填料塔内喷淋氨水同时脱碳脱硫实验研究

通过在填料塔内喷淋较低质量分数的氨水,同时脱除模拟烟气中的CO2和SO2.对氨水质量分数、液气比、CO2体积分数、pH值、反应温度和SO2体积分数等影响因素进行研究,选出最佳工况进行连续循环运行,并探讨了实验参数对气溶胶排放的影响,提出控制气溶胶携带的措施.结果表明:氨水质量分数增大、液气比增大和初始CO2体积分数降低均会提高脱碳效率;pH值减小不利于CO2的脱除,但在9.6~10.2出现波动;在15~60℃内,35℃时脱碳效率最高;SO2体积分数的增大会降低脱碳效率;上述影响因素对脱硫效率影响不大,脱硫效率维持在99%以上;260min连续循环运行的实验中,脱碳效率在5min内达到95%以上且能维持30min,脱硫效率在3min内可达到近100%,且保持在92%以上.     

新型喷淋鼓泡塔钙基吸收烟气中气相As2O3实验研究

在喷淋鼓泡塔实验台上研究了新型喷淋鼓泡技术对气相As2O3的吸收特性,探讨了液气比、浸液深度、CaCO3质量分数和进口SO2体积分数等因素对脱砷效率的影响.结果 表明:脱砷效率随着CaCO3质量分数的增大先提高后降低,随液气比的增大而不断降低;增大浸液深度会使脱砷效率不断降低,这主要与鼓泡阶段散射孔与液面之间的压降变大、气液反应不充分密切相关;脱砷效率随进口SO2体积分数的增大先提高后降低,当进口SO2体积分数达到15×10-4时,脱砷效率达到最高;主要工艺参数对脱砷效率的影响大小依次为CaCO3质量分数、液气比、进口SO2体积分数和浸液深度.     

水合物法分离生物质气化气中CO2的研究

以生物质气化气中的CO2为研究对象,研究压力、气液比、四丁基溴化铵(TBAB)浓度和洗焦废水对CO2分离效率的影响。结果表明:CO2的分离效率(分离因子)随进气压力的增大先增大后减小;随气液比的增加先减小后增大;达到水合物形成的平衡压力后,随TBAB浓度的增大而减小。较低浓度的洗焦废水由于可增加气体的溶解速率并减少水合物的诱导时间而增加水合物的形成速率。在2.1 MPa、气液比14.63、TBAB物质的量浓度为0.29%时,CO2分离效率最高,分离后气相CO2气体含量由17.85%下降到8.71%,目标气体H2、CO损失率约为5%,水合物相中CO2含量达81.63%。     

氨法脱除燃煤烟气中CO_2的实验研究

利用氨水喷淋脱除燃煤烟气中的CO2温室气体是一种新的CO2捕集方法.为研究氨水浓度、CO2浓度及温度等参数对CO2脱除率的影响,以稀氨水为吸收剂,采用CO2连续在线检测,在阶梯环填料塔内进行了不同参数下的喷淋实验研究.结果表明,稀氨水同样具有较高的脱除率,随着氨水浓度的增加,反应达到平衡状态所需的时间和平衡状态时的CO2脱除率也逐渐增大;随着烟气中CO2初始浓度的增大,CO2脱除率将随之减小;在22～50℃的温度区间内,CO2脱除率受反应温度的影响显著,波动比较明显,并在40℃附近达到最大值.     

O2/CO2气氛下生物质混煤燃烧SO2排放特性的实验研究

在水平管式炉上通过在线烟气分析仪研究了O2/CO2气氛下生物质混合比例、温度、燃烧气氛及氧浓度对生物质混煤SO2排放特性的影响规律。结果表明,O2/CO2气氛下,随着生物质混合比例的增大,生物质混煤SO2释放峰值减小,SO2排放完毕的时间减少,SO2的排放量降低;随着温度的升高,生物质混煤SO2的排放量增加。O2/CO2和O2/N2气氛下随着氧浓度的增大,生物质混煤SO2的排放量均增加。相同氧浓度时,O2/CO2气氛下生物质混煤SO2的排放量略小于O2/N2气氛下的情况,其降低幅度约为5%左右。     

