旋转填充床吸收模拟工业废气中SO2的研究

选择3%SO2作为模拟工业废气,一乙醇胺（MEA）作为吸收剂在超重力条件下对模拟工业废气中脱硫工艺进行了实验研究,考察了旋转填充床转速、气液比、吸收剂入口温度以及吸收剂浓度对脱硫率的影响,确定了MEA作为吸收剂时适宜的操作条件。同时在旋转填充床中考察了几种不同吸收剂对3%SO2脱除率的影响。研究表明,1 mol/L哌嗪（PZ）的脱除率最优,1 mol/L N-甲基乙醇胺（MDEA）的脱除率最低。     

旋转填充床吸收模拟工业废气中SO2的研究

选择3%SO2作为模拟工业废气,一乙醇胺(MEA)作为吸收剂在超重力条件下对模拟工业废气中脱硫工艺进行了实验研究,考察了旋转填充床转速、气液比、吸收剂入口温度以及吸收剂浓度对脱硫率的影响,确定了MEA作为吸收剂时适宜的操作条件.同时在旋转填充床中考察了几种不同吸收剂对3%SO2脱除率的影响.研究表明,1 mol/L哌嗪...     

Improved Spray Dry Scrubbing through Grinding of FGD Recycle Material

A laboratory size spray dry scrubbing unit consisting of a spray dryer and a pulse Jet baghouse was used to study the effect of grinding recycle waste on SO₂ removal across the spray dryer and on sorbent utilization. The equipment treats simulated flue gas with a dry flow rate of 1.5 m³ h^?1 (stp) and utilizes an ultrasonic nozzle for atomization. The apparatus was initially tested over a broad range of operating conditions; a close agreement in SO₂ removal was found with data from much larger units. The effect of grinding the FGD recycle material on the SO₂ removal across the spray dryer was found to be great. Grinding the recycle material can enhance the SO₂ removal efficiency to a level comparable to operation with a large excess of fresh lime.     

超重力脱除模拟烟气中一氧化氮简

以NO和N₂的混合气作模拟烟气,以酸性尿素溶液为吸收剂,在超重力机中进行了脱除模拟烟气中NO实验研究。实验考察了混合气中NO初始含量、进气流量、吸收液流量、超重力机转速对NO脱除率的影响,确定了在超重力中尿素吸收NO的适宜条件。实验结果表明,在常温常压下,N₂体积流量为1.0 m³/h,控制NO初始浓度为3 300 mg/m³,吸收液流量为250 L/h,超重力机转速为650 r/min时,NO脱除率可达89.5%。     

Spray-dry desulfurization of flue gas from heavy oil combustion

An experimental investigation on sulfur dioxide removal in a pilot-scale spray dryer from the flue gas generated by combustion of low-sulfur (S) heavy oil is reported. A limewater slurry was sprayed through an ultrasonic two-fluid atomizer in the spray-dry chamber, and the spent sorbent was collected downstream in a pulse-jet baghouse together with fly ash. Flue gas was sampled at different points to measure the desulfurization efficiency after both the spray-dry chamber and the baghouse. Parametric tests were performed to study the effect of the following variables: gas inlet temperature, difference between gas outlet temperature and adiabatic saturation temperature, lime-to-S ratio, and average size of lime particles in the slurry. Results indicated that spray drying is an effective technology for the desulfurization of low-S fuel oil flue gas, provided operating conditions are chosen carefully. In particular, the lowest gas inlet and outlet temperatures compatible with baghouse operation should be selected, as should a sufficiently high lime-to-S ratio. The attainment of a small lime particle size in the slurry is critical for obtaining a high desulfurization efficiency. A previously presented spray-dry flue gas desulfurization model was used to simulate the pilot-scale desulfurization tests, to check the ability of the model to predict the S capture data and its usefulness as a design tool, minimizing the need for pilot-scale experimentation. Comparison between model and experimental results was fairly good for the whole range of calcium/S ratios considered.     

