Study on the reaction activity of CuO/γ-Al_2O_3 for dry flue gas desulfurization

The copper oxide bed regenerable adsorber process can efficiently remove sulfur dioxide (SO2) and sulfur trioxide (SO3) and reduce nitrogen oxides (NOX) from flue gas with no solid or liquid byproducts. This paper investigates the dry flue gas desulfu- rization activities of the CuO/γ-Al2O3 under different operation conditions finding that the dispersion degree of copper oxide can achieve a threshold value, which is 0.47 mg/m2 carriers. The conclusion confirms that the sulfur capacity of desulfurizer is asso- ciated with flue gas’ space velocity, reaction temperature, copper content and the struc- ture of sorbent pellet, etc. And with the condition of the desulfurization reaction tem- perature 673 K, the space velocity 11 200 h-1 and the S/Cu mole ratio under 1, the sulfur removal efficiency can go upwards to 95%.

Removal of SO_2 from flue gas using Bayer red mud:Influence factors and mechanism

The absorbent composing of Bayer red mud and water was prepared and applied to removing SO2 from flue gas.Effects of the ratio of liquid to solid(L/S),the absorption temperature,the inlet SO2 concentration,the O2 concentration,SO4^2-and other different components of Bayer red mud on desulfurization were conducted.The mechanism of flue gas desulfurization was also established.The results indicated that L/S was the prominent factor,followed by the inlet SO2 concentration and the temperature was the least among them.The optimum condition was as follows:L/S,the temperature and the SO2 concentration were 20:1,25℃and 1000 mg/m^3,respectively,under the gas flow of 1.5 L/min.The desulfurization efficiency was not significantly influenced when O2 concentration was above 7%.The accumulation of SO4^2-inhibited the desulfurization efficiency.The alkali absorption and metal ions liquid catalytic oxidation were involved in the process,which accounted for 98.61%.

Resource utilization of flue gas calcium-based desulfurization ash:a comprehensive review

Calcium-based desulfurization ash(CDA)is mainly produced in dry and semi-dry flue gas desulfurization processes.The property of CDA is extremely unstable because its main component,calcium sulfite,makes it difficult to be directly applied to the field of building materials.The modification of desulfurization ash can be realized by high-temperature oxidation and wet oxidation.After modification,CDA can be widely used in building materials.Hydrothermal oxidation has broad development prospects because it can complete the oxidation of CDA and the removal of impurity elements at the same time.CDA can be used to prepare high value-added products of calcium sulfate whiskers and ecological rubber fillers.

氧化镁法脱硫三循环超低排放工艺及副产品回收

本文分析了我国氧化镁法脱硫技术中副产品回收的问题,回顾了我国氧化镁脱硫技术的发展历程,提出采用三循环超低排放工艺和催化氧化提浓硫酸镁技术、烟气浓缩和降温结晶技术,在实现超低排放的同时,可有效回收副产品,实现资源化利用。

Clean Coal Technology and Market in China

This paper briefs the current clean production and consumption levels of coal in China and the pollution harmbrought to the atmospheric environment, present status and orientation of clean coal technology development in Chinacoal industry, progress and perspective of clean coal power generation technology in China, as well as application andmarket of flue gas desulphurization technology in coal-fired power plants.[

Experimental and mechanism studies on simultaneous desulfurization and denitrification from flue gas using a flue gas circulating fluidized bed

The oxidizing highly reactive absorbent was prepared from fly ash,industry lime,and an oxidizing additive M.Experiments of simultaneous desulfurization and denitrification were carried out in a flue gas circulating fluidized bed(CFB).The effects of influencing factors and calcium availability were also investigated on the removal efficiencies of desulfurization and denitrification.Removal efficiencies of 95.5%for SO2 and 64.8%for NO were obtained respectively under the optimal experimental conditions. The component of the spent absorbent was analyzed with chemical analysis methods.The results in- dicated that more nitrogen species appeared in the spent absorbent except sulfur species.A scanning electron microscope(SEM)and an accessory X-ray energy spectrometer were used to observe micro-properties of the samples,including fly ash,oxidizing highly reactive absorbent and spent absorbent.The simultaneous removal mechanism of SO2 and NO based on this absorbent was pro- posed according to the experimental results.