Efficiency Comparison of CO_2 Removal Respectively with Ammonia Solution and MEA

介绍了氨水及MEA捕集CO2的反应原理,探讨了吸收液中吸收剂的质量分数、CO2体积分数、入口烟气体积流量、溶液的pH值和反应温度等因素对氨水、MEA脱碳效率的影响,通过吸收容量试验分别测定了氨水和MEA的CO2吸收容量,并利用红外吸收光谱对其产物进行测定分析.结果表明：提高吸收剂的质量分数和pH值均可增大脱碳效率;温度对氨水和MEA的脱碳效率均有较大的影响;氨水对CO2的吸收容量远远大于MEA的吸收容量;氨法工艺在吸收剂再生、能耗以及副产品利用价值等方面优于MEA吸收法.     

单乙醇胺溶液捕集烟气中CO2的传质过程研究

通过建立CO2散装填料(玻璃弹簧)吸收系统,以乙醇胺(Monoethanolamine)溶液为吸收剂,考察了MEA浓度、CO2分压和液气吸收比等对模拟烟气中CO2传质过程的影响。研究结果表明:在实验条件下,随着液气比的增大,CO2脱除率不断增大;液气比过大,将降低吸收液利用率,液气比过小,将导致CO2脱除率太低。此外,在试验条件下,对填料塔气相总体积传质系数KGav进行了分析,试验结果为实际燃煤CO2吸收填料塔的设计及优化提供必要的理论支撑。     

I_2/KI溶液同时脱硫脱硝的试验研究

采用I2/KI溶液作为吸收液,以Fe3＋作为催化剂在自制的鼓泡反应器内,对模拟烟气进行同时脱硫脱硝的试验研究,主要考察I2物质的量浓度,Fe3＋物质的量浓度,吸收液初始pH值,反应温度,模拟烟气中NO、SO2及O2的体积分数、烟气气体流量等因素对SO2和NO脱除效率的影响.结果表明：烟气中SO2极易被脱除,在各试验条件下SO2脱除率均大于98%;NO的脱除率随吸收剂初始浓度、Fe3＋浓度、烟气中的O2、NO及SO2体积分数的增大而增大,随烟气流量的增加而降低;吸收液pH值对脱硫脱硝率的影响不是很大,因此吸收液的pH值可取在弱酸到弱碱的范围内,降低对设备材质防腐蚀性能的要求.     

基于喷淋散射技术的臭氧前置氧化氨法同时脱硫脱硝特性研究

基于喷淋散射技术采用前置臭氧氧化结合氨水吸收的方法,开展了烟气同时脱硫脱硝实验研究,测试了O_3与NO物质的量比、SO_2质量浓度、NO质量浓度、液气比和浸液深度等对脱硫脱硝效率的影响,建立了喷淋散射传质面积计算模型。结果表明:O_3与NO物质的量比增大可明显提高脱硝效率;SO_2质量浓度增大会促进NO_2的吸收;液气比和浸液深度的增大均会使总传质面积增大,从而提高脱硫脱硝效率;在O_3与NO物质的量比为1、液气比为6 L/m~3的工况下,浸液深度为50 mm、氨水质量分数为0.06%时,采用喷淋散射技术后脱硫效率和脱硝效率分别可达99.6%和82.5%,均高于同参数下仅喷淋技术和仅鼓泡技术。     

用氨水作为吸收剂脱除燃煤烟气中CO2的实验研究

电站CO2排放是一个迫切需要解决的问题,用氨水作吸收剂吸收烟气中CO2的研究十分重要.研究了不同氨水流量和烟气流量时的CO2吸收率.结果表明:氨与CO2的摩尔比、氨水浓度、烟气停留时间和温度等对CO2吸收率有显著影响.氨与CO2的摩尔比增大,氨水浓度增加或烟气停留时间增加,CO2吸收率均增大;反应温度增高,则CO2吸收率降低.     

