Designing Wet Scrubbers for SO2 Absorption into Fairly Concentrated Sulfuric Acid Solutions Containing Hydrogen Peroxide

Absorption of SO₂, diluted with nitrogen up to concentrations of 500 Pa, was performed at 20 °C and 1 atm, with water and sulfuric acid solutions containing hydrogen peroxide in two different contactors: a packed column and a cable scrubber. The absorption rate was determined for various SO₂ partial pressures, as well as different concentrations of sulfuric acid (up to 40 wt %) and of hydrogen peroxide in the scrubbing liquid. It was found that the SO₂ absorption rate increases with the hydrogen peroxide concentration, and decreases as the acidity of the scrubbing liquid increases. Taking into account hydrodynamic and mass transfer characteristics of the packing for both scrubbers, a practical enhancement factor depending on the liquid phase H₂SO₄ and H₂O₂ contents, was deduced from semi‐continuous tests. As a good concordance was observed between results determined for both contactors, a single correlation is proposed, allowing the computation of this kinetic factor for quite simple simulation or design of SO₂ scrubbers, provided the gas and liquid phase mass transfer coefficients k_Ga and k_La are known.     

碳酸钠溶液吸收处理硫化氢试验研究

研究了碳酸钠(Na2CO3)溶液吸收处理硫化氢(H2S)气体的效果。常温(20℃)常压下,当Na2CO3溶液质量浓度为10 g/L、H2S空间速度和初始质量浓度分别为5 L/(L.m in)和200 mg/m3时,可以得到以下结论:碳酸钠溶液吸收硫化氢的穿透时间是570 m in;在穿透时间570 m in内吸收效率维持在80%以上;吸收液pH值维持在9~12之间;吸收液pH=9.5时,吸收效率可以维持在80%以上。     

Simultaneous Absorption of Hydrogen Sulfide and Carbon Dioxide into di-isopropanolamine Solution

The simultaneous absorption of hydrogen sulfide and carbon dioxide into di-isopropanolamine (DIPA) solution was investigated in a 183 cm long, 2.72 cm OD wetted-wall column at atmospheric pressure. The influence of liquid flow rate, gas flow rate, temperature and liquid concentration on the absorption rate, overall gas-phase mass transfer coefficient and selectivity factor were studied at a constant gas feed ratio. The results show that the absorption rate of CO₂ increases rapidly with increasing liquid flow rate (the Reynolds number of the turbulent liquid film ranges from 2600 to 4350) but increases moderately with increasing gas flow rate (G = 18-91 L/min), indicating that it is liquid-phase mass transfer controlled. In contrast, the absorption rate of H₂S increases very slowly with increasing liquid flow rate but increases rapidly with increasing gas flow rate, indicating that it is gas-phase mass transfer controlled. The absorption rate of CO₂ also increases with increasing temperature (26-80°C) but H₂S absorption rate decreases with increasing temperature. When the concentration of DIPA solution increases from 0.2 to 2.6 mol/L, the absorption rate of both CO₂ and H₂S increases but with a larger rate of increase for CO₂ For selective H₂S removal, it is preferable to operate at low liquid and high gas flow rates, low temperatures and low DIPA concentrations.     

Selective Partial Oxidation of Hydrogen Sulfide by the BrOx Cycle

Neutralization of the toxic gas hydrogen sulfide is an important step in almost every natural gas processing plant. A novel method for the conversion of hydrogen sulfide is a combination of bromination and oxidation reactions (BrOx). The first of those, the bromination of hydrogen sulfide, is investigated experimentally. An analysis of the potential by‐products reveals that their formation during the reaction can be excluded. Furthermore, a parameter study showed that reaction yields of up to 94 % are achievable by suitable reaction conditions.     

