共沉淀法制备铁锌基中高温煤气脱硫剂

采用共沉淀法制备Cu—Zn—Fe脱硫剂,优化共沉淀制备工艺。固定床实验结果表明,共沉淀溶液中金属离子总浓度为0．6mol／L,焙烧温度600℃,添加10％活性助剂Cu时所得Cu—Zn—Fe脱硫剂循环脱硫性能最佳,此时ZFDCu10脱硫剂的硫容可达到41．2gS／100g脱硫剂。XRD和SEM对铁锌基脱硫剂的表征结果表明,加入Cu助剂后少量的ZnO、CuO可阻碍ZnFe2O4晶粒聚集,增强铁锌基脱硫剂活性组分的分散性,避免大晶粒的ZnFe2O4硫化时形成较多的产物层而降低脱硫剂的利用率。实验结果为制备脱硫性能较好的Cu-Zn-Fe脱硫剂提供了理论依据。     

共沉淀法制备铁锌基中高温煤气脱硫剂简

采用共沉淀法制备Cu-Zn-Fe脱硫剂,优化共沉淀制备工艺。固定床实验结果表明,共沉淀溶液中金属离子总浓度为0.6 mol/L,焙烧温度600℃,添加10%活性助剂Cu时所得Cu-Zn-Fe脱硫剂循环脱硫性能最佳,此时ZFDCu10脱硫剂的硫容可达到41.2 g S/100 g脱硫剂。XRD和SEM对铁锌基脱硫剂的表征结果表明,加入Cu助剂后少量的ZnO、CuO可阻碍ZnFe₂O₄晶粒聚集,增强铁锌基脱硫剂活性组分的分散性,避免大晶粒的ZnFe₂O₄硫化时形成较多的产物层而降低脱硫剂的利用率。实验结果为制备脱硫性能较好的Cu-Zn-Fe脱硫剂提供了理论依据。     

酸碱改性对氧化铁脱硫剂脱硫性能影响的研究

通过酸碱改性制备了酸式和碱式2种不同表面性质的常温氧化铁脱硫剂,并采用FT-IR技术对其表面酸碱性质和净化硫化氢废气活性进行了研究.结果表明,表面酸碱件质不同的脱硫剂其脱硫反应行为也不同,在脱硫过程中硫化氢氧化生成的硫酸及亚硫酸会影响脱硫剂的表面酸碱性质,造成酸式脱硫剂的表面酸性更强,从而抑制了硫化氢分子在酸式脱硫剂表...     

空速和二氧化碳对沼气脱硫剂硫容确定的影响

为了弄清空速与二氧化碳含量对氧化铁脱硫剂硫容确定的影响,分别在实验气源为纯硫化氢,空速为40、80、120和160 h-1以及实验气源为二氧化碳含量分别在0%、20%、40%和80%,其余为硫化氢,空速为80 h-1条件下,对T502(粗脱硫剂)和HXT-2(精脱硫剂)2种氧化铁脱硫剂进行了不同测试条件对氧化铁硫容确定影响的研究。研究结果表明,T502和HXT-2氧化铁脱硫剂硫容测试结果随着空速和二氧化碳含量增加而减少,结果显示了在空速较低条件下(120h-1),二氧化碳含量在40%以下时对氧化铁脱硫剂硫容测试结果影响不大,但二氧化碳含量在40%以上时,对氧化铁脱硫剂硫容测试结果影响显著。     

纳米零价铁脱硫剂的制备及其脱硫性能评价

以溶胶-凝胶法制备的炭气凝胶为载体,硝酸铁为主要原料,并通过浸渍法煅烧得到纳米铁高温脱硫剂50%Fe/C500。同时,以沸石分子筛(ZSM-5)为载体,采用溶胶-凝胶法制备50%Fe_2O_3/ZSM-5高温脱硫剂作为对比。以炭气凝胶为载体的脱硫剂较ZSM-5为载体的脱硫剂得到的活性组分不同,其中炭气凝胶为载体得到的活性组分纳米铁,ZSM-5为载体活性组分为Fe_2O_3。利用N_2吸附/脱附、场发射扫描电镜、X射线衍射、分析手段对脱硫剂脱硫前后的表面结构、物相和化学结构进行表征,并在固定床反应器中研究了脱硫剂的硫化温度、气氛组分(H_2、CO)、载体对其脱硫性能的影响。研究结果表明,在500~650℃温度范围内,高温脱硫剂的最佳硫化反应温度为600℃;50%Fe/C500脱硫剂的穿透硫容比50%Fe_2O_3/ZSM-5脱硫剂大,还原性气体对纳米铁脱硫剂的影响较小。     

