液相催化氧化法脱除烟气中SO2的研究

采用含Mn^2＋的吸收液催化氧化脱除烟气中SO2研究了吸收液硫酸浓度、吸收液催化剂浓度、气体分布器和气体流量等控制条件对SO4的吸收率的影响。试验结果表明，采用埘（MnSO4）为0．05％～1．00％的吸收液，其中的埘（H2SO。）为2％～6％，选择理想的吸收设备，脱硫率可达98％以上。针对中小型燃煤锅炉中的废气和硫酸生产尾气，液相催化氧化法是一种很有前途的脱硫方法。     

铁法氧化还原脱硫溶液再生实验室内研究

在室内研究络合铁吸收溶剂配方溶液进行吸收低浓度硫化氢实验的基础上,进行了常压空气氧化再生的实验研究。通过一系列单因素实验,考察了溶液初始pH值、液气比和温度在一定时间范围内对再生率的影响,并且在最佳再生实验条件下确定了合适的再生时间,最后对3个不同配方在最佳工艺条件下进行了对比实验,得到再生率较高的脱硫再生溶液。     

空气氧化管式反应器处理油井伴生硫化氢的试验研究

近期多个油田都对油井伴生硫化氢采取了单井井口脱硫的源头治理方式。受井筒温度、采出液复杂性的影响,目前存在加药量大、成本高的问题。以廉价的空气作为脱硫剂,建立模拟实验流程,利用管式反应器,研究了流速、气液比和反应器内构件(SK型、SV型和拉西环)对硫化氢转化速率的影响。结果表明,硫化氢转化速率随着管道内流速和气液比的增加而增加,SV型内构件下硫化氢的转化速率较快。建立管式反应器,对GD2-25P530井开展了空气氧化脱硫现场试验,脱硫率达到了80%以上,处理成本节约70%以上。     

液相催化氧化法脱除烟气中SO2的研究

采用含Mn2 的吸收液催化氧化脱除烟气中SO2,研究了吸收液硫酸浓度、吸收液催化剂浓度、气体分布器和气体流量等控制条件对SO2的吸收率的影响。试验结果表明,采用w(MnSO4)为0.05%~1.00%的吸收液,其中的w(H2SO4)为2%~6%,选择理想的吸收设备,脱硫率可达98%以上。针对中小型燃煤锅炉中的废气和硫酸生产尾气,液相催化氧化法是一种很有前途的脱硫方法。     

萘醌法脱除沼气中硫化氢的工艺改进

萘醌法湿式氧化脱硫技术用于脱除沼气中的硫化氢 ,克服了传统的干法脱硫存在的操作不连续、更换脱硫剂劳动强度大、运行费用高等缺点 ,并可回收硫磺。由日本开发的萘醌法使用碳酸钠作为吸收液、1 ,4-萘醌 - 2 -磺酸钠作为催化剂 ,用于煤气脱硫时 ,脱硫率可达 99% ,吸收液硫容为 0 .1 0g/L。当该法用来脱除沼气中的硫化氢时 ,由于沼气硫化氢含量较低 (一般 <1 0g/m3) ,脱硫率往往只有 98%。而且因吸收液硫容低 ,循环液量较大。我们在萘醌法的基础上 ,结合其它脱硫方法的优点 ,对吸收液的组成进行了改进。实验证明 ,脱硫效率有明显的提高。具…     

硫化氢废气处理新方法研究

酸性铁盐溶液氧化脱H2S是目前世界上比较先进的技术，其具有反应速度快、副反应少、硫磺回收率高和回收剂价格便宜等优点，是目前很有发展前途的H2S脱除方法。主要通过对该方法的原理及影响因素进行分析和研究，提出了最佳的工艺条件：酸性吸收液Fe^3＋浓度〉0．5mol／L，吸收温度60℃，吸收液高度1m，气嘴直径0．05mm，使废气H2S脱除率达99％以上，用于吸收镓生产尾气完全可以实现达标排放。工艺简单，消耗组分价格低廉，具有一定的应用价值。     

