脉冲电晕结合Ca(OH)2吸收法脱硫脱硝

Removal of SO2 and NOx by pulsed corona combined with in situ alkali absorption was experimentally investigated.In the reactor,a plate-wire-plate combination is devised for generating pulsed corona and then alkaline absorbent slurries were introduced into the reactor by a continuous band conveying system to capture the gaseous reaction products.It was found that both SO2 and NO could be removed by corona combined with in situ alkali absorption.The removal of SO2 increased to 75%with the corona discharge,compared with 60%removal only with Ca(OH)2 absorption.About 40%removal of NO was reached by pulsed corona combined with in situ Ca(OH)2 absorption.It was found that SO2 and NO in the gas stream are oxidized to SO3 and NO2 by pulsed corona respectively,and then absorbed by the alkali in the reactor.The removals of SO2 as well as NO were higher with Ca(OH)2 as the absorbent,compared with using CaCO3 or ZnO.     

负载金属改性活性炭纤维的脱硫性能

Metal-loaded activated carbon fibers （ACFs） were prepared by impregnation and characterized by N2 adsorption at 77K, XRD, XPS and SEM. Their properties on SO2 removal were examined in a tubular fixed bed reactor with a model flue gas. Cobalt-loaded ACF showed the best activity among the prepared metal-loaded ACFs and a constant removal ratio of SO2 above 87% during continuous exposure to the flow of SO2/O2/H2O/N2 at 45℃ for more than 216h. The characteristic of the prepared loaded-ACFs showed that the exceptional activity of Co-ACF was attributed to the high amount of active sites due to modification by loading cobalt.     

Integration of coal pyrolysis process with iron ore reduction:Reduction behaviors of iron ore with benzene-containing coal pyrolysis gas as a reducing agent☆

An integrated coal pyrolysis process with iron ore reduction is proposed in this article. As the first step, iron oxide reduction is studied in a fixed bed reactor using simulated coal pyrolysis gas with benzene as a model tar compound. Variables such as reduction temperature, reduction time and benzene concentration are studied. The carbon deposition of benzene results in the retarded iron reduction at low temperatures. At high temperatures over800 °C, the presence of benzene in the gas can promote iron reduction. The metallization can reach up to 99% in20 min at 900 °C in the presence of benzene. Significant increases of hydrogen and CO/CO2 ratio are observed in the gas. It is indicated that iron reduction is accompanied by the reforming and decomposition of benzene. The degree of metallization and reduction increases with the increasing benzene concentration. Iron oxide can nearly completely be converted into cementite with benzene present in the gas under the experimental conditions. No sintering is found in the reduced sample with benzene in the gas.     

Performance characteristics of fluidized bed syngas methanation over Ni-Mg/Al2O3 catalyst

The performance characteristics of isothermal fluidized bed syngas methanation for substitute natural gas are investigated over a self-made Ni–Mg/Al2O3 catalyst. Via atmospheric methanation in a laboratory fluidized bed reactor it was clarified that the CO conversion varied in 5% when changing the space velocity in 40–120 L·g?1·h?1 but the conversion increased obviously by raising the superficial gas velocity from 4 to 12.4 cm·s?1. The temperature at 823 K is suitable for syngas methanation while obvious deposition of uneasy-oxidizing Cγoccurs on the catalyst at temperatures around 873 K. From a kinetic aspect, the lowest reaction temperature is suggested to be 750 K when the space velocity is 60 L·g?1·h?1. Raising the H2/CO ratio of the syngas increased proportionally the CO conversion and CH4 selectivity, showing that at enough high H2/CO ratios the active sites on the catalyst are sufficient for CO adsorption and in turn the reaction with H2 for forming CH4. Introducing CO2 into the syngas feed suppresses the water gas shift and Boudouard reactions and thus increased H2 consumption. The ratio of CO2/CO in syngas should be better below 0.52 because varying the ratio from 0.52 to 0.92 resulted in negligible increases in the H2 conversion and CH4 selectivity but decreased the CH4 yield. Introducing steam into the feed gas affected little the CO conversion but decreased the selectivity to CH4. The tested Ni–Mg/Al2O3 catalyst manifested good stability in structure and activity even in syngas containing water vapor.     

