化学吸收CO2的初步研究

以NaOH水溶液和Na2CO3水溶液吸收CO2属于化学吸收,吸收液的pH值随着吸收剂流量的增大而增大,呈现出对CO2完全吸收的趋势。由于化学反应增加了吸收速率,可根据增强因子利用物理吸收的方法计算化学吸收时所需的填料层高度。     

纳米颗粒对氨水鼓泡吸收CO_2影响的实验研究

为探究纳米颗粒对氨水吸收CO_2的影响,采用两步法配制了不同基液质量分数、不同纳米颗粒添加量的纳米流体,搭建了氨水鼓泡吸收CO_2的实验装置。分别测试了CO_2在纳米颗粒质量分数为1—8 g/L的TiO_2,CuO,SiO_2的纳米流体中尾气中CO_2吸收情况,并与空白吸收溶液进行对比,得出纳米颗粒的添加量、纳米颗粒种类、基液质量浓度等因素对脱除效率、脱除速率的影响。实验结果表明:添加TiO_2纳米颗粒能够增大脱除效率和脱除速率,脱除效率和脱除速率都随着颗粒添加量的增加先增大后减小,存在一个最佳固含量;SiO_2纳米流体更多地表现出的是对反应的抑制作用;CuO纳米流体其增强因子始终在1附近,未表现明显的增强或抑制作用;最佳固含量随着基液质量分数的增大而逐渐减小。结合实验结果对其机理进行了分析。     

浆料反应器中吸附剂粒子对CO2气体的吸收强化

研究了吸附剂粒子对气体吸收的增强作用。在一个带有搅拌的间歇反应釜中,分别测定了CO2在活性炭/水、S iO2/水浆液以及在活性炭/环己烷、S iO2/环己烷浆液中的吸收速率和增强因子。实验温度为298.15 K,初始压力为0.1 MPa,浆液中粒子的固含率为0—2 kg/m3,搅拌速度为1 s-1和4 s-1。结果表明,活性炭/水、S iO2/环己烷体系对CO2的吸收具有明显的增强作用,而S iO2/水、活性炭/环己烷体系则没有发现增强作用。因此,只有具有界面亲合能力且对溶质有吸附作用的颗粒才能对气体吸收产生显著的强化作用。将界面划为粒子覆盖和未覆盖区,提出了一个预测增强因子的一维双区模型,并进行了求解,模型预测值与实验结果吻合良好。     

微细颗粒强化氧气吸收实验

引言目前,石灰石-石膏湿法烟气脱硫工艺是在燃煤电厂应用最广的烟气脱硫技术,脱硫的副产品是脱硫石膏(CaSO4.2H2O)。但在实际运行过程中由于氧化率未达到要求值,从而使得产生的石膏晶体不足,形成了亚硫酸钙和硫酸钙的混合晶体[1];另外,燃煤锅炉产生的烟气虽经除尘,但进入脱硫装置时仍含有大量粉尘颗粒[2-3]。因此,在电厂实际的脱硫过程中,发生的并不是单纯的两相     

CO_2微细气泡在NaOH溶液中吸收速率研究

以喷气机械搅拌精炼过程为背景,研究了搅拌方式、喷气流量、搅拌转速等因素对气体吸收速率的影响,通过测定NaOH吸收CO2的速率研究气泡微细化过程,探讨了各种因素对容积传质系数和CO2利用率的影响规律.结果表明,中心搅拌情况下传质系数和气体利用率按单向、间歇和双向模式增加;容积传质系数无论在何种搅拌模式下均随着气体流量的增加而增加,但气体利用率则随着气体流量的增加而呈现先减小后增大的趋势:中心单向搅拌模式下容积传质系数和气体利用率均随着搅拌速率的增加而变小.在实验基础上,应用因次分析原理关联了容积传质系数与相关数群的准数方程,为高温实验的气泡微细化了提供科学和实验依据.     

活性炭/水浆料中CO2吸收过程的增强

针对分散相微粒增强难溶气体的吸收过程,提出了一个一维非稳态非均相传质的二区模型,并进行了理论求解。根据表面更新理论,得到了增强因子的数学表达式。利用恒温反应釜,对活性炭/水浆料中发生的CO2吸收过程进行了实验研究,测定了不同颗粒浓度及转速下的增强因子。实验结果与模型预测值吻合良好,表明本文模型具有很高的预测精度。     

三乙烯四胺吸收CO2的初探

在常压下,采用搅拌式反应器对ＴＥＴＡ（三乙烯四胺）水溶液吸收ＣＯ２进行了研究,测定了不同温度下,不同浓度的ＴＥＴＡ的ＣＯ２吸收情况,并与常用醇胺吸收剂ＭＥＡ（一乙醇胺）、ＤＥＡ（二乙醇胺）、ＴＥＡ（三乙醇胺）的吸收效果作了比较,同时观察了ＴＥＴＡ－胺－水多元体系对ＣＯ２的吸收情况,得出最佳配比。有关ＴＥＴＡ吸收ＣＯ２研究尚无报道。     