一种新型吸收剂吸收油气效果与影响因素分析

油气回收在倡导节约资源、保护环境的当今社会有着重要的意义。吸收法作为常见的油气回收手段,影响其吸收效果的关键因素之一是吸收剂的选用。分析了传统油气吸收剂的优缺点,在AbsFOV-97油气吸收剂基础上改进开发得到一种新型吸收剂,搭建了小试平台比较新型与传统吸收剂的吸收效果,并针对新型吸收剂,研究了影响吸收效果的因素,包括进塔油气浓度、吸收剂温度、吸收液喷淋量、进塔油气流量等,根据单因素小试实验设计了正交实验。结果表明,新型吸收剂回收率比改进前提高3.06%,进塔油气浓度为影响吸收效果的最大因素。     

超重力-磷酸钠法脱除低浓度SO2

为开发脱硫率高、成本低、可回收SO2的脱硫技术,以旋转填料床为吸收设备,磷酸钠溶液为吸收剂,系统开展了液气比L／G、转速N、气体中SO2浓度CSO2,in吸收剂磷酸浓度CL和初始pH等工艺参数和溶液再生循环次数对脱硫率叼影响的实验研究。结果表明,叩随L／G、N、CL和初始pH的增加而增大,且它们的值越低时,叩增加越明显;受G和CSO2,in影响较小。在适宜操作条件下,脱硫率达99％以上,出口SO2浓度低于100mg／m^3。磷酸钠溶液可再生循环使用,脱硫率稳定在99％以上。表明超重力-磷酸钠法脱硫技术在小的液气比下即可达到高的脱硫率,吸收剂循环使用,可实现低成本并达标治理SO2废气,且适用范围宽,具有良好的工业应用前景。     

亚铁离子生物氧化-还原法连续脱除硫化氢

为了降低工业废气中的硫化氢去除工艺成本和运行费用,对三价铁盐吸收与氧化亚铁硫杆菌对Fe²⁺的生物氧化联合作用脱除H₂S进行了研究。通过生物氧化塔中的固定化氧化亚铁硫杆菌细胞再生的Fe³⁺溶液,在H₂S还原吸收塔中脱除H₂S。通过单因素实验分别优化了生物氧化塔和H₂S吸收塔的运行参数,在生物氧化塔曝气量为150 L/h,停留时间为11 h,吸收液中Fe³⁺浓度为0.121~0.143 mol/L,吸收液流量为0.3 L/h,进气量为100 L/h条件下,进气中H₂S浓度分别为2.28和9.11 mg/L,系统连续运行至200 min时趋于相对稳定,当系统连续运行稳定时,H₂S的脱除率可分别达到95%和91%,脱除效果显著。     

Formation and removal of PCDD/Fs in a municipal waste incinerator during different operating periods

The PCDD/F concentrations and removal efficiencies achieved with air pollution control devices (APCDs) during different operating periods (start-up, normal operation, and shut-down) at an existing municipal waste incinerator (MWI) in Taiwan are evaluated via stack sampling and analysis. The MWI investigated is equipped with electrostatic precipitators (EP), wet scrubbers (WS), and selective catalytic reduction system (SCR) as APCDs. The sampling results indicate that the PCDD/F concentrations at the EP inlet during start-up period were 15 times higher than that measured during normal operation period. The PCDD/F concentration observed at shut-down period was close to that measured at normal operation period. The CO concentration was between 400 and 1000 ppm during start-up period, which was about 50 times higher compared with the normal operation. Hence, combustion condition significantly affected the PCDD/F formation concentration during the waste incineration process. In addition, the distributions of the PCDD/F congeners were similar at different operating periods. During the normal operation and shut-down periods, the EP decreases the PCDD/F concentration (based on TEQ) by 18.4-48.6%, while the removal efficiency of PCDD/Fs achieved with SCR system reaches 99.3-99.6%. Nevertheless, the PCDD/F removal efficiency achieved with SCR was only 42% during the 19-h start-up period due to the low SCR operating temperature (195 degrees C).     

