木质素磺酸钠吸收烟道气中的SO2

本文就木质素磺酸钠溶液脱除烟道气中SO_2进行了实验研究。实验采用双搅拌气-液反应器,探讨了木质素磺酸钠的浓度、温度等因素对SO_2吸收的影响,并求取了化学吸收增强因子。结果表明,木质素磺酸钠能有效地脱除烟道气中的SO_2。     

Rate-based modelling of SO2 absorption into aqueous NaHCO3/Na2CO3 solutions accompanied by the desorption of CO2

A rate-based model of a counter-current reactive absorption/desorption process has been developed for the absorption of SO₂ into NaHCO₃/Na₂CO₃ in a packed column. The model adopts the film theory, includes diffusion and reaction processes, and assumes that thermodynamic equilibrium among the reacting species exists in the bulk liquid. Model predictions were compared to experimental data from literature. For the calculation of the absorption rate of SO₂ into NaHCO₃/Na₂CO₃ solutions and concomitant CO₂-desorption, it is important to take into account all reversible reactions simultaneously. It is clear that the approximate analytical based model cannot be expected to predict the absorption rates under practical conditions because of the complicated nature of the reactive absorption processes. The rigorous numerical approach described here only requires definition of the individual reactions in the system, and subsequent solution is independent of specific assumptions made, or operational variables like pH or compound concentrations. As an example of the flexibility of this approach, additional calculations were conducted for SO₂ absorption in a phosphate-based buffer system.     

A MECHANISTICALLY BASED MATHEMATICAL MODEL OF SULFUR DIOXIDE ABSORPTION INTO A CALCIUM HYDROXIDE SLURRY IN A SPRAY DRYER

A mathematical model has been developed to predict So₂ absorption and removal during the constant rate drying period of a spray dryer. The model, based on film theory, treats the atomized slurry droplets as spheres containing discrete sorbent particles of slaked lime with the fluid uniformly distributed around the individual particles. The model includes gas and liquid phase mass transfer coefficients as well as resistance to Ca(OH)₂ dissolution. A sensitivity analysis has been conducted and a comparison was made between pilot-scale experimental data and model-predicted values of S0₂ removal efficiency.     

火电厂二氧化硫排放量的测算方法研究

SO2排放量的准确测算是企业内部科学管理和有效控制其排放量的基础,针对传统的SO2排放量的测算方法存在的问题与局限,本文提出了一种基于硫平衡的更简单、科学地测算SO2排放量的方法。通过该方法,可以准确地测算火电厂生产过程中二氧化硫的排放量,从而有利于对火电厂生产的工艺与组织实施更有效的监控,既节省了时间,又节约了成本,并提高了工作效率。     

Studies on the deactivation of NOx storage-reduction catalysts by sulfur dioxide

The interaction of sulfur dioxide with a commercial NO_x storage-reduction catalyst (NSR) has been investigated using in situ IR and X-ray absorption spectroscopy. Two pathways of catalyst deactivation by SO₂ were identified. Under lean conditions (exposure to SO₂ and O₂) at 350 °C the storage component forms barium sulfates, which transform from surface to hardly reducible bulk sulfate species. The irreversible blocking of the Ba sites led to a decrease in NO_x storage capacity. Under fuel rich conditions (SO₂/C₃H₆) at 350–500 °C evidence for the formation of sulfides on the oxidation/reduction component (Pt) of the catalyst was found, which blocks the metal surface and thus hinders the further reduction of the sulfides.     

新型HS—2钒催化剂上SO2氧化的本征动力学研究

HS-2钒催化剂是在钾-钒系催化剂内添加了适量的低温活性物质而成。作者用无梯度反应器和积分反应器,在较宽的温度范围(653～843K)和转化率范围(3.9%～89%)内对其动力学特性进行了测试,并采用 Powell 非线性最小二乘法回归出动力学方程。     

CHEMICAL ABSORPTION OF CO2 AND SO2 INTO Ca(OH) 2 SLURRY

Chemical absorption of CO₂ and SO₂2 as single gases and as a mixture into slurries of Ca(OH) ₂ was studied in a stirred vessel with a flat gas-liquid interface. In the case of CO₂, the reaction product interrupted the subsequent gas absorption in the absence of a surface active agent. With single gases, the enhancement factor for SO₂ was much larger than that for CO₂, though both were larger than that into saturated solution. With the mixed gases, the enhancement factor for S02 was almost equal to that for the single gas absorption, but for CO₂ it was only slightly larger than that into the saturated solution     