循环灰加湿量对密相塔半干法脱硫效率的影响

为了进一步提高密相塔半干法脱硫工艺的脱硫效率和脱硫剂利用率,研究了系统含湿量对脱硫效率的影响。首先,通过模拟实验探索了系统含湿量与脱硫剂失效时间的关系,然后利用MATLAB编程软件计算了系统中CaO脱硫剂利用率与系统含湿量的关系。结果表明,脱硫剂CaO的失效时间随着系统含湿量的增加而逐渐增大;系统中SO2脱除量和CaO脱硫剂利用率均随着含湿量的增加而显著提高,当系统含湿量为9%时,分别达到1 210 mg和70%。在实际工程中可结合链式搅拌器的使用,进一步提高脱硫剂的利用率和脱硫效率,满足日益严格的排放标准。     

螺旋切割强化湿法烟气脱硫的传质动力学

针对开发的新型静态螺旋切割强化湿法烟气脱硫技术,根据双膜理论从动力学角度建立了静态螺旋切割强化Ca(OH)_2溶液吸收烟气SO_2的动力学模型,并采用单因素实验探究了烟气SO_2浓度、烟气流量、脱硫剂浓度以及脱硫剂循环流量对传质速率的影响。结果表明:模型能较好地描述静态螺旋切割强化湿法烟气脱硫的实际过程,理论计算与实验数据都发现,烟气SO_2浓度、烟气流量、脱硫剂浓度以及脱硫剂循环流量的增加均有助于提高传质速率;但当脱硫剂浓度大于5%时,传质速率随脱硫剂浓度的增加改变不大。     

FeSO4/Ac脱硫剂脱硫性能的研究

为寻找经济适用且具有较高效率的烟气脱硫方法．研制了FeSO4／Ac脱硫剂。并对FeSO4／Ac脱硫剂的脱硫性能进行了实验研究。实验研究结果显示,烟气中O2、水蒸气含量的多少及脱硫温度的高低会影响FeSO4／Ac脱硫剂的脱硫性能。实验证明,当n(O2):n(SO2)=7～10、n(H2O)：n(SO2)=3～5、脱硫温度取120℃时,FeSO4／Ac脱硫剂具有良好的脱硫性能,脱硫效率可达92．1％～96．8％。FeSO4／Ac脱硫剂能够再生重复使用。采用水蒸气加热再生法对FeSO4／Ac脱硫剂进行再生,实验结果显示,经4次加热法再生的FeSO4／Ac脱硫剂的脱硫效率仍能达到91％。     

钙基烟气脱硫剂制备的实验研究

采用正交实验 ,研究了水合制备高效钙基烟气脱硫剂时各制备条件对产物的影响。结果表明 ,水合时间、水合温度Ca(OH) 2 /CaSO4的质量比 ,以及飞灰 / (Ca(OH) 2 +CaSO4)质量比四个条件对脱硫剂比表面积的形成有显著的影响 ;从而由单因素实验得出一最佳钙基脱硫剂制备条件组合。此外 ,通过XDR分析 ,测定了脱硫剂的物相组成 ,扫描电镜观察显示飞灰和水合吸收剂具有不同的表面形态     

粗媒体颗粒流化床半干法烟气脱硫

开发了粗媒体颗粒流化床半干法烟气脱硫技术.在流化床内加入惰性粗媒体颗粒,改善脱硫剂与烟气的接触,延长脱硫剂在床内的停留时间,促进脱硫反应进行,提高脱硫效率和脱硫剂利用率.以工业用石灰石为脱硫剂,实验研究了粗媒体颗粒的加入量及其他操作条件对此过程脱硫效率的影响.结果表明:随着粗媒体颗粒粒径减小及床内加入量增加,烟气脱硫效率提高;随着Ca/S增大、饱和接近度降低、空速及脱硫剂颗粒粒径减小,脱硫效率提高.当粗媒体颗粒的静止床高为122 mm,饱和接近度为15～18℃、空速为2850 h-1、钙硫比为1.0～1.1、脱硫剂粒径为64μm时,脱硫效率可达90%以上.     