环丁砜对乙醇胺溶液吸收和解吸CO2的影响

利用物理溶剂环丁砜替代部分水,采用气液搅拌实验装置和真实热流量热法测定了环丁砜对乙醇胺（MEA）溶液吸收和解吸二氧化碳（CO₂）过程的影响,考察了CO₂循环负载、吸收速率、吸收热和解吸热等性质变化。研究表明：环丁砜对MEA溶液负载CO₂的吸收热影响较小,但对吸收速率、循环吸收容量和解吸过程影响较大。环丁砜可降低MEA溶液对CO₂的表观吸收速率,且随CO₂负载量的增大,降幅也逐渐变大。环丁砜有利于富液解吸过程,加快解吸速率,增大CO₂解吸程度,同时单位热流负荷、单位冷流负荷和单位能耗均有不同程度的降低。在燃煤电厂烟气条件下,20% MEA+20% sulfolane体系相对20% MEA体系,其表观吸收速率平均降低约10%,CO₂循环吸收容量增加24%,单位CO₂解吸能耗降低18%。     

CO2混合胺吸收剂的研究进展

综述了近年来醇胺、烯胺两类混合胺吸收剂的研究进展,研究结果显示较为突出的混合胺吸收剂包括MEA＋AMP、MEA＋MDEA及MDEA＋PZ复合溶液;混合胺吸收剂是未来脱碳剂的研究热点,而离子液体作活化剂为混合胺吸收剂的研究提供了新的思路。     

膜吸收CO2工艺中不同吸收液对膜润湿的影响

以单乙醇胺（MEA）、二乙醇胺（DEA）和N-甲基二乙醇胺（MDEA）作为吸收液,利用聚丙烯（PP）中空纤维膜组件进行分离模拟烟气中CO₂的实验研究,考察不同吸收液的脱除效率以及长时间连续运行下的膜润湿现象。建立膜相传质阻力随时间变化模型,与实验数据拟合较好。同时将膜丝在不同吸收剂中浸泡,结合接触角、场发射扫描电镜（FE-SEM）、衰减全反射红外光谱（ATR-IR）以及热重（TG）表征分析膜性能的改变。结果表明,相同浓度下,单一吸收剂的CO₂脱除效率大小为MEA > DEA > MDEA;当吸收液为1mol/L MEA时,16天后CO₂脱除效率从93.3%下降到72.1%;而吸收液为1mol/L DEA时,脱除效率从88.3%到第16天的78%,下降约12%;理论计算得吸收液为1mol/L MEA和1mol/L DEA时,膜相传质阻力分别为10564.06s/m和4881.08s/m;浸渍时间增加,膜接触角减小,疏水性减弱,同时膜孔径变大,出现润湿现象;红外光谱和热重分析表明在MEA溶液作用下膜丝出现溶胀。     

CaO制备及悬浮态下对CO2吸收率的影响

通过煅烧的方法得到氧化钙二氧化碳吸收剂,将碳酸化反应放入高温悬浮炉中进行颗粒特性研究,结果表明,在悬浮炉中的吸收剂微观结构对吸收剂的吸收率的变化规律与热重中相同,即吸收剂的微观结构影响着吸收剂的吸收率,具有大量小孔径,比孔容积大,累积比表面积大的吸收剂颗粒具有更好的吸收效果。     

The Influence of Interfacial Areas for Gas Absorption in the Presence of Solid Particles

The mass transfer is investigated for physical absorption of oxygen in water for varying interfacial areas as well as the influence of suspended glass beads and activated carbon. Under higher rotational speed, the volumetric mass transfer coefficient as well as the mass transfer coefficient values increase for all specific interfacial areas due to the changes in hydrodynamics. The configuration of the free gas‐liquid interface is of minor relevance. In the presence of glass beads, the mass transfer is reduced compared to physical adsorption, whereas an enhancement of the mass transfer can be observed in the presence of activated carbon. This indicates that the mobility of the gas‐liquid interface is the determining factor. The renewal of the fluid elements is increased by adsorption of surfactants on the surface of activated carbon, leading to an improved mass transport.     

离子液体吸收页岩气中CO_2的展望

页岩气作为新型的清洁低碳能源迅速引起各国的高度重视,因此页岩气中CO2的吸收就尤为重要。离子液体因挥发性低、溶解能力强、结构和性质可调控性强等特点,在气体净化方面获得高度关注。本文系统地总结了离子液体吸收CO2的研究,包括常规离子液体、功能化离子液体、聚合物离子液体;讨论了离子液体结构等因素对吸收性能的影响;对各方法的优缺点及使用条件进行详细的阐述;并提出今后离子液体在页岩气中CO2气体净化方面的发展方向。     

Optical Absorption in Sol-Gel-Derived Crystalline Barium Titanium Fine Particles

Pure, translucent, and highly crystallized barium titanate (BaTiO₃) monolithic gels were synthesized via a sol-gel technique at temperatures down to 90°C by using a high-concentration solution of barium alkoxide and titanium alkoxide. The gels consisted of fine particles with an average diameter of ~10 nm and showed the X-ray diffraction patterns of a pseudo-cubic BaTiO₃ system at room temperature; however, in bulk crystal, the tetragonal structure was more stable. The optical transmission spectra of the polycrystalline gels were similar to those for single-crystalline BaTiO₃. From the excitation energy dependence of the absorption-edge structures, the optical-gap energies for the gels were estimated to have values that were ~0.1 eV higher than those for the single crystal; these higher optical-gap energies may be attributed to size effects.     