Fluidization Characteristics of Silicon Particles with a Wide Size Distribution

Fluidization characteristics of silicon particle system are studied by the pressure fluctuation method. The existence of fine particles in the system can improve fluidization. Silicon particles with a wide size distribution, preferably with some fines, behave as Group A particles according to Geldart classification, although the system belongs to Group B actually. The system is also approved to be suitable for organochlorosilane monomer production using a fluidized bed reactor. Experimental data obtained in this work are important for the design and operation of commercial fluidized bed reactors for the production of organochlorosilane monomers.     

宽筛分硅粉颗粒的流化特性

Fluidization characteristics of silicon particle system are studied by the pressure fluctuation method.The existence of fine particles in the system can improve fluidization. Silicon particles with a wide size distribution,preferably with some fines, behave as Group A particles according to Geldart classification, although the system belongs to Group B actually. The system is also approved to be suitable for organochlorosilane monomer production using a fluidized bed reactor. Experimental data obtained in this work are important for the design and operation of commercial fluidized bed reactors for the production of organochlorosilane monomers.     

组合式流化床中以高钙镁钛渣为原料制取TiCl4

This paper describes a new method for producing TiCl4 by chloridizing materials of high content CaO and MgO, in which a combined fluidized bed is used as a reactor to avoid agglomeration between particles caused by molten CaCl2 and MgCl2. The combined fluidized bed consists of at least a riser tube and a semi-circulating fluidized bed. Two kinds of high titanium slag, in which the total mass content of CaO and MgO is 2.03% and 9.09% respectively, are employed to examine the anti-agglomeration effect and the conversion of the materials when the temperature ranges are between 923.15K and 1073.15K, gas apparent velocity 0.7-1.1m·s-1, and inlet amount of solid materials is 4.6-7.0kg·h-1. It is found that the anti-agglomeration effect in the combined fluidized bed is satisfactory and the new method can achieve a TiCl4 production capacity of 14.0-75.4t·m-2·d-1 in relation to 25.0-40.0t·m-2·d-1 from the conventional bubble bed. Furthermore, low-temperature chloridization, for example, at 923K or 973K, can also be used to produce TiCl4 and avoid agglomeration.     

Coupling non-isothermal trickle-bed reactor with catalyst pellet models to understand the reaction and diffusion in gas oil hydrodesulfurization

In this work, a trickle-bed reactor coupled with catalyst pellet model is employed to understand the effects of the temperature and catalyst pellet structures on the reaction–diffusion behaviors in gas oil hydrodesulfurization(HDS). The non-isothermal reactor model is determined to be reasonable due to non-negligible temperature variation caused by the reaction heat. The reaction rate along the reactor is mainly dominated by the temperature,and the sulfur concentration gradient in the catalyst pellet decreases gradually along the reactor, leading to the increased internal effectiveness factor. For the fixed catalyst bed volume, there exists a compromise between the catalyst reaction rate and effectiveness factor. Under commonly studied catalyst pellet size of 0.8–3 mm and porosity of 0.4–0.8, an optimization of the temperature and catalyst pellet structures is carried out, and the optimized outlet sulfur content decreases to 7.6 wppm better than the commercial level at 0.96 mm of the catalyst pellet size and 0.40 of the catalyst porosity.     

合成气制二甲醚三相淤浆床反应器的数学模型研究

A mathematical model for a bubble column slurry reactor is presented for dimethyl ether synthesis from syngas. Methanol synthesis from carbon monoxide and carbon dioxide by hydrogenation and the methanol dehydration are considered as independent reactions, in which methanol, dimethyl ether and carbon dioxide are the key components. In this model, the gas phase is considered to be in plug flow and the liquid phase to be in partly back mixing with axial distribution of solid catalyst. The simulation results show that the axial dispersion of solid catalysts, the operational height of the slurry phase in the bubble column slurry reactor, and the reaction results are influenced by the reaction temperature and pressure, which are the basic data for the scale-up of reactor.     