Experimental and Numerical Studies on the Diffusion of CO2 from Oil to Water

Injecting CO2 into oil reservoirs can improve the oil recovery,meanwhile achieve CO2 storage.The diffusion of CO2 in oil-water systems has a substantial impact on this process.The interface significantly affects the mass transfer of CO2 between oil and water phase.In this paper,based on the determination of the CO2 diffusion coefficient in oil or water phases,the diffusion processes of CO2 from oil to water were experimentally investigated under different pressures.A numerical method was proposed to calculate the pressure drop and the diffusion coefficient in the process of CO2 diffusion from oil to water.The experimental results indicated that the CO2 diffusion coefficient in oil or water increased rapidly with pressure up to the critical pressure of CO2 and gradually slowed down thereafter.The CO2 diffusion from oil to water was much slower than that in oil or water.The diffusion coefficient of CO2 from oil to water was one magnitude lower than that in the single liquid phase of oil or water,and the effect of pressure was not significant.Based on the diffusion coefficient of CO2 in a single liquid phase and the proposed numerical method,the pressure drop and the numerical diffusion coefficient in the process of CO2 diffusion from oil to water were calculated.The relative errors between the experimental and numerical results were within 9%.Therefore,the numerical method proposed herein can be used to predict the diffusion process of CO2 from oil to water and the diffusion coefficient associated with this process.     

An experimental and kinetic modeling study of 2-methyltetrahydrofuran flames

Clean combustion processes are of paramount importance in the transition of the energy system towards increased sustainability. In an attempt to partially replace conventional fossil fuels, bio-derived oxygenates attract rising attention as alternative transportation fuels. Among this class of fuels, cyclic structures that can be derived from cellulosic biomass are particularly interesting. Here we present a study of premixed, laminar low-pressure flames of 2-methyltetrahydrofuran (2-MTHF) with an equivalence ratio of ? = 1.7 at 40 mbar. Time-of-flight molecular-beam mass spectrometry (MBMS) with electron ionization (EI) was used to analyze and quantify mole fraction profiles of reactants, products, and most intermediate species including radicals involved in the combustion process. As a valuable complement, MBMS using single-photon ionization (PI) by vacuum ultraviolet radiation permitted isomer identification as well as independent concentration information under similar flame conditions. A detailed combustion model for 2-MTHF was developed, and the flame structure and species information were examined in conjunction with these experiments.     

应用Na2O2吸收控制汽车尾气中CO2排放物

简述了汽车排放污染物的种类、危害及各种相应的减排控制措施,针对CO2这一温室气体提出了通过Na2O2吸收的解决方案,并给出了CO2吸收器的基本构造和反应机理,同时也指出了这一方案在实际运行中存在的问题。     

Removing CO2 and H2S from the Gas Produced during Underground Coal Gasification (UCG)

Abstract

The new method of simultaneous disposal of CO₂ and H₂S in coal gas generated during underground coal gasification (UCG) using industrial waste alkali liquor is put forward and studied for the first time. The rationale of absorption of CO₂ and H₂S by the alkali liquor is analyzed, and the mass transfer model for the above process is established. The impact of the existence of H₂S on absorbing CO₂ by the alkali liquor is studied on the basis of the model experiment. Research shows that as the velocity of coal gas increases, the selection coefficient of H₂S improves, the temperature rises, the selection coefficient of H₂S deceases, but the removal rate of CO₂ increases. By means of study, it can be found that the removal rate of CO₂ can reach more than 60% under the conditions of the suitable concentration of the alkali liquor and the ratio of liquid to gas, the heat value of underground coal gas can heighten by 12.3%, 17.7%, and over 20%, respectively, when the removal rate of CO₂ is 58%, 80%, and greater than 90%.     

二价铁系离子对混合菌种光合产氢的影响

针对不同浓度的Fe2+、Co2'和Ni2+对混合菌种的光合产氢与生长的影响进行实验研究.结果表明适当浓度的二价铁系离子对产氢及生长具有一定促进作用.Fe2+、Co2+和Ni2+最佳产氢浓度分别为9.00、0.45和0.10wnol/L,而对产氢的影响作用大小顺序为:Fe2+>Ni2+>Co2+.二价铁系离子在适当浓度范围内可提高生长速率,其中Co2+对生长的促进作用最大.由于pH值影响二价铁系离子对产氢酶活性的作用,针对Fe2+浓度在不同初始pH值时对混合菌种光合产氢的影响进行实验研究.结果表明当pH=7.0时,Fe2+ 浓度的变化对产氢的影响最显著.而在本试验范围内,随着pH值偏离7.0,Fe2+浓度的变化对产氢的影响逐渐减小.     