Adsorption of SO2 on Activated Carbon for Low Gas Concentrations

Adsorption experiments of SO₂ on activated carbon has been carried out for low concentrations (about 100 ppm) at room temperature (15 to 33 °C) with varying humidity in the air. The breakthrough curves show that at high relative humidity or relative higher SO₂ concentration, the load capacity increases with respect to temperature. The humidity of the air is also of benefit to the load capacity of SO₂. When an adsorption process is interrupted and the activated carbon is kept closed for a while, the SO₂ concentration at the exit of a fixed‐bed adsorber is similar to that of the fresh activated carbon and begins at a very low value. It appears that the sorption potential has been refreshed after the storage period. Analysis of desorption experiments by simultaneous thermal analysis combined with mass spectrometry (MS) after loading, shows that the physisorbed SO₂ and H₂O are desorbed at low temperatures. At higher temperatures, the MS peak of SO₂ and H₂O occur at the same time. Compared with desorption immediately after loading, after one day, the desorption peak due to the physisorbed SO₂ disappears. From this, it can be concluded that the refreshment of the loading capacity of the activated carbon after storage is mainly due to a change in the nature of the SO₂ from a physisorbed state to a chemisorbed form. The same mechanism leads to a continuous refreshment of the sorption potential by means of a chemical reaction during the adsorption process.     

浅析脱硫技术的发展及应用

煤炭是贵州省的重要资源,针对遵义碱厂的废弃物电石渣,利用其组分中含有Ca(OH)2,用于吸收煤燃烧过程中的SO2,从而达到以废治废,变废为宝。     

The electrochemical oxidation of aqueous sulfur dioxide: A critical review of work with respect to the hybrid sulfur cycle

Literature regarding the mechanism of the electrochemical oxidation of aqueous sulfur dioxide to sulfuric acid has been critically evaluated to provide a detailed understanding of the reaction under various applied conditions. This reaction is of high relevance to the hybrid sulfur cycle for large scale hydrogen production, as well as other industrial applications such as flue gas desulfurisation. Widespread disagreement in the literature and non-reproducible behaviour of the electrochemical oxidation reaction has been found in this review to often be a result of poorly defined electrode preconditioning procedures. It has also been found that the mechanistic pathway of the oxidation reaction is heavily influenced by the electrode material, solution pH and the applied anodic potential. These factors are thought to influence adsorption and the reductive formation of sulfur species at low potentials.     

烟气脱硫技术的研究

概述了国内外烟气脱硫技术的应用现状、脱硫原理及其特点,并提出了我国烟气脱硫技术的研究开发方向。     

煤燃烧烟气中CO2的吸收控制技术研究进展

阐述了燃煤烟气中二氧化碳脱除的各种方法。研究了各种CO2的吸收方法,包括物理吸收法中的膜吸收法、吸附剂等,物化吸附法,还有化学吸收剂中的氨水、有机氨等吸收方法,并分析各种方法的特点及优缺点。     

Absorption of Carbon Dioxide into Aqueous Solution of Sodium Glycinate

Abstract

Carbon dioxide was absorbed into aqueous solution of sodium glycinate (SG) at different SG concentrations, CO₂ partial pressures, and temperatures in the range of 0.5–3.0 kmol/m³, 25–101.3 kPa, and 298–318 K, respectively, using a stirred semi-batch vessel with a planar gas-liquid interface. Both the reaction order and rate constant are determined from gas absorption rates under the fast reaction regime. The reaction was found to be first order with respect to both CO₂ and SG. The activation energy for the CO₂-SG reaction has been found to be 59.8 kJ/mol. The second-order reaction rate constants were used to obtain the theoretical values of absorption rate based on the film theory.     

EFFECT OF HETEROCYCLIC AMINE ADDITIVES ON THE ABSORPTION RATES OF CARBONYL SULFIDE AND CARBON DIOXIDE IN AQUEOUS METHYLDIETHANOLAMINE SOLUTIONS

Absorption rates of carbonyl sulfide and carbon dioxide into aqueous methyldiethanolamine solutions with and without heterocyclic amine additives were measured in a stirred cell apparatus. All of the heterocyclic amine additives catalyzed COS absorption more strongly than that for CO₂. In instances in which absorption rates were improved by the additives, those with the lowest pK_b's were the most effective, although steric factors also apparently influence reaction kinetics.