Removal Of Sulfur Dioxide Research Articles

Removal of Sulfur Dioxide from Dried Grapes before Handling

Removal of Sulfur Dioxide from Dried Grapes before Handling

Porphyrin-based schiff-base and aminal nitrogen-rich porous organic polymers for capture of SO2 and CO2

Due to its serious hazards to human health and the environment, the deep removal of sulfur dioxide (SO2) has been of great significance. Thus, it is critical to develop high efficient SO2 capture and sequestration materials in gas purification process. Herein, we reported two novel prophyrin-based nitrogen-rich porous organic polymers (POPs), PrPOA-BP and PrPSN-BP, constructed through the simple catalyst-free condensation reaction. Owing to the strong affinity to SO2 from the conjugate-electron macrocycles structure of prophyrin and nitrogen-rich porous networks, also the high porous structure, these two POPs demonstrated excellent SO2 capture and separation performance with the adsorption uptakes up to 18.2 mmol g−1 (273 K, 1 bar), 13.3 mmol g−1 (298 K, 1 bar), 1.68 mmol g−1 (298 K, 0.01 bar). This very competitive performance has far exceeded most of the prior reported nanoporous materials. Meanwhile, the IAST selectivities of SO2/CO2 (10/90, v/v) could reach 107.8 and 72.0 at 273 and 298 K, 1 bar. This study represents a new type prophyrin-based POPs materials and confirms the intrinsic potential for high efficiency SO2 capture and sequestration.

Modelling of Sulfur Dioxide Removal by Seawater in a Flue Gas Desulfurization Absorber

Although Indonesia has set a target for increasing the use of renewable energy for electricity generation, the use of coal as a source of energy will still dominate at least until 2040. Sulfur dioxide (SO2) along with other gases and particulates released from the use of coal in coal-fired power plants (CFPPs) may cause air pollution. The use of seawater, an abundant source of absorbent in a maritime country such as Indonesia, in flue gas desulfurization (SWFGD) absorbers, is an economical option for treating SO2 in an absorption tower compared to other alkaline chemicals, e.g. limestone (CaCO3) or magnesium hydroxide (Mg(OH)2). A model, which correlates the equilibrium of the reaction with the salinity of the absorbent, was developed to predict the sulfur dioxide scrubbing process inside an SWFGD absorber. The simulation also took into account the mass and energy balance during the scrubbing process. The calibration using field SWFGD data showed a good correspondence between field data and modelling results.

Effect of dry sorbent injection at different stages of industrial hybrid electrostatic filter on particle penetration and sulfur dioxide removal

This study investigates the influence of in-duct dry sorbent injection at different stages of an industrial hybrid electrostatic filter on particle penetration and sulfur dioxide removal. Installed downstream of a 220 MW coal-fired power boiler, the hybrid system includes a single-field electrostatic precipitator, kinematic unipolar electrostatic agglomerator, and bag filter. Three sets of in-duct dry sorbent injection nozzles are located at the system's inlet, upstream of the electrostatic agglomerator, and upstream of the bag filter. Dry sorbent injection of sodium bicarbonate resulted in SO2 removal efficiency >83% with outlet SO2 concentration ≪400 mg/m3. Results showed that the hybrid system exhibits PM2.5 mass collection efficiency of >99.9%. Sorbent injection at different stages influences the particle penetration and agglomeration of the sorbent and fly ash particles. The optimal results, regarding the SO2 removal, were obtained for injection of dry sorbent downstream of electrostatic agglomerator.

Kinetic study of sulfur dioxide removal reaction with manganese dioxide by random pore model using thermogravimetry

Kinetic study of sulfur dioxide removal reaction with manganese dioxide by random pore model using thermogravimetry

Simultaneous determination of eight organic amines in desulfurization solution by ion chromatography