Optimization of a wet scrubber with electrolyzed water spray—Part I: Ammonia removal

Electrolyzed water (EW) is an effective disinfectant with a wide range of pH. EW in acid range was proved to be an ammonia absorbent which make it valuable for wet scrubbers used in animal feeding operations (AFOs). This study aimed to optimize the design and operating parameters of a wet scrubber with EW spray for ammonia removal, based on the size distribution of droplets, the property of EW and the reduction efficiency of ammonia. The optimized parameters included droplet size, nozzle flow rates, pH and available chlorine concentration (ACC) of EW, nozzle number at single stage, stage number, initial ammonia concentration and air speed in the duct. The ammonia removal efficiency increased with the decrease of droplet size and the increase of flow rate. The pH values of EW showed significant influence on ammonia removal efficiency (P ? 0.05), while ACC of the EW showed no significant influence (P > 0.05). For inlet ammonia concentration of 70 ppm with one and three spray stages, the wet scrubber with EW (pH = 1.35) spray was able to reduce 55.8 ± 4.3 % and 97.2 ± 3.0 % of ammonia, respectively, when the nozzles with 0.9 mm orifice diameter operated at a flow rate of 1.20 L min^-1. Response surface analysis showed that orifice diameter, nozzle flow rate, and their combination were all significant factors impacting ammonia removal efficiency for both pH =1.35 and 5.50 at a 95% confidence level. Optimal ammonia removal efficiency was obtained at orifice diameter 0.9 mm and flow rate 1.20 L min^-1 within the selected range. The results of this study demonstrated that wet scrubber with EW spray could be a very effective and feasible ammonia mitigation technology for animal feeding operation.

Implications: It is difficult to effectively reduce ammonia emitted from the animal feeding operations (AFOs). Both the acidity and disinfection effects of electrolyzed water (EW) make it a potential absorbent used for spray in wet scrubber to reduce the ammonia and microorganisms. Based on some preliminary field test results, lab tests were conducted to optimize the design and operation parameters of a wet scrubber with EW spray to improve the ammonia removal efficiency. A better understanding of the application and influence factors of the wet scrubber with EW spray can contribute to effective mitigation of ammonia emission from animal houses and improve the atmosphere air quality.     

Destruction of PCDD/Fs by SCR from flue gases of municipal waste incinerator and metal smelting plant

Partitioning of PCDD/F congeners between vapor/solid phases and removal and destruction efficiencies achieved with selective catalytic reduction (SCR) system for PCDD/Fs at an existing municipal waste incinerator (MWI) and metal smelting plant (MSP) in Taiwan are evaluated via stack sampling and analysis. The MWI investigated is equipped with electrostatic precipitators (EP, operating temperature: 230 degrees C), wet scrubbers (WS, operating temperature: 70 degrees C) and SCR (operating temperature: 220 degrees C) as major air pollution control devices (APCDs). PCDD/F concentration measured at stack gas of the MWI investigated is 0.728 ng-TEQ/Nm(3). The removal efficiency of WS+SCR system for PCDD/Fs reaches 93% in the MWI investigated. The MSP investigated is equipped with EP (operating temperature: 240 degrees C) and SCR (operating temperature: 290 degrees C) as APCDs. The flue gas sampling results also indicate that PCDD/F concentration treated with SCR is 1.35 ng-TEQ/Nm(3). The SCR system adopted in MSP can remove 52.3% PCDD/Fs from flue gases (SCR operating temperature: 290 degrees C, Gas flow rate: 660 kN m(3)/h). In addition, the distributions of PCDD/F congeners observed in the flue gases of the MWI and MSP investigated are significantly different. This study also indicates that the PCDD/F congeners measured in the flue gases of those two facilities are mostly distributed in vapor phase prior to the SCR system and shift to solid phase (vapor-phase PCDD/Fs are effectively decomposed) after being treated with catalyst. Besides, the results also indicate that with SCR highly chlorinated PCDD/F congeners can be transformed to lowly chlorinated PCDD/F congeners probably by dechlorination, while the removal efficiencies of vapor-phase PCDD/Fs increase with increasing chlorination.     