吸收法制取硫化氢气体的工艺设计

充矿鲁南化肥厂根据合成氨生产装置的工艺特点,采用聚乙二醇二甲醚溶剂(NHD)通过物理吸收酸性气及加热再生的方法,对其排出的酸性气体进行处理来制取高纯度硫化氢气体。该工艺流程简单,两塔流程中吸收塔和再生塔均为填料塔,选用新型填料QH-1扁环,成功生产出体积分数大于95%的硫化氢产品。     

Prediction of the Removal Efficiency of a Novel Two‐Stage Hybrid Scrubber for Flue Gas Desulfurization

Emission of SO₂ from various industrial sources occurs in varying concentrations and quantities. The operation of scrubbers as SO₂ control devices is getting more and more attention as pollution control regulations are tightened. Experimental investigations on the scrubbing of SO₂ in a novel two‐stage hybrid (spray‐cum‐bubble column) scrubber using water and dilute sodium alkali are reported. Empirical and semi‐empirical correlations are developed for the prediction of the performances of the bubble and the spray sections in terms of various pertinent variables of the system for water and alkaline scrubbing, respectively. The contribution of the mass transfer enhancement factor towards the removal of SO₂ has been exploited while developing the semi‐empirical correlation for the prediction of performance in alkaline scrubbing. The predicted values are in excellent agreement with the experimental values. Finally, the operating features of the scrubber and design aspects are discussed in order to develop our understanding for practical applications.     

Gas-Phase Ozone Oxidation of Hydrogen Sulfide for Odor Treatment in Water Reclamation Plants

Gas-phase O₃ oxidation is effective to treat H₂S emitted from wastewater treatment processes. The reaction is fast for full-scale applications. In most cases, 67–96% of total H₂S removed in 40-s reaction time was achieved within the first 8 s of reaction time. The initial [O₃]/[H₂S] ratio of 8 was sufficient to reduce H₂S from up to 8 ppmv to less than 0.5 ppmv in 40-s reaction time. The reaction stoichiometry ratio of [O₃]/[H₂S] ranged from 2.0 to 3.7, depending on the initial [O₃]/[H₂S] ratio. The moisture content, dimethyl sulfide, and dimethyl disulfide in the odorous air influence H₂S removal.     

Predictive Dynamic Model of Air Separation by Pressure Swing Adsorption

A general dynamic model is developed for separation of air over a carbon molecular sieve and a zeolite adsorbent for production of nitrogen and oxygen. The proposed model is validated using experimental data from working laboratory scale N₂–PSA and laboratory scale O₂–PSA systems. Simulations studies are performed to investigate the effect of changing various process variables, such as the duration of PSA steps, bed length and feed inlet velocity.     

碱液吸收在炼油厂硫化氢治理中的应用

以炼油厂的副产物酸性气为原料,通过碱液吸收,吸收液经过精制提纯后得到液体硫氢化钠产品。该工艺可有效处理炼油厂酸性气中的硫化氢,降低污染物排放,减少装置一次性投资。     

微量硫化氢和硫醇的汞量测定法

介绍了硫化氢和硫醇的汞量测定法。含有硫化氢和硫醇的气体 ,用碱溶液吸收 ,以双硫腙为指示剂 ,用标准汞溶液滴定。硫化氢和硫醇共存时 ,可加入丙烯腈掩蔽硫醇 ,从而得到硫化氢和硫醇的含量。同时介绍了锌掩蔽—非均相直接滴定测定硫醇的方法。本方法可测定含量 1× 10 - 71× 10 - 2 的硫化氢和硫醇。     

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。     

A New Method of Eddy Diffusivity Calculation for Droplets of a Venturi Scrubber

An analytical model using eddy diffusivity is applied for predicting droplet concentration distribution and liquid film formation in a Venturi scrubber. By comparing experimental data of film formation reported in literature (Viswanathan et al., 1984) and the results obtained from this model, a semi‐empirical correlation for liquid droplets eddy diffusivity is obtained. The validity of this correlation is confirmed by obtaining good agreement between theoretical and experimental data of droplet concentration distribution and film formation in a Venturi scrubber (Viswanathan, 1998; Viswanathan et al., 1984).     