TiO2/SiO2及其表面改性光催化剂的分子级分散结构与吸光特性

以氯化醇钛盐表面反应法制备系列TiO2/SiO2,根据化学分析、XRD、Raman、XPS和DRS表征分析,载体表面具有分子级分散的锐钛矿型TiO2微晶粒子和非晶TiOx物种。与本体TiO2相比,系列TiO2/SiO2的吸收带边显著蓝移,能隙相应增大;随Ti物种载量的增加,TiOx物种的配位数增加,能隙相对减小。当金属M(M:Pd,Cu,Ni)负载于TiO2/SiO2表面,可使其光吸收域扩展到可见光区,并引起吸收带边红移,这取决于金属与界面的相互作用。当金属氧化物MoO3负载于TiO2/SiO2上时,可以调变TiO2/SiO2的吸收带边并增强对可见光的吸收;随MoO3载量的增加,表面物种的相互作用增强,形成一定复合结构并相应改变了其吸光特性。     

Investigation on the charging process of Li2O2-based air electrodes in Li-O2 batteries with organic carbonate electrolytes

The charging process of Li₂O₂-based air electrodes in Li-O₂ batteries with organic carbonate electrolytes was investigated using in situ gas chromatography/mass spectroscopy (GC/MS) to analyze gas evolution. A mixture of Li₂O₂/Fe₃O₄/Super P carbon/polyvinylidene fluoride (PVDF) was used as the starting air electrode material, and 1-M lithium bis(trifluoromethylsulfonyl)imide (LiTFSI) in carbonate-based solvents was used as the electrolyte. We found that Li₂O₂ was actively reactive to 1-methyl-2-pyrrolidinone and PVDF that were used to prepare the electrode. During the first charging (up to 4.6 V), O₂ was the main component in the gases released. The amount of O₂ measured by GC/MS was consistent with the amount of Li₂O₂ that decomposed during the electrochemical process as measured by the charge capacity, which is indicative of the good chargeability of Li₂O₂. However, after the cell was discharged to 2.0 V in an O₂ atmosphere and then recharged to ∼4.6 V, CO₂ was dominant in the released gases. Further analysis of the discharged air electrodes by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy indicated that lithium-containing carbonate species (lithium alkyl carbonates and/or Li₂CO₃) were the main discharge products. Therefore, compatible electrolytes and electrodes, as well as the electrode-preparation procedures, need to be developed for rechargeable Li-air batteries for long term operation.     

H2O2添加剂改善柴油机排放的机理

柴油机排放中两大排放物-NOx和碳烟的生成条件相互制约,所以难于同时降低.本文针对这种情况,在对双氧水本身的性质特点进行分析后,探讨了采用双氧水添加剂改善柴油机排放的方法,并讨论了其机理与可行性.     

H_2O_2/Nafion-纳米TiO_2复合膜强化日光光解脱色甲基橙染料研究

用流延法在石墨板上成功制备出用于光催化的Nafion-纳米TiO_2复合膜。在H_2O_2存在的条件下,用Nafion-纳米TiO_2复合膜对甲基橙染料进行可见光照射处理。结果表明,H2_O_2/Nafion-纳米TiO_2复合氧化工艺中甲基橙降解脱色速率显著提高,两者之间存在明显的协同效应。在协同体系中,酸性媒介比碱性媒介更有利于甲基橙染料光解脱色。实验所用的NO_3~-、Cl~-和SO_4~(2-)等阴离子,均对降解脱色有抑制作用,其中NO_3~-对脱色作用抑制最显著。可见光辐射处理前后,UV-Vis谱图分析表明在H_2O_2/Nafion-纳米TiO_2复合膜处理中甲基橙溶液脱色是因为染料发生氧化光解作用。     

Fe_2O_3/SiO_2/TiO_2复合薄膜的制备与表征

采用溶胶.凝胶法制备了Fe2O3/SiO2/TiO2三元复合薄膜.通过XRD表征、紫外.可见透射光谱分析,考察了Fe2 O3/SiO2对TiO2晶型、亲水性、光催化性能的影响.结果表明:加入Fe2O3、SiO2后TiO2仍然保持完整的锐钛型,抑制了TiO2晶粒的增长,且加入Fe2O3后TiO2的吸收波长发生了"红移".Fe2O3/SiO2/TiO2光催化性能、亲水性能优于SiO2/TiO2、Fe2O3/TiO2及单-TiO2膜.