湿式烟气脱硫喷淋塔内部流场数值模拟研究

以300MW机组湿法烟气脱硫喷淋塔为研究对象,利用计算流体力学通用软件对其内部两相流场进行模拟。气相湍流由标准k 模型描述,喷淋液滴由拉格朗日颗粒轨道模型描述。预测了无喷淋和有喷淋2种条件下的气相湍流流场分布、沿塔高方向不同截面上的气速分布以及喷淋液滴的轨迹。模拟结果表明,引入喷淋液后,出口截面气速分布明显均匀化,其最大值由无喷淋时的12m/s降至6m/s。该最大值出现在靠近塔壁处,是由塔壁附近喷淋密度较低造成的,可通过改进周边喷嘴的布置方式及喷嘴型式进行优化。

柴油的光诱导氧化脱硫研究

将一定比例的柴油与饱和9,10-二氰蒽(DCA)乙腈溶液混合,在高压汞灯照射下通空气氧化,每隔一定时间取油样,用KW-3型微库仑仪测定油中的硫含量。考察DCA对模型体系、催化裂化柴油、催化加氢柴油的脱硫效果,也考察了剂油比对脱硫效果的影响。分析了乙腈相中不同组分的硫含量。结果表明,光敏剂DCA对柴油的光诱导氧化脱硫有一定的效果。胜华炼油厂催化裂化柴油光诱导氧化10h后,脱硫率为49％-60％,精制油收率为72％-85％,加入DCA后比不加DCA脱硫率大8-10个百分点。光氧化后乙腈相的石油醚萃取物及残余物中的硫含量都比未处理柴油中的硫含量高,且加入DCA增加了光氧化的程度,残余物的量及其中硫含量都比不加的高。

HZSM-5催化剂的催化脱硫反应研究

采用浸渍法制备了一系列不同镧负载量的HZSM 5分子筛催化剂,并对其进行了X射线衍射、红外光谱、比表面和NH3-程序升温脱附等方面的表征。结果表明,HZSM 5分子筛的结晶度均达到了85%以上,掺镧后的HZSM 5分子筛在波数1100cm-1附近的非对称振动特征峰有一定程度的蓝移,BET法的比表面积及直径、单点体积、BJH法的吸附体积及脱附体积均有所增大,反应的比表面活性有所提高,致使弱酸量大幅度减少,中强酸、强酸量大幅度增大。在活性氢物质甲醇存在时,固定床微型反应器中噻吩的催化转化反应结果表明,催化剂的脱硫反应活性明显增强,噻吩转化率提高,噻吩转化为H2S的量增加,但液相产物趋向复杂,选择性有所降低,且在掺镧约1 0%左右噻吩的转化率达到51.3%。

厌氧菌对化石燃料中有机硫的还原降解

对硫酸盐还原菌D.desulfuricansM6及模型化合物和原油的脱硫活性。苯并噻吩脱硫率高达96%,硫醇低于10%。一些模型化合物的降解受到正十二烷的抑制,石油重馏分的脱硫率高于原油和轻馏分。在微生物还原降解模式中,与脂肪族含硫化合物相比,芳香含硫化合物中的碳硫键易于受到攻击而降解,某些石油样品的低脱硫率源于样品中硫的赋存形态。介绍了DesulfomicrobiumescambiuK114和Desulfovibriolonggreachill213及其同生群在仅有氮气的环境中对模型物的还原降解。

几种汽油脱硫工艺中含硫化合物类型变化规律

采用气相色谱 -原子发射光谱联用 (GC -AED)技术 ,研究了几种不同的脱硫工艺 (加氢脱硫、吸附脱硫和抽提脱硫 )中各种含硫化合物的变化。加氢脱硫工艺中含硫化合物的脱除效果最好 ,硫脱除率可达 98%以上 ,硫醇、硫醚最易脱除 ,仅有少量的烷基取代噻吩不易被脱除 ,加氢脱硫条件的选择应以汽油中噻吩类化合物的含量而定 ;吸附脱硫工艺中 ,硫醇、硫醚、四氢噻吩类化合物最易脱除 ,受空间位阻的影响 ,取代噻吩比噻吩难脱除 ;在抽提脱硫工艺中 ,因苯并噻吩与所用抽提剂结构相近 ,最易被脱除 ,而空间位阻较大的三甲基噻吩和四甲基噻吩不能被脱除。采用GC -AED技术 ,可根据汽油馏分中含硫化合物的分布来选择合适的脱硫工艺。