实心锥喷嘴喷淋塔脱除硫化氢性能初探

采用实心锥喷嘴自制的喷淋塔,用硼酸钠和盐酸配置的p H值=8.5的缓冲液作吸收剂,对空气中所含H2S气体进行吸收效果初探。实验结果证明:空气中H2S的脱除率不仅受气液量的影响,同时也受空气中H2S含量的影响。在偏碱性的缓冲溶液流量为600 L/h,气体流量为1.4 m3/h,H2S初始含量为9.0×10-3,H2S脱除率可达近80%。     

An Electrochemical Model of a Solid Oxide Steam Electrolyzer for Hydrogen Production

An electrochemical model was developed to simulate the J–V characteristics of a solid oxide steam electrolyzer (SOSE) used for hydrogen production. Activation, concentration, and ohmic overpotentials were considered as the main factors for voltage loss. The Butler‐Volmer equation, Fick's model, and Ohm's law were applied to determine the overpotentials of a SOSE cell. The simulation results were compared with experimental data from the literature and good agreement was obtained. Additionally, parametric modeling analyses were conducted to study how the operating temperature and gas composition affected the electrical characteristics. It was found that the voltage loss could be reduced by increasing the operating temperature and steam molar fraction. It was also observed that an anode‐supported SOSE cell exhibited a higher hydrogen production efficiency than electrolyte‐supported and cathode‐supported cells. The electrochemical model can be used to perform further analysis in order to further understand the principles of SOSE hydrogen production, and to optimize SOSE cell and system designs.     

Fabrication of Arsenic Sulfide Optical Fiber with Low Hydrogen Impurities

Arsenic sulfide glass optical fibers typically possess extrinsic absorption bands in the infrared wavelength region associated with residual hydrogen and oxygen related impurities, despite using purified precursors. We report a purification process based on the addition of tellurium tetrachloride (TeCl₄) to the glass. During melting, the chlorine from TeCl₄ reacts with the hydrogen impurities to produce volatile products (e.g., HCl) that can be removed by subsequent dynamic distillation. The processing conditions have been modified accordingly to produce optical fibers with significantly reduced loss due to hydrogen sulfide impurity content (1.5 dB/m).     

Fe(Ⅲ)-EDTA吸收H2S反应动力学的实验研究

本文采用双搅拌无梯度气液反应器实验研究了Fe(III)-EDTA吸收H2S的反应动力学.建立并求解了H2S吸收数学模型,实验确定 Fe(III)-EDTA吸收H2S的化学反应速度常数为     

催化裂化汽油中硫化物的研究

研究了催化裂化汽油中的硫含量、硫分布及硫化物的形态,硫含量大部分集中在中、重组分中,占80％以上;汽油中的硫化物主要是噻吩,占整个硫化物的70％左右,其次是硫醇和硫醚。     

Chemoadsorption for Separation of Hydrogen Sulfide from Biogas with Iron Hydroxide and Sulfur Recovery

Hydrogen sulfide (H₂S) removal from biogas is essential to allow biogas storage in the natural gas grid. Several established methods exist, most of them making use of non-reusable substrates such as iron sponge or active carbon. Coated metallic foams provide a reusable sustainable alternative. Several iron oxides and hydroxides were tested to validate the H₂S adsorption properties before and after thermal regeneration, i.e., sulfur removal. Amorphous iron hydroxide proved to efficiently clean biogas after maximum four sulfur removal cycles and showed an almost ten times larger capacity for sulfur adsorption than crystalline hematite Fe₂O₃. Very low H₂S contents could be realized until breakthrough.     

粗硫化钙碳化生产硫化氢气体小试

介绍了以硫酸钙煅烧而形成的粗硫化钙及窑气为原料 ,制备硫化氢的试验研究。本工艺为生产硫化氢开辟了一条新途径。