Takahax脱硫法吸收剂的改进

Takahax法是一种湿式氧化脱硫技术,是日本于20世纪60年代开发的,该法用碳酸钠作为吸收液,l,4-萘酿-2-磺酸钠作为催化剂,用于煤气脱硫时,脱硫率可达99％,吸收液硫容为0.10g/L。在城市污水和其它有机废水处理中,常用的厌氧发酵法产生出大量含硫化氢的沼气,在沼气使用之前必须脱除其中的硫化氢。采用Takahax法脱除沼气中的硫化氢,克服了传统的干法脱硫工艺存在的操作不连续、更换     

油井采出液硫化氢空气氧化反应动力学研究

高含硫化氢油井采出液面临一次处理达不到排放要求的问题,而硫化氢的空气氧化法操作简单,成本低廉,对现有生产流程改动和影响较小,是井口硫化氢预处理的有效方法之一。空气氧化硫化氢是一个伴有化学反应的传质过程,采出液相界面处,硫化氢解离为HS^-离子,在液膜(或液相主体)内HS-离子,在液膜(或液相主体)内HS^-与溶解氧发生氧化还原反应。研究了压力、温度、含水率、硫化氢浓度、氧气浓度等反应条件对表面反应速率的影响,并建立得到反应动力学方程为:■,为井口硫化氢的空气高效处理提供理论依据。并根据反应速率方程和阶梯模拟计算的方法,计算出一定实验条件下,距离空气进气口不同位置的硫化氢转化率,为工业上空气氧化脱硫的设计提供理论依据。     

超重力氧化还原法用于天然气脱硫的探索性研究

报道了用氮气和硫化氢的混合气模拟含硫天然气,在超重机中应用配合铁氧化还原法进行脱硫实验,研究了原料气中硫化氢浓度、原料气中气体流量、脱硫液流量、超重机转子转速和脱硫液pH值对H2S脱除率和气相传质系数的影响,确定了配合铁体系在超重机中适宜的反应条件。结果表明,在本实验条件下H2S脱除率稳定在99.9%左右。实验设备体积小,硫化氢脱除率稳定且高效。     

MN法回收低浓度SO_2的试验研究

以蜜胺浆液为吸收剂,采用高效三相反应器在实验室进行了脱除低浓度SO_2的工艺条件及设备的试验研究。获得了脱硫的最佳工艺条件:吸收温度为45℃,气体中SO_2含量低于0.4％时,一级吸收脱硫率在95％以上,排放尾气SO_2含量小于200ppm,液气比为15升/米~3。 加入1‰阻氧剂,能够阻止亚硫酸蜜胺氧化。添加1‰的添加剂,可以防止设备和管道的阻塞,有利于液固分离。     

Biological oxidation of ferrous iron: study of bioreactor efficiency

The bio‐oxidation of ferrous iron is a potential industrial process for the regeneration of ferric iron in the removal of H₂S. In the first stage, H₂S is selectively oxidized to elemental sulfur using ferric sulfate. The ferrous sulfate produced is oxidized to ferric sulfate using Thiobacillus ferrooxidans for recycle and reuse in the process. The aim of the work described here was to investigate continuous oxidation of ferrous iron by immobilized T ferrooxidans and the factors which can directly affect the oxidation rate in order to assess the feasibility of this technique on an industrial scale. An analysis of the evolution of bioreactor performance with time (125 days) was performed in order to assess the feasibility of this technique on an industrial scale. A good oxidation rate was obtained despite the transport problems encountered due to occlusion of the porous support. On the other hand, the toxic effects due to absorption in the ferric solution of one or more compounds from the gas digester were studied using a ferric iron solution from the absorption process. The results indicate the feasibility of the biological system for the regeneration of the ferric‐absorbing solution. Finally, a previous study for the design of an industrial bioreactor to regenerate ferric sulfate solutions, used to remove H₂S from biogas in a wastewater‐treatment plant (Jerez de la Frontera, Spain), is introduced. Good biological oxidation performances have been obtained using a pilot plant bioreactor of 500 dm³. Copyright © 2003 Society of Chemical Industry     