Application of the Solvothermal Process in the Synthesis of High-performance Ag/γ-Al_2O_3 Catalysts

1 INTRODUCTION Since Cu-ZSM-5 was reported as an effective catalyst for the selective catalytic reduction (SCR) of NO by hydrocarbons in the presence of excess oxygen, the SCR of NOx has received much attention as a kind of potential technology for cleaning NOx in various oxygen-rich exhausts of diesel engine, lean burning gasoline engine and gas engine. Although a number of catalysts have been tested, to date, it still seems to be difficult to find a catalyst that is completely suit…     

气-固-固流化床用于燃煤电厂尾气同时脱硫脱硝

采用新型干法气–固–固流化床反应器进行模拟燃煤电厂尾气的高效同时脱硫、脱硝. 在内径53 mm的流化床中,以砂粒作为固相介质、自制的K2CO3/Al2O3为吸附剂,考察了温度、吸附剂粒径、吸附剂活性组份(K)与气相中污染组份(SO2,NO)的摩尔比、模拟气中SO2/NO摩尔比等工艺条件对脱硫脱硝效率的影响. 在无氨条件下同时脱硫、脱硝的效率可分别达到100%和92%. 大量数据表明,尾气中的SO2对吸附剂表面NO的脱除反应有显著促进作用.     

A Novel Dry Process for Simultaneous Removal of SO2 and NO from Flue Gas in a Powder‐Particle Fluidized Bed

A novel sorbent, potassium carbonate impregnated on porous fine alumina, was produced, and its reactive and regenerative properties were evaluated for dry‐type simultaneous removal of SO₂ and NO from flue gas under stack temperatures, by using a powder‐particle fluidized bed (PPFB) with I.D. of 53 mm as the reactor. High removal efficiencies for SO₂ and NO were achieved simultaneously. An apparent beneficial effect of SO₂ on the enhancement of NO removal was found based on a large amount of data. The alumina carrier was successfully regenerated and used repeatedly for the production of fresh sorbent particles. With no ammonia, low temperature, high removal efficiency, and no second waste emission as main characteristics, this dry process can be a competitive technology for pollution control of flue gas from power plants in the future.     

Simultaneous SO2/NOx removal by a powder-particle fluidized bed

Simultaneous dry removal of SO₂ and NO_x from flue gas has been investigated using a powder-particle fluidized bed. In a process of flue gas desulfurization by use of solid sorbents such as FeO (dust from a steel plant) and CuO, the smaller the particle size of sorbents, the higher the expected SO₂ conversion. In a powder-particle fluidized bed (PPFB), fine particles less than 40 μm in diameter fed into the bed are fluidized with coarse particles. But only the fine particles are entrained from the bed, and their residence time in the bed is remarkably long.

The reduction of NO_x with NH₃ in the fluidized bed is catalyzed by coarse particles or both coarse and fine particles. In this study, PPFB was applied to simultaneous dry SO₂/NO_x removal process, and several kinds of sorbents or catalysts were evaluated in a PPFB. Using the selected sorbents and catalysts, kinetic measurements were made in the temperature range of 300 to 600°C. SO₂ removal efficiencies were affected by reaction temperature, sorbent/S ratio, and static bed height. NO_x removal efficiencies in excess of 95% were achieved at NH₃/NO_x mole ratio of 1.0. When FeO was used as sorbent, SO₂ conversion increased with increasing temperature and reached 80% at 600°C.     

CO2对石灰石脱硫剂的活化作用

在间歇式鼓泡反应器的烟气脱硫实验装置中,研究了CO2气体活化处理对石灰石脱硫剂浆液烟气脱硫效率的影响. 依据脱硫过程中石灰石脱硫剂浆液pH值随脱硫反应时间的变化规律,初步分析了CO2对石灰石脱硫剂的活化作用及活化后石灰石脱硫剂的烟气脱硫过程机理. 结果表明,CO2气体的活化处理促进了石灰石在水溶液中的溶解,进而改善了石灰石脱硫剂浆液的烟气脱硫反应活性,使处理后的石灰石脱硫剂浆液的烟气脱硫效率和脱硫剂的利用率提高. 基于流化床反应器连续过程的实验结果,证实了CO2对石灰石脱硫剂的活化作用. 为提高石灰石在烟气脱硫中的反应活性提供了一种新的工艺,可用于烟气脱硫中对石灰石脱硫剂浆液的活化.     

