and SiO2 exerted a slight effect on the uptake of [Bmim][BF4]. However, it was observed that increasing the ionic strength of the solution by adding salts would deteriorate the adsorption of [Bmim]+ on the resin. The adsorption behaviors of two ILs fit well with the Sips model, suggesting the heterogeneous adsorption of ionic liquids onto resin. The adsorption of ionic liquids onto Amberlite IR 120Na resin was found to be pseudo-second-order adsorption. The regeneration tests showed stable performance of ion-exchange resins over three adsorption–desorption cycles.


2010 ◽  
Vol 2 (3) ◽  
pp. 597 ◽  
Author(s):  
M. V. Srikanth ◽  
S. A. Sunil ◽  
N. S. Rao ◽  
M. U. Uhumwangho ◽  
K. V. Ramana Murthy

Ion exchange resins (IER) are insoluble polymers that contain acidic or basic functional groups and have the ability to exchange counter-ions within aqueous solutions surrounding them. Based on the nature of the exchangeable ion of the resin as a cation or anion, it is classified as cationic or anionic exchange resins, respectively. The efficacy of ion exchange resins mainly depends upon their physical properties such as degree of cross-linking, porosity, acid base strength, stability, purity and particle size. Modified release of drugs from resinate (drug-resin complexes) is another potential application of ion exchange resins.  Due to the versatile utility of ion exchange resins, they are being used for various drug delivery and therapeutic applications. Resins used are polymers that contain appropriately substituted acidic groups, such as carboxylic and sulfonic for cation exchangers; or basic groups, such as quaternary ammonium group for anion exchangers. This review addresses different types of ion exchange resin, their properties, the chemistry; role of IER in controlled drug delivery systems, its therapeutic applications, methods of preparation of IER along with their resonates. Keywords: Anion exchange; Cation exchange; Resin; Controlled release; Resinates; Drug delivery. © 2010 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. DOI: 10.3329/jsr.v2i3.4991               J. Sci. Res. 2 (3), 599-613 (2010) 


2019 ◽  
Vol 7 (31) ◽  
pp. 18285-18294 ◽  
Author(s):  
Ping He ◽  
Kok-Giap Haw ◽  
Shichen Yan ◽  
Lingxue Tang ◽  
Qianrong Fang ◽  
...  

Carbon beads with a well-defined micropore structure and excellent CO2 capture ability were obtained by carbonization of K-exchanged cation exchange resin precursors.


Author(s):  
Людмила Сергеевна Авфукова

Статья посвящена одному из современных методов и технологий извлечения никеля, кобальта и меди из многокомпонентных растворов - сорбционный метод. В качестве сорбентов выступают ионообменная смола КУ-2-8 и хелатообразующие смолы. Рассмотрен один изметодов удаления веществ, сопутствующих, мешающих извлечению ценных компонентов, одним из которых является железо. The paper considers one of the modern methods and technologies of nickel, cobalt and copper recovery from multicomponent solutions; that is a sorption method. KU-2-8 ion exchange resin and chelating resins are present as sorbents. One of the method of substances which prevent removing valuable components is discussed. One of such substance is considered to be iron.


Author(s):  
Gen-ichi Katagiri ◽  
Morio Fujisawa ◽  
Kazuya Sano ◽  
Norikazu Higashiura

Fuji Electric had developed the low pressure oxygen plasma technology for mild decomposition and mineralization of an organic material such as ion exchange resin. This method is suitable for radioactive spent resin volume/weight reduction and stabilization for final disposal. On this process, the ion-exchange resins are vaporized and decomposed into gas-phase with pyrolysis, and then, they are decomposed and oxidized with low-pressure plasma activity based on oxygen. And this process is achieved under moderate condition for radio active waste. • incinerate temperature: 400–700 deg C; • low-pressure (low-temperature) plasma condition: 10–50 Pa. From the result of this process, named of LPOP(low pressure oxidation process) by the inductively coupled plasma, we have confirmed that the process is applicable for organic fireproof waste including ion-exchange resin, and found that the used resin treatment performance is the same as cold test (using imitate spent resin) [1] [2] [3]. In this paper, the outline of the LPOP technology, and two research results on the possibility of solidification with cement of LPOP residue for geological disposes are reported. (1)Study of the residue chemical form after LPOP process (2)Study of the solidification character with cement.


Molecules ◽  
2018 ◽  
Vol 23 (8) ◽  
pp. 1866 ◽  
Author(s):  
Sarah Tschirner ◽  
Eric Weingart ◽  
Linda Teevs ◽  
Ulf Prüße

A mixture of hexafluoroisopropanol (HFIP) and water was used as a new and unknown monophasic reaction solvent for fructose dehydration in order to produce HMF. HFIP is a low-boiling fluorous alcohol (b.p. 58 °C). Hence, HFIP can be recovered cost efficiently by distillation. Different ion-exchange resins were screened for the HFIP/water system in batch experiments. The best results were obtained for acidic macroporous ion-exchange resins, and high HMF yields up to 70% were achieved. The effects of various reaction conditions like initial fructose concentration, catalyst concentration, water content in HFIP, temperature and influence of the catalyst particle size were evaluated. Up to 76% HMF yield was attained at optimized reaction conditions for high initial fructose concentration of 0.5 M (90 g/L). The ion-exchange resin can simply be recovered by filtration and reused several times. This reaction system with HFIP/water as solvent and the ion-exchange resin Lewatit K2420 as catalyst shows excellent performance for HMF synthesis.


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