烧结烟气脱硫剂性能的研究

为了提高脱硫效率和合理利用烧结过程中产生的机头灰,在半干法烟气脱硫剂生石灰中,加入一定量的烧结机头灰作为脱硫催化剂。在测定机头灰与生石灰化学成分、粒度和比表面积的基础上,研究和分析了机头灰与生石灰的质量配比对于脱硫效率的影响。结果表明,脱硫剂与机头灰在粒径分布和比表面积上都较接近,但经过消化活化后的混合脱硫剂的比表面积明显增大。当机头灰添加量为脱硫剂质量的2%～5%时,脱硫效率提高了2%～3%。机头灰与生石灰的胶凝反应以及机头灰中Fe2O3的催化作用是主要的作用机理。     

钙质煤渣吸附剂脱除烟气中二氧化硫的实验研究

利用锅炉本身排出的煤渣作脱硫剂的基本核粒,配人少量的石灰,加水搅拌均匀,使石灰裹覆在煤渣颗粒表面,制成具有较大比表面积的钙质煤渣脱硫剂,用于烟气脱硫实验研究.实验结果表明,钙制煤渣脱硫剂比未经处理的煤渣脱硫率高,在一定的石灰添加范围内(10%～20%),脱硫率随石灰添加量的增加而增加,并存在一最佳用量.     

硫化氢吸收净化技术研究进展

综合评述了硫化氢气体的吸收净化方法及特点。净化方法分为干法和湿法两大类。大部分干法脱硫剂均不能再生 ,硫容量相对较低 ,主要适于气体精细脱硫。吸收净化工艺能适应较高负荷的脱硫要求 ,应用面广 ,其中尤以吸收氧化法较突出。指出吸收氧化法中的铁基工艺尽管在工艺控制方面还有一定难度 ,但仍可作为一种有较大发展前途的方法。     

文丘里水膜除尘器除尘脱硫增效技术研究

介绍了三相流化床技术用于文丘里水膜除尘器除尘脱硫增效的原理、工艺流程以及在410t／h锅炉上的工业应用结果。工业运行测试结果表明，其脱硫效率可达85％左右，除尘效率达98％左右。该系统结构简单、运行可靠，具备了工业应用的条件。     

烟道式脱硫装置处理冶炼厂高浓度SO2烟气的工程实践

本文介绍了烟道式脱硫装置的特点及工艺原理 ,采用该装置处理某冶炼厂高浓度SO2 烟气 ,其脱硫率达 90 %以上 ,净化后的烟气可直接达标排放 ,并年产合格脱硫石膏近万吨。烟道式脱硫装置解决了常规脱硫除尘装置共同存在的结垢和堵塞问题 ,在冶炼烟气治理方面具有一定的推广应用价值。     

De novo formation characteristics of dioxins in the dry zone of an iron ore sintering bed

The objectives of this work are to understand the details of the mechanism of dioxin formation in the part of a sintering bed termed the dry zone, and to obtain ideas on how to prevent their formation. Sinter mixtures of various composition types were heated in a packed bed reactor, and dioxins in the outlet gas and in the sinter mixture residue were measured. The dioxin formation potential of a simple sinter mixture composed of iron ore, coke and limestone was markedly lower than that of fly ash from a municipal solid waste incinerator (MSWI). In consideration of this result, a series of experiments were conducted using a sinter mixture impregnated with CuCl2. Experimental results showed that dioxin formation was temperature-dependent in the range of 300-550 degrees C, with the maximum observed at around 300 degrees C, which was quite similar to that of fly ash from the MSWI. The homologue distribution of PCDD/Fs in gas and solid reflected the possible difference in carbonaceous materials in coke and activated coke. Gaseous hydrogen chloride acted as a chlorinating reagent for dioxin formation.     