The applications of organic-amine desulfurization have steadily increased owing to its high efficiency, low cost, and low energy consumption. Different proportions of organic amines exert different effects on sulfur dioxide removal. Therefore, the accurate determination of different organic amines in the desulfurization solution is of great importance. The ion-chromatographic method for the detection of organic amines does not require a derivatization step, has simple pretreatment procedures, and allows for the simultaneous determination of many types of organic amines. In this study, a method based on ion chromatography was developed for the simultaneous determination of ethanolamine (MEA), diethylethanolamine (DEEA), n-methyldiethanolamine (MDEA), 2-amino-2-methyl-1-propanol (AMP), hydroxyethylethylenediamine (AEEA), piperazine (PZ), n-hydroxyethylpiperazine (HEPZ), and diethylenetriamine (DETA). The separation efficiency of the eight organic amines in different types of columns, leaching solutions, and column temperatures were compared. The determination was performed using an IonPac CS17 column with column temperature of 35 ℃ and gradient leaching with methyl sulfonic acid (MSA) solution via the inhibition conductance method. Samples of the desulfurization solution were analyzed using ultrapure water filtered through a 0.22 μm nylon microporous filter membrane and an OnGuard Ⅱ RP column; thus, the pretreatment steps are simple. The eight organic amines showed a good linear relationship within a certain concentration range, and the coefficient of determinations (R2) were greater than 0.998. The limits of detection (LODs) and quantification (LOQs) were determined from the mass concentrations of the organic amines corresponding to signal-to-noise ratios (S/N) of 3 and 10, respectively. LODs of 0.02-0.08 mg/L and LOQs of 0.07-0.27 mg/L were determined from a 1.0 μL sample injection. The actual recoveries ranged from 93.0% to 111%, and the relative standard deviations (RSDs, n=5) ranged from 0.31% to 1.2%. The results indicated that the proposed method has good accuracy and precision; thus, it is suitable for the determination of various organic amines in desulfurization solution.

SO2 Emissions Reduction Effect of China’s Pollution Levy Standard Adjustment: A Short-Term and Long-Term Analysis

As one key environmental regulation measure, China’s pollution levy policy has been widely discussed; however, existing research has solely concentrated on the emissions reduction effect of pollution levy policies in the short term but has ignored long-term effectiveness, which may cause research bias. Thus, taking pollution levy standard adjustments as the core independent variable, this study builds firm-level pollution data and proves that the pollution levy policy is effective both in the short and long term. Furthermore, it demonstrates that the emissions reduction effect is achieved mainly by decreasing production and increasing the removal of sulfur dioxide (SO2). In addition, it is uncovered that the emissions reduction effect is mainly a result of two processes—the first is the greater use of clean energy and higher energy efficiency that can cause a decrease in the production of SO2, and the second is the utilization efficiency of waste gas treatment facilities, which can increase the removal of SO2.

Evaluating the impact of gypsum as a novel bedding material on broiler performance, foot pad health, and fear response

Flue Gas Desulfurization (FGD) gypsum is a byproduct of the coal-fired power plant process commonly used to remove sulfur dioxide emissions from the flue gas. FGD gypsum has numerous industrial, agricultural, and environmental applications. This study aimed to explore a novel approach involving the use of FGD gypsum combined with different litter treatments as bedding for broiler production. It focused on performance metrics, including adjusted feed conversion ratio (AFCR) and average body weight (BW), foot pad dermatitis (FPD), and fear response over 5 consecutive flocks. A total of 1,800 one-day-old Ross 708 chicks were randomly assigned to 24 pens (75 birds/pen), divided into 6 treatment groups (4 pens/treatment), with 5 replications and raised until 42 d old (d). Treatments were gypsum that was decaked (D), rotovated (E), and rotovated then windrowed (F) between flocks. Control treatments using pine shavings were decaked (A), rotovated (B), and windrowed postrotovating (C). AFCR, average BW, and mortality were used as a measure of production. Foot pad dermatitis scores were taken on d42 using a scale of 0 (absence), 1 (mild), and 2 (severe). Response to observer and human approach test were used to measure fear response. Data were analyzed as a 2-way ANOVA (Proc Glimmix) for the main effects of bedding type and litter treatment. Means were identified using Tukey's HSD. No effect of bedding type or litter treatment was found for AFCR, BW, or mortality. FPD scores 2 and 1, were higher with pine shavings than gypsum (P = 0.01 and P = 0.01, respectively). While FPD scores 0 were higher for gypsum than the pine shaving (P = 0.01). No difference in fear response was found among birds raised on any of the gypsum litter treatments and any of the pine shaving litter treatments. Overall, the use of gypsum as bedding results in equivalent production and fear response to pine shavings, while increasing FPD quality when compared to pine shaving.