O_(3)oxidation combined with semi-dry method for simultaneous desulfurization and denitrification of sintering/pelletizing flue gas

With the vigorous development of China's iron and steel industry and the introduction of ultra-low emission policies,the emission of pollutants such as SO_(2)and NO x has received unprecedented attention.Considering the increase of the proportion of semi-dry desulfurization technology in the desulfurization process,several semi-dry desulphurization technologies such as flue gas circulating fluidized bed(CFB),dense flow absorber(DFA)and spray drying absorption(SDA)are briefly summarized.Moreover,a method for simultaneous treatment of SO_(2)and NOx in sintering/pelletizing flue gas by O_(3)oxidation combined with semidry method is introduced.Meantime,the effects of key parameters such as O_(3)/NO molar ratio,Ca SO_(3),SO_(2),reaction temperature,Ca/(S+2 N)molar ratio,droplet size and approach to adiabatic saturation temperature(AAST)on denitrification and desulfurization are analyzed.Furthermore,the reaction mechanism of denitrification and desulfurization is further elucidated.Finally,the advantages and development prospects of the new technology are proposed.

湿法氧化技术在碱回收脱硫脱硝系统中的应用效果

介绍了采用碱和NaClO湿氧化技术对碱回收工段中的烟气进行脱硫脱硝的基本原理、工艺流程和应用效果。结果表明:利用稀白液中的NaOH结合NaClO湿氧化技术,可将烟气中的硫完全脱除,脱硝率也达到43.29%。

Low-temperature oxidation behavior and mechanism of semi-dry desulfurization ash from iron ore sintering flue gas

The low-temperature wet oxidation behavior of semi-dry desulfurization ash from iron ore sintering flue gas in ammonium citrate solution was investigated for efficiently utilizing the low-quality desulfurization ash. The effects of the ammonium citrate concentration, oxidation temperature, solid/liquid ratio, and oxidation time on the wet oxidation behavior of desulfurization ash were studied. Simultaneously, the oxidation mechanism of desulfurization ash was revealed by means of X-ray diffraction, Zeta electric resistance, and X-ray photoelectron spectroscopy (XPS) analysis. Under the optimal conditions with ammonium citrate, the oxidation ratio of CaSO_(3) was up to the maximum value (98.49%), while that of CaSO_(3) was only 8.92% without ammonium citrate. Zeta electric resistance and XPS results indicate that the dissolution process of CaSO_(3) could be significantly promoted by complexation derived from the ammonium citrate hydrolysis. As a result, the oxidation process of CaSO_(3) was transformed from particle oxidation to SO_(3)^(2−) ion oxidation, realizing the rapid transformation of desulfurization ash from CaSO_(3) to CaSO_(4) at low temperature. It provides a reference for the application of semi-dry desulfurization ash and contributes to sustainable management for semi-dry desulfurization ash.

液相催化氧化脱除烟道气中SO_2和NO_x的研究

针对我国国情提出了液相催化氧化脱硫脱氮的新方法,在鼓泡反应器内进行了液相催化氧化脱硫脱氮的实验.就催化剂的选择、吸收液的pH值、催化剂浓度等对SO2和NOx吸收效率的影响及其变化规律进行了研究.结果表明,氨中和Fe3+液相催化氧化法脱硫脱硝有较好的效果,采用本方法可以脱除90%以上的SO2以及50%左右的NOx.

回收法氧化镁湿法烟气脱硫机理和工艺基础研究

以氧化镁浆液作为吸收液，对空气与SO2混合气的鼓泡吸收做了全过程的实验观察．测试分析表明，在高效而稳定的脱硫过程中，吸收液的酸化是由HSO3^-所致；酸化趋势与SO2水解规律相一致，由初期高pH值下SO3^2-为主的缓变到低pH值下HSO3^-为主的剧变；吸收液温度对脱硫率的影响不敏感；MgSO3相对高的溶解度和易氧化性及MgSO4良好的水溶性保持了MgO脱硫的高效率（〉98％）和高利用率燃煤烟气脱硫工业试验确认了MgSO4经吸收液循环可提浓至实验温度（40～50℃）下的饱和浓度而不产生有害影响，脱硫率因脱硫活性物质的富集反而提高，从而显示出回收工艺的技术经济可行性。