酸碱溶液改性竹基活性炭生物降解H2S

对竹基活性炭采用酸、碱溶液浸渍的方法改性,并用化学和表面形态分析等表征方法测试了其改性前后的特性,研究了不同溶液对改性竹基活性炭在微生物挂膜和滴滤塔去除H2S方面的影响。研究结果表明,用10％NaOH溶液改性后的竹基活性炭较未改性的竹基活性炭碱性基团含量增加了0．614mmol／L,平衡含水率增加了6．08％,碘吸附值增加了29．6mL／g,这些物化性能的改变更有利于生物竹基活性炭去除H2S。对比5种改性方法对生物降解H2S性能的影响,在H2S人口浓度为150～4500mg／m^3、循环液喷淋量0．2L／h、pH6．5—7．5、气体停留时间66s的条件下,经NaOH溶液改性后的竹基活性炭,对H2S的去除率达93．4％以上,效果好于其他改性方法的竹基活性炭。     

基于正交实验的颗粒移动床烟气脱硫工艺参数优化

石灰石颗粒移动床脱硫工艺参数是影响脱硫效率和操作压降变化的重要因素,考虑到工艺参数对脱硫过程的影响,基于正交实验方法,通过直观分析和方差分析得到喷淋密度、空床气速、SO2浓度、烟气温度和床层下移速度对脱硫效率影响程度的主次顺序和脱硫效率与各因素之间的关系,并且分析了各因素对脱硫效率的影响规律。研究发现,各因素对脱硫效率的影响程度依次是空床气速>喷淋密度>SO2浓度>烟气温度>床层下移速度。喷淋密度对脱硫效率的影响高度显著,呈正相关;空床气速对脱硫效率的影响高度显著,呈负相关;SO2浓度和烟气温度对脱硫效率有影响但不显著,呈负相关。床层下移速度与脱硫效率呈正相关。     

膜吸收法处理高浓度甲醛废气资源化技术研究

采用疏水性中空纤维膜接触器,以NaHSO₃为吸收液处理高浓度甲醛废气。研究了吸收液流量、吸收液温度、吸收液浓度、气体进口流量和气体进口浓度等因素对甲醛去除率和总传质系数的影响。结果表明,当吸收液流量为4.17×10^-6m³/s,吸收液温度为60℃,甲醛进气流量为3.7×10^-6m³/s,甲醛进气浓度为566 mg/m³时,甲醛出气浓度可低至2.8 mg/m³,甲醛的去除率可达99.5%,总传质系数为4.46×10^-5m/s。反应产物（ɑ-羟基磺酸钠）易分离,并可作为重要的有机合成原料或用于制备高纯甲醛而得到充分利用,NaHSO₃溶液经适当稀释后仍可作为吸收液循环使用。表明膜吸收法可基本实现高浓度甲醛废气处理的资源化。     

H2O2溶液同时脱硫脱硝实验研究

二氧化硫和氮氧化物是电厂产生的主要大气污染物,研究焦点越来越集中在在一个反应器内实现同时脱硫脱硝。实验以H2O溶液作为吸收液,在自制的鼓泡反应器内,对模拟烟气进行同时脱硫脱硝的实验研究,实验结果表明：H2O浓度、反应温度、NO浓度、SO2浓度、烟气流量对脱除率影响显著,pH、氧含量对脱硝率影响不大。在整个实验范围内脱硫效率总是保持在98．5％以上,脱硝效率最高达到67．4％。     