Integrated Absorption–Adsorption Process for Waste-Free Decontamination of Gases from Sulfur Dioxide, Part 2: CFD Modeling and Experimental Investigation of a Bubble-Cap Tray

There are many technologies for removal of sulfur dioxide (SO2) from flue gases. They are intrinsic part of the efforts for sustainability of energy production as they reduce the harmful impact of fossil fuel combustion on the environment by minimizing one of the main air pollutants. A wide range of methods use alkaline absorbents. In most cases, the products obtained from the absorption process have to undergo further oxidation, which increases the cost of carrying out the process. As a final result, the sulfates obtained (Na2SO4 and CaSO4) have limited practical application and there is a problem with their disposal. Scientific and engineering efforts have been directed towards the development of a practically waste-free technology for gas purification from SO2. An absorption–adsorption method is proposed, which comprises absorption of SO2 in water with simultaneous adsorption of the resultant sulfurous acid (H2SO3) from the aqueous solution with a synthetic anion-exchange resin. Regeneration of the adsorbent is accomplished with a dilute solution of ammonia (NH3), followed by decomposition of the resulting ammonium sulfite ((NH4)2SO3) with nitric acid (HNO3). The products of the processes are pure gaseous (liquefied) SO2 and an aqueous solution of ammonium nitrate (NH4NO3). Sulfur dioxide has a wide range of applications in the chemical industry; ammonium nitrate is a product with a variety of commercial uses as well, the most common of which is as a soil fertilizer. The new absorption–adsorption method offers a practically waste-free technology. The basic unit of this technology is a bubble-cap tray column where the absorption–adsorption process is carried out in an aqueous suspension of a synthetic anion-exchange resin. This work presents a CFD simulation of the flow on the bubble-cap tray. A physical model of the column is constructed, which contains a bubble-cap tray fabricated by 3D printing. As a result of this experimental study, new data on the tray pressure drop, gas holdup, and the kinetics of the absorption–adsorption process were obtained.

Removal of Sulfur Dioxide in Flue Gas Using Invasive Weed Optimization–Based Control Method

Removal of Sulfur Dioxide in Flue Gas Using Invasive Weed Optimization–Based Control Method

Mathematical modeling of pickling of bamboo shoot strips and their sulfur dioxide removal during cooking

Mathematical modeling of pickling of bamboo shoot strips and their sulfur dioxide removal during cooking

Trace SO2 capture within the engineered pore space using a highly stable SnF62--pillared MOF.

Developing reliable solid sorbents for efficient capture and removal of trace sulfur dioxide (SO2) under ambient conditions is critical for industrial desulfurization operations, but poses a great challenge. Herein, we focus on SNFSIX-Cu-TPA, a highly stable fluorinated MOF that utilizes SnF62- as pillars, for effectively capturing SO2 at extremely low pressures. The exceptional affinity of SNFSIX-Cu-TPA towards SO2 over CO2 and N2 was demonstrated through single-component isotherms and corroborated by computational simulations. At 298 K and 0.002 bar, this material displays a remarkable gas uptake of 2.22 mmol g-1. Among various anion fluorinated MOFs, SNFSIX-Cu-TPA shows the highest SO2/MF62- of 1.39 mmol mmol-1 and exhibits a low Qst of 58.81 kJ mol-1. Additionally, SNFSIX-Cu-TPA displays excellent potential for SO2/CO2 separation, as evidenced by its ideal adsorbed solution theory (IAST) selectivity of 148 at a molar fraction of SO2 of 0.01. Dynamic breakthrough curves were obtained to reveal the effective removal of trace SO2 from simulated flue gas (SO2/CO2/N2; v/v/v 0.2/10/89.8) with a high dynamic capacity of up to 1.52 mmol g-1. Furthermore, in situ TGA demonstrated the efficient and reversible capture of 500 ppm SO2 over 20 adsorption-desorption tests. This durable material presents a rare combination of exceptional SO2 capturing performance, good adsorption selectivity, and mild regeneration, thus making it a good candidate for a realistic desulfurization process.

Extraction of sulfur (IV) oxide, nitrogen oxides and carbon oxide from flue gases using a sorbent under conditions of its mechanical activation

The paper substantiates the feasibility of creating an adsorption technology with controlled activation of the adsorbent for the removal of sulfur dioxide, nitrogen oxides, and carbon from the flue gases of coal-fired power plants. In laboratory conditions, the effect of mechanical activation on the adsorption capacity of ash was studied. It is shown that the controlled mechanical activation is able to increase the adsorption capacity of ash relative to sulfur dioxide by 2.7 times, to nitrogen oxides by 2.1 times, to carbon monoxide by 5 times or more.