在超声条件下过氧化氢-三氟乙酸对柴油氧化脱硫性能的研究

采用H2O2-三氟乙酸作为氧化剂将盘锦催化裂化柴油中的硫化物(主要为苯并噻吩类)氧化成相应的砜,同时又用功率超声作用于该过程。然后根据相似相容原理用合适的溶剂将这些砜萃取除去。最佳的操作条件为:反应温度70℃;氧化剂与油的体积比为1:10;氧化时间60min;萃取剂为N,N-二甲基甲酰胺(DMF);萃取剂油比为1:1。加入功率超声后,可使反应时问由60min缩短为10min,同时也使脱硫率提高了10个百分点。

直接生产清洁汽油的FDFCC工艺

FDFCC是理想的降低FCC汽油烯烃和硫含量的工艺技术。中试及工业应用结果表明:FDFCC装置操作稳定可靠、工艺参数调节灵活。汽油提升管反应器对催化汽油的改质效果十分显著,改质汽油烯烃含量可下降至18%(φ)以下,芳烃增加13个百分点以上,硫含量下降20%～30%,改质汽油诱导期>1000min,MON和RON不下降,苯含量<1%。采用适当的FDFCC工艺形式,可直接生产满足国内清洁燃料或欧洲Ⅲ类燃料标准的清洁汽油。

脉冲流光电晕脱硫反应器电极配置数值模拟

线-板式非热等离子体烟气脱硫反应器的电极配置形式是影响反应器脉冲流光电晕放电特性及脱硫效率的主要因素之一,线-板电极的配置在一定范围内存在最优方案.从工程应用角度出发,在分析脉冲流光电晕放电机理的基础上,进行了反应器静电场数值模拟,得出了不同电极配置的静电场分布,结合流光形成、发展和传播所必备的静电场条件,优化电极配置.数值模拟结果表明:在施加峰值电压为80kV,放电极半径为0.2cm,线-板间距为10cm时,线线最佳间距为6～8cm.

Desulfurization characteristics of slaked lime and regulation optimization of circulating fluidized bed flue gas desulfurization process--A combined experimental and numerical simulation study

Circulating fluidized bed flue gas desulfurization(CFB-FGD) process has been widely applied in recent years. However, high cost caused by the use of high-quality slaked lime and difficult operation due to the complex flow field are two issues which have received great attention. Accordingly, a laboratory-scale fluidized bed reactor was constructed to investigate the effects of physical properties and external conditions on desulfurization performance of slaked lime, and the conclusions were tried out in an industrial-scale CFB-FGD tower. After that, a numerical model of the tower was established based on computational particle fluid dynamics(CPFD) and two-film theory. After comparison and validation with actual operation data, the effects of operating parameters on gas-solid distribution and desulfurization characteristics were investigated. The results of experiments and industrial trials showed that the use of slaked lime with a calcium hydroxide content of approximately 80% and particle size greater than 40 μm could significantly reduce the cost of desulfurizer. Simulation results showed that the flow field in the desulfurization tower was skewed under the influence of circulating ash. We obtained optimal operating conditions of 7.5 kg·s^(-1)for the atomized water flow, 70 kg·s^(-1)for circulating ash flow, and 0.56 kg·s^(-1)for slaked lime flow, with desulfurization efficiency reaching 98.19% and the exit flue gas meeting the ultraclean emission and safety requirements. All parameters selected in the simulation were based on engineering examples and had certain application reference significance.

地瓜干加工创新工艺研究

针对地瓜干传统加工法存在高硫(>1000mg·kg-1)、高糖(总糖含量60%-70%)、高杂菌、低水分(≤15%)的严重问题,研究出了无硫护色剂、臭氧灭菌、微波-蒸汽协同杀菌等先进技术和设备,应用到地瓜干加工中,生产出低硫(<10mg·kg-1)、低糖(总糖含量为40%左右)、低杂菌(低于商业标准)、高水分(水分大于20%)的地瓜干产品。规模生产实践表明,本工艺安全可靠,操作简便,易于实现生产自动化;产品安全卫生,口感好,色泽佳,已畅销日本、韩国、美国等市场。

Fabrication of Silane and Desulfurization Ash Composite Modified Polyurethane and Its Interfacial Binding Mechanism