化学法处理混合电镀废水的工艺流程及药剂选择

通过热动力学分析、理论计算和试验，确定在碱性条件下用NaCIO作氧化剂，Na2S和FeSO4作还原剂处理混合电镀废水的工艺流程，并通过计算和试验确定了Na2S和FeSO4的最佳药剂比为：Na2S80％～90％，FeSO410％～20％。Na2S FeSO4比单独使用FeSO4少产生60％～70％的污泥。该工艺在实际工程运行过程中效果良好。     

筛板塔Fe/Cu湿式催化氧化脱除H2S气体制硫磺的实验

阐述了筛板塔Fe/Cu湿式催化氧化脱除H₂S气体制硫磺流程,考察了操作空塔气速、液气比、起始pH值和H₂S入口浓度对H₂S脱除效率的影响及鼓风量、液柱高度对Fe^3＋氧化再生的影响;并进行了综合实验。结果表明,含120g/L的Cu²⁺、70g/L的Fe²⁺及70g/L的Fe³⁺的吸收体系即能对体积分数为1000×10^－6的H₂S废气近100％稳定脱硫,流程简短、能耗低,体系除消耗O₂外,过程不消耗原料,不产生二次污染,体系无降解问题。     

Kinetics and mechanism of MnO2 dissolution in H2SO4 in the presence of pyrite

This paper describes a study of the kinetics and mechanism of MnO2 dissolution in H2SO4 in the presence of pyrite through leaching and electrochemical parameters. Manganese(iv) was found to dissolve mainly through reduction by the ferrous ion generated during oxidation of pyrite by the ferric ion. The oxidation which is slower and rate controlling may proceed through two different reactions, one producing S0 and the other SO42–. Manganese dissolution runs at the same rate as that of pyrite oxidation by maintaining ferrous ion concentration at a much lower level than that of ferric. Kinetic equations based on corrosion coupling principles are developed to explain the observed leaching behaviour.     

A study of the state of water and stoichiometry of bottle-hydrated Ca3SiO5

The state of water in hydrated C₃S is studied by Differential Thermal Analysis and Thermo Gravimetric Analysis techniques. Samples were conditioned at several relative humidities for lengthy periods starting from d-dry, 100 per cent R. H. and 11 per cent R. H. It was found that the stoichiometry of the bottle-hydrated CSH gel at 11 per cent R. H. approached from 100 per cent R. H. is 3.28 CaO: 2SiO₂: 3.92H₂O. Results suggested that at higher humidities higher hydrates exist which decomposed on drying at relative humidities below 40 per cent R. H. Decomposition might occur at humidities above this level.     

Hydrogen sulfide removal by catalytic oxidative absorption method using rotating packed bed reactor

Using catalytic oxidative absorption for H_2S removal is of great interest due to its distinct advantages. However,traditional scrubbing process faces a great limitation in the confined space. Therefore, there is an urgent demand to develop high-efficiency process intensification technology for such a system. In this article, H_2S absorption experimental research was conducted in a rotating packed bed(RPB) reactor with ferric chelate absorbent and a mixture of N_2 and H_2S, which was used to simulate natural gas. The effects of absorbent p H value, gas–liquid ratio, gravity level of RPB, absorption temperature and character of the packing on the desulfurization efficiency were investigated. The results showed that H_2S removal efficiency could reach above 99.6% under the most of the experimental condition and above 99.9% under the optimal condition. A long-time continuous experiment was conducted to investigate the stability of the whole process combining absorption and regeneration. The result showed that the process could well realize simultaneous desulfurization and absorbent regeneration, and the H_2S removal efficiency kept relatively stable in the whole duration of 72 h. It can be clearly seen that high gravity technology desulfurization process, which is simple, high-efficiency, and space intensive, has a good prospect for industrial application of H_2S removal in confined space.     