碳酸钾一乙醇胺复合溶液吸收烟气中C02的实验研究

分别以不同浓度的碳酸钾溶液及不同配比的碳酸钾一乙醇胺复合溶液作为吸收剂,以吸收速率和吸收量为指标,研究了吸收剂对烟气中C02的吸收效果。结果表明,纯碳酸钾溶液吸收效果不佳,而掺入乙醇胺后的吸收效果显著改善,部分复合溶液的吸收效果甚至好于同浓度纯碳酸钾溶液与纯乙醇胺溶液的吸收效果之和,碳酸钾与乙醇胺在吸收过程中存在正交互作用。确定0．6mol·L-1碳酸钾-O．4mol·L-1乙醇胺复合溶液为最佳的吸收弃1,其饱和吸收量最大（O．185m01）、再生温度最低（105℃）、再生率最高（98．8％）。     

利用胶质气体泡沫分离细微颗粒

This paper presents a method of separation of fine particles, of the order of a few microns or less, from aqueous media by flotation using colloidal gas aphrons (CGAs) generated in aqueous solutions. More than 150 experiments were conducted to study the effects of surfactant type, surfactant concentration, CGAs flow rate, and particle concentration on the removal efficiency (fine particles of polystyrene were used as a target compound). The results indicate that CGAs, generated from cationic surfactant of hexdecyltrimethyl ammonicum bromide (HTAB) and anionic surfactant of sodium dodecylbenzne sulfonate (SDBS), are an effective method for the separation off ine particles of polystyrene from wastewater. The flotation yields are higher than 97%.     

活性炭粒子对K2CO3溶液中CO2化学吸收的强化

The enhancement of chemical absorption of CO2 by K2CO3/H2O absorbents in the presence of activated carbon (AC) particles was investigated. The results show that the gas absorption rates can be enhanced significantly in the presence of AC particles,and the maximum enhancement factor 3.7 was observed at low stirring intensities.The enhancement factor increased rapidly with the solid loading during the initial period of absorption and then became mild gradually to a maximum value. Both the liquid-solid contact area and the probability of solid particles residing at the gas-liquid interface decreased with the increase of the particle size,leading to a negative effect on the enhancement of mass transfer. The influence of the particles on gas absorption decreased with the reaction rate. The stirring speed changed the interfacial coverage and mass transfer rate on the liquid side and consequently affected the mass transfer between the gas and liquid phases; the enhancement factor decreased with the stirring intensity. A heterogeneous two-zone model was proposed for predicting the enhancement factor and the calculated results agreed well with the experimental data.     

分子筛疏水改性对CO2吸收强化的影响

Two methods of the modification of zeolite were employed:framework element modification and surface coating,and the influence of the zeolites before and after modification on the CO₂ absorption was investigated.It was found that although hydrophobicity of zeolite could be obtained by means of the surficial organic coating in the method of surface coating modification,partial channel of zeolite would be plugged,as a result,leading to the surface area reducing greatly.Distinctively,the framework element modification method could maintain not only complete lattice structure and adsorption capability of zeolite,but would also obtain a good hydrophobic property.Consequently,significant enhancement on gas absorption by this modified zeolite was achieved and up to a maxi-mum enhancement factor of 2.62.This shows that the solid particles with good enhancement role to gas absorption need not only good adsorptive capability but also certain hydrophobicity.An unsteady heterogeneous model was employed to predict enhancement factor and the calculated results agree well with the experimental data.     

Taylor流下微细颗粒增强CO2:吸收研究（英文）

The physical absorption of CO2 in water containing different types of particles was studied in a microchannel operated under Taylor flow.The maximum enhancement factors of 1.43 2.15 were measured for activated carbon (AcC) particles.The analysis shows that the enhancement effect can be attributed to the shuttle mechanism.Considering the separate contributions of mass transfer from bubble cap and liquid film,a heterogeneous enhancement model is developed.According to this model,the enhancement factors E Cap,E Film and E Ov are mainly determined by mass transfer coefficient KL (KL,Cap and KL,Film),adsorptive capacity of particles m,and coverage fraction of particles at gas-liquid interface ζ.With both effects of particle-to-interface adhesion and apparent viscosity included,the model predicts the enhancement effect of AcC particles reasonably well.