氨水土壤混合物脱除CO2温室气体的实验研究

为了脱除CO2温室气体,提出了利用氨水土壤混合物去除CO2的新方法.分别考察了土壤颗粒粒径、CO2初始流量、氨水浓度(质量比)和温度对CO2脱除量和脱除率的影响.实验结果表明,该方法去除CO2的量较土壤物理吸附量和氨水化学吸收量的总和提高了大约15%;随着氨水浓度的增大,CO2的脱除率和脱除量都增大;随着土壤颗粒粒径和CO2初始流量的增大,CO2的脱除率和脱除量都减小;当温度由22℃升高到31℃,CO2的脱除率随着温度的升高而增大,但是继续升高温度到40 ℃,CO2的脱除率反而下降.     

Biofiltration Control of Hydrogen Sulfide 1. Design and Operational Parameters

Laboratory scale biological filter systems for control of hydrogen sulfide (H₂S) in waste gas have been studied and the optimum design and operating parameters determined. Extensive tests have been conducted to evaluate the effect of various filter bed operating parameters such as temperature, retention time, H₂S concentration, and H₂S loading rate. Variable properties of new and used composts such as sulfate content, acidity, and water content have been studied for their influence on H₂S removal efficiency. The effects of compost particle size distribution on system pressure drop and the maximum H₂S elimination capacity were examined. Biofiltration systems containing various types of yard waste compost as the filter material have been observed to remove hydrogen sulfide with efficiencies greater than 99.9 percent for H₂S inlet concentrations in the range from 5 to 2650 ppmv.     

Removal of insoluble heavy metal sulfides from water

The necessity of heavy metal removal from wastewater has led to increasing interest in absorbents. We have developed a new approach to obtain high metal adsorption capacity by precipitating metal sulfides with sodium sulfide on the surface of bentonite and adhere them to the absorbent. This method allowed to remove approximately 90% of cadmium as CdS from 10(-4)-10(-6) M CdCl2 solutions. Additional reactions are related to the removal of excess sodium sulfide by the release of hydrogen sulfide and oxidation to sulfur using carbogen gas (5% CO2, 95% O2) followed by aeration.     

氨水土壤混合物脱除CO2温室气体的实验研究

为了脱除CO2温室气体,提出了利用氨水土壤混合物去除CO2的新方法。分别考察了土壤颗粒粒径、CO2初始流量、氨水浓度（质量比）和温度对CO2脱除量和脱除率的影响。实验结果表明,该方法去除CO2的量较土壤物理吸附量和氨水化学吸收量的总和提高了大约15%;随着氨水浓度的增大,CO2的脱除率和脱除量都增大;随着土壤颗粒粒径和CO2初始流量的增大,CO2的脱除率和脱除量都减小;当温度由22℃升高到31℃,CO2的脱除率随着温度的升高而增大,但是继续升高温度到40℃,CO2的脱除率反而下降。     

Dynamic purification of coal ash by a gas-solid fluidized bed

Fluidized bed filtration classified as granular bed filtration is a solution for removing particles from flue gas. Fine particles are captured by colliding with bed material. Binary mixtures including fines exist in the fluidized bed; the situation becomes more complex because the fines increases with time as particles enter continuously. Coal ash was put into the inlet gas of a gas-solid fluidized bed with silica sand and the variations in concentration with time was monitored, to elucidate the dynamic purification of fines by bed material and the interaction therewith. Water was injected into the inlet gas also to study the influence of water content on the removal of particles. Experimental results showed that the particle concentration rapidly increased with time until equilibrium was achieved. The outlet concentrations exceeded the inlet concentration (such that the removal efficiency was negative) at operating time between 26 and 30 min, yielding an efficiency as low as -35%. The removal efficiency increased with the relative humidity from 30% to 70%. The maximum cumulative collection ratios of particles (by mass) were 20%, 22% and 27% at humidities of 30%, 50% and 70%, declining to 7%, 13%, and 19% at the end.