乙醇胺改性活性炭及其对二氧化碳的吸附性能

研究了用浸渍法将乙醇胺(MEA)负载于活性炭孔径表面制备新型CO_2吸附剂。在改性剂乙醇胺用量130mL、改性温度60℃、改性时间6h、干燥时间6h条件下对50g活性炭进行改性,然后用改性前后的活性炭从模拟烟气中吸附CO_2,结果表明,改性前活性炭对CO_2吸附量为0.941 mmol/g,改性后为4.165mmol/g,吸附量提高了3.4倍。此方法对活性炭改性有明显效果。     

微波联合改性活性炭处理不同SO2浓度烟气脱硫效率

以活性炭为研究对象,通过微波辐照改性,并协同微波在线处理具有不同浓度SO_2成分的模拟烟气,分别改变微波加热温度、加热时间、活性炭质量、烟气流速以及SO_2浓度,分析改性活性炭与微波联合处理不同SO_2浓度模拟烟气脱硫效率的影响因素。结果表明,提高微波温度会使脱硫效率增大,温度为800℃时,脱硫效率达到72%;适当延长加热时间有利于提高脱硫效率,加热时间为6 min时脱硫效率达到69%,继续延长加热时间对脱硫效果影响不明显;增加活性炭质量有利于脱硫效率的提高,在质量为50 g时,脱硫效率达到最大值76.45%;增大烟气流速会减小活性炭的脱硫效率,烟气流速为0.3 L/min时脱硫效率最大值81.05%;提高SO_2浓度会使脱硫效率减小,当SO_2浓度为400×10~(-6)时,脱硫效率为84%。     

烟气脱硫活性炭改性方法研究进展

干法脱硫应用较广的吸附剂是活性炭,活性炭具有较大的比表面积和较为丰富的孔结构,对烟气中SO_2有较强的物理吸附能力,但仅靠物理吸附脱硫无法达到环保要求,为了得到更好的吸附效果,就需对活性炭进行改性处理。首先介绍了活性炭的结构特征和脱硫原理,然后对微波辐照法、高温热处理法、氧化法、还原法和负载金属氧化物法改性活性炭的特点、原理及研究现状进行了介绍。随着对烟气脱硫活性炭改性的深入研究,活性炭用于干法烟气脱硫会有非常广阔的发展前景。     

粉煤灰的改性及从模拟烟气中吸附脱除SO_2试验研究

采用煅烧—水热化合法对粉煤灰进行改性,并用改性后的粉煤灰进行模拟烟气脱硫试验,研究了改性粉煤灰脱硫机制。试验结果表明,在助熔剂Na_2CO_3用量12g、Ca(OH)_2用量15g、温度80℃、水合消化8h条件下,对50g粉煤灰进行改性,改性后的粉煤灰含湿率30%,对SO_2最大吸附率达93.5%,平均吸附率为85.2%,吸附效果较好。     

改性活性炭对烟气中CO2吸附性能的影响

研究了以NaOH为改性剂浸渍改性活性炭,考察了改性活性炭吸附烟气中CO_2的性能,确定了NaOH浸渍改性活性炭的最佳条件。结果表明:未改性活性炭对烟气中CO_2的吸附量不超过1.0 mmol/g,而改性后活性炭对CO_2吸附量达3.50 mmol/g;在改性剂用量140 mL、改性温度70℃、改性时间6 h、干燥时间4 h条件下对活性炭进行改性,所得改性活性炭对CO_2的吸附效果最好,吸附量是未改性时的3.9倍。     

RH用低氟型CaO+Al_2O_3基熔剂深脱硫工业试验

采用低氟型CaO+Al2O3复合基熔剂替代传统CaO-CaF2系脱硫剂,利用RH投入法进行钢液深脱硫工业试验.20个试验炉次的结果表明,RH平均脱硫率ηS可达到53.44%,脱硫后钢液中[S]≤24×10-6.分析了钢包顶渣的改性处理以及RH脱硫终渣组成对RH脱硫的影响.在此基础上,确定了RH脱硫剂的优化组成为:CaO+BaO(60%～65%)–Al2O3 (20%～25%)-MgO (5%～7%)–CaF2(＜5%).     