Polyurethane/desulfurization ash(PU/DA)composites were synthesized using"one-pot method",with the incorporation of a silane coupling agent(KH550)as a"molecular bridge"to facilitate the integration of DA as hard segments into the PU molecular chain.The effects of DA content(φ)on the mechanical properties,thermal stability,and hydrophobicity of PU,both before and after the addition of KH550,were thoroughly examined.The results of microscopic mechanism analysis confirmed that KH550 chemically modified the surface of DA,facilitating its incorporation into the polyurethane molecular chain,thereby significantly enhancing the compatibility and dispersion of DA within the PU matrix.When the mass fraction of modified DA(MDA)reached 12%,the mechanical properties,thermal stability,and hydrophobicity of the composites were substantially improved,with the tensile strength reaching 14.9 MPa,and the contact angle measuring 100.6°.

The Selection and Application of Anticorrosive Materials for Flue Gas Desulfurization (FGD) System in Cement Plant

This paper combined with the actual case of flue gas desulfurization (FGD) system in cement Plant, analyzes the corrosion environment in each area of the FGD system, and selects appropriate anticorrosive materials for different corrosion environment, so as to provide operating experience and reference for the safe, stable and efficient operation of the FGD system.

国外炼油技术新进展及其启示

综述了近几年国外在催化汽油加氢脱硫技术、催化重整技术、催化裂化技术、柴油加氢超深度脱硫技术、加氢裂化技术、天然气合成油技术、异构脱蜡技术、渣油固定床加氢处理技术、渣油延迟焦化技术和渣油/石油焦气化联合循环一体化技术等10种传统炼油技术和相关催化剂方面的新进展,并对其进行了分析、展望与评述。

Synergistic catalysis of the N-hydroxyphthalimide on flower-like bimetallic metal-organic frameworks for boosting oxidative desulfurization

Synergic catalytic effect between active sites and supports greatly determines the catalytic activity for the aerobic oxidative desulfurization of fuel oils.In this work,Ni-doped Co-based bimetallic metal-organic framework(CoNi-MOF)is fabricated to disperse N-hydroxyphthalimide(NHPI),in which the whole catalyst provides plentiful synergic catalytic effect to improve the performance of oxidative desulfurization(ODS).As a bimetallic MOF,the second metal Ni doping results in the flower-like morphology and the modification of electronic properties,which ensure the exposure of NHPI and strengthen the synergistic effect of the overall catalyst.Compared with the monometallic Co-MOF and naked NHPI,the NHPI@CoNi-MOF triggers the efficient activation of molecular oxygen and improves the ODS performance without an initiator.The sulfur removal of dibenzothiophene-based model oil reaches 96.4%over the NHPI@CoNi-MOF catalyst in 8 h of reaction.Furthermore,the catalytic product of this aerobic ODS reaction is sulfone,which is adsorbed on the catalyst surface due to the difference in polarity.This work provides new insight and strategy for the design of a strong synergic catalytic effect between NHPI and bimetallic supports toward high-activity aerobic ODS materials.

Oxidative desulfurization of model and real oil samples using Mo supported on hierarchical alumina–silica: Process optimization by Box–Behnken experimental design

The catalytic performance of Mo supported on hierarchical alumina–silica(Si/Al = 15) with Mo loadings of 3, 6 and 15 wt% was investigated for the oxidative desulfurization(ODS) of model and real oil samples. Hierarchical alumina–silica(h Al–Si) was synthesized by economical and ecofriendly silicate-1 seed-induced route using cetyltrimethylammonium bromide(CTAB) as mesoporogen. The effect of CTAB on the structure of catalyst was studied by characterization techniques. The results revealed that 6%Mo/h Al–Si had the highest sulfur removal compared to the other catalyst loadings. The effect of operating parameters was evaluated using Box–Behnken experimental design. The optimal desulfurization conditions with the 6%Mo/h Al–Si catalyst were determined at oxidation temperature of 67 ℃, oxidation time of 42 min, H2O2/S molar ratio of 8 and catalyst dosage of 0.008 g·ml^-1 for achieving a conversion of 95%. Under optimal conditions, different sulfur-containing compounds with initial concentration of 1000 ppm, Dibenzothiophene(DBT), Benzothiophene(BT) and Thiophen(Th), showed the catalytic oxidation reactivity in the order of DBT > BT>Th. According to the regeneration experiments, the 6%Mo/h Al–Si catalyst was reused 4 times with a little reduction in the performance. Also, the total sulfur content of gasoline and diesel after ODS process reached 156.6 and 4592.2 ppm, respectively.