Emissions of polychlorinated dibenzo-p-dioxins and dibenzofurans from stack flue gases of sinter plants

This study investigated four sinter plants, classified into two categories--with selective catalytic reduction (SCR) (S1, S2 and S3) and without SCR (S4) as its air pollution control device. Polychlorinated dibenzofurans (PCDFs) are dominant in the stack flue gases of sinter plants with and without SCR. The polychlorinated dibenzofurans/polychlorinated dibenzo-p-dioxins (PCDFs/PCDDs) ratio exceeds 1 extremely. The degree of chlorination of the sinter plant without SCR is towards hepta and hexa congeners while that of the sinter plant with SCR is towards penta and hexa congeners. PCDD/Fs are indeed decomposed (75.5% and 69% on ng and ng TEQ bases, respectively) and not only reduced in degree of chlorination. The overall concentration in the stack flue gas of sinter plants with SCR (7.97-14.1 ng/Nm(3); 0.995-2.06 ng TEQ/Nm(3)) is lower than that of the sinter plant without SCR (28.9 ng/Nm(3); 3.10 ng TEQ/Nm(3)). In Taiwan, based on the emission factors of 0.970 microg TEQ/ton-feedstock (sinter plants with SCR) and 3.13 microg TEQ/ton-feedstock (sinter plant without SCR), the annual PCDD/F emission of 44.7 g TEQ/year from sinter plants is 60 and 121 times higher than those from municipal solid waste incinerators (0.750 g TEQ/year) and MWIs (0.369 g TEQ/year). These results show that sinter plants have become the dominating PCDD/F emission source since tighter emission limits have been applied to incinerators.     

氢氧化钠-钢渣双碱法烧结烟气脱硫工艺

在鼓泡反应器中考察了氢氧化钠-钢渣双碱法烧结烟气脱硫的主要影响因素。结果表明,在温度为常温,钢渣反应时间为2 h,钢渣加入量为40 g,SO2进口浓度为2 400 mg/m3,钢渣粒径为200目以上,烟气流量为0.05 m3/h,循环液pH保持在7～8,Na+浓度为0.5 mol/L,循环液为500 mL的条件下,脱硫率可长时间保持在80%以上。同时,对钢渣-氢氧化钠双碱法烧结烟气脱硫机理进行了探讨。     

钢渣脱除烧结烟气中二氧化硫的实验研究

通过对钢渣的分析,确定了其作为脱硫剂的可能性.从钢渣在不同操作条件下脱硫的实验研究看,钢渣能有效地脱除烟气中的SO2,在湿润状态、低流速条件下,微细钢渣的脱硫能力较强,钢渣作为脱硫剂使用将具有良好的经济效益和环境效益.     

A pilot study for determining the optimal operation condition for simultaneously controlling the emissions of PCDD/Fs and PAHs from the iron ore sintering process

In this study, the cost-benefit analysis technique was developed and incorporated into the Taguchi experimental design to determine the optimal operation combination for the purpose of providing a technique solution for controlling both emissions of PCDD/Fs and PAHs, and increasing both the sinter productivity (SP) and sinter strength (SS) simultaneously. Four operating parameters, including the water content, suction pressure, bed height, and type of hearth layer, were selected and all experimental campaigns were conducted on a pilot-scale sinter pot to simulate various sintering operating conditions of a real-scale sinter plant. The resultant optimal combination could reduce the total carcinogenic emissions arising from both emissions of PCDD/Fs and PAHs by 49.8%, and increase the sinter benefit associated with the increase in both SP and SS by 10.1%, as in comparison with the operation condition currently used in the real plant. The ANOVA results indicate that the suction pressure was the most dominant parameter in determining the optimal operation combination. The above result was theoretically plausible since the higher suction pressure provided more oxygen contents leading to the decrease in both PCDD/F and PAH emissions. But it should be noted that the results obtained from the present study were based on pilot scale experiments, conducting confirmation tests in a real scale plant are still necessary in the future.