改性活性炭吸附烧结烟气中氮氧化物的研究

以煤质活性炭为原料,制备了碳酸钾(K2CO3)改性活性炭,模拟烧结烟气条件,考察了其在有SO2、CO2和O2条件下的NOx 吸附效果.试验表明:0.65 mol/L K2CO3改性活性炭的NOx 吸附量最高,120℃时NOx 吸附量可达15.17 mg/g,较原样提高了 20倍以上;随着吸附温度的升高,NOx饱和吸附量...     

烧结烟气脱硫脱硝活性炭的研究进展

活性炭因具有较大的比表面积和孔容,较强的吸附能力,原料成本低,制备方式简单及可重复使用等优点成为目前常用的脱硫脱硝方式之一,在烟气净化领域得到广泛的应用。活性炭的比表面积、表面的孔结构和表面官能团及活性组分对活性炭脱硫脱硝性能有较大影响,适当增加活性炭含氧、氮官能团或表面活性组分有利于活性炭物理吸附和化学吸附能力协同增长。介绍了活性炭脱硫脱硝的原理,综述了脱硫脱硝活性炭的制备和表面改性的研究进展,分析了活性炭原料配比、活性剂种类、改性方式对活性炭脱硫脱硝的影响。明确了优化制备原料及改性方式与活性炭脱硫脱硝反应之间的机制和规律性研究将会成为未来的研究重点。     

吸附塔工艺参数对活性炭烧结烟气脱硫的影响

活性炭可高效脱除烧结烟气中的SO₂,但同时受到吸附塔工艺参数的制约。为了揭示工艺参数对脱硫率的影响规律,采用控制变量法,通过模拟烧结烟气进行活性炭脱硫研究。结果表明,空速、烟气湿度、含氧量和活性炭床温度对脱硫影响较大,活性炭粒度对脱硫率影响较小;降低空速、活性炭床温度及活性炭粒度,均有利于SO₂物理吸附进而促进脱硫率提高;烟气湿度和含氧量的增加,有利于SO₂的化学吸附进而提高脱硫率,但湿度大于12%时,水蒸气会在活性炭上聚集形成水膜而导致脱硫率下降。     

HNO3和γ-Fe2O3改性椰壳活性炭吸附性能研究

为了提高活性炭的吸附性能,对市售椰壳活性炭进行硝酸改性和负载γ-Fe2O3催化剂改性。对改性前后的椰壳活性炭分别进行了碘值吸附和亚甲基蓝吸附实验,结果表明:硝酸改性和负载γ-Fe2O3催化剂改性后椰壳活性炭的碘吸附值分别提高了16.1%和39.3%;硝酸改性后椰壳活性炭的亚甲基蓝吸附值提高了10.7%,负载γ-Fe2O3催化剂改性椰壳活性炭的亚甲基蓝吸附值降低了3.5%。两种改性方法对椰壳活性炭的总体吸附能力都有所增强,其中负载γ-Fe2O3催化剂改性椰壳活性炭总体吸附能力强于硝酸改性椰壳活性炭。本研究结果可为活性炭治理钢铁企业烧结烟气中的SO2和NOx提供借鉴。     