斯纳姆工艺CO_2原料气的精脱硫

我国引进的SHELL渣油气化工艺的九江大化肥厂 ,由于尿素CO2 原料气中H2 S含量较高(有时达 (2～ 3)× 10 - 6 (φ) ) ,为保证生产正常运行 ,防止设备腐蚀 ,需在现工艺流程中增设精脱硫装置。经技术分析论证 ,在原CO2 压缩机段间串联了脱硫塔、分液罐、过滤器 ,并选用了国产T - 70 3特种氧化铁精脱硫剂。运行表明 :增设的脱硫系统 ,在一个生产周期后 ,脱硫塔出口H2 S小于 0 .1× 10 - 6 (φ) ,床层压差小于 0 .0 4MPa ,脱硫剂强度较好 ,完全可以满足装置一个生产周期使用要求 ,且价格便宜。

Simultaneous desulfurization and denitrification of sintering flue gas via composite absorbent

Experiments on simultaneous absorption of SO_2 and NO_X from sintering flue gas via a composite absorbent NaClO_2/NaClO were carried out. The effects of various operating parameters such as NaClO_2 concentration(ms), NaClO concentration(mp), molar ratio of NaClO_2/NaClO(M), solution temperature(TR), initial solution pH, gas flow(Vg) and inlet concentration of SO_2(CS) and NO(CN) on the removal efficiencies of SO_2 and NO were discussed. The optimal experimental conditions were determined to be initial solution pH = 6, TR=55 °C and M = 1.3 under which the average efficiencies of desulfurization and denitrification could reach99.7% and 90.8%, respectively. Moreover, according to the analysis of reaction products, it was found that adding NaClO to NaClO_2 aqueous solution is favorable for the generation of ClO_2 and Cl_2 which have significant effect on desulfurization and denitrification. Finally, engineering experiments were performed and obtained good results demonstrating that this method is practicable and promising.

Modeling and Simulation of Hot Metal Desulfurization by Powder Injection

The desulfurization of hot metal by the mono-injection of lime powder and the co-injection of lime, calcium carbide and magnesium powders is mathematically modeled. The mono-injection model is derived from the continuity equation and is validated using experimental results and data previously reported in the literature. The co-injection model and the rate constant of the injected mixture are determined from the molar fractions and rate constants of the individual powders. The effect of the lime content of the mixture on the desulfurization dynamics is studied and discussed.

Oxidative Desulfurization of Fuel Oil at Room Temperature Catalyzed by Ordered Meso-macroporous HPW/SiO2

A serial of ordered meso-macroporous phosphotungstic acid(HPW) supported on SiO2 nanocomposites were successfully prepared by a homogeneous precipitation method, using monodispersed polystyrene(PS) microspheres and cationic surfactant as structure directing agent. These nanocomposites were used as catalysts for oxidative desulfurization(ODS) of model fuel. The materials were characterized by scanning electron microscopy(SEM), transmission electron microscopy(TEM), N2 adsorption-desorption isothrem, X-ray diffraction(XRD), and Fourier transform infrared spectra(FTIR). The characterization results suggested that the as-prepared material possessed ordered meso-macroporous architectures with Keggin type phosphotungstic acid dispersed homogeneously in SiO2 matrix. Under the selected reaction conditions, dibenzothiophene(DBT) in model fuel can be removed within 2 h at room temperature(30 ℃). In addition, only 1.2% of efficiency lose than the fresh catalyst even after 5 cycles.

Manganese leaching in high concentration flue gas desulfurization process with semi-oxidized manganese ore

Manganese leaching during high concentration flue gas desulfurization process with semi-oxidized manganese ore was studied in this paper.It was found that there were different reaction pathways among which MnO2,Mn2O3 and MnCO3 in semi-oxidized manganese ore during flue gas desulphurization and manganese leaching.High SO2 concentration facilitated redox reaction between MnO2 and SO2,and high concentration of H2SO4 accelerated MnCO3/Mn2O3 leaching from semi-oxidized ore.Kinetics study showed that manganese leaching in flue gas desulfurization process with semi-oxidized ore was controlled by a mixed-control model,that is the surface chemical reaction and mass diffusion dominated both the oxidation of SO2 and manganese leaching process.The apparent activation energy was 13.05 k J·mol-1 and the reaction orders with respect to SO2 and H2SO4 concentration were 1.38 and 0.10,respectively.Finally,a semi-empirical rate equation based on shrinking core model was derived to describe the process.