从硫铁矿矿渣中制备聚合硫酸铁

以硫铁矿矿渣为原料 ,按反浮选和选择性浸出原理除去杂质 ,在 1 0 0°C用硫酸浸得硫酸铁和硫酸亚铁混合液 ,并测定了 Fe2 + 和 Fe3 + 含量。同时对废铁屑经硫酸洗涤和纯碱洗涤后 ,把过量的废铁屑加入该混合液中 ,使整个溶液还原成硫酸亚铁溶液。采用氯酸钠氧化法 ,在 65°C经氧化、水解、聚合得聚合硫酸铁溶液 ,讨论了影响聚合反应的主要因素。对炼油厂废水进行处理 ,合成的聚合硫酸铁的处理效果明显优于市售三氯化铝     

过硫酸钠与双氧水催化降解印染废水的试验研究

为了考察Fe2+/Na_2S_2_O8/H_2O_2氧化体系对实际印染废水的处理效果,首先试验确定Fe2+/H_2O_2和Fe2+/Na_2S_2O_8氧化体系的最佳药剂投加量以及Fe2+/Na2S2O8/H2O2氧化体系的最佳p H,基于最佳p H条件下以药剂投加量为自变量,废水COD去除率为响应值,通过Box-Behnken设计方法设计试验,利用响应曲面分析优化,以优化结果为基础,改变氧化体系中药剂的投加时间与顺序,得出Fe2+/Na2S2O8/H_2O_2氧化体系最优工艺参数,经过90 min反应后,出水COD达到纺织染整行业废水排放限值。     

Bio‐oxidation of ferrous ions by Acidithioobacillus ferrooxidans in a monolithic bioreactor

BACKGROUND: The bio‐oxidation of ferrous iron is a potential industrial process in the regeneration of ferric iron and the removal of H₂S in combustible gases. Bio‐oxidation of ferrous iron may be an alternative method of producing ferric sulfate, which is a reagent used for removal of H₂S from biogas, tail gas and in the pulp and paper industry. For practical use of this process, this study evaluated the optimal pH and initial ferric concentration. pH control looks like a key factor as it acts both on growth rate and on solubility of materials in the system. RESULTS: Process variables such as pH and amount of initial ferrous ions on oxidation by A. ferrooxidans and the effects of process variables dilution rate, initial concentrations of ferrous on oxidation of ferrous sulfate in the packed bed bioreactor were investigated. The optimum range of pH for the maximum growth of cells and effective bio‐oxidation of ferrous sulfate varied from 1.4 to 1.8. The maximum bio‐oxidation rate achieved was 0.3 g L^?1 h^?1 in a culture initially containing 19.5 g L^?1 Fe²⁺ in the batch system. A maximum Fe²⁺ oxidation rate of 6.7 g L^?1 h^?1 was achieved at the dilution rate of 2 h^?1, while no obvious precipitate was detected in the bioreactor. All experiments were carried out in shake flasks at 30 °C. CONCLUSION: The monolithic particles investigated in this study were found to be very suitable material for A. ferrooxidans immobilization for ferrous oxidation mainly because of its advantages over other commonly used substrates. In the monolithic bioreactor, the bio‐oxidation rate was 6.7 g L^?1 h^?1 and 7 g L^?1 h^?1 for 3.5 g L^?1 and 6 g L^?1 of initial ferrous concentration, respectively. For higher initial concentrations 16 g L^?1 and 21.3 g L^?1, bio‐oxidation rate were 0.9 g L^?1 h^?1 and 0.55 g L^?1 h^?1, respectively. Copyright © 2008 Society of Chemical Industry