Comparative evaluation of effectiveness indexes of column packings in benzol absorbers

Coke-oven gas is produced during coking of charge coal in a coking chamber and it constitutes a mix of different substances. A composition of different components in the gas depends on a composition of the coal charge and conditions of the coking. At a recovery plant, aromatic hydrocarbons are retrieved from the coking gas by absorption oil in packed absorbers. Mass-transfer apparatus demand the equability of the phase distribution. Hydrodynamic conditions, appearing inside contacting apparatus, determinate the effectiveness of the mass-transfer, which means that unbiased evaluation of any given mass-transfer apparatus can be made while simultaneous considering its hydrodynamic and mass-transfer indicators. The different types of column packing have been investigated in this study. The calculations of benzol absorbers have been performed basing on the initial data using the standard methodologies for the recovery plant of JSC EVRAZ NTMK coke and by-product enterprise. For comparison of the results obtained, the complex indexes of effectiveness, that simultaneously take into account the mass-transfer rate, the device capacity, the features of packings and energy cost, have been used. © Published under licence by IOP Publishing Ltd

Peculiarities of sorption isotherm and sorption chemisms of caesium by mixed nickel-potassium ferrocyanide based on hydrated titanium dioxide

Sorption isotherm of caesium from tap water by mixed nickel-potassium ferrocyanide based on hydrated titanium dioxide is obtained for a wide range of concentrations of caesium. It is shown that there are three types of specificity to caesium sorption sites in this sorbent. Sorption chemisms of caesium are studied, factors conditioned high sorption capacity of the sorbent are revealed. It is shown that occupation of sorption sites I and II is well approximated by Langmuir equilibrium and this process can be described within the bounds of theory of ion exchange. The expected sorption chemism of caesium by sorption sites III at high concentrations of caesium (>50 mg L-1) is precipitation of mixed nickel-caesium ferrocyanide in pore space of the sorbent. © 2013 Akadémiai Kiadó, Budapest, Hungary

Статика и кинетика сорбции цезия из водных сред ферроцианидами никеля-калия на основе гидратированных диоксидов титана и циркония

Optimization of the synthesis of the mixed nickel-potassium ferrocyanide based on hydrated titanium dioxide has been realized. The influence of the conditions of synthesis of the sorbents on the elemental composition, surface texture, statics and kinetics has been shown. The synthetic technique was used to prepare sorbents based on hydrated titanium dioxide carrier. The influence of the chemical properties of the carrier on sorption behaviour of the ferrocyanides was determined.Описана оптимизация синтеза смешанного ферроцианида никеля-калия на основе гидратированного диоксида титана. Показано влияние условий синтеза сорбентов на их элементный состав, текстуру поверхности, статику и кинетику сорбции. Методика синтеза была использована для получения сорбента на основе гидратированного диоксида титана. Определено влияние химических свойств носителя на сорбционное поведение ферроцианидов

METHOD OF PRODUCING INORGANIC FERROCYANIDE SORBENT (VERSIONS)

FIELD: chemical or physical processes. SUBSTANCE: invention relates to production of inorganic sorbents on a carrier, which can be effectively used for purification of natural water and process solutions, liquid radioactive wastes from cesium, strontium, uranium and plutonium radionuclides, for combined immobilisation of cesium and strontium radionuclides, rehabilitation of radioactive contaminated soils for their introduction into agricultural use, radiochemical analysis. Method of producing inorganic ferrocyanide sorbent includes treatment of support with aqueous solution of nickel sulphate salt, obtained system is treated with aqueous solution of potassium hexacyanoferrate salt, washed with water and dried. Carrier used is hydrated titanium dioxide-zirconium, clinoptilolite or quartz-glauconite concentrate. Carrier before treatment with aqueous solution of nickel sulphate is first converted and hydrogen-sodium form by successive treatment first with solution of hydrochloric acid, then with sodium hydroxide solution to pH 6–7. EFFECT: higher sorption capacity of inorganic ferrocyanide sorbent and its complexity due to possible absorption of radionuclides of cesium, strontium, uranium and plutonium. 3 cl, 2 tbl, 2 ex.Изобретение относится к получению неорганических сорбентов на носителе, которые могут быть эффективно использованы для очистки природных вод и технологических растворов, жидких радиоактивных отходов от радионуклидов цезия, стронция, урана и плутония, для совместной иммобилизации радионуклидов цезия и стронция, реабилитации радиоактивно-загрязнённых почв с целью их введения в сельскохозяйственное использование, радиохимического анализа. Способ получения неорганического ферроцианидного сорбента включает обработку носителя водным раствором соли сульфата никеля, полученную систему обрабатывают водным раствором соли гексацианоферрата калия, промывают водой и сушат. В качестве носителя используют гидратированный диоксид титана-циркония, клиноптилолит или кварц-глауконитовый концентрат. Носитель перед обработкой водным раствором соли сульфата никеля предварительно переводят и водородно-натриевую форму последовательной обработкой сначала раствором соляной кислоты, затем раствором гидроксида натрия до рН 6-7. Обеспечивается увеличение сорбционной емкости неорганического ферроцианидного сорбента и его комплексности за счет возможности поглощения радионуклидов цезия, стронция, урана, плутония. 3 н.п. ф-лы, 2 табл., 2 пр

A study of ferrocyanide sorbents on hydrated titanium dioxide support using physicochemical methods

The paper describes how the conditions of preparing ferrocyanides on hydrated titanium dioxide support affect the surface texture of the resulting materials, their elemental and phase composition, and their ability to sorb cesium. The sorbents prepared under the optimal conditions exhibited increases specificity to Cs (K d = 10 5.6±1.0 ml g -1) and high capacity (no less than 270 mg g -1). © Pleiades Publishing, Inc., 2012