Facile synthesis of regenerable NaY zeolite adsorbent relying on alcohol-terminated compounds for efficient trace sulfur dioxide capture

The selective removal of sulfur dioxide (SO2) is of importance for the desulfurization and purification of exhaust gases, but it is still challenging to design adsorbents with high capture capacities (particularly at low partial pressures) and great cyclic stability. Herein, a facile strategy is proposed to optimize the adsorption performance of NaY zeolites, where various alcohol-terminated compounds (n-pentanol, ethylene glycol, polyethylene glycol) with different molecular structures are introduced as auxiliaries to facilitate the zeolite nucleation process and the formation of microporous structures. These alcohols promote the crystallization of NaY, increase the specific surface area and expand the microporosity due to the formation of micelles during synthesis. Coupled with the rise of surface basic sites, the chemisorption and physisorption of SO2 on designed zeolites is considerably improved. The PEG-Y sample derived from polyethylene glycol gives the highest dynamic adsorption of SO2 (315 mg/g), high-level SO2 equilibrium adsorption (2.18 mmol/g) under exceptionally low pressure (0.002 bar), preferred separation performance of SO2 from SO2/N2, robust stability and great regenerability. This technique can be further employed to fabricate analogous adsorbents for other gas adsorption and separation processes.

Simultaneous removal of sulfur dioxide and nitrogen oxide from flue gas by phosphorus sludge: The performance and absorption mechanism

Developing low-cost and green simultaneous desulfurization and denitrification technologies is of great significance for sulfur dioxide (SO2) and nitrogen oxide (NOx) emission control at low temperatures, especially for small and medium-sized coal-fired boilers and furnaces. Herein, phosphorus sludge, an industrial waste from the production process of yellow phosphorus, has been developed to simultaneously eliminate SO2 and NOx from coal-fired flue gas. The key factors affecting the experimental results indicate that desulfurization and denitrification efficiency of over 95% can be achieved at a low temperature of 55 °C. Further, the absorption mechanism was investigated by characterizing the solid and liquid phases of the phosphorus sludge during the absorption process. The efficient removal of SO2 is attributed to the abundance of iron (Fe3+) and manganese (Mn2+) in the absorbent. SO2 can be rapidly catalyzed and converted to SO42− by them. The key to NOx removal is the oxidation of NO toward water-soluble high-valent nitrogen oxides by oxidizing reactive substances induced via yellow phosphorus, which are then absorbed by water and converted to NO3−. Meanwhile, yellow phosphorus is oxidized to phosphoric acid (H3PO4). The spent absorption slurry can be reused through wet process phosphoric acid production, as it contains sulfuric acid (H2SO4), nitric acid (HNO3), and H3PO4. Accordingly, this is a technology with broad application prospects.

Investigating activated carbons for SO2 adsorption in wet flue gas

The removal of sulfur dioxide from flue gas is an important process for the mitigation of acid rain. Activated carbons have a low affinity for water and a high affinity for polarizable molecules, such as sulfur dioxide, making them good candidates for selective adsorbents for flue gases. This work presents results on the multicomponent adsorption of N2/CO2/SO2 and N2/CO2/SO2/H2O flue gas mixtures on four activated carbons prepared from petroleum coke, and one carbon black. Multicomponent adsorption was measured at T = 30, 60, 90 °C. All five activated carbons had a high affinity and selectivity for SO2 in both the presence and absence of water. The activated carbons prepared with KOH (P_K) and NaOH (P_Na) showed the highest capacity for SO2 under wet conditions with thermal swing regeneration (P_K: nadsSO₂ = 0.148 ± 0.002 mmol g−1, P_Na: nadsSO₂ = 0.13 ± 0.01 mmol g−1). In pressure swing experiments of the wet flue gas mixture, the activated carbon prepared with a K2CO3 and KOH (P_CK) (nadsSO₂ = 0.077 ± 0.002 mmol g−1) and P_K (nadsSO₂ = 0.064 ± 0.005 mmol g−1) activated carbons had the highest SO2 capacities. Of the activated carbon, P_K had the greatest SO2/H2O selectivity for the thermal swing adsorption (T = 30 °C, SSO₂/H₂O = 3.0 ± 0.2) and pressure swing adsorption (T = 90 °C, SSO₂/H₂O = 3.9 ± 0.6) experiments. It was observed that activated carbons with higher carbon fraction were less likely to have a difference in SO2 adsorption from dry versus wet conditions. After the wet SO2 multicomponent adsorption, no change in the adsorption performance of any activated carbons was observed after 10 cycles.