氧化镁烟气脱硫反应特性研究

利用实验室规模的鼓泡式反应装置,对比了碳酸钙、氧化镁和氧化镁/硫酸镁脱硫剂的反应活性,证实脱硫液中高浓度硫酸镁的存在是保证镁法脱硫效率高于钙法的重要因素,并考察了硫酸镁浓度、脱硫剂(氧化镁)浓度、烟气量、SO2浓度和吸收液温度等因素对脱硫效率的影响。结果表明,脱硫反应可以根据pH分为2个不同阶段;反应过程中脱硫效率随着硫酸镁浓度的增加而显著升高;烟气量增加将会导致脱硫效率有所下降;入口SO2浓度升高,脱硫效率下降;氧化镁浓度、温度对脱硫效率影响不显著。结合实验现象进行推断,氧化镁脱硫的反应过程受SO2在气液两相界面的传质扩散和其水解产物在液相的扩散控制。

氧化镁湿法烟气脱硫回收工艺的技术经济可行性初步分析

介绍了回收结晶硫酸镁的氧化镁湿法烟气脱硫工艺的基本工艺流程,在抛弃法脱硫系统上所作的工业试验证明了吸收液循环提浓MgSO4的可行性。参照工业硫酸镁生产工艺对130 t/h燃煤锅炉烟气脱硫作了回收工艺的投资效益分析和整体工艺的经济性评价,结果表明回收工业硫酸镁具有良好的经济效益。

湿式氧化镁法烟气脱硫中吸收塔系统的设计与应用

介绍了湿法氧化镁烟气脱硫技术应用的原理及工艺,对吸收氧化反应所在的吸收塔系统进行了装置的设计与应用,并提供理论依据和参考影响吸收因素。

液相催化氧化脱除烟气中SO_2和NO_x机理讨论

对液相催化氧化ＳＯ２和ＮＯｘ进行了较为系统的理论讨论，综述了液相催化氧化吸收ＳＯ２和ＮＯｘ以及过渡金属离子的催化作用，探讨了液相溶液中ＳＯ２和ＮＯｘ同时存在时可能发生的反应，为今后研究ＳＯ２和ＮＯｘ的湿式脱除提供参考。

湿式镁法烟气脱硫副产物MgSO_4热解回收MgO

通过对MgSO4的热解研究为湿式镁法烟气脱硫副产物的综合利用探索适宜的热解条件。实验结果表明,在升温速率为20℃/min、热解温度为850℃、恒温时间为2.0 h的条件下,由无水MgSO4热解制得的MgO收率高达99.8%,由MgSO4.7H2O热解制得的MgO收率仅为72.1%。由此表明,干燥的MgSO4对热解更有利。

金属氧化物在烟气脱硫技术中的应用及发展前景

着重介绍了金属氧化物在烟气脱硫技术中的应用及其脱硫机理,以及它在国内外的发展现状。通过研究分析,比较了各种金属氧化物脱硫的优缺点,阐述了金属氧化物脱硫从单一到复合,从简单负载到与纳米技术相结合且联合脱硫脱硝的发展趋势,表明了该方法发展前景无限。

镁剂在烟气脱硫领域中的应用

文章对利用镁剂 (氢氧化镁、氧化镁和碳酸镁 )进行烟气脱硫作了评述。详述了我国镁质矿物资源 ,镁剂烟气脱硫发展进程 ,日本镁剂烟气脱硫现状和前景展望。

镁法烟气脱硫研究进展

从Mg(OH)2—SO2—H2O系统工业应用谈起,介绍了镁法脱硫的现状及近期研究进展,对镁法烟气脱硫的不同工艺——再生法、硫酸镁回收法、亚硫酸镁回收法、抛弃法与双碱法分别进行评述。并针对我国国情,展望了镁法烟气脱硫的发展前景。

从国外镁法烟气脱硫的研发进程看国内发展前景

针对镁法烟气脱硫在国外诸如日本、美国、前捷克斯洛伐克和波兰的研发进程与工业应用情况,结合国内镁资源丰富的特点,探讨了国内燃煤烟气脱硫的发展方向,提出镁法烟气脱硫要"远离钙、消耗镁、关注硫",展望了发展前景。