烟气脱硫脱硝一体化吸收/催化剂研究进展

由于对控制NOx排放的日益重视,具有同时脱硫脱硝功能的整体流程对于老厂改建和新厂建设有极大优势。详细介绍了采用金属氧化物在同一系统中实现烟气联合脱硫脱硝技术的研究现状、存在的问题及其发展前景。     

一种新型烟气净化剂─—混合有机钙盐

制备了一种新型烟气净化剂─—混合有机钙盐。在模拟工业条件的喷雾干燥型反应器中,９００～１１００℃温度范围内,混合有机钙盐的快速脱硫的钙基利用率＞ＣａＡｃ２＞Ｃａ（ＯＨ）２＞ＣａＣＯ３：混合有机钙盐的脱硝利用率约是ＣａＡｃ２的２．５倍,而ＣａＣＯ３和Ｃａ（ＯＨ）２基本看不出脱硝能力。在实验条件下温度升高,净化剂的脱硫利用率略有增加,醋酸钙和混合有机钙盐的最佳脱硝温度大约在１０００℃;较低的氧浓度既有利于脱硫也有利于脱硝;有机钙净化剂的硫酸化能提高其脱硝能力。     

Simultaneous SO x /NO x removal in a fluidized bed reactor using natural manganese ore

In this experiment, the simultaneous removal of SO₂ and NO from flue gases was investigated through the use of natural manganese ore as a sorbent‐catalyst in a fluidized bed reactor. Selective catalytic reduction behavior was determined as a function of the sulfation degree within the temperature range from 100 °C to 500 °C. The natural manganese ore showed a high activity in the production of nitrogen and water by the reaction of nitric oxide with ammonia and oxygen up to around 200 °C. At higher temperatures, the nitric oxide removal efficiency decreased due to the oxidation of ammonia by oxygen. With the increase of sulfation degree, the temperature at which the maximum selective catalytic reduction of nitric oxide appears gradually increased, however the maximum nitric oxide removal efficiency decreased. Additionally, we investigated the removal efficiency of sulfur dioxide and nitric oxide with reaction time in a batch fluidized bed reactor within a temperature range of 350 °C to 500 °C. As the reaction temperature increased, the adsorption capacity of sulfur dioxide increased, but the nitric oxide removal efficiency decreased. © 2001 Society of Chemical Industry     

臭氧氧化—钙法吸收同时脱硫脱硝的试验研究

针对国内某石化企业CFB锅炉烟气特点,进行实验室烟气模拟,采用臭氧氧化—钙法吸收同时脱硫脱硝工艺进行小试研究.实验采用臭氧将NO氧化为NO2,再通入鼓泡反应器中与Ca（OH）2浆液发生吸收反应,达到同时脱硫脱硝的目的.实验结果表明：NOx脱除率与臭氧投加量成正比,当臭氧投加量为1.1时,NOx脱除率可达到90％以上;SO2初始浓度的变化对NOx脱除率影响不大;NO初始浓度和烟气含氧量对SO2脱除率影响效果均不显著;烟气含氧量的增大有利于NOx的脱除.     

湿法同步脱硫脱硝技术研究现状及发展趋势

燃煤烟气排放的二氧化硫和氮氧化物是重要的大气污染物质,同步脱硫脱硝技术是目前研究的热点。本文主要从吸收剂的成本及脱硫脱硝产物的可资源化利用两个方面对目前广泛研究的湿法同步脱硫脱硝技术进行了综述,并指出资源化同步脱硫脱硝技术是研究的发展趋势。     

氨吸收法同时脱硫脱硝的实验研究

在自行设计的吸收塔反应器中,以氨水作为吸收剂,研究其对SO2和NOx的脱除效果,在氨法脱硫的工艺条件下对SO2的脱除率为100%,NOx脱除率可达72%。对SO2和NOx的吸收条件进行了研究,发现吸收液中SO32-浓度是影响脱硫脱硝率的重要因素。提出了选择性催化氧化(SCO)和氨法烟气脱硫相结合的氨吸收法同时脱硫脱硝技术,此法可用于改造现有氨法烟气脱硫设备,达到SO2和NOx同时脱除的目的。