Green gospel effect of regional financial expansion: evidence from urban commercial banks in China.

The regional financial expansion represented by the development of regional small and medium-sized banks, such as urban commercial banks, is an essential factor affecting the environmental behavior of enterprises. We found that both the marginal expansion and the scale expansion of regional finance help reduce the sulfur dioxide emission intensity and improve the environmental performance of enterprises, indicating a green gospel effect of regional financial expansion. In terms of the impact path, regional financial expansion cannot only reduce the sulfur dioxide generation intensity and improve the front environmental performance of enterprises, but also increase the sulfur dioxide removal intensity as well as improve the terminal environmental performance. However, in the context of high fiscal pressure on local governments, regional financial expansion exacerbates sulfur dioxide emission and generation intensity of enterprises, worsening environmental performance and creating a green curse effect. Further study finds that the cross-regional expansion of urban commercial banks can strengthen the green gospel effect; the improvement of enterprises' environmental performance by regional financial expansion is mainly found in polluting industries and non-SOEs.

Red mud with enhanced dealkalization performance by supercritical water technology for efficient SO2 capture

The total de-alkalization treatment of industrial solid waste red mud (RM) has been a worldwide challenge. Removing the insoluble structural alkali fraction from RM is the key to enhancing the sustainable utilization of RM resources. In this paper, supercritical water (SCW) and leaching agents were used for the first time to de-alkalize the Bayer RM and to remove sulfur dioxide (SO2) from flue gas with the de-alkalized RM slurry. The results showed that the optimum alkali removal and Fe leaching rates of RM-CaO-SW slurry were 97.90 ± 0.88% and 82.70 ± 0.95%, respectively. Results confirmed that the SCW technique accelerated the disruption of (Al–O) and (Si–O) bonds and the structural disintegration of aluminosilicate minerals, facilitating the conversion of insoluble structural alkalis to soluble chemical alkalis. The exchangeable Ca2+ displaced Na+ in the remaining insoluble base, producing soluble sodium salts or alkalis. CaO consumed SiO2, which was tightly bound to Fe2O3 in RM, and released Fe2O3, which promoted Fe leaching. RM-SCW showed the best desulfurization performance, which maintained 88.99 ± 0.0020% at 450 min, followed by RM-CaO-SW (450 min, 60.75 ± 6.00%) and RM (180 min, 88.52% ± 0.00068). The neutralization of alkaline components, the redox of metal oxides, and the liquid-phase catalytic oxidation of Fe contributed to the excellent desulfurization performance of the RM-SCW slurry. A promising approach shown in this study is beneficial to RM waste use, SO2 pollution control, and sustainable growth of the aluminum industry.

Treating waste with waste: Facile KHCO3-modified calcium carbide slag for simultaneous removal of NO and SO2

The simultaneous removal of nitric oxide (NO) and sulfur dioxide (SO2) in a cost-effective and environmentally friendly method is a major challenge in the field of industrial tail gas purification. In this study, the solid waste calcium carbide slag (CS) was modified by potassium bicarbonate (KHCO3) to achieve simultaneous removal of NO and SO2 under low temperature conditions. Experimental results confirmed that this low-cost KHCO3-modified calcium carbide slag (KCS) has excellent simultaneous removal of NO and SO2 activity, which is attributed to its unique morphology and abundant surface adsorbed oxygen species (Oads). Interestingly, the presence of SO2 improved the capacity of KCS for NO removal. In-situ diffuse reflectance infrared Fourier-transform spectroscopy results demonstrate that the addition of SO2 promote the formation of oxygen-containing functional groups. Further studies indicated that increasing the Oads could effectively facilitate oxidation of NO and SO2 to nitrate (NO3–) and sulfate (SO42-), while the SO42- formed on the KCS surface continuously provided Oads for the oxidation reaction. Over all, the study proposes a strategy for typical solid waste (CS) resource utilization, to attain simultaneous removal of NO and SO2 under low temperature conditions, thus achieving the goal of “treating waste with waste”.

Tribocorrosion Framework of (Iron, Nickel, Zinc)-Doped Graphene Nanosheet: New Sights into Sulfur Dioxide and Hydrogen Sulfide Removal Using DFT/TD-DFT Methods

Tribocorrosion Framework of (Iron, Nickel, Zinc)-Doped Graphene Nanosheet: New Sights into Sulfur Dioxide and Hydrogen Sulfide Removal Using DFT/TD-DFT Methods