改性兰炭烟气SO2吸附材料的制备及其再生性能

利用活性炭（焦）等吸附剂将烟气中的污染物分离出来是一种有效的烟气治理与资源化方式。兰炭作为一种廉价半焦碳素材料,是一种有潜力代替现有商用活性焦的多孔材料。本文采用陕西兰炭作为研究对象,研究炭化时间、炭化温度、黏结剂添加量等改性工艺对所制备的吸附剂性能的影响,考察了微观形貌变化,利用X射线光电子能谱（XPS）探究在吸附解吸过程中的表面官能团的变化。结果表明,炭化温度对耐磨强度、耐压强度指标影响显著,炭化时间对饱和脱硫值和穿透脱硫值影响显著;在煤焦油添加比例50%,700 ℃炭化20 min,900 ℃活化60 min条件下制得改性兰炭参数为:耐磨强度95.81%,抗压强度536.1 N·cm?1,每克兰炭饱和脱硫值45.71 mg,每克兰炭穿透脱硫值23.45 mg;经历多次吸脱附过程第一次失活时,表面被大面积刻蚀,孔隙与小颗粒增多。兰炭吸附剂失活后可以通过二次活化的方式提高其吸附性能,但衰减速度比新改性兰炭要快。二次失活后,在酸蚀刻、水蒸气扩孔等共同作用下致使骨架结构过度烧蚀而坍塌;改性兰炭表面含氧基团的量和构成比例会影响吸附性能。含氧与含碳基团的比值与吸附性能相对应,含氧基团比例越高,吸附性能越差。二次活化再生改变了各含氧基团所占比例,令C=O显著下降,O?C=O显著增加,C?O变化不大。O?C=O官能团尽管含氧,但可能对吸附抑制作用不显著。本研究将为工业烟气治理提供一种新型吸附剂的制备方法,同时也为兰炭表面改性以及二氧化硫吸附解吸机制的研究提供参考。      

低阶煤一步法制备活性炭的脱硫脱硝性能

 活性炭法是能实现多种污染物综合控制的烟气治理技术,可同时处理烧结过程中产生的二氧化硫和氮氧化物等有害物质,但由于活性炭较高的生产和使用成本,限制了其在烧结烟气多污染物净化领域的推广应用。以低阶煤为基炭,氧化球团为活化剂,利用低阶煤热解和气化反应与铁氧化物还原之间的耦合作用,一步完成低阶煤炭化和活化,制备活性炭(SF AC),并与商品活性炭(ZJ AC)在产品工业分析、比表面积、碘吸附值、脱硫脱硝性能和再生活性炭吸附性能等方面进行综合比较。结果表明,SF AC的碘吸附值、比表面积分别为695.13 mg/g、370.42 m2/g,而ZJ AC仅530.54 mg/g、157.50 m2/g,单独脱硫时SF AC、ZJ AC的穿透硫容分别为368.11 mg/g、73.58 mg/g,单独脱硝时SF AC、ZJ AC的穿透硝容分别为250.39 mg/g、14.99 mg/g,前者较后者具有更优的吸附性能;就再生性能而言,SF AC、ZJ AC的脱硫脱硝性能均出现下降,但前者的脱硫脱硝性能更优;与单独脱硫、脱硝相比,两种活性炭同时脱硫脱硝时脱硫性能均提高,脱硝性能却降低,采用NH₃低温催化还原可改善脱硝性能差的问题。     

煤基活性炭改性及其甲烷吸附能力

针对无烟煤制备成的煤基活性炭,采用酸式改性、碱式改性和联合改性的方法对其进行改性处理。通过低温液氮吸附实验、傅里叶红外光谱技术、高压甲烷吸附实验,分析了煤基活性炭的表面物理、化学结构、甲烷的吸附能力。借助Langmuir吸附等温模型、Freundlich模型进行数据拟合,研究了吸附热力学和动力学特征。结果表明,联合改性后的煤基活性炭比表面积和孔容均明显增大,其中比表面积增大66.66%,总孔容增大30.89%;煤基活性炭的甲烷吸附能力明显提高,甲烷吸附量提升25.686%。煤基活性炭的孔隙结构和表面官能团共同决定了其对甲烷的吸附作用,且较于孔隙结构,表面官能团的极性对甲烷吸附量起主要作用。      

Different Approaches for the Development of Low-Cost CO2 Adsorbents

Different carbon materials were tested as precursors for the production of CO2 adsorbents. The chemical modification of the surface of the prepared adsorbents was studied by means of three different approaches: impregnation with amines, electrophilic aromatic substitution, and heat treatment in the presence of ammonia. The samples were chemically characterized and the porous texture was evaluated from the N2 adsorption isotherms at ?196°C. The CO2 adsorption capacities of the adsorbents at 25 and 100°C were evaluated in a thermogravimetric analyzer. In general, the incorporation of basic nitrogen functionalities enhanced the CO2 capture capacities of the modified carbons, but this increase depended on the textural properties of the support and the surface modification methodology. CO2 adsorption capacities of up to 111?mg CO2/g at room temperature were attained. All the tested samples were completely regenerated when subjected to heat treatment at 100°C under inert atmosphere.     

解析参数对活性焦再生过程及再生效果的影响

 活性焦的热解析参数对再生活性焦的脱硫脱硝性能和机械强度至关重要。为了明确解析参数对活性焦再生过程和再生效果的影响规律,通过热解析试验探究活性焦硫残余比例、CO₂和CO生成量及再生活性焦脱硫脱硝性能随解析温度和解析时间的变化规律,继而明确适宜的活性焦热解析参数。结果表明,活性焦升温解析过程中,脱硫产物在317 ℃左右迅速分解,随后分解速率下降;在进入恒温解析阶段后脱硫产物分解速率先快速下降,而后进入缓慢解析状态。硫残余比例随恒温解析温度的升高而下降,在530 ℃下解析3 h可使脱硫产物完全解析;解析温度高于430 ℃后,活性焦表面的酚基、醌基、内酯基等含氧官能团分解量明显增加,并随恒温解析温度的升高而持续增加,分解所生成的CO和CO₂也随之大幅增加,这将使活性焦的孔隙结构进一步发展,继而不利于活性焦机械强度的保持;解析温度低于530 ℃时,硫残余比例随解析温度的升高而持续降低,使再生活性焦的脱硫脱硝性能持续提高;解析温度高于530 ℃后,含氧官能团分解量随解析温度的升高而持续增加,这将有利于提高活性焦表面SO₂氧化反应速率,继而使再生活性焦的脱硫性能持续升高,但酚基、内酯基等酸性含氧官能团的分解使再生活性焦对NH₃的吸附性能降低,进而使其脱硝性能降低。在兼顾再生活性焦脱硫脱硝性能、机械强度和生产效率等多方面因素时,430 ℃恒温解析3 h是相对较优的解析参数。在此解析条件下,再生活性焦的硫残余比例仅为1.8%,含氧官能团尚未发生大量分解,脱硫脱硝性能相对较为优良。     

基于Freundlich吸附等温方程测定氰化提金工艺用活性炭的吸附金容量

活性炭作为金的良好吸附剂广泛地应用在氰化提金生产工艺中,因此对活性炭吸附金性能的评价是非常重要的。在参考氰化提金生产工艺的基础上,模拟活性炭吸附氰化液中金的工艺过程,基于Freundlich吸附等温方程,建立活性炭吸附金容量的测定方法。通过考察一系列对吸附金容量测定的影响因素,优化和确定了测定方法的条件:吸附振荡时间为16h,吸附溶液体积为150mL,活性炭粒度在0.074mm以下,振荡器转速为200r/min,吸附溶液pH值为11.5,振荡温度为(30±1)℃,吸附溶液中氰化钠质量浓度为0.2g/L。按照实验方法测定了2个活性炭实际样品的吸附金容量,结果的相对标准偏差(RSD,n=11)分别为4.2%和4.8%。并对不同活性炭的吸附金容量情况与碘值进行对比,结果表明实验方法具有可比性。     

基于Freundlich吸附等温方程测定氰化提金工艺用活性炭的吸附金容量

活性炭作为金的良好吸附剂广泛地应用在氰化提金生产工艺中,因此对活性炭吸附金性能的评价是非常重要的。在参考氰化提金生产工艺的基础上,模拟活性炭吸附氰化液中金的工艺过程,基于Freundlich吸附等温方程,建立活性炭吸附金容量的测定方法。通过考察一系列对吸附金容量测定的影响因素,优化和确定了测定方法的条件:吸附振荡时间为16h,吸附溶液体积为150mL,活性炭粒度在0.074mm以下,振荡器转速为200r/min,吸附溶液pH值为11.5,振荡温度为(30±1)℃,吸附溶液中氰化钠质量浓度为0.2g/L。按照实验方法测定了2个活性炭实际样品的吸附金容量,结果的相对标准偏差(RSD,n=11)分别为4.2%和4.8%。并对不同活性炭的吸附金容量情况与碘值进行对比,结果表明实验方法具有可比性。     

Effect of Fe/Cu/Ce loading on the coal-based activated carbons for hydrolysis of carbonyl sulfide

Fe/Cu/Ce modified coal-based activated carbon(AC) was prepared by the sol-gel method,and the effect of Fe/Cu/Ce on catalytic properties of Fe/AC,Fe-Cu/AC and Fe-Cu-Ce/AC was investigated in the hydrolysis of carbonyl sulfide(COS) at 50 °C.Their surface properties were evaluated by means of nitrogen adsorption and were characterized by using scanning electron microscopy(SEM),X-ray diffracto-metry(XRD) and X-ray photoelectron spectroscopy(XPS).The catalytic activities results showed that addition of Cu and Ce could enhance the activities of COS hydrolysis and Fe-Cu-Ce/AC with n(Fe):n(Ce)=20 exhibited a higher stability.The XRD and XPS results revealed that Cu loading controlled the crystalline phases and Ce could affect the crystalline phase of Fe2O3 and change the products formation and content of SO42-.     

Sintering flue gas desulfurization with different carbon materials modified by microwave irradiation

Modification of metallurgical coke, biomass char and semi-coke was carried out using a microwave device with power of 450–850 W and irradiation time of 6–12 min. The desulfurization rates of three carbon materials before and after modification were tested. The effects of microwave power and irradiation time on the pore texture and surface chemical characteristics of the three carbon materials were examined by SEM, BET and Fourier transform infrared spectroscopy (FTIR). The results showed that the specific surface area, total pore volume and pore diameter of biomass char and semi-coke after irradiation decreased slightly. Noteworthily, the pore diameter turned small and the acidic functional groups on their surface decomposed, thereby the basicity of carbon surface increased by microwave modification. The optimal promotion of desulfurization rate of three carbon materials was semi-coke irradiated at 850 W for 9 min and the sulfur dioxide adsorption rate was up to 45%.     

Effect of rare earth addition on Cu-Fe/AC adsorbents for phosphine adsorption from yellow phosphorous tail gas

Phosphine(PH3) is a highly toxic air pollutant,commonly produced in phosphorous chemical industry.But it has received less research attention due to its handling difficultly.CO is the main content of the phosphorous chemical industry tail gas,the concentration of which is always more than 80 vol.%,and it can be the feed gas to produce various valuable products such as formate,oxalate,and methanol and so on.But,PH3 is one of the important barriers,which is harmful to the following chemical process.In order to make use of the tail gas,PH3 should be removed firstly,and CO should be covered in the whole purified procedure at the same time.In this work,the modified activated carbon(MAC) was used as the adsorbent to separate PH3 from the mixture tail gas.Series of MAC adsorbents were prepared for the adsorption of PH3,which loaded Cu-Fe and Ce(La),or separately.The PH3 adsorption capacities,chemical and physical properties of MAC were all investigated.The results showed that over 99% PH3 adsorption efficiency was achieved when used MAC adsorbents.The removal efficiency and PH3 adsorption capacity of the Cu-Fe-Ce/AC(20:1:0.4) were both much higher than those modified activated carbons.The maximum PH3 adsorption capacity was 71 mg of PH3/g of MAC on the Cu-Fe-Ce/AC,which were much higher than literature data using CuO only for adsorbing hydride gases.