The Effect of Structure Modification of Sodium Compounds on the SO2 and HCl Removal Efficiency from Fumes in the Conditions of Circulating Fluidised Bed

The article presents the effects of mechanical and thermal modification on the surface area of sodium bicarbonate and its ability to remove SO2 and HCl from exhaust fumes. The mechanical modification consisted of grinding in an impact mill. The thermal modification consisted of heating in the temperature range from 373 K to 673 K. The applied modifications caused a change in the grain structure of sodium bicarbonate and parameters such as specific surface area and the pore size. The parameters were determined by low-pressure nitrogen adsorption (LPNA) and mercury porosimetry (MIP) methods. The largest development of the active surface, which was up to 6 m2 g–1 (LPNA), was achieved after crushing and heating in the temperature range of 423–523 K. The efficiency of a simultaneous purification of fumes from SO2 i HCl on a continuous-combustion installation with a circular fluidised bed CFB was determined. The samples were fed into the installation in three different molar ratios 2Na/S (0.5; 1.0; 2.1) in a gas jet of 573 K. It was shown that the removal of SO2 and HCl took place simultaneously and mainly on the grain surface. The average efficiency of SO2 purification was between 17 % and 89 %, and it depended on the comminution degree and the amount of the sorbent. The efficiency of HCl removal was between 54 and 78 %. This work is licensed under a Creative Commons Attribution 4.0 International License

Upwelling events, coastal offshore exchange, links to biogeochemical processes - Highlights from the Baltic Sea Sciences Congress at Rostock University, Germany, 19-22 March 2007

The Baltic Sea Science Congress was held at Rostock University, Germany, from 19 to 22 March 2007. In the session entitled"Upwelling events, coastal offshore exchange, links to biogeochemical processes" 20 presentations were given,including 7 talks and 13 posters related to the theme of the session.This paper summarises new findings of the upwelling-related studies reported in the session. It deals with investigationsbased on the use of in situ and remote sensing measurements as well as numerical modelling tools. The biogeochemicalimplications of upwelling are also discussed.Our knowledge of the fine structure and dynamic considerations of upwelling has increased in recent decades with the advent ofhigh-resolution modern measurement techniques and modelling studies. The forcing and the overall structure, duration and intensity ofupwelling events are understood quite well. However, the quantification of related transports and the contribution to the overall mixingof upwelling requires further research. Furthermore, our knowledge of the links between upwelling and biogeochemical processes is stillincomplete. Numerical modelling has advanced to the extent that horizontal resolutions of c. 0.5 nautical miles can now be applied,which allows the complete spectrum of meso-scale features to be described. Even the development of filaments can be describedrealistically in comparison with high-resolution satellite data.But the effect of upwelling at a basin scale and possible changes under changing climatic conditions remain open questions

Efficacy of home-based visuomotor feedback training in stroke patients with chronic hemispatial neglect

Hemispatial neglect is a severe cognitive condition frequently observed after a stroke, associated with unawareness of one side of space, disability and poor long-term outcome. Visuomotor feedback training (VFT) is a neglect rehabilitation technique that involves a simple, inexpensive and feasible training of grasping-to-lift rods at the centre. We compared the immediate and long-term effects of VFT vs. a control training when delivered in a home-based setting. Twenty participants were randomly allocated to an intervention (who received VFT) or a control group (n = 10 each). Training was delivered for two sessions by an experimenter and then patients self-administered it for 10 sessions over two weeks. Outcome measures included the Behavioural Inattention Test (BIT), line bisection, Balloons Test, Landmark task, room description task, subjective straight-ahead pointing task and the Stroke Impact Scale. The measures were obtained before, immediately after the training sessions and after four-months post-training. Significantly greater short and long-term improvements were obtained after VFT when compared to control training in line bisection, BIT and spatial bias in cancellation. VFT also produced improvements on activities of daily living. We conclude that VFT is a feasible, effective, home-based rehabilitation method for neglect patients that warrants further investigation with well-designed randomised controlled trials on a large sample of patients

Simultaneous desulphurization and denitrification gas bicarbonate sodium

Przedstawiono wyniki badań nad zastosowaniem surowego bikarbonatu sodu jako sorbentu do odsiarczania i odazotowania spalin w procesie fluidalnego spalania. Stosowany sorbent charakteryzował się bardzo wysoką skutecznością w redukcji S02 i NO. Jego efektywność zwiększała się wraz ze wzrostem nadmiaru Na/S.Results of the research of raw sodium bicarbonate application as sorbent in desulfurization and denitrification process in fluidized furnace were described. High efficiency of S02 as well as NO removal was reached, which was increasing according to Na/S rate increase

Nitrogen oxides removal from flue gases using sodium bicarbonate

W artykule przedstawiono wyniki pomiarów strukturalnych oraz badań zdolności usuwania NOx, wodorowęglanu sodu w postaci sody oczyszczonej oraz bikarbonatu surowego bez oraz po modyfikacji mechanicznej. Wyznaczano parametry strukturalne: uziarnienie i powierzchnię właściwą. Badania sorpcji prowadzono w temperaturach: 300°C i 850°C. Zdolności sorpcyjne oceniano wyznaczając cząstkową skuteczność i całkowitą sprawność usuwania NOx. Stwierdzono, że największą skuteczność w usuwaniu tlenków azotu uzyskano w sorbentach po aktywacji mechanicznej.This paper presents the results of study on structural measurements and ability to remove nitrogen oxides of sodium bicarbonate in the form of baking soda and raw bicarbonate, without and after mechanical activation. Structural parameters were evaluated by: particle size and surface area. The studies of NOx sorption were carried out at temperatures of 300 and 850°C. The sorption ability was evaluated by: partial and overall NOx removal efficiency. The highest NOx removal efficiency was obtained for the sorbent after mechanical activation

Flue gas desulfurization by mechanically and thermally activated sodium bicarbonate

This paper presents the results of study on structural parameters (particle size, surface area, pore volume) and the sorption ability of mechanically and thermally activated sodium bicarbonate. The sorption ability of the modified sorbent was evaluated by: partial and overall SO2 removal efficiency, conversion rate, normalized stoichiometric ratio (NSR). Sodium bicarbonate was mechanically activated by various grinding techniques, using three types of mills: fluid bed opposed jet mill, fine impact mill and electromagnetic mill, differing in grinding technology. Grounded sorbent was thermally activated, what caused a signifi cant development of surface area. During the studiem of SO2 sorption, a model gas with a temperature of 300°C, of composition: sulfur dioxide at a concentrationof 6292 mg/mn3 oxygen, carbon dioxide and nitrogen as a carrier gas, was used. The Best development of surface area and the highest SO2 removal efficiency was obtained for the sorbent treated by electromagnetic grinding, with simultaneous high conversion rate

Modeling of adsorption cycle in the TSA system with a fixed bed of zeolite adsorbent

W pracy przedstawiono wyniki analizy teoretycznej procesu odzyskiwania toluenu z powietrza w układzie TSA (adsorpcja zmienno-temperaturowa) z nieruchomym złożem adsorbentu zeolitowego. Cykl TSA składał się z trzech etapów: adsorpcji toluenu ze strumienia powietrza, desorpcji toluenu za pomocą strumienia ogrzanego azotu oraz chłodzenia złoża przy użyciu strumienia chłodnego azotu. W celu polepszenia efektywności odzyskiwania toluenu zastosowano układ z zamkniętym obiegiem gazu. Jako adsorbent wybrano odaluminiowany zeolit typu Y (DAY-20F). Rozkłady stężenia adsorbatu w złożu podczas adsorpcji, desorpcji i chłodzenia wyznaczano wykorzystując model matematyczny nieizotermicznej adsorpcji równowagowej. Celem pracy było zbadanie wpływu temperatury gazu na wlocie do złoża oraz na wylocie ze skraplacza podczas desorpcji na efektywność oczyszczenia powietrza.Theoretical studies on toluene recovery from air in the TSA (thermal swing adsorption) system with a fixed bed of zeolite adsorbent are presented. The TSA cycle consisted of three steps: adsorption of toluene from air, desorption of toluene with hot nitrogen, and cooling of the adsorbent bed with cold nitrogen. The closed-loop method was used to enhance the efficiency of toluene recovery. Dealuminated Y zeolite (DAY-20F) was chosen as adsorbent. A nonisothermal, equilibrium mathematical model was used to simulate concentration data for adsorption, desorption and cooling steps. The aim of research was to study the influence of gas temperatures in the bed inlet and condenser outlet during desorption on air purification efficiency

Flue Gas Desulfurization by Mechanically and Thermally Activated Sodium Bicarbonate

This paper presents the results of study on structural parameters (particle size, surface area, pore volume) and the sorption ability of mechanically and thermally activated sodium bicarbonate. The sorption ability of the modified sorbent was evaluated by: partial and overall SO2 removal efficiency, conversion rate, normalized stoichiometric ratio (NSR). Sodium bicarbonate was mechanically activated by various grinding techniques, using three types of mills: fluid bed opposed jet mill, fine impact mill and electromagnetic mill, differing in grinding technology. Grounded sorbent was thermally activated, what caused a signifi cant development of surface area. During the studiem of SO2 sorption, a model gas with a temperature of 300°C, of composition: sulfur dioxide at a concentrationof 6292 mg/mn3 oxygen, carbon dioxide and nitrogen as a carrier gas, was used. The Best development of surface area and the highest SO2 removal efficiency was obtained for the sorbent treated by electromagnetic grinding, with simultaneous high conversion rate

Sorption properties of sodium bicarbonate

Przedstawiono wyniki badań laboratoryjnych określających wpływ aktywacji mechanicznej i termicznej na właściwości sorpcyjne wodorowęglanu sodu. Stwierdzono, że najlepsze właściwości sorpcyjne, uzyskano w sorbencie mielonym po aktywacji w 250 st. C. Badania powierzchni właściwej potwierdziły makroporowaty charakter modyfikowanego wodorowęglanu sodu. Testy reaktywności potwierdziły jego znakomite właściwości sorpcyjne.The results of laboratory tests to determine the effect of mechanical and thermal activation on the sorption properties of sodium bicarbonate are reported. The best sorption properties were found in ground sorbent after activation at 250 st. C. The examination of the surface area confirmed the macroporous character of the modified sodium bicarbonate. Reactivity tests ascertained